The Distribution of the Foraminiferida
in the Albian and Cenomanian of
S.W. England.
by
M.B. Hart, B.So., F.C.S.
VOL
Thesis submitted for the Degree of Doctor of Philosophy of the University of London.
February 1970. 2
Abstract
An attempt has been made at resolving some of the difficulties of British mid—Cretaceous stratigraphic correlation using Foraminiferida.
Over six hundred samples have been collected from all the major Albian and Cenomanian sections in south and south west
England and these have been processed for their foraminiferal content. Over two hundred species and varieties from eighty six genera have been documented, many for the first time.
These fossils have been used in the ratification of a zonal scheme and as a testing ground for a correlation technique based on the varying proportions of planktonic and benthonic individuals in each sample.
The results of these investigations have demonstrated the value of Foraminiferida in the solution of stratigraphic problems, and as a result of this a new correlation scheme for the Albian and Cenomanian of southern England has been tentatively suggested.
The Albian/Cenomanian and Cenomanian/Turonian boundaries have also been determined in the British lithological successions and characteristic faunas for each stage outlined.
The main feature of stratigraphic interest has been the determination of a period of mid,-Cenomanian folding and its resulting affect on the stratigraphy.
3
Table of Contents
page Abstract 2 Table of Contents 3 Index of Figures 4 Index of Text Plates 5 Index of Plates 6 Index of Enclosures 7 Acknowledgements 8
Chapter 1. Introduction 10
Chapter 2. History of Previous Research 15
Micropalaeontology 15
Stratigraphy 18
Chapter 3. Techniques .. 26 Sampling 26
Processing 28
Method of Study 28
Compilation of Data 30 Preparation of Illustrations 39
Chapter 4. Location of Sections 42
Chapter 5. Systematic Micropalaeontology 77
Chapter 6. Stratigraphic Summary 226
Chapter 7. Conclusions 268
General Bibliography 274
Micropalaeontological Bibliography 280
Plates of Foraminiferida 301
4
Index of Figures,
page Fig.l. Outline of Processing Techniques 29
Fig.2. Outline of Zonal Scheme 32
Fig.3. Key for C.F.P. Graphs 36
Fig.4. Details of the Membury Quarry excavations 74
Fig.5. Sketch map of the south of England shoWing the main axes of mid—Cenomanian folding 75
Fig.6. Evolutionary trends within the genus qtrenobulimina'.. 106
Fig.7. Evolutionary trends within the genus 'Arenobulimina'.. 108
Fig.8. Evolutionary trends within 0.1enticularis (Blum) 119
Fig.9. Evolutionary trends within the Globigerinacea 186
Fig.10. Evolutionary trends within the Globigerinacea 198
Fig.11. Evolutionary trends within the genus 'Gavelinella' 218
Fig.12. Evolutionary trends within the genus 'Lingulogavelinella' 222
Fig.13. Schematic illustration of the main facies variations related to the non—sequence 239
Fig.14. Details of the Fetcham Mill Borehole 257 5
Index of Text Plates T.Plate 1. Rhythmic sedimentation in the Lower Chalk of Culver Cliff, Isle of Wight.
T.Plate 2. a) General view of the Lower Chalk succession at Culver Cliff. b) General view of the Lower Chalk succession at Compton Bay.
T.Plate 3. a) Reef of Exanthesis labrosus (T.Smith) in the Chalk Marl of Culver Cliff. b) Washout channel in the Upper Cenomanian of Culver Cliff.
T.Plate 4. a) General view of the Lower Chalk succession at Durdle Door, Dorset.
b) Enlarged view of the Basement Bed at Durdle Door.
T,Plate 5. a) General view of the Snowdon Hill Quarry, Chard, Somerset. b) General view of the Dead Maid. Quarry, Mere, Wiltshire.
T.Plate 6. a) The Cenomanian Limestone succession at Tom Tizzards Hole, Beer, Devon. b) General view of the Cenomanian Limestone succession at the southern end of Beer Bay.
T.Plate 7. a) General view of Purley Quarry, Membury, Devon. b) The Fallen Block at the Pinnacles, Little Beach, Branscombe, Devon.
T.Plate 8. Enlarged view of the Fallen Block at the Pinnacles.
T.Plate 9. a) The Cenomanian Sands succession, Bovey Lane Sandpit, Beer, Devon. b) The Cenomanian Sands succession, White Hart Sandpit, Wilmington, Devon. 6
Index of Plates
Plate 1. Ammodiscacea& Lituolacea. Plate 2. Lituolacea. Plate 3. Lituolacea, Plate 4. Lituolacea. Plate 5. Lituolacea. Plate 6. Lituolacea. Plate 7. Lituolacea, Miliolacea, Nodosariacea. Plate 8. Nodosariacea. Plate 9. Nodosariacea. Plate 10. Nodosariacea. Plate 11. Nodosariacea. Plate 12. Nodosariacea. Plate 13. Nodosariacea. Plate 14. Nodosariacea. Plate 15. Buliminacea & Discorbacea. Plate 16. Discorbacea, Spirillinacea, Globigerinacea. Plate 17. Globigerinacea. Plate 18. Globigerinacea. Plate 19. Globigerinacea. Plate 20. Globigerinacea. Plate 21. Globigerinacea, Orbitoidacea, Cassidulinacea. Plate 22. Cassidulinacea. Plate 23. Cassidulinacea. Plate 24. Cassidulinacea. Plate 25. Cassidulinacea & Robertinacea. 7
Index of Enclosures
Enc. 1. Geological Maps of Southern England — with locality details.
Enc. 2. Eastbourne (Beachy Head).
Enc. 3. Culver Cliff (Isle of Wight).
Eno. 4. Compton Bay (Isle of Wight).
Enc. 5. GaUlt/Lower Chalk — including the Cambridge Greensand.
Enc. 6. The Dorset Coast. Enc. 7. The Mid—Dorset Area (1).
Enc. 8, The Mid—Dorset Area (2).
Enc. 9. Devon — Coastal Sections.
Enc. 10. Devon — Inland Sections.
Enc. 11. Devon — (Inland) and Somerset.
Enc. 12. Upper Greensand of the Devon/Dorset Coast.
Enc. 13. Lower Chalk (Wilts and Bucks).
Enc. 14. C.F.P. Correlations (1).
Enc. 15. C •P•1 11 • Correlations (2). 8
Acknowledgements The author is primarily indebted to D.J. Carter of Imperial College who has guided the research from its inception in 1966 when the first material was collected from the mid-Dorset area. It was after this preliminary excursion that the value of a full scale research venture was realised and since that time the author has benefitted in many ways from the experienced guidance of Mr. Carter. For all this help and guidance the author is deeply grateful. The author is also indebted to Dr. B. Denness (ex-Imperial College) for his assistance in the collection of material from the Isle of Wight, and to Dr. W.J. Kennedy (Oxford University) for discussion of the macrofossil distribution in the Lower Chalk. Many other people deserve a mention at this stage but, for reasons of space, they cannot all be mentioned in the above manner. The author apologises for this and trusts that the following will serve as an acknowledgement of their assistance. Discussion of Stratigraphy Mr. D. Curry, Dr. J.M. Hancock, Dr. C. Jeans, Dr. R.P.S. Jefferies, Dr. W.J. Kennedy, Dr. H.G. Owen. Discussion of Palaeontology Dr. R. Casey, Dr. J.M. Hancock, Dr. C. Jeans,
Dr. W.J. Kennedy, Dr. H.G. Owen, Dr. C.J. Woods. Discussion of Micropalaeontology - including those who have sent reprints of papers and comparative material. Dr. C.G. Adams, Dr. O.L. Bandy, Dr. A. Butt, Mr. D. Curry, Dr. C.G. Douglas, Dr. D.L. Eicher, Dr. Z.R.M. El-Naggar, F. Jannin, Dr. R.P.S. Jefferies, M. Malapris, Dr. T. Neagu. 9
Photography and production of plates Mrs. M. Culpam, Mr. J. Gee, Dr. M. Muir, and Mr. E. Lawson (Newcastle). General assistance and discussion S.S. Ali, I. Al—Kassab, P.J. Bigg, B. Cann, S. Darmoian, W.L. Diver, R.J.O. Hamblin, Jaworski, Dr. M.S, Norvick, G.M. Williams. The author is also indebted to members of the Staff at the University of Newcastle upon Tyne and in particular to Professor T.S. Westoll, for assistance in the completion of this thesis. The author gratefully acknowledges the award of a Research Studentship from the Natural Environmental Research Council during the tenure of which (1966-69) the work for this thesis was executed. Finally there are the thanks to my wife who has helped in almost every field of the research, from the collection of samples to the preparation of the final plates. Apart from these more active pursuits there are the countless times when patient silence was the greatest assistance one could have wanted. 10
CHAPTER l
Introduction
During the past five years most geologists have been involved to a greater or lesser degree in a new wave of stratigraphio inter- pretation. Commissions and Committees have been set up in many countries to consider where and on what grounds stratigraphic divisions can be drawn. There are naturally many factors to be taken into consideration when dealing with divisions of this magnitude but for the purpose of most geological work only two main conditions must be fulfilled. They are:- 1. Time units (stages, zones, etc.) should be defined palaeontologically and should not be based on lithological units unless direct palaeontological evidence is lacking. 2. In defining these units only the base of each unit should be so defined. In this situation the base of one unit is of necessity the top of the preceding unit.
In this country we have a classic situation in the mid-Cretaceous where these two rules have been greatly abused. For the last one hundred and fifty years geologists have been studying this part of the geological record in great detail and it is somewhat surprising to find that there are large gaps as well as anomalies in our knowledge. If one follows the course of research from the original sources to the present time one can immediately see where judge- ment and science have gone astray. A detailed account of this shall follow but in order to delimit the scope of the present research a few comments must be made here. William Smith was the first to begin this particular dialogue when he divided the Cretaceous into the basic lithological units of 11
the Chalk, Greensand, Gault clay, etc. He amplified this in his writings by saying that some of the beds could be identified by the fossils they contained. In the 1840's D'ORBIGNY following this maxim defined the stages of the mid-Cretaceous on faunal grounds. It was at this time that the terms Albian, Cenomanian and Turonian appeared in the literature. Unfortunately, D'ORBIGNY did not completely follow our two rules of stratigraphic division. His type Cenomahian is a completely restricted facies with very few fossils and between this and the base of the type Turonian section there is an unknown period of time. If we enforce the second of the two rules, the base of the Turonian would be in the centre of a sequence of chalk, uniform both faunally and lithologically, which is clearly not acceptable. Thus at the outset there was no definite Cenomanian/Turonian boundary and because of the lack of a true Cenomanian fauna there could be no certain delimitation of the Albian/Cenomanian boundary. In 1876 BARROIS visited England for a few weeks and was immediately impressed at how easily he could apply the terms Albian, Cenomanian, and Turonian to the British successions. These stratigraphic terms were launched into British stratigraphy although nobody really knew in what way or how well they had initially been defined. The resulting confusion was so great that in 1896 JUKES-BROWNE presented a paper to the Geological Society of London on "The Delimitation of the Cenomanian". In this paper he redefined the Cenomanian 'in a manner more suited to British sequences'. Thus at the close of the last century one had the French geologists arguing about what D'ORBIGNY's initial definitions meant in terms of more normal sequences while in England the most eminent geologists of the time decided to redefine the stage in the 12
hope that it would then fit more easily with their previous lithologioal correlations. Since the initial burst of activity there has been a lull of some fifty years during which time views have not radically altered. When alieletHIES (1963) presented his paper on the Plenus Marls to the Geologists Association a major part of the discussion was not on the excellent content of the paper but on the fact that his title indicated that he thought that the Plenus Marls were the basal sub—zone of the TUronian. D'CRBIGNY's definitions of the Cenomanian and Turonian did not include any lithological unit resembling the Plenus Marls and so, theoretically, they should not be placed in either stage. SMITH (1957, etc.) while producing excellent work on the Cretaceous of Devon has in many ways perpetuated some of the initial lithological correlations of MEYER (1874) despite the fact that the faunal evidence for these ideas is by no means conclusive. More recently the work of
JEANS (1968) and KENNEDY (1969, in press) have reviSed our ideas to some extent but the author feels that there are still many basic questions that remain unanswered. During the period 1958-1966 there were two major surveys made for a possible Channel Tunnel route under the Straits of Dover. The section of Gault Clay and Lower Chalk between Dover and Sangatte was therefore studied more intensively than any other mid— Cretaceous sequence in the world. Boreholes were sunk nearly every half kilometer and these were studied for the foraminiferal content. The micropalaeontologist involved in this work was D.J. Carter and when the survey was completed he had produced a zonal scheme for the mid—Cretaceous, based on foraminiferal assemblages. In the latter of the two surveys the work was of 13
necessity limited by time and so a rapid correlation technique was developed for the Lower Chalk using the relative proportions of planktonic and benthonic foraminiferida. These two techniques of correlation, while providing great accuracy in the relatively short distances across the Channel were untried over the rest of the British Isles and it was decided to attempt a correlation of the mid-Cretaceous across southern England using similar methods. This would, it was hoped, provide an opportunity for testing both the zonal and the planktonic/benthonic correlation schemes. At the same time it was thought that this would offer the opportunity to completely re-study many of the classic Cretaceous sections in a way never before attempted, and thus obtain fresh evidence and ideas as to their stratigraphic position. World-wide planktonic foraminiferal zonation has now been largely accepted and it was hoped that this could solve the hundred year old problem of the meaning of the Cenomanian in Great Britain.
The study of the Foraminiferida for the solution of stratigraphic problems has been little used in this country and for this reason the present account has been split into separate sections on the stratigraphy and micropalaeontology. The microfauna has been shown to be extensive and the present work will serve as a framework within which later work can be inserted. When this is done it should be possible to reduce the deficiencies in our knowledge of the British mid-Cretaceous Foraminiferida to a level which is at least acceptable. The Lower Chalk is ideal for testing correlation techniques as along its outcrop it displays great differences, not the least of which is the marked change in overall thickness. There is also a 14
striking alteration in lithology from south east to south west, from a manly chalk to a sandy limestone. This study therefore includes an account of the Fbraminiferida of the Albian and Cenomanian; a delimitation of the Albian/ Cenomanian and Cenomanian/Turonian boundaries (both faunally and stratigraphically); and an outline mid,-Cretaceous correlation of southern and more especially south western England. 15
CHAPTER 2
History of Previous Research As indicated in the Introduction there has been little, if any, serious use of micropalaeontology in stratigraphy in this country and because of this the two disciplines can be dealt with in separate accounts. Only WILLIAMS-MITCHELL (1948) attempted the synthesis but his work has never been expanded in detail.
Micropalaeontology Although the faunas of the Albian and Cenomanian show strong similarities this has not been recognised before as most research workers have tended to study one stage to the exclusion of the other. In fact the majority of them have only studied particular groups of individuals to the exclusion of all else. The author feels that this lack of an overall summary is somewhat distressing. Although a large number of important contributions to the subject have been omitted from this account they are all included in a fairly substantial bibliography. As already mentioned we owe our stratigraphic nomenclature to Alcide D'Orbigny and it is to him that we give the pride of place in the realm of micropalaeontology. His Memoir of 1840 on the Upper Chalk of France and adjacent countries has remained one of the major contributions to this field. Although his paper lacked adequate illustrations his knowledge and grasp of the subject was such that he has left an everlasting mark in the field of geology. REUSS (1844, etc.), working mainly on German material, continued describing and cataloguing the vast Cretaceous miorofauna and while the majority of his illustrations are well below present standards he nevertheless made a valuable contribution to our understanding of the Poraminiferida. 16
During the last twenty years of the nineteenth century four major publications appeared, two of which are still considered the most important works in their particular fields. CHARM:Ws (1891-1898) monograph of the Foraminiferida of the Gault Clay of Folkestone, which recorded 265 species and varieties, has remained the only comprehensive work on the British Albian. He was preceded on the continent by BERTHELIN (1880) whose monograph on the Albian of France described thirty-nine new species, most of which were later described by CHAPMAN from England. Two other important contributions at this time were a monograph on the Albian foraminiferida of Europe by EGGER (1899-1902) and a paper on the Red Chalk of northern England by BURROWS, SHERBORN AND BAILEY (1890). As in the field of stratigraphic research there was then a hiatus. The next British publication of any significance was an account by
WILLIAMS41ITCHELL (1948) on the Foraminiferida from the Portsdown borehole. This account, although very brief and lacking in detail, could have heralded the beginning of new endeavours in this country but this work was not followed up. During this period of British inactivity however continental and American geologists were pressing ahead with research, the latter largely under the impetus of the oil industry. At this time one man probably made more of an impression than anyone else has before or since. J.A. Cushman's publications will be seen to occupy a substantial part of the palaeontological bibliography. The subjects of his work ranged from individual genera of Foraminiferida to whole superfamilies and while he was basically interested in the fauna as such he always presented his data in such a way that it was potentially useful to strati- graphers. During this time there was sporadic interest in the
European Foraminiferida witnessed by the publications of 17
FRAME (1925 & 1928), EICHENBERG (1933, 35, 36), BROTZEN (1934, 36, 42), TEN DAM (1948, 50), and MARIE (1938, 41). During the last twenty years research has accelerated at an ever increasing rate both on the continent and in America while in Britain publication has been somewhat restricted. Since 1940 the names of Helen Tappan and A.R. Loeblich have become entrenched in the literature. To them we owe the Treatise on Invertebrate Palaeontology, Part C, Protista (1964). Their joint publication (1961) on the Cenomanian planktonic Foraminiferida has been extensively used in the present study though the later publication by PESSAGNO (1967) is probably more comprehensive. Unfortunately PESSAGNO (1967) and DOUGLAS (1969) in their recent publications tend to oversplit: they erect many new genera, change the generic position of nearly all the previously described planktonic species, and thus greatly increase the length of already vast synonymies. BANDY (1967) on the other hand has been a pioneer in planktonic foraminiferal zonation both in the Tertiary and the Cretaceous. IRS work on the latter has, in the authors opinion, done infinitely more for the progress of micropalaeontology than the systematic adjustments of PESSAGNO and DOUGLAS. In Europe many research centres have been studying selected parts of the Cretaceous sequence while others have been producing valuable data on selected groups of individuals. The planktonic Foraminiferida have received the attention of CARON (1966), KLAUS (1960), and HOFKER (1957, 60, 61), while various groups of benthonic Foraminiferida have been studied by HOFKER (1954, 57, 63), MICHAEL (1966), NALAPRIS (1956, 65), and JANNIN (1967). The latter has attempted a statistical approach to the study of the Albian faunas. These together with the stratigraphic papers of NEM (1965), 18
BUTT (1966), and FUCHS (1967), have given a balanced approach to
European research. In Britain however this has not been the case. The Upper Cretaceous arenaceous Foraminiferida from various localities in southern England have received the attention of BARNARD and BANNER (1953) but since that time BARNARD (1958, 1962, 1963) has only presented non-stratigraphical papers on isolated groups. BANNER and BLOW (1959) produCed a new classification for the planktonic Foraminiferida and this has been followed in preference to the subsequent work of LOEBLICH and TAPPAN (1964, Treatise). The above is only a short summary of the pattern of research to the present day. It is immediately apparent how little we know about the British Cretaceous miorofaunal sequences. Mention must be made at this time to two publications on the
Cretaceous microplankton. The work of CLARKE and VERDIER (1967) has produced a scheme of zonation for the Upper Cretaceous of the Isle of Wight while that of COOKSON and HUGHES (1964) has given some interesting observations on the dating of the Cambridge Greensand. These two papers, and the apparent lack of notice taken of them will be discussed in their stratigraphic context.
Stratigraphy There is no apparent need to discuss the research before 1903 as JUKES-BROWNE (1903) gives a complete historical acoount of the study of the Lower Chalk as an introduction to his work. However it was during this time that many of the generally accepted ideas were introduced into the literature. This was also the period when the main lithological and bio-stratigraphic units were described.
As there is such a concise account available however only the more 19
important contributors will be mentioned in the following paragraphs. William Smith began the sub-division of the Cretaceous in the south of England by describing the lithological units of the Gault, Greensand and Chalk. English geologists in the succeeding years concentrated their attention on the further lithological sub- division of the Chalk. Notable contributors during this period were MANTELL (1818), PHILLIPS (1818), WOODWARD (1833), and SHAM (1853). The first major advance was made by WHITAKER (1859) who divided the chalk into seven lithological units and was the first to define the positions of the Chalk Hock and the Totternhoe Stone. EVANS
(1870) followed this by recognising a series of six zones based on index fossils, and while this was obviously rudimentary it was at least the first faunal subdivision suggested for the British Chalk. WHITAHER (1871), working in the south west of England, succeeded in producing a correlation scheme which although inaccurate, was the first attempt at placing these marginal deposits in their true stratigraphic positions♦ He equated the Cenomanian Limestones with part of the Upper Greensand and largely because of this correlated the overlying Turonian Chalk with the Lower Chalk of the south east of England. Following on this work on the south west of England MEYER (1874) separated the Cenomanian Limestones into a series of beds and correlated them with the IChloritic Marl' of the south coast. He also retained the erroneous correlation of the overlying Turonian with the normal Lower Chalk. In 1876 Professor Barrois visited England and in a very short time completely re-wrote British Cretaceous stratigraphy. He did this by applying the French nomenclatural system and palaeontological zones which had been in operation on the continent for more than thirty years. At this point - the fusion of the two main trends 20
of thought - it seems appropriate to mention the great advances being made on the continent in the application of palaeontology to bio-stratigraphy. The name Cenomanian was coined in 1847 by Alcide D'Orbigny for the sandy beds that were seen to occur below chalk ascribed to the TUronian stage. Originally they were included within that stage and their removal by D'ORBIGNY was predicted by D'ARCHILC (1847) on the basis of their fossil content. Unfortunately a great many of the latter's palaeontological identifications were incorrect and little attention has been paid to this otherwise important work. In the succeeding years MILLER and BIZET had many heated discussions with HEBERT and others concerning the exact position of the Cenomanian as described by D'ORBIGNY. The main point of dissention throughout this time was the exact stratigraphic position of the Rouen Chalk. Eventually it was agreed that it was no more than a chalky facies of the upper part of the Cenomanian sands of Orne and Sarthe. At the same time the French geologists were having problems with the boundary between the Albian and the Cenomanian. As this is the boundary between the Lower and Upper Cretaceous they naturally went to some pains in an attempt to define it accurately. The original Albian fauna of D'ORBIGHY was largely of Lower Albian age and so a fauna from the Upper Albian of another area could be referred either to the Albian or Cenomanian as initially described. Thus we see that when Barrois visited England and applied the terms Albian and Cenomanian to our successions, divisions not fully accepted by French geologists studying the type successions, it is not surprising that the English geologists were quick to refute his work. 21
JUKES-BROWNE and HILL (1896) in their paper on the 'Delimitation of the Cenomanian' outlined in no mean terms what they meant by the Cenomanian which was in some opposition to the views of BARROIS. He had defined the Cenomanian in England on much wider terms than the British had wanted. He included nearly half the upper Greensand in this stage, while the English geologists preferred the Cenomanian to be equivalent to the Lower Chalk. It had only just been established that the Gault and the Upper Greensand were lateral equivalents of one another and to enforce this fusion JUKES-BROWNE even suggested that a name should be found for this Gault/Upper Greensand stage (eventually called the Selbornian). As this problem of nomenclature is central to the whole of this project it is worth mentioning two of the main objections of JUKES-BROWNE to the suggestions of BARROIS. The result of British investigation, therefore, has been to tell us that our subdivisions into Gault, Upper Greensand, and Lower Chalk do not tally in any way with their Albion and Cenomaien stages and that if we wished to adopt the French nomenclature we should have to draw a hard and fast line in the middle of the Upper Greensand'. 'The work of English geologists has therefore tended to consolidate the Gault and Greensand, and to separate them as a whole from the overlying Lower Chalk, which has generally a bed of glauconitic marl at its base, and is often marked off from the Upper Greensand by a very clear plane of division. The faunal assemblages agree with this method of classification and no modern English geologist would imagine that a more natural division could be made by grouping a part of the Upper Greensand with the Lower Chalk'.
The bulk of the present work has been an investigation of the facts relevant to this obvious difference of opinion between these two great geologists. BARROIS was a little ambitious in making such a rapid application of an uncertain nomenclatural system while JUKES-BROWNE was also rather hasty in dismissing it in favour of his own largely lithological correlation. Certain points from both of their arguments are now mentioned and it is hoped that in 22
the later stratigraphio assessment their objections may all be answered.
1. The stages of the Vabien and Cenomanien' were defined on palaeontological grounds - albeit inadequately. 2. The boundaries of the Albien/Cenomanien and Cenomanien/ Turonien were not delimited either by the base of one or the top of the other.
3. The possibility of the equivalence of a chalk to a greensand facies was certainly not unacceptable to BARROIS as he had been engaged in the discussions about the age of the Rouen Chalk.
4. JUKES-BROWNE, in claiming that the major faunal change was at the base of the chalk, was taking no account of any change in the fauna because of the change in the facies, and hence the depositional environment. 5. While claiming that he (JUKES-BROWNE) wanted a palaeontological scheme he persisted in pressing for a lithological delimitation of the Cenomanian. 6. There was no real evidence for dating the upper part of the Upper Greensand in the south west of England. Those fossils that are found rarely in these deposits are usually long ranging forms completely controlled in distribution by the particular environment. Even today, after seventy years of further research, modern stratigraphers still find no firm basis for a dating of this part of the Upper Greensand.
From this time (1896) the lithological terms of the English geologists and the bio-stratigraphic terms of the French have appeared side by side in many publications and both have been much misused. The French position has altered little and even today some workers are still trying to redefine the Cenomanian in terms
of the type successions. In Ehgland, however, attempts to clarify the stratigraphy have appeared sporadically. JUKES-BROWNE produced a major contribution in 1900-04 with his series of memoirs on the "Cretaceous Rocks of Britain" and his ideas and conclusions have in many ways formed the basis for all later research. It is only in recent years that
many of his ideas are being refuted but even so these books 23
still oontain the most complete account of the Cretaceous of these
Islands. SPATH (1923, 1926, 1923-43) and WRIGHT & WRIGHT (1947) have attempted. Ammonite zonations of the Albian and Cenomanian and while the Gault Clay is a suitable medium for study of this kind neither the Upper Greensand nor the Lower Chalk have responded to investigation. WRIGHT & WRIGHT (op. cit.) came to the conclusion that over most of south Dorset the Lower Chalk basement bed is of
Middle Cenomanian age and that Lower Cenomanian ammonites are often found in fissures in the underlying greensand (especially at Punfield). SMITH (1957, etc.) continued the stratigraphic work of MEYER in the south west of England and came to the conclusion that many of the stratigraphic anomalies seen in that area were the result of intra-Cretaceous tectonic activity. In the last decade research has begun to accelerate alarmingly and it is in these last few years that the micropalaeontological approach has been employed. In 1962-63 J.P,rietaIES produced two papers on the Plenus Marls which he had studied in great detail from both the stratigraphic and palaeontological standpoints. This work showed for the first time the advantage of studying a small part of the succession in great detail. His work demonstrated that uniform chalk may in fact display alarming changes over quite small stratigraphic thicknesses, and it was partly his approach that inspired the mode of the present research. He showed that the Plenus Marls are made up of a very
variable series of beds, units of which however, can still be traced over considerable distances. It was from this work that the author decided to use the tight correlations of the Plenus Marl
units as a datum line for the present research. This datum line 24 has therefore been used in all the sections enclosed in this thesis, with the successions plotted downwards from it. Other workers of recent years, e.g. TREASISE (1960) have persisted in using the base of the chalk as a datum line even after WRIGHT & WRIGHT (1947) had demonstrated that the base of the Chalk becomes younger towards the south west. JEANS (1968) has shown that a series of pulse faunas can be recognised in the Lower Chalk and for his diagrams of clay mineral distribution over southern England has plotted his sections from the Plenus Marls downwards. More weight to this argument has been forwarded by Bandy (1967) who, in his paper on Cretaceous planktonic foraminiferal zonation, demonstrates that the upper limit of the Cenomanian all over the world is seen to coincide with the disappearance of the Rotalipora app. group. The last occurrence of this fauna in England occurs in the Plenus Marls (Bed 4) and this adds weight to the use of this level as a datum for correlation. This also goes some of the way to answering one of the main questions of this research — the position of the Cenomanian/Turonian boundary. This will be expanded in a later section but this will serve as a temporary explanation of why all the sections have been plotted using the Plenus Marls (Bed 4) as a datum. The last major work with any relevance to the present problem is that of KENNEDY (1969, in press). His work is the latest attempt to clear the confusion using the standard ammonite faunas. His study is based on assemblages and while it certainly goes a long way to solving some of the problems of the mid-Cretaceous the author feels that there are still some explanations lacking. KENNEDY's work in the south east has in many ways been accepted by the author but in the south west of England differences still remain. 25
These differences of opinion will be discussed where necessary in the full stratigraphic account.
Summary It is proposed in the succeeding chapters to expIain how this present work was done and what initial conclusions have been reached. The details of the stratigraphy can best be appreoiated in the light of the full discussion of that subject and the results of all the previous workers will be discussed then in their true context. 26
Techniques It is very difficult to give an account of the methods adopted by micropalaeontologists as every worker tends to develop his own sampling and processing techniques. In many cases, what would normally be a standard procedure is slightly altered to suit the particular problem in hand. The following account is given not with the intention of announcing new methods but only to serve as an indication of how the work was in fact carried out. In micro- palaeontological work the sampling and the processing techniques can ultimately govern the results produced. Care at this stage of the research can make a great deal of a poor section that would otherwise be discarded as useless. As already mentioned this survey has oovered a great variety of rock types - each of which requires different treatment* Each of these methods is now outlined with comments as to their effectiveness. This it is now hoped will serve as a guide to those following this work or to any who wish to study these faunas themselves.
1. Sampling The size of the sample naturally varies with the availability
of the rock and in many cases one has to be satisfied with what can be obtained. In general however a three inch cube of rock is required, of which two thirds is processed and one third retained as a reserve. Samples were generally cleaned in the field to remove any vegetation, decalcified rock, detritus, etc. The freshness of the sample is perhaps the most important single feature to note
when collecting for Foraminiferida. The various techniques that 27
can be employed are discussed at some length in KIMMEL &R&M
(Editors: 1964). Two different methods of sampling have been employed and these are outlined here:-
a. 3" block samples at regular intervals This form of collecting was done.in sequences like the Gault,
Upper Greensand, and the Lower Chalk where the variations in the fauna are not so great. The usual interval between the samples was three feet but in some of the sections it was found necessary to spread this to five feet. In some apparently uniform successions it is usually possible to see those layers which are intensely bioturbated but in any sediment there must be some mixing at the sediment/water interface during deposition. This has been discussed at some length by BERGER &HEATH (1968). Using their data and graphs one can postulate a mixing in the Lower Chalk and similar deposits to a depth of 40cm (16 ins.) which will not drastically effect the occurrences and proportions of species in samples at 36 inch intervals.
b. 3" block samples at specific intervals In beds like the Plenus Marl and the Cenomanian Limestones where rapid changes occur over very short stratigraphic thicknesses samples were taken from every available bed. Even in the larger, more uniform sections extra samples have been taken from levels where changes in the fauna were possible or expected. Several sections proved so complex, or such a tight correlation was required that they were sampled continuously in three inch blocks. In beds like the Cenomanian Limestone where boring and reworking can be seen great care has been taken to avoid taking contaminated samples, and when
processing these one has to be very careful in processing the matrix 28
and not the pebbles so prominent in this deposit.
2. Processing Various accounts of processing techniques are available and new methods are usually described in such publications as Mioropalaeontology and the Journal of Paleontology. Many of the more recent works and publications on this subject also include accounts of the techniques used by the individual workers, e.g. WILLIAMS-MITCHELL (1948) and JEPFERIES (1962).
In any piece of work it is usually desirable to process every sample in the same way so as to retain some measure of uniformity but in a study such as this, where lithological variation was so great, many methods have to be adopted in order to obtain the best results from each sample. All the methods employed in this work have been summarised in Text Fig.l, and this needs only slight amplification. In continuous long sections of uniform lithology, e.g. the Lower Chalk, a single method of processing was used as it is in these sections where counts have been made of the constituent foraminiferida. In the case of spot samples or the short sequences of the Cenomanian Limestone any method was used in order to obtain a full faunal list. Records were kept of the order in which the samples were processed and wet sieved so that checks could be made on the contamination. Only twice did this occur and because of these records the faunal lists could be partly corrected.
3. Method of Study Throughout this work the samples were collected in batches and processed in blocks of suitable numbers. Processed residues were
1 2 3 4 5
CLAY SANDY CLAY HARD CHALK LIMESTONE NODULES MA R LY CHALK SOFT CALC. HARD G'S' ND CALC. GR 1 TS MACR 0 F OSSILS CHALKY G' S' ND SANDS
DRY IN OVE N DRY IN OVEN 4 b 5b AT 100'C AT 100 'C
ADD AN EXCESS SOAK OVERNIGHT IN SAMPLE CRUSHED OF TURPS. SUBS. SOLUTION OF .CALGON. UNDER WATER (SODIUM IN A HEAVY HEXA META PHOSPHATE) PESTLE & MORTAR
POUR OFF EXCESS SAMPLE DISOLVED — ADD WATER THIN SECTIONS I N 50% NCI AND LEAVE FOR CUT & AFTER ONE HOUR MORE WATER REACTION SAMPLE POUR OFF ANY ADDED AND WASHED AND REMAINING TURPS TRANSFERRED DECANTED WIT H TO ENAMEL WATER UNTIL SAUCEPAN. CLEAN.
STORAGE
S OIL FOR 30 MINUTES AFTER A DOING 20 gms OF NaCO TO 3 THE SAUCEPAN IF 1 FAILS USE 3 v IF 2 FAILS USE 3 USUALLY YIELDS A IF 3 FAILS USE 4c FRAGILE RESIDUE If 1. 2, 3, 4 (a•c) .3 5 (a-b) SIEVE SAMPLE ON ( Normally studied A 200 MESH fail to expose a fauna SIEVE UNDER A immediately under the sample is taken to MODERATE WATER water) JET. be unfossi liferous. FIG. 1 OUTLINE OF PROCESSING
DRY RESIDUE STORAGE IN OVEN AT 100' C 30 stored prior to study in an index system recording the previously processed sample, the method of processing and any comments as to the possibility of re-processing being necessary. For the purpose of examination the residues were separated into three size fractions using the standard 60 mesh and 30 mesh sieves. These residues were then studied in different ways:-
(a) greater than 30 fr - total faunal list compiled. (b) 60 - 30 fr - 1. In major sections individuals of all species were counted to a total of at least 300, and then the rest of the size fraction was studied until six slides of residue revealled no new species. 2. In spot samples, or those that were poorly disaggregated only a faunal list was compiled.
(C) less than 60 fr A faunal list was compiled from the raw residue and after this initial inspection each sample was given flotation treatment with carbon tetrachloride. This heavy liquid separation concentrates the lighter elements of the fauna enabling the compilation of a more complete faunal slat.
The reason for this treatment of the 60 - 30 fr. will be outlined in the section on the compilation of data. In the case of acid reductions or thin sections an abbreviated faunal list was all that was available.
4. Compilation of Data Although the previous three sections have been dealt with very briefly this deserves greater attention. As already mentioned in the introduction there were two lines of attack open for the elucidation of the stratigraphy and they are outlined in more detail here.
31
a. The zonal scheme The scheme as developed in the Channel Tunnel Survey was published in BRUCKSHAW et al (1961) and although this is incomplete in the light of later work it has formed the basis for this research. Ant abbreviated form of the scheme is to be found on Text Fig.2. Although only the zonal indicators are shown in the figure it must be emphasised that in most of these cases a zone can be defined by an association and that these individuals were only selected for the purpose of naming the zones. The numbers applied to them (although not in numerical sequence) are those used in the Channel Tunnel Project so direct reference can be made to the initial (1961) figure. There now follows a summary of the zones with the lithology based on the sequence seen in the cliffs between Dover and Folkestone.
Plenus Marls (zone 14) recognised by the lithology and the total fauna. Lower Chalk (zone 13) based on the presence of Plectina sp.21, Glandulopleuro- stomella pleurostomelloidqs rFit-riICE,—T abundant planktmic foraminiferida and the lack of arenaceous species.
Lower Chalk (zone 11a) - based on abundant Flourensina Sp. A in association with Biorostella sp. 1 and the disappearance of Pseudotextular- iella cretosa (CUSHMAN).
Lower Chalk (zone llii) based on the presence of Pleotina sp. 21 and abundant planktonic foraminiferida.
The Mid-Cenomanian non-sequence - recognised by a complete change in the fauna from a predominantly benthonic fauna to a largely planktonic fauna. This level, while not affecting the calcareous benthonics to any great extent, reduces the arenaceous species to an insignificant percentage of the total fauna. This level can also 32
PLENUS MARL S
1 R. cushmani I 13 I Plectina 1 sp. 21 I • I I Ila 1 1 allib ft • i r• VIVA 4Fe. I )lit VOI. Or 1
...... — 0••••••••• ••••••••••• L. ,v.v */ 11;" - - ..0... 11 i yr it -..... 10 -- • P. cretosa '7' ... H. advena rQ a • ant iqua M. ozawai .- A. sabulosa 9 .
.
111) F. in termedia ilit OAF A. chapmani vr' ill OC) ocli3 A 4 i C. pinnaeformis E. spinulifera .1, BASE OF GAULT CLAY
L FIG. 2 OUTLINE OF ZONAL SCHEME 33
be recognised by the occurrence of Praeglobotruncana (gedbergella) washitensis (COSBY) in the beds immediately below the non-sequence.
Lower Chalk (zone 110 - based on the occurrence of Plectina sp. 21 associated with an abundant fauna of arenaceous benthonics, including P.cretosa (CUSHMAN), Hagenowina advena CUSHMAN and Arenobulimina englica CUSHMAN.. Lower Chalk (zone 10) - although there is no specific index fossil for this zone it can be recognised by the abundance of arenaceous benthonio species and the lack of any numbers of planktonic individuals. Lower Chalk (zone 9) - based on a similar assemblage to zone 10 but also including the arenaceous form Marssonella ozawai CUSHMAN Lower Chalk (zone 8) - based on the occurrence of Mozamai CUSHMAN and Flourensina intermedia TEN DAM. Glauconitic Marl (zone 7) - indicated by the association of F.intermedia TEN DAM, M lozawai CUSHMAN, and As:muliammina folkestonien0771015TT. 'Gault Clay' (tone 6a) - recognised in some of the Channel bore-hole sections by the association of Citharinella laffitei MARIE and Arenobulimina sp. H, and while they are rarely seen together in inland sections some samples record one or the other and so the use of this subzone is still uncertain. 'Gault Clay' (zone 6) - based on the association of Arenobulimina sabulosa (CHAPMAN) and Arenobulimina chapmank CUSHMAN. 'Gault Clay' (zone 5) - based on the association of A.chapmani CUSHMAN and Citharinellapinne,eformis (CHAPMAN). 'Gault Clay' (zone 4a) - based on the association of A.chapmani CUSHMAN and Epistomina spinulifera (OUSS). 34
'Gault Clay' (zone 4) indicated by the presence of E.spinulifera (REUSS). In the lower part of the zone the specimens are almost smooth, becoming more coarsely ornate up the succession, finally being somewhat degenerate in zone 4a.
'Gault Clay' (pre-zone 4) - although divided into zones in the Channel Tunnel Project it has been found impracticable in this present survey to separate this small part of the Gault succession on faunal grounds.
This outline zonal scheme is intended as an introduction to the project as a whole. It has been tentatively suggested as a suitable zonal scheme for the British mid-Cretaceous and it is hoped that the section on its stratigraphic use will demonstrate its capabilities to the full. Although failing in same areas there are immediate explanations for this and they should not be used to denounce the scheme as a whole.
b. Cumulative Frequency Polygons Although as outlined above, all the species in the 60 - 30 size fraction were counted it was found necessary to condense the data to a manageable proportion. As this research is stratigraphio rather than taxonomic the data on all these species was tending to overshadow any significance any of it may have had in that field. This data is still available and will be used when the present study is continued in greater depth. For the present it was decided to use the method adopted with some success in the Channel Tunnel Survey. The counts have been converted to percentages of the total population and summed up under the following headings:-
1. Rotalipora spp. (excluding R.greenhornensis) total % 2. R.greenhornensis total % 35
3. Praeglobotruncana (Hedberk.ella) spp total % 4. Praeglobotruncana (Praeglobotruncana) spp total % 5. Calcareous benthonic foraminiferida total % 6. Arenaceous benthonic foraminiferida total %
(The 60 — 30 fraction was chosen for this work as it contains the majority of mature individuals in these groups. The greater than 30 fraction rarely contains any planktonic individuals while the less than 60 fraction generally consists of juveniles or immature specimens). These percentages have then been plotted as cumulative frequency polygons and these graphs and their subsequent correlative use are to be seen in the enclosures at the back of the thesis. A key to these figures is inoluded in Text Fig. 3. which shows the main symbols to be encountered on the correlative figures. These graphs, while appearing useful for correlation purposes, in this case must be the result of fundamental changes in the depositional history of the rocks they represent. The discussion at the present is aimed largely at elucidating the reasons for uld the consequences of the variation displayed by the graphs in the Lower Chalk sequence. The changes seen in a succession like the Plenus Marls, where erosion surfaces can be seen in the field, are fairly easy to explain but in the more uniform lithology of the Lower Chalk the explanation is not so obvious. It seems appropriate at the present time to mention the publication of GRIMSDALE & =MOVEN (1955). They attempted at that time to determine a method whereby one could estimate accurately the depth of deposition of a rock from the constituents of the fauna. For many years it had been known that a thanatoceonoses from abyssal depths would contain 90 — 100 planktonic foraminiferida while that from the neritic zone would be almost totally composed of benthonic
Agglutinated species (bent honic)
V)
Calcareous species Et (b en thonic ) (5
Praeglobotruncana spp, et: N. "•., -, ,..... N N .. , c) c..) . . , Hedbergeita spp. cr cr) 1113 , . . c , to ...... R. greennornensis t3 N tiu a) k . 0. , . . — tv) . to . R. cushmani 4. , 0 % I--. \.- 37
individuals, However there has never been any way of relating these extremes to a method of determining the depth of deposition. GRIMSDALE & MORIGIOVEN (op. cit.) attempted to solve this problem by using the counts of samples collected on twelve traverses (largely neritic) made by PHLEGER & PARKER (1951). The whole basis for their discussion is the fact that numbers of benthonic individuals decrease with depth while numbers of planktonic individuals increase as a result of the increase in the height of the water column above the sea floor. They discuss the lack of correspondence of the graphs and after compiling a list of the limitations concluded that while it is still a basic idea there is no proof that the depth of deposition can be estimated using this technique. More recently EICHER (1969) has used population percentages to demonstrate in a general way the deepening and subsequent shallowing of the Greenhorn Sea in Colorado. His graphs while looking remarkably similar to those from this work (allowing for the separation of his planktonic group into genera) have only been used as a depth indicator and no suggestion has been made as to any other possible use. Returning to our own Lower Chalk sequence the variation in some of the graphs from 10% to 60% planktonic foraminiferida would seem to indicate, by the above arguments, a marked deepening of the water. Such oscillations, occurring every three to five feet, are clearly not viable and another cause has to be suggested. One of the changes however may be attributable to such a depth increase and this is the change over the mid-Cenomanian non-sequence. This marked change in the planktonic population coupled with a steep drop in the arenaceous benthonic population would seem to indicate 38
a sudden deepening of the water. This may however be only partly true as such a change could be engineered by the opening of the sea allowing the Anglo—Paris Basin to become truly open marine. This would allow an increase in the number of planktonic individuals but would not necessarily reduce the benthonic population unless depth was also involved. Having suggested a possible explanation for this change there remains the other minor oscillations that are seen throughout the Lower Chalk, Planktonic foraminiferida, as their name suggests are largely at the mercy of the ocean currents for their distribution. It is also known from research on recent groups that in modern oceans keeled forms are usually more indicative of warmer water than the non—keeled forms. Although this is a marked generalisation it may in fact be a possible answer to the problem in hand. The oscillations recorded in the Lower Chalk may be no more than reflections of mass water movements over the Anglo—Paris basin. These are on a relatively small scale below the non—sequence while above that level variations of up to 40% are to be expected. These mass movements must have been on a very large scale when one places the Cenomanian on a time scale like that proposed by KULP (1961). His figure for the duration of the Cenomanian of twenty million years, allows enough time for these proposed movements. The changes in the population displayed by these graphs suggest that some of them were 'geologically' quite rapid. Changes in the pattern of mass water movement would probably be rapid enough and over a large enough area to produce these variations. Thus any of these correlation lines built onto these graphs, while not representing a true time plane, may be sufficiently close to one as to make their use justified. This is discussed in full in a 39
publication under preparation by D.J. CARTER, where he outlines the use of these graphs in correlation across the English Channel. Over the whole of southern England however, while less precise than in a smaller area, an approximate correlation using this method has been shown to be possible. A full summary of the use of this method will be found in the chapter on the stratigraphic correlations and it is hoped that the above discussion will go some way to justifying their use in this work.
o. International Planktonic Zonation In recent years many workers (notably BANDY (1967)) have attempted to use the evolutionary trends of the planktonic foraminiferida as a basis for correlation. In many instances this can be used with some success and while such a zonation has not been developed during the course of this research the planktonic foraminiferida have been used to develop an international basis for the main zonal scheme. In some cases however use has been made of some of the main features of planktonic zonation and these will be mentioned whenever they arise. Their main use has been in the delimitation of the major stratigraphic boundaries — especially that between the Cenomanian and the Turonian.
5. Preparation of the Illustrations The individual photographs reproduced in the plates of the Foraminiferida have been prepared in the Geology Department, Imperial College, using the 'Stereoscan' — scanning electron microscope. As the techniques involved in the taking of these photographs are relatively new the author thought it necessary to give an account of the various stages in the preparation of the prints. 40
Specimens were prepared for photography by cleaning in an ultra—sonic bath for a few seconds, after which they were mounted on the specially machined 'stubs' prepared for the instrument. The adhesive plays an important role in this process and various mediums have been tested. Double sided gummed tape was found to be the most successful for microfossils as it allows the easy mounting and removal of small objects. Specimens can be adjusted to the correct orientation by moistening the tape underneath and immediately adjacent to the individual. Edge views of the foraminiferida were obtained by cutting a small slit in the surface of the tape into which the specimen could be settled. All the stubs were then coated with gold, evaporated under vacuum. Two coatings were made giving a total thickness of 100 -6 0 150 A. (The stubs were coated twice, rotating on planes at 45 degrees to one another). This allows a complete covering of the specimenB, even under the edge of each individual, where the contact with the coating of the stub is of some importance. This Lcating is necessary to afford an electrical contact and it also gives a high emission surface to the specimen. The photographs were taken with the specimens normal to the beam and a filament voltage of 20Kv. Owing to the design of the instrument objects with a relief often appear brighter on one side and so some adjustment had to be made during the printing. It must be emphasised that this shading of the negative during the printing process only evens the lightness of the final print and in no way alters any of the detail. There has been no retouching or emphasising of features either on the negatives or on the prints. 41
These then are the basic techniques that have been employed 5nring the course of this research. The overriding technique, if it can be labelled as such, is the approach of a stratigraphic geologist. Throughout this work attention has always been given to the field relations of the strata under study and the following chapter will give the details of the sections visited as well as the general field observations. 42
MUTER 4
„Location of Sections There are already many accounts available which give details of both localities and lithological descriptions throughout southern England. JUKES-BROWNE (1900, 1903) gives perhaps the most comprehensive account of every Cretaceous locality in the country, but unfortunately many of these sections are now degraded. Other accounts of sections produced prior to the last decade must also be viewed with suspicion - especially in the south east of England where many of the more important quarries and pits are now filled with refuse. Coastal sections are also extremely variable and while many sections may be clearer now than when they were initially described, others like Penfield Cove are in a hopeless condition. As already indicated the Albian and Cenomanian deposits of south west England (Hampshire, the I.O. Wight, Dorset, Devon, Somerset and Wiltshire) display a remarkable variation in lithological units. In the Isle of Wight the Gault Clay and the Lower Chalk present typical lithologies while only in south Dorset and Devon the former is represented by the Foxmould sands and the Chert Beds (?) while the latter is replaced by a few feet of sandy limestone. While the main correlative work of this research has been directed at the localities within these western counties (see Enclosure 1 - the locality map), it was thought necessary to provide some indication of the relationships these rocks have with the more typical successions of south east and south central England. This view was further strengthened in the light of some of the results that began to emerge at an early stage of the research. The mid-Cenomanian 43
non-sequence (Chapter 3, section 4(1)) hem provided perhaps the most important single feature of the research and it was thought necessary to locate this stratigraphically over a wide an area as possible. With this in mind the author has studied two of the main sections of south east England as well as those in the south west. The cliffs between Dover and Folkestone provide one of the clearest successions in the country of the strata between the base of the Gault Clay and the Plenus Marls. A detailed account of
this section is to be found in the recently published Memoir on the Folkestone area (MART et al., 1966), and in KENNEDY (1969, in press). It provides a complete sequence from the sulphur bed at the base of the Gault Clay (at Copt Point) to the base of the Middle Chalk (at Shakespeare Cliff, Dover). Copt Point provides the classic section of the Gault Clay described by PRICE (1874) and JUKES-BROWNE (1900) as well as the succession from which CHtPMAN (1892-8) produced his monograph on the Poraminiferida. Tho Gault sequence has been studied in some detail but the tower Chalk succession (zonal scheme and C.F.P. graphs) are reproduced by permission of D.J. Carter. The other complete sequence studied in the south east of England is that of Beachy Head, Eastbourne. JUKESBROWNE (1903) provides little information about this section as he claims that the faulting associated with this area renders the measurement of a section impossible. A full sequence however from the Gault/ Upper Greensand boundary to the Plenus Marls has been measured and collected. Further details of this section are available in KENNEDY (1966, 1969 in press), the former being an account of
the lithological features displayed by the Lower Chalk. 44
At this time it seems necessary to give an account of the lithology of the Lower Chalk which is by no means a stratum of uniform composition. KENNEDY (1967) gives a very full account of the various burrows associated with the Lower Chalk and his introduction gives a concise summary of the overall lithology. The Lower Chalk can, for convenience, be divided into two main units, vizs- 1. Chalk Marl 2. Grey Chalk
Ilhese are basically the original lithological divisions used by the early English geologists but for the purpose of describing the main lithological features they are quite adequate. 1. The Chalk Marl. This is basically a series of alternations of more marly, and less marly chalk. A typical 'unit' is illustrated in Text. Plate 1. This shows a cycle with a 'marl unit' 50 cm thick and a 'limestone unit' approximately 20 cm thick. These figures are quite representative and can almost be regarded as average sizes for the two members. The 'unit' shown in this plate shows a few of the more salient features of this sort of deposition:— a. the sharpness of the upper surface of the limestone unit. b. almost horizontally arranged streaks and 'pebbles' of limestone material seen within the lower part of the marl unit. c. the intense burrowing of the limestone marl contact at the top surface of the marl unit. These burrows are well developed in the neighbourhood of the lens cap (diameter 50 mm.). d. near the lower edge of the photograph burrows of many material are seen within the limestone although not on quite the same scale as those already mentioned. 45 Text Plate 1.
Rhythmic Sedimentation in the Lower Chalk of Culver Cliff, Isle of Wight. The main features of these rhythmic deposits can be seen in this illustration. They are:-
1. The moderately well defined top of the limestone unit — which is only slightly bored. 2. The very diffuse and bioturbated top of the marly unit which shows a slight gradation into the overlying limestone
unit.
3. Stringers of less marly material can be seen within the main marl units. These often appear to be oriented in a way that would suggest some current activity. (Lens cap diameter 50 mm)
47
These rhythms appear to be of a primary nature as indicated by:— a. piping of the marls into the limestone and vice versa. b. occurrence of limestone pebbles within the marls with no apparent means of connection with the main mass of the limestone. Some of the limestones however appear almost nodular which may indicate that there is also some secondary effects of solution and redistribution but the author believes that there is certainly some indication that there were primary differences in the deposition of the two members. Text plate 2a (Culver Cliff) shows these alternations very clearly, including the change from 'manly dominating' to 'limestone dominating' cycles. As can be seen from the photograph this change is only one of degree and the two deposits are basically similar. Text plate 2b (Compton Bay) shows the same features but they are rather more indistinct because of the large amount of talus now covering this section. The lowest part of the Chalk Marl in the sections at Dover, Eastbourne, Culver and Compton displays another important feature with depositional interest. Text plate 3a (Culver Cliff) shows again the limestone, marl, limestone and marl sequence (reading from bottom right to top left). In the second limestone horizon one has abundant remnants and one whole colony of the sponge
Exanthesis labrosus (T. SMITH)—(syn. Plocoscyphia labrosa). These sponges seem to be restricted to the limestone bands and only rarely are fragments seen 'floating' in the marls.
2. The Grey Chalk. In the higher levels of the Lower Chalk sequence the limestone units dominate over the marls and in the uppermost beds the marls are reduced to thin wispy seams. 48
,„ , Text Plate 2. a) General view of the Lower Chalk succession at Culver Cliff.
The full succession from the Lower Greensand to the
Grey Chalk is shown in this photograph. The dark grey slipped mass of the Gault Clay would seem to be accessible but field inspection has shown that this is not the case.
The Chalk Marl and Grey Chalk units can be easily recognised and one can readily appreciate how these divisions were used for stratigraphic subdivision by the early workers.
b) General view of the Lower Chalk succession at Compton Bay.
The same sequence can be seen here in the reverse direction. It will be noticed at once that the Lower Chalk succession here is in a much poorer condition. A recent fall over the Upper Greensand has further reduced the value of this section since the photograph was taken. The junction between the Chalk Marl and the Grey Chalk can still be seen, as can the faint trace of the Plenus Marls at the top of the
Lower Chalk sequence. 49
-t•
4
`‘\
• 50 Text Plate 1. a) Reef of Exanthesis labrosus CT. Smith) in the Chalk Marl of Culver Cliff.
These sponge colonies are commonly found in the lower levels of the Chalk Marl wherever this lithology occurs. As can be seen in the case of this colony it lies within the limestone part of the rhythmic sequence shown in Text Plate 1. Isolated fragments of sponge can be seen in the more marly units but these give the impression of having being torn from the substrate of the less marly units.
b) Washout channel in the Upper Cenomanian of Culver Cliff.
In the higher levels of the Grey Chalk there is no distinct bedding but in most cases thin wispy marl seams can be seen to give an approximate indication as to the orientation of the beds.
(This can be seen beside the left hand margin of the plate).
9he rubbly phosphatised surface is seen to cut across these levels at a shallow angle. The chalk immediately adjacent to the lens cap is toughened and has definitely undergone some degree of erosion. The marl seams in the bottom right hand corner continue the general sense of the bedding below the feature. in
i
d 52
These occasionally break the main rock units into lens', which can in places cut across the main depositional features. In some horizons these seams are seen to wrap around concretionary bodies and while in some cases pressure solution may be the method of formation (PETTIJOHN, 1957, p.215) the author feels that perhaps something more than this is involved. Horizontal seams of marl could possibly be explained by the action of load pressure solution. Text plate 3b shows these horizontal wispy marl seams which in many places can approximate to the bedding. This plate also shows an important feature of the Eastbourne and Culver sections which is possibly a little easier to explain. One can follow this cross cutting erosion feature for some distance at Culver Cliff where it is very well exposed. Wherever this feature is developed the chalk beneath is always hard and nodular and very often shows a marked degree of phosphatisation. This appears to represent in both these sections a period of marked erosion which must have interrupted the normal course of chalk deposition. The Plenus Marls at the top of the succession has been well described by JavieERIES (1962, 1963) and no further discussion is thought necessary. Returning to the account of the south eastern localities the two main sections of the Isle of Wight have been studied in some detail. Culver Cliff (Text plate 2a) displays a complete succession of the Uppermost Upper Greensand and the Lower Chalk. The Gault Clay at this locality is so slipped and overgrown that the measurement of a succession is rendered impossible. Compton Bay however used to show a complete succession from the Carstone (base of the Gault Clay) to the Plenus Marls. When the section was first visited it was 53
possible to collect from the whole of the four hundred feet section but unfortunately large parts of this are now covered by slipped material. The chalk is covered in a fine muddy talus with one or
two larger scree slopes (Text plage 2b) while the Gault Clay (middle distance — text plate 2b) has slipped out over most of the beach. During the winter 1968/9 a large fall of rock partly covered the succession of the Upper Greensand completing the almost total destruction of the section. Punfield Cove, as already noted, is badly exposed and only the
base of the Lower Chalk at its contact with the Upper Greensand is available for collecting. This is also true at Lulworth and Durdle Door where the full succession is reduced to about thirty feet by the tectonics described by ARKELL (1947) and PHILLIPS (1964). The various successions of this coastline are well described by WRIGHT (in ARKELL 1947) including comprehensive faunal lists for each locality. The full sequence available for study at Durdle Door is shown in text plate 4a, where the basement bed of the Lower Chalk at the Plenus Marls are only twenty five feet apart. The shears causing this great reduction can be seen on the photograph. W.L. Diver is standing on the topmost bed of the Upper Greensand (the chert conglomerate) with his right foot placed at the level of the phophatised basement bed (Text plate 4b). This surface shows clearly that there must have been a period of marked erosion — coupled with a prolonged break in the sedimentation — before the continued deposition of the Lower Chalk. Rolled phosphatised fossils can easily be collected from this bed and these indicate — as demonstrated by WRIGHT (in ARKELL 1947) — that this bed is of at least Middle Cenomanian age. Two localities on either side of Dorchester, at Bincombe 54 Text Plate 4. a) General view of the Lower Chalk succession at Durdle Door. Dorset. The succession visible from left to right comprises the
Middle Chalk (Plenus Marls appears dark grey), the much thinned Lower Chalk, the Lower Chalk Basement Bed (indicated by the right foot of the figure), the Upper Greensand, and the slumped mass of the Gault Clay. The prominent nodular
Chert Bed at the top of the Upper Greensand sequence is a distinctive marker. The shears which reduce the Lower
Chalk from over 1001 to less than 30' can be seen clearly in the central area of the photograph.
b) Enlarged view of the Basement Bed at Durdle Door. This more detailed photograph was taken at the position
of the figure in the above photograph. It shows the nodular, highly irregular upper surface of the cherty Upper Greensand, overlain by glauconitic sandy chalk that contains abundant phosphate pellets and rolled phosphatised macrofossils.
56
(JUKES-BROWNE & HILL 1903, p.99) and Maiden Newton, display full successions of the Plenus Marls which demonstrate the continuation of Plenus Marls (Beds 1 - 8) of aftairtHIES (1962, 1963) from the south east of England. Maiden Newton (see Enclosure 1), because of its position in central Dorset is the focal point of all correlation to and from the south west of England. Together with the nearby quarry at Buckland Newton, they display the most westerly complete section of Lower Chalk lithology from the Plenus Marls to the Basement Bed.
Buckland Newton is a worked quarry with faces on three or four. levels - all of which contain a part of the Lower Chalk sequence. Although a totally complete sequence cannot be pieced together, sufficient is exposed to demonstrate that the overall thickness of this horizon is about 70 - 80 feet. This marked reduction in the thickness of the Lower Chalk (tectonics of the Dorset coast excepted) is explained by DRUMMOND (1967, thesis) and KENNEDY (1969, in press) as the result of chalk deposition over a submarine ridge of some magnitude. This feature has been given the name of the mid-Dorset Swell and it is hoped that in the final stratigraphic analysis this feature can be fully described and accounted for both structurally and in its stratigraphic context. This 'swell' (striking NW - SE) as pointed out by DRUMMOND (1967) separates two distinct basins of Cenomanian
deposition. To the east of the 'swell' one has normal chalk deposition to some thickness (250 ft. at Dover) while to the west of this feature one has only thin limestones and sands. DRUMMOND regards this feature as being part of the disturbances at the boundary between the Albian and the Cenomanian which are also seen on the Devon coast (SMITH 1957, etc.). However the author hopes to 57
demonstrate that this disturbance is in fact associated with the mid-Cenomanian non-sequence and that this level provides the key to the correlation between these two quite different areas of deposition. Thus all the localities studied to the east of this 'swell' have been sampled with a view to allowing this east to west correlation. A lithological correlation within each of the separate basins can have remarkable success but a palaeontological approach is required when one is attempting this cross facies correlation. It is because of this fact that the planktonic foraminiferida have proved so useful in this work. They are remarkably little affected by the changing facies and it is only in deposits like the Wilmington sands where 'facies variants' occur, and even these are on a very minor scale. Having now considered the localities up to the 'swell' from the south east, mention must be made of a few more localities that have been sampled within the easterly basin before the account is
given for the south western area. As Buckland Newton is almost on the crest of the 'swell' it was decided to study all the available sections to the north east in the hope of determining the sequence of strata down the flanks of the ridge. Thus the sections at Stoke Wake (KENNEDY 1969, in press), Mere (Wiltshire), and Maiden Bradley (Wiltshire) have been
studied in some detail. Stoke Wake pit is an overgrown chalk quarry with very little of the original face now exposed. The basement bed of the chalk is no longer exposed but it can be dug out from under the tree roots near the entrance to the quarry. The Dead Maid Quarry at
Mere has received a great deal of attention as shown by the 58
publications of JUKES-BROWNE & SCANES (1901, p.113), JUKES-BROWNE & HILL (1903, p.148), POPE-BARTLETT & SCANES (1916, pp.117-20), EDMUNDS (1938, pp.184-7), SMITH & DRUMMOND (1962, pp.335-7) and finally KENNEDY (1969, in press). The general aspect of the macrofauna (KENNEDY; pers. com.) indicates a Lower Cenomanian age for the basal part of the chalk in this quarry, at some level above the general level of the Glauconitic Marl in the south east of England. This quarry - once famous for its 'popple bed' is now completely degraded (Text plate 5b) and only a small part of the succession is now available. In the easterly basin there remains only five localities worthy of mention in the present account. They have been studied for the various reasons listed below:-
1. 100 ft. borehole of Lower Chalk at Liddington (near Swindon) which is the most complete section of the chalk available in this area. 2. Upton/Chilton railway cutting (JUKES-BROWNE & HILL 1903, p.170). This fairly substantial section displays over one hundred feet of chalk in isolated patches, including a section through the Totternhoe Stone. This part of the section was studied in great detail in an attempt to determine the position of the Totternhoe Stone in the above mentioned borehole. 3. Totternhoe Lime Kilns quarry continues the section of the railway cutting upwards and provides another opportunity of placing the Totternhoe Stone in its true stratigraphic position.
4. Arlesey Clay Pit shows a succession across the Albian/ Cenomanian boundary, including the controversial Cambridge Greensand. This section - although some distance from the main area of this 59 Text Plate 5. a) General view of the Snowdon Hill Quarry, Chard, Somerset.• Although this quarry is now completely overgrown a section can be obtained across the Basement Bed of the Lower
Chalk. The Upper Greensand sequence, part of which used to be exposed, is now completely inaccessible.
b) General view of the Dead Maid Quarry, Mere, Wiltshire.
This quarry has also become completely overgrown in the last few years but a short succession can still be obtained across the 'Popple Bed' under the hopper in the north east corner of the pit. CZ CO 61
study - was included in the work in the hope that it might help to establish the faunal change associated with this major boundary. There was also the possibility that a microfaunal approach might finally solve the problem of the exact age of this deposit. The fifth locality is that of Barrington (Cambridgeshire) where there is a full succession from the Cambridge Greensand to the Burwell Rock (Totternhoe Stone). This has been documented by BURNABY (1962) and his results have shown that the zonal scheme followed by this research holds in East Anglia - including an accurate assessment of the age of the Cambridge Oreenaand. In the south western region there are many recent accounts which adequately describe and discuss the stratigraphy of each of the localities. For the purposes of this research it has been necessary to visit all these localities and in order to save lengthy duplication of this descriptive work only short references will be given for each section. In some cases however the dathor has had to excavate or extend a section and where this has been necessary further details will be given. The Devon Coast The sections of the Cenomanian Limestones between Lyme Regis and Branscombe have been studied in great detail by SMITH (1957, etc.), and his lithological observations have been shown to be extremely satisfactory and in many ways his work has obviated the need for any further descriptions.
Rousden In the cliffs near Charton Goyle the Melbourn Rock (basal Middle Chalk) rests unconformdbly on the Upper Greensand with the whole of the Cenomanian Limestone missing (SMITH 1965, pp.125-6, p1.5 and fig.4). 62
Bindon Landslip Divisions A2 and B of the Cenomanian Limestone are fully described by SMITH (1965, p.124, fig.4.)
Beer Beach (Tom Tizzards Hole) This section is fully documented in SMITH's (1957, pp.115-35) account of the Beer district. The section sampled for the purpose of this research is illustrated in Text Plate 6b which shows clearly the thinning of the A2 division towards the axis of the Beer Pericline (SMITH 1957). Text Plate 6a shows in detail the location of the sampled section, in a place where both the units (A2 & B) are of a reasonable thickness.
Pinnacles This is perhaps one of the most important sections on the whole of this coastal region. It has been fully described by SMITH (1961) and his account has been verified by this present work. Text Plate 7 shows a general view of the fallen block described in such detail by SMITH (1961, pp.101-04, fig.4a). This slipped mass shows Divisions A2, B and C as well as the basal Middle Chalk. A more detailed illustration of the section is shown in Text Plate 8 which shows clearly all the main planes of division as well as all the major nodular horizons. The zone of streaked glauconite lens' in the middle of Division B can also be differentiated from the nodular horizons above and below. Divisions A2 and B have been sampled at one foot intervals but Division C has been subjected to more intensive investigation. This 51 6n unit has been sampled in successive 3" blocks in the hope that it could then be accurately correlated with the Plenus Marls of the south east of England. This slipped block is resting in a precarious position against the upper levels of the Foxmould sands. The section of Upper Greensand between Branscombe Mouth and Little Beach is one of 63 Text Plate 6. a) The Cenomanian Limestone succession at Tom Tizzards Hole, Beer, Devorl. At this locality the two main units of the Cenomanian Limestone series (A2 & B) are reduced to only a few feet, a thickness which varies markedly across the bay. This variation can be seen in T.Plate 6b. The prominent break in the succession between the Upper Greensand and Division A2 can be seen just below the notebook (7" x 4").
b) General view of the Cenomanian Limestone succession at the southern end of Beer Bay. The right hand margin of this photograph is only twenty yards from the section shown in T.Plate 6a and the lateral variation in thickness of the A2 unit can be seen as one follows this bed along to the left. Just out of the field of view to the left of the figures the A2 unit is completely missing from the succession. Although the Upper Greensand is highly disturbed one can obtain an indication of the bedding, which is seen to be at an angle to that of the overlying limestone units. ~~ 65 Text Plate 7. a) General view of Purley smaajailezE,lamaa. (It would be useful to study this photograph in relation to Fig.4.) This shows the old degraded face of the quarry before the excavations were begun. The main trench was dug into the scree slope in the centre of the photograph* The other shallow trench, leading to the trial pit, is down to the left flank of the photographer's vantage point.
b) The fallen block at the Pinnacles, Little Beach, Branscombe, Devon. This block displays a very clear section of Divisions B & C, and these have therefore been studied in some detail at this locality. The Melbourn Rock can also be clearly seen by the right shoulder of the figure. The beds at the right hand side of the photograph are the Foxmould Sands (in situ) with the prominent ledges formed by the Cowstones (concretions).
67 f
Text Plate 8
Enlarged view of the fallen block at the Pinnacles•
The sequence shown in T.Plate 7b can be seen in more
detail here.
The main planes of division stand out clearly and the
most prominent feature is seen to be at the base of the
Melbourn Rock (the prominent overhanging ledge in the centre of the photograph). Division C occupies the 5' 6" below this ledge — the junction with Division B being the darker
grey line in the centre of the two nodule beds. It was this
short sequence that has been sampled in continuous three inch
blocks. Division B continues the succession downwards and
although the junction with Division A2 is obscure in the
photograph the nodular rock at the top of this older unit can
be seen just above the pebbles. The darker area in the centre
of Division B is the zone of glauconitic stringers mentioned
in the text.
All these planes of division, although quite prominent,
are not comparable to the Upper Greensand/Cenomanian Limestone
boundary shown in T.Plate 6b. The main differences ares-
1. There is no angular discordance of the beds.
2. The surfaces between them are not so open and
distinct.
3. Some material has been transferred between the beds
of the limestone sequence by burrowing organisms, and this
suggests that they had not undergone complete diagenesis
when the succeeding bed was deposited. The broken blocks of
Upper Greensand seem to indicate that its surface had been
eroded from a previously lithified sequence.
69
the most complete in south western England and as such has been used in an attempt to place the Foxmould sands and the Chert Beds in their approximate time-stratigraphic positions. Samples have been collected from these sequences but for the most part they are either decalcified, unprocessable or unfossiliferous. The Chert Beds of this section display one interesting sedimentological feature very like that already described in detail for the Lower Chalk. It is essentially a rhythmic deposit with bands of brown chert approximately every three feet. These chert horizons are separated by 2' to 2' 6" of sand of variable grain size - and frequently cross bedded. These rhythms are on very nearly the same scale as those described in the Lower Chalk of south east England, and in many ways they appear to be of a similar nature. The charts were probably formed during periods of non-deposition in a similar way to the limestone unit at the top of the Lower Chalk cycles. It is suggested tentatively here, and in more detail in a succeeding chapter, that these deposits - the Chert Beds and the Lower Chalk - were in fact deposited under similar sedimentary controls, one being arenaceous and the other calcareous in basic environment. There is also some faunal evidence to suggest that not only were the sedimentary controls of a similar nature but that they were probably operating over the same period of time.
The Inland Sections Nearly all the localities referred to in the literature have been visited but only the more important sequences with a bearing on the stratigraphic interpretation of the region have been investigated in detail.
70
Bovey Lane Sandpit (222E) This section, though now somewhat deteriorated since SMITH (1961, pp.117-20) first desoribed the succession. Most of the units he determined are still visible although most are now decalcified to some depth below the surface. Macrofossils are still quite abundant, including Actinocamax plenus (DE BTAINVILLE) at about the equivalent level of Bed 4 in the Plenus Marls sections in south east England. SMITH & DRUMMOND (1962,
PP.344-45) and Dil Y (1969, in press) have added more observations as to the correlation of these sands - especially with the succession seen at the sand pit in Wilmington. The section is shown in Text Plate 9a which shows Bed C. in the top right hand corner.
White Hart Sandpit (Wilmington) When first visited in 1967 this section exposed no more than 15 - 20 ft. of the calcareous sands below the 'grizzle' - described adequately by SMITH (1961) and SMITH & DRUMMOND (1962). However a return visit in 1968 allowed the inspection of a trial pit sunk at the base of tho working face. This pit is behind the figure shown on Text Plate 9b, which also shows the main cliff of the sands at the southern end of the quarry. The Middle Chalk can be seen just capping the face immediately below the vegetation. This trial pit showed the full extent of the sands down to the coarse conglomerate resting on the broken and somewhat uneven surface of the Upper Greensand. Below this basal conglomerate there are coarse cemented sands which pass downwards into very coarse laminated sands. These laminated beds however contain abundant Orbitolina lenticularis (BLUMENBACH) - a fact that will figure with some importance in the final stratigraphic account.
Membury The old chalk pit on the Farley road has been 71
A \ Text Plate p. a) The Cenomanian Sands succession, Bovey Lane Sandpit, Beer, Devon.
The main features of these friable sands can be seen here
with the nodular horizons standing out from the otherwise
smooth quarry face. The more glauconitic Division C (Plenus
Marls) can also be seen immediately below the soil level.
b) The Cenomanian Sands succession, White Hart Sandpit, Wilmington, Devon.
The face shown here is not being worked at the
present time and one can appreciate how rapidly these sands
decalcify and obscure a fresh surface. The capping of
limestone can be seen all along the section just below the
soil level. The trial pit, displaying the top of the
Upper Greensand, is in the depression immediately behind
the figure. 72
• -.
•
• , 73
the scene of intensive activity by the author. When first visited the section displayed a somewhat degraded sequence of chalk up to about 25 ft. in thickness. The initial appearance of the quarry is shown in Text Plate 7a. Many earlier workers have described and discussed this quarry in their accounts and included within this are reports by JUKES-BROWNE & HILL (1903, pp.121-2), SMITH (1957, 1961), SMITH & DRUNMOND (1962) and KENNEDY (1969, in press). The age of this deposit, until the paper of =MEDI has always been taken as Cenomanian and it has caused some concern to stratigraphers as to how this succession of chalk correlated with the limestone successions at the coast only eight miles away. KENNEDY has now cast some doubt on this determination of a Cenomanian age by suggesting that one of the ammonites found in the pit is in fact a Lower Turonian Watinoceras, sp. and not a Schloenbachia sp. as initially thought. He has also excavated a pit near the western end of the quarry (beside the old railway lines) and obtained from it a rich Middle Cenomanian phospha•iised fauna and a green stained Lower Cenomanian fauna (composed mainly of pebble fossils). The author has attempted to resolve all these arguments about this section and with these in mind has excavated two trenches and a small pit in the quarry. These 'earthworks' are shown in Fig.4. which also includes the details as to which faces of the quarry have been sampled.
Chard The Snowdon Hill Quarry west of Chard (Text Plate 5a) displays a section across the junction of the Chert Beds and the chalk. Although now completely overgrown since the work of DAVIDSON (1852, p.114), JUKES-BROWNE & HILL (1903, 1900) and 74
FIG. 4 DETAILS OF THE MEM BURY EXCAVATIONS. 0 Mts. 25 130 0A VW IN
NY \ d
070 ---1---„ Major synclinal feature GI DURRANCE d HAMBLIN ---4--- Major anticlinal feature .,-.... Minor anticlinal feature
76
SMITH & DRUMMOND (1962) the chalk Basement Bed with its derived Lower Cenomanian ammonites is still accessible.
Chardstock This small pit ( IP x Y 1969, in press) displays an unusual section across the Upper Greensand/Chalk boundary. Unlike the sequence at Chard the Basement Bed rests on a sandy limestone which has been correlated with division A2 (?) of the Cenomanian limestone sequence.
EggardonJiill This hill, capped with an ancient British hill fort, is remarkably interesting in that it is on the west flank of the Mid Dorset Swell. Here the chalk rests, with only a thin Basement Bed on four feet of very hard grit (the Eggardon Grit) which in turn is underlain by softer greensand containing more calcareous concretions.
Haldon Hills While most of the sections in these Hills south west of Exeter are now completely overgrown, recent road works on Telegraph Hill have exposed about 45 ft. of sand between the Haldon Gravels and the basal conglomerate (which rests on an uneven surface of Permian marls). This section, in the author's knowledge, was the only section available for study during the whole period of this research. This has been a short account of the localities investigated during this research project and more detailed accounts of all of them can be found in -BROWNE & HILL (1900, 1903) as well as in the various references cited in the text. All the sections referred to in this chapter can be found plotted in detail on the enclosed sheets at the back of the thesis - together with any explanatory notes that appear to be necessary. 77
CHAPTER
Systematic MicrooalaeontologY There now follows an abbreviated taxonomic summary covering the 86 genera covered by the present research. The breakdown of these genera is as follows:-
Genera 86 - 7 planktonic, 79 benthonic (1 new) Species 203 - 18 planktonic, 185 benthonic (51 new) Varieties 12 - 2 planktonic, 10 benthonic (2 new) Forms 6 - 6 benthonic.
The classification followed is that of the Treatise of Invertebrate Palaeontology, Part C Protista, LOEBLICH & TAPP1N (1964). There are only a few deviations from this and they are mentioned when they arise. The main deviation is the use of the classification of BANNER & BLOW (1959) for the Globigerinacea. This taxonomy is in a shortened form with descriptions of only the new species. The synonymies are not complete but only the main works are cited except in the cases of the more important species. Any discussion about the species is confined to the remarks following each synonymy, and discussion about evolutionary trends are included within these accounts. The plates (Numbers 1 - 25) are to be found at the end of the written text. Each plate has an index on the page immediately opposite.
Order FORNWINIFERIDA EICHWALD 1830 Suborder TEXTULARIINA IMAGE & HEROUARD 1896 Superfamily AMMODISCACEA REUSS 1862 Family SACC1MWINIDAE BRADY 1884 Subfamily SACCANMINAE BRADY 1884 78
Pelosina BRADY 1879 Type species: Pelosina variabilis CUSHMAN 1910
'Pelosina' sp. 20, sp. nov. Plate 1 s Fig.l. Determination: Test free, flattened, almost subcircular except for small tubular neck produced at one end, test agglutinated with grains of a moderate size although occasionally some of the grains may be much larger than average, aperture a simple hole at the end of the short neck. pemarkss This species, which is not uncommon throughoUt the sequence under consideration, occurs as single chambers possessing necks of variable lengths. Although appearing to be totally agglutinated this may not in fact be the case and the agglutination may be confined to the outer layer of the test. This may be the species named as Reophax lageniformis by CHAPMAN (1892). Occurrence: Middle to Upper Albian Clay with rare occ-irrences on the mid-Cenomanian non-sequence.
Family AMMODISCIDAE REUSS 1862 Subfamily. AMKODISCINAE REUSS 1862
Ammodiscus REUSS 1862 Type species: Ammodiscus infimus BORNEMANN 1874
Ammodiscus cretaceous (REUSS) Plate 1 Fig.2. Operculina cretacea REUSS, 1845, p.35, p1.13, figs. 64,65a-b. Cornuspira " (REUSS): REUSS, 1860, pp.177-8, p1.1, fig.la-b. (REUSSit REUSS, 1863, PP.34-5, P1.1, fig.lOa-b.
79
asuapral cretacea (REUSS): BURROWS, SBERBORN & BAILEY, 1890, p.552, p1.8, figs.5-6. (REUSS): CHUM, 1891, pp.10-11, p1.9, ft involvens (REUSS): CHAPMAN, 1891, pal, p1.9, fig.12a-b. foliacea PHILLIPI: CHAPMAN, 1891, p.11, p1:9, fig.13a-b. cretacea REUSS s EGGER, 1899, p.18, p1.22, figs .1-2. " REUSS s FRANKE, 1925, p.7, p1.1, fig.5. t• REUSS s CUSHMAN, 1926, p.608, p1.21, fig.3a-b. ft REUSS s FRANKE, 1928, p.16, p1.1, fig.22. REUSS : WRITE, 1928, p.188, p1.27, fig.9. Ammodiscus cretaceus(REUST HAM, 1953, p.4, p1.1, fig.3. (REUSS FRWMILL, 1954, p.58, p1.1, fig.15, Cyclogyra Z7-17MTREUSS): FUCHS, 1967, p.274, P1.4, fig.7. Remarks: CHAPMAN (1891) separated this species into three units:- "C,cretacea" - a biconcave form with no inflated proloculus. "C.involvens" -a biconcave form with an inflated proloculus. "C.foliacea" -a flat form with an inflated proloculus. These are probably the 'B' form, 'A' form, and a flattened 'A' form of the same species. This species is definitely agglutinated - a fact that many authors have never checked. In the Lower Chalk many specimens appear smooth and shiny but treatment with acid reveals that this is only the affect of a greater thickness of calcitic cement, the bulk of the test still being composed of fine sand grains. Occurrences Middle Albian to basal Turonian.
Glomospira RZEHAK 1885 Type species: Trochamminaeouamata JONES & PARKER var. Aordialis JONES & PARKER 1860
Glomospira gaultina (BERTHELIN) Plate 1 Fig.3. Ammodiscusgaultinus BERTHELIN, 1880, p.19, p1.1, figas-b. Opthalmidium tumidulum BRADY: CHAPMAN, 1891, p.10, p1.9, fig.10. 80
Ammodiscusipmitinus BERTHELIN: TAPPIN, 1940, p.95, p1.14, fig.6a-c. rt to BERTHELIN: TAPPIN, 1943, p.481, p1.77, fig.6a-b. BERTHELIN: FRIZZELL, 1954, p.58, p1.1, fig.17a-c. “ BERTHELIN: BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.140, p1.1, fig.29. Occurrence: Middle to Upper Albian clay.
Superfamily LITUOLACEA DE BLAINVILLE 1825
Family HORMOSINIDAE HAECKEL 1894 Subfamily HORMOSININAE HAECKEL 1894
Hormosina BRADY 1879 Type species: Hormosina globulifera CUSHMAN 1910
Hormqsina LaRenarium (BERTHELIN) Plate 1 : Fig.4. LiApl2phragmium azaallm BERikiLLIK, 1880, p.21, p1.1, fig.2a-b. Reonhalc =malacca BRADY: CHAPMAN, 1892, p.2, p1.15, figaa-b. Occurrence: Middle Albian to Lower Cenomanian. Reo2hax MONTFORT 1808 Type species: Reopha scorpiurus MONTFORT 1808 Reonhax sp. 23, sp. nov. Plate 1 Fig.5. Determination: Test free, coarsely agglutinated, chambers few, generally flask-shaped joined by short stout necks. Most specimens are broken and only the final chamber is found. Each chamber is almost circular in plan and the aperture is the open neck of the short neck. The overall surface is rough as there is comparatively little cement. Remarks: Although this form is usually formed of three or more chambers one rarely sees more than the final chamber in any of the samples studied. It is apparently restricted in distribution 81
and it occurs only at certain levels where it is commonly in flood abundance. Occurrence: Lower Cenomanian chalk to Plenus Marls (very abundant in Bed 2 of JzievERIES),
Subfamily CRIBRATININAE LOEBLICH & WPM 1964
Cribratina SAMPLE 1932
Type species: Nodosaria texana CONRAD in EMORY 1857
Cribratina cylindracea (CHAPMAN) Plate 1 : Fig.6. Reophax cylindracea CHAPMAN, 1892, p.3, p1.5, fig.7a-b. Lituola cylindrica PERNER, 1892, p.52, p1.2, figs.?-12, p.22, t.fig.6. Remarks: Cribratina is the only genus agreeing with most of the characters of this species ('A' form) except the asymmetry of the proloculus. No mention is made of the 'A' and 'B' forms in the type description and it seems possible that most of the type material - like that seen in England - is broken. Until the initial growth stages are verified from the type material this specimen is temporarily placed in Cribratina. Occurrence: Albian to Turonian. This species is abundant in the later - especially in samples from the type section of the Fertevou Chalk in Touraine - though not recorded by BUTT (1966).
Family LITUOLIDILE DE BLAINVILLE 1825
Subfamily HAPLOPBRAGMOIDEUE MAYNC 1952 82
Haplophragmoides CUSHMAN 1910 Type species: Nonionina canarienses D'ORBIGNY 1839
Haplophragmoides concava (CHAPMAN) Plate 1 : Fig.7. Trochammina concava CHAPMAN, 1892, p.327, p1.6, fig.14a-b. Remarks: Although most of the specimens referable to this species were badly squashed the overall shape of the test, with four or five chambers in the final whorl, seems to suggest that the generic determination of CHAPMAN is incorrect. Occurrences Middle to Upper Albian clays.
Labrospira HOGLUND 1947 Type species: Haplophragmium crasqimarqo NORMAN 1892
Labrospira latidorsata (B0RNEMANN) Plate 1 Figs.8,9. Nonionina latidorsata BORNEMANN, 1855, p.339, p1.16, Haplophragmium latidorsatum (BORNEMANN): CHAPMAN, 1892, p.5, p1.5,
Occurrence: Middle to Upper Albian - ? Upper Cenomanian.
Labrospira nonioninoides (REUSS) Plate 1 Fig.10. Haplophragmium nonioninoides REUSS, 1862, p.30, p1.1, fig.8. " REUSS: CHAPMAN, 1892, pp.3-4, p1.5, fig.9a-b. acutidorsatum CHAPMAN, (not HANTEEN), 1892, P.4, P1.59 Haplophragmoides sp. 2. NEAGU, 1965, p.4, p1.2, figs.4-5. Occurrence: Middle to Upper Albian - ? Lower Cenomanian sands. 83
Notes on the Labrospira group
LOEBLICH & TAPPAN (1964, Treatise) regard Labrospira as being the junior synonym of the genus Cribrostomoides CUSHMAN 1910. Cribrostomoides is thought to be similar to Haplophrmmoides, differing only in the apertural characters — that of the former being an areal aperture, with only a single elongate slit in the younger stages. Labrospira was initially described as possessing this slit aperture in all growth stages. The views of LOEBLICH & TAPPAN seem to suggest that they regard Labrospira as being contained in the junior growth stages of Cribrostomoides. The slit seen in the juvenile form is supposedly closed by apertural teeth which on expansion reduce the aperture to a series of pores. Most of the material found in this survey has not shown the apertural features very clearly but those that are better p_•eserved show no more than the plain slit, even in the very large and obviously mature specimens. For this reason the generic name Labrospira has been retained although its use could be verified in the light of better material.
Subfamily LITUOLINAE DE BLAINVILLE 1825
Ammobaculites CUSHMAN 1910 Type species: Spirolina agglutinans D'ORBIGNY 1846
Ammobaculites parvispira TEN DAM
Plate 1 Fig.14. 84
BaPlollwalam aequale CHAFMAN,(not ROEMER), 1892, p.323, p1.6, figs.1-3. It EICHENBERG,(not R. ai ear ), 1933a, p.170, p1.17, figs.7a-b. HaploPhragmium aequale EICHENBERG,(not ROEMER), 1935b, p1.7, fig.1, p1.8, figs.1-3. Ammobaculites parvispira TEN DAM, 1950, p.10, p1.1, fig.8a-b. ft TEN DAM: NEAGU, 1965, PP.4-5, p1.1, Occurrence: Middle to Upper Albian clay.
Ammobaculites subcretacea CUSHMAN & ALEXANDER Plate 1 : Figs. 12,13. Haplophragmium agglutinans CHAPMAN,(not D'ORBIGNY), 1892, P.324, p1.5, fig.14. Ammobaculites subcretacea CUSHMAN & ALEXANDER, 1930, p.6, p1.2, figs.9-10. sUbcretaceus CUSHMAN & ALEXANDER: ALBRITTON, 1937, p.20, p1.4, figs.3-4. CUSHMAN & ALEXANDER: CUSHMAN, 1946, P.23, p1.3, figs.18,19. ft r, CUSHMAN & ALEXANDER: LOEBLICH & MEW, 1949, p.251, p1.46, figs.9-13. Ammobaculites subcretacea CUSHMAN & ALEXANDER: TEN DAM, 1950, p.10, p1.1, fig.8. subcretaceus CUSHMAN & ALEXANDER: STEAD, 1951, p.589, p1.1, figs.719. is CUSHMAN & ALEXANDER: BARTENSTEI1, 1952, p.319, p1.1, fig.8, p1.2, figs.1-9. CUSHMAN & ALEXANDER: FRIZZELL, 1954, P.62, p1.2, figs.27,28. CUSHMAN & ALEXANDER: BARTENSTEIN, BETTENSTAEDT, & BOLLI, 1957, p.17, p1.2, figs.32,33. ft ft CUSHMAN & ALEXANDER: SKOLNICK, 1958, p.282, p1.37, fig.4. CUSHMAN & ALEXANDER: SZTEJN, 1958, p.13, figs.17,19. CUSHMAN & ALEXANDER: CRESPIN, 1963, p.43, p1.10, figs.13,14. CUSHMANAALEXANDER: BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.139, p1.1, figs.3-5, p1.7, fig.11. CUSHMAN & ALEXANDER: FUCHS, 1967, p.267, p1.2, fig.6. Occurrence: Middle to Upper Albian clay.
Bulbophragmium MAYNC 1952 Type species: Haplophragmium aequale REUSS 1860 85
Bulbophragmium aequale (MAYNC) Plate 1 : Fig.l1.
Haplophragmium aequale REUSS, 1860, p.218, p1.11, REUSS: FRANKE, 1928, p.170, p1.15, fig.15. fr " REUSS: EICRENBERG, 1933, p.170, p1.17, fig.?. ft " REUSS: TEN DM, 1946, P.570. p1.87, figs.3-4. Occurrence: Upper Albian ? Lower Cenomanian greensand and chalk.
#10ellamminoPsis MALECKI 1954 Type species: Plabellamminopsis vatiabilis NALECKI 1954
Flatellamminopsis sp. 1, sp. nov. Plate 1 : Fig.15. Determination: Test free, uniserial, with a pseudo- labrynthic interior, wall composed of uniformly sized sand grains held with little if any cement. Each chamber is roughly rounded and produced slightly towards the connection with the following chamber. The aperture is simple, rounded, at the end of the very slightly produced final chamber. Remarks: The wall, which is usually composed of uniformly sized sand grains, appears to be somewhat labrynthic. This may be due however, to the rough inner surface of the wall. Occurrence: Middle to Upper Albian clay.
Subfamily PLACOPSILININAE RHUMBLER 1913
Placopsilina D'ORBIGNY 1850 Type species: Placopsilina cenomana D'ORBIGNY 1850 86
Placopsilina cenomana - D'ORBIGNY Plate 2 s Fig.l.
Placopsilina cenomana D'ORBIGNY, 1850, p.185. " DIORBIGNY: REUSS, 1854, p,71, p1.28, figs.4-54 " D'ORBIGNY: CHAPMAN, 1892, P.324, P1,61 Remarks: This adherent form is extremely common in the lower part of the Cenomanian succession and although the spiral is normally difficult to see, it can usually be seen in some of the many broken specimens that occur in these levels. Occurrence: Foxmould sands(?), Upper Albian to Cenomanian greensands and Lower Cenomanian chalk.
Aoruliammina LOEBLICH & TAPPAN 1946 Type species: Placopsilina longs TAPPAN 1940
"Aoruliammina" folkestoniensis (CHAPMAN) Plate 2 Fig.5. Reophax folkestoniensis CHAPMAN, 1892, p.321, p1.5, fig.6a-b. Remarks: The generic position of this species is very doubtful but as only one or two specimens have been found very little can be done with them. It is probably an ecophenotypic variety of Bulbophragmium aequale MAYNC. Occurrence: Seen only in the Glauconitic marl of Copt Point (basal Cenomanian) and in the basal Plenus Marl of the Newbury section.
Family TEXTULARRIDAE EHRENBERG 1838
Subfamily SP1ROPLECTAKKINIWIE CUSHMAN 1927 87
...p.zSi olectamminasp CUSHMAN 1927 Type species: Textularia agglutinans D'ORBIGNY var. biformis PARKEN & JONES 1865
Spiroplectammina rectangularis TEN DAM Plate 2 : Figs. 2,3. Textularia praelonga CHAPMAN (not REUSS), 1892, p.329, p1.6, fig.23. Spiroplectammina reotangularis TEN DAM, 1947, P.25, t.fig.2a-b. tt TEN DAM var. cretosa TEN DAM, 1950, p.11, plat fig.9. Spiroplectammina elongate BARNARD & BANNER, 1953, pp.182-3, p1.9, fig.la-d. Remarks: The form described as S.elongata BARNARD & BANNER (1953) appears to be the microspheric generation of S.rectangularis TEN DAM and is therefore included in this synonymy. Inspection of BARNARD & BANNER'S type specimens in the Brit. Mus. (Nat. Hist.) has confirmed this opinion. Occurrence: Lower to Upper Cenomanian chalk, with a final appearance in Bed 2 of the Plenus Marls succession.
Spiroplectammina sp. B, sp. nov. Plate 2 : Fig.4. Determination: Test free, elongate, early portion of test appears to be a planispiral coil, and the later chambers are always biserially arranged; aperture indistinct but appears to be at the inner margin of the final chamber; most of the specimens encountered were coarsely agglutinated with very little calcareous cement. Occurrences Lower Cenomanian chalk.
Subfamily TEXTULARIINAE EHRENBERG 1838 88
Textularia DEFRANCE in DE BLAINVILLE 1824 Type species: Textularia sagittula DEFRANCE in DE BLAINVILLE 1824
Textularia chapmani LALICKER Plate 2, Figs.6,7. Textularia chapmani LALICKER, 1935, P.13, p1.2, figs.8,9. " LALICKER; TEN DAM, 1950, pp.11-12, plat fig.10. " LALICKER: JtiortkIES, 1962, p1.78, fig.23. Remarks: This form, with a range from the Lower Gault up into the Turonian, shows a variation from small forms with low chambers to large forms with high chambers in the upper levels. Occurrence: Middle to Upper Albian, throughout the Cenomanian, and is recorded from the basal Lower Turonian.
Textularia minuta BERTHELIN Plate 2 : Fig.8. Textularia minuta BERTHELIN, 1880, p.26, p1.6, fig.15. BERTHELIN; CHAPMAN, 1892, pp.9-10, p1.6, ig.15.
Remarks: A small form occurring occasionally in samples of Gault Clay. Occurrence: Middle to Upper Albian clays.
Textularia sp. 20, sp. nov. Plate 2 : Fig.9. Textularia of. washitensis CARSEY: amolatIES, 1962, p1.78, Gaudryina foedalITENETiMeDURIES, 1962, p1.79, fig.3. Determination! Test free, elongate, biserial, compressed in the plane of biseriality, numerous chambers closely appressed with only slightly inclined sutures; chambers slightly inflated in the later growth stages; wall finely agglutinated with no internal structures; aperture a simple low arch at the base of the last chamber.
89
Remarks: This typically Upper Cenomanian form is usually long and tapering with horizontal depressed sutures. drat7NRIES (1962) records variants of this species from the Plenus Marls under varying names - either of which may be the true determination of this species. Occurrence: Lower to Upper Cenomanian chalk and greensand, final appearance in Bed 4 of the Plenus Marls.
Textularia sp. 21, sp. nov. Plate 2 : Fig.lO. Determination: Test free, slightly elongate, biserial, with chambers expanding in size rapidly; nearly all chambers inflated with deep almost horizontal sutures; final chamber much larger than all the others; wall very finely agglutinated with a large amount of calcareous cement; aperture is a simple low arch at the base of the final chamber. Remarks: This sharply tapering form with a smooth test is found in abundance at the level of the Cambridge Greensand in the Arlesey section. Occurrences Upper Albian clay to Lower Cenomanian chalk - also occurs in both Albian and Cenomanian greensands.
Textularia sp. 22, sp. nov. Plate 2 s Fig.11. Determination: Test free, slightly elongate, markedly biserial and flattened in the plane of biseriality. Chambers only slightly inflated giving an overall straight-sided appearance; sutures indistinct but almost horizontal, not deeply depressed; final chamber only slightly inflated, producing an almost flat 90
apertural face; aperture indistinct, at the base of the final chamber. Remarks: This species would probably be better placed in the Qaudrvina group but the very small distal end makes determination difficult. It is moreover very closely related to the Textularia group described here.
•Occurrence:I•MMI..MMM.MMM••ktB•P Lower to Upper Cenomanian - final appearance in Zone lla,
Textularia sp. 24, sp. nov. Plate 2 s Fig.12. ?Textularia gramen BURROWS, SBERBORN & BAILEY, (not DI(BIGNY), 1890, p.553, p1.8, fig.l3a-b. nextlilaria anglica LALICKER, 1935, p.10, p1.2, figs.6-7. Determination: Test free, moderately elongate, biserial, rapidly expanding in size due to the inflation of the chambers, sutures distinct, depressed, inclined to the horizontal; last two or three chambers markedly inflated; wall coarsely agglutinated with little if any calcareous cement; aperture simple at base of final chamber, which is somewhat overhanging. Remarks: This coarsely agglutinated species with inflated later chambers is abundant at certain levels in the Gault Clay. Occurrences Middle to Upper Albian Clay.
Family TROCHAMMINIME SCHWAGER 1877
Trochammina PARKER & JONES 1859 Type species: Nautilus inflatus MONTAGU 1808 91
Trochammina sp. 20, sp. nov. Plate 2, Pig.14. Banlophragmium globigeriniforme (PARKER & JONES): CHAPMAN, 1892, p.324, p1.5, fig.16. Determination: Test free, trochospiral, slightly globular chambers, inoreasing gradually in size throughout the specimen; wall coarsely agglutinated with very little calcareous cement; four Chambers commonly seen in the final whorl with the aperture being a low interiomarginal extra-umbilical - umbilical arch under the final, more inflated, chamber. Occurrence: Middle to Upper Albian clays and sands, (?)Cenomanian greensands.
Trochammina sp. 23, sp. nov. Plate 2 : Pig.13. Determination: Test free, troohospiral, only slightly inflated chambers with only moderately distinct sutures; commonly five chambers in the last whorl, increasing uniformly in size; wall coarsely agglutinated especially in the early growth stages; aperture is a low, interiomarginal, extra-umbilical - umbilical arch. Occurrence: Middle to Upper Albian (of the Isle of Wight).
Tritaxis SCHUBERT 1921 Type species: Rotalina fusee. WILLIAMSOfiN 1858
Tritaxis fusca (CHAPMAN 1892, non WILLIAMSON 1858) Plate 3 s Piga. Valvulina fuses CHAPMAN, (non WILLIAMSON), 1892, p.754, p1.11, fig.12. Remarks: This attached form is almost identical with 92
Trochaminella ,siphonifera CUSHMAN — a recent species from a variety of localities which includes Britain. It was initially discarded as being Recent contamination of the coastal section at Copt Point. CHAPMAN also recorded this species from that locality but more significant are the records of the Channel Tunnel Survey which records the ser:3 species in the Gault Clay of some of the boreholes. In this case contamination is impossible and so the species is recorded with the specific name used by CHAPMAN although it is not in fact WILLIAMSON's Recent species. Occurrences Middle to Upper Albian, including ftxmould Sands.
Family ATAXOPBRAGMIIDAE SCHWAGER 1877
Included in this family are many genera that have been encountered in this present survey. LOEBLICH & TAPPAN (1964, Treatise) have been followed with only slight exception. The generic descriptions of Gaudryina, Uvigerammina, Soiroclectinatao Tritaxia, Eggerellina, and Plectina were found to agree with the present observations. LOEBLICH & TAPPAN (1964) have followed the suggestion of TRUJILLO (1960, p.308) in placing Marssonella in the synonymy of Dorothia. They reject however BOWEN's (1955, p.363) suggestion that Gaudrvina, Dorothia and Marssonella are cogeneric. This rejection has been confirmed and Gaudriina appears to be a distinct form. The author is in basic agreement with LOEBLICH & TAPPAN's former statement but while the separation is somewhat artificial it is thought to be useful when considering species as distinot as those in the British Albian and Cenomanian. 93
There has been a great deal of discussion as to the generic status of Flourensina, Avenobulimina and Hagenowina. This work has not been extensive enough for the author to pronounce on their validity and because of this LOEBLICH8CTAPPAN (1964) have been followed using the following (abbreviated) definitions:—
Flourensina - triserial, interior simple. Arenobulimina - trochospiral, more than three chambers per whorl, no internal subdivisions. Hagenowina — trochospiral, three or more chambers per whorl, internally subdivided.
Subfamily VERNEUILMINAE CUSHMAN 1911
Fluorensina MARIE 1938 Type species: Flourensina douvillei MARIE 1938
Flourensina intermedia TEN DAM Plate 3 : Fig.2. Flourensina intermedia TEN DAM, 1950, p.15, p1.1, fig.16. Remarks: This characteristic species develops from Assabulosa at the top of Bed 13 in the Copt Point succession, and persists through zones 6a — 8 in the basal Cenomanian. Occurrence: Lower Cenomanian chalk, and Cenomanian greensands.
Flourensina sp. A, sp. nov. Plate 3 s Fig.3. Determination: Test free, triserial, with chambers slightly inflated into a triangular shape; coarsely agglutinated with 94
very little calcareous cement; final chamber inflated but still possessing a flat apertural face; aperture a loop in the face of the final chamber extending upward from the basal suture; this aperture may have slight lips on either side; margins of chambers often appear crenulate in the latdr growth stages and this is a reflection of some degree of internal sub-division. Remarks: This Upper Cenomanian form appears to be a late member of the F.intermedia lineage. It is definitely triserial in the early portion and it is this fact that places it in this group as against the quadriserial A.anglica CUSHMAN lineage. The peripheral edge of all the later chambers is crenulate and this gives an overall rough appearance to the surface of the test. Occurrence: Upper Cenomanian chalk, more abundant in Zone lla.
Notes on the Flourensina lineage As noted above F.intermedia develops from A.saloulosa in the uppermost Albian. This is done by the reduction from four to three chambers in each whorl. A.sabulosa is markedly quadriserial, being almost square in cross section. F.intermedia is markedly triserial but in many cases the difference is very difficult to discern. Both are coarsely agglutinated and this can, in some cases, obscure the chamber arrangement. F.intermedia has a very restricted range in zones 6a-- 8 and this shows that it is quite likely to be a facies controlled species.
Flourensina op. A is another triserial form appearing much later in the Cenomanian. Unlike the others in this group the 95
agglutination is not strong enough to cover the chamber arrangement. In the later chambers there are signs of the development of some form of internal structures. These can be seen on the surface of the test in the crenulate margin that some of these chambers possess. This is probably a late development of the Assabulosa - P.intermedia lineage as this is the only triserial group that is seen in the Albian and Cenomanian. A.anglioa develops similar final chambers at higher levels but it is unlikely that Flourensina sp.A arose from this quadriserial stock.
Gaudryina D'ORBIGNY in DE LA. SAGRA 1839 Type species: Gaudryina ruesa D'ORBIGNY 1840
Gaudryina cruadrane CUSHMAN Plate 3 : Figs. 4,5. Gaudryina quadrans CUSHMAN, 1936, p.6, p1.1, fig.12a-b. CUSHMAN: CUSHMAN, 1937, p.47, p1.7, figs.l1-12. Remarks: The British species are only half the size of the American holotypes and it is possible that the two groups of individuals are not cospeoific. There is a complete transition into G. onesiana WRIGHT and because of this these Cenomanian forms may be better referred to that species. Occurrence: Cenomanian chalk and greensand to basal Turonian. Frequently more abundant where there is evidence of :hallowing or disturbance, e.g. t mid-Cenomanian non-sequence, zone 11a, and Plenus Marls.
'Gaudryina' sp. JEtevatIES Plate 3 : Fig.7. 96
gaudryino sp. araPrNRIES, 1962, p1.78, fig.22. Remarks: This species only occurs in the Plenus Marls succession — Bed 2. Most of the specimens obtained from this level are badly preserved and none of the specimens observed in this research have enabled a more definite determination than that given above. This species shows no affinities to any other described species and it is doubtful if it should even be referred to this genus. Occurrences Bed 2 Plenus Marls succession.
Gaudryina sp. 25, sp. nov. Plate 3 : Fig.6. Determination: Test free, elongate, early stage triserial, triangular in appearance; later part of the test is usually biserial, slightly flattened in the plane of biseriality; wall coarsely agglutinated; aperture indistinct but probably interio— marginal at base of last chamber. Occurrences Lower to Upper Cenomanian chalk.
Spiroplectinata CUSHMAN 1927 Type species: Textularia annectens PARKER & JONES 1863
Spiroplectinata annectens PARKER & JONES Plate 3 : Figs.8,9,10. Textularia annectens PARKER & JONES', 1863, p.92, t.fig.l. Spiroplecta annectens (PARKER & JONES): CHAPMAN, 1892, p.750, p1.11, fig.3. tt (PARKER & JONES): CHAPMAN, 1899, p.58, fig.4. Spiroplectinata annectens (PARKER & JONES): TEN DAM (part), 1950, p.13, p1.1, fig.14.
97
Bigenerina complanata (REUSS): NOTE (pal, 1951, P•34, p1.2, Spiropleotinata annectens (PARKER & JONES NEAGU, 1965, p.6, p1.2, fig.19. (PARKER & JONES): FUCHS, 1967, Pp.269-70, p1.31 fig.1, and synonymy. Pseudospiroplectinate Plana GORBENKO, 1957, pp.879-880, fig.la-c. Proroporous complanatus REUSS, 1860, p.231, p1.12, fig.5. Textularia 'complanata (REUSS): CHAPMAN, 1898, p.13, p1.2, fig.7. Spiroplectinata annectens (PARKER & JONES): TEN DAM (part), 1950, p.13, play fig.13. Spiropleotinata of. com lanata (REUSS): JterSHIES, 1962, p1.78, fig.6. Spiroplectinataoomplanata REUSS): FUCHS, 1967, pp.270-71, p1.3, fig.5, and synonymy. Remarks: The two forms of this species occur in the Gault and Lower Chalk of southern England where they are both abundant. The larger, more elongate, biserial megalospheric (2.00mplanata) form can be distinguished from the parallel sided, microspheric (S.annectens) form with the typically uniserial adult growth stage. In the Upper part of the Lower Chalk and in the Plenus Marls the longer form develops totally flattened uniserial chambers with a terminal aperture commonly seen in the later growth stages. GORBENKO (1957) placed this 'new' species in a new genus but the observations of this present survey indicate that it is no more than the end member of the present lineage. Occurrences Lower to Upper Cenomanian Chalk.
Tritaxia REUSS 1860 Type species: Textularia tricarinata REUSS 1844
Tritaxia macfadyeni CUSHMAN Plate 3 : Fig.11. Tritaxia macfadTeni CUSHMAN, 1936, p.3, p1.1, fig.6a-b.
41=111•1111•111111111101111•11.111110 CUSHMAN: CUSHMAN, 1937, PP.23-41 p1.3, figs.9-11. It CUSHMAN: WILLIAMS4IITCHELL, 1948, p.98, p1.8, fig.2.
98
Tritaxia macfadyeni CUSHMAN: BARNARD, 1953, p.195, p1.7, figaa-b. It tricarinata (REUSS) var. plummerae CUSHMAN: J4FVEHIES, 1962, p1.78, fig.2. it 411.11411M101111111111MINPIMMO (REUSS) var. macfa4yeni CUSHMAN: JEFAXIES, 1962, p1.78, fig.4. Tritaxia macfadyeni CUSHMAN: UGUZZONISGRADRTmANI, 1967, p.11879 p1.515, figs.2-5. Occurrence: Lower Cenomanian chalk to Bed 1. Plenus Marls succession.
Tritaxia macfadyeni CUSHMAN var. subrotunda TEN DAM Plate 3 : Fig.12. Tritaxia subrotunda TEN DAM, 1950, p.12, p1.1, fig.11. Remarks: In the lower levels of the Cenomanian this small variety appears as an intermediate form between T.pyramidata REUSS and T.macfadyeni CUSHMAN. This may be an unjustified separation but in all specimens of the variety the edges are by no means as sharp as those commonly seen in T.pyramidata. Occurrences Upper Cenomanian chalk only.
Tritaxia pyramidata REUSS Plate 3 : Figs.13,14. Tritaxia pyramidata REUSS, 1862, pp.32.88, p1.1, fig.9a-c. Verneuillina triouetra CHAPMAN, (not MUNSTER), 1892, p.329, p1.6, fig.24a-b, Tritaxia tricarinata CHAPMAN, (not REUSS), 1892, pp.749-50, p1.1, fig.la. " pyramidata REUSS: CUSHMAN, 1937, pp.22-3, p1.2, figs.21-41 p1.3, figs.1-8. Tritaxia pyramidata REUSS: TEN DAM, 1950, pp.12-13. " tricarinata (REUSS) var. pyramidata REUSS: 'won:RIES, 1962, p1.78, fig.3. Occurrence: Middle Albian clays to basal Turonian chalk.
Tritaxia trioarinata REUSS Plate 3 : Fig.15. 99
Textularia tricarinata REUSS, 1844, p.215. REUSS: REUSS, 1845, 13.39, P1.8, fig.60. Verneuillina dubia REUSS, 1851, p.40, pl.4, fig.3. Tritaxia tricarinata REUSS: REUSS, 1860, p.228, p1.12, figs.1-2. 01avulina augularia FRANKE, (not D'ORBIGNY), 19281 p.140, p1.13, fig.l. Tria tricarinata FRANKE, 1928, p.137, p1.12, fig.17. " REUSS: CUSHMAN, 1937, p.25, p1.3, figs.16-25. teTri 711273InTES): CUSHMAN, 1937, P.26, p1.4, figs.1-4. tricarinata REUSS: CUVILLIER & SZAKALL, 1949, p.20, p1.7, fig.7. " REUSS: BARNARD, 1953, P.193, p1.8, fig.la-e, ••••••=11.01•1•••••••• t.fig.3a-j. Tritaxia tricarinata REUSS: BUTT, 1966, pp.171-2, p1.1, fig.l. Occurrences Plenus Marls and Turonian chalk.
Tritaxia sp 20 sp. nov. Plate 3 : Fig.16. Determination: Test free, triserial, triangular in cross section; wall coarsely agglutinated with little calcareous cement; aperture indistinct and often completely obscured by the agglutinated material; (in those specimens with the aperture visible it appears to be terminal in adult specimens;) the overall shape is very like that of T.pyramidata and this may only be a facies variation of this species. Occurrence: Middle to Upper Albian sands and clays.
Uvigerinammina MAJZON 1943 Type species: Uvigerinammina jankoi MAJZON 1943
Uvikerinannina moesiana NEAGU Plate 4 : Figs.1,2. Uvigerinammina moesiana NEAGU, 1965, p.5, p1.2, figs.11 -18. Occurrence: Lower and Upper Cenomanian,chalk and greensand.
100
Subfamily GLOBOTEXTULARIME CUSHMAN 1927
Arenobulimina CUSHMAN 1927
Type species: Buliminapresli ' S 1846
Arenobulimina anglica CUSHMAN Plate 4 Fig.3. Arenobulimina anglica CUSBMAN, 1936, P.27, p1.4, fig.8a-b. " CUSHMAN: CUSHMAN, 1937, p.37, p1.4, figs.31, ?32,?33 (not 34). te ' CUSHMAN: OREKOFP, 1947, P.2, p1.1, fig.5a-b. Remarks: A.anglica was described from the Chalk Marl detritus of Charing, Kent, and the holotype is typical of specimens seen throughout the whole of the Chalk Marl. However CUSHMAN's (1937) paratype (fig.33) is very like A.cf.oblioua (WORBICNI) and his other specimen (fig.34) is apparently an internally subdivided species better referred to H.advena CUSHMAN. Although the holotype shows no sign of internal subdivisions specimens from higher levels of the Cenomanian show a folding of the margins of the later chambers and this could possibly affect the generic position of the species. Occurrence: Lower Cenomanian chalk below the mid-Cenomanian non-sequence.
Arenobulimina chapmani CUSHMAN Plate 4 s Fige.4,5. Bulimna preslii CHAPMAN (not REUSS), 1892, P.755, p1.12, Arenobulimina chapmani CUSHMAN, 1936, p.26, p1.4, fig.7abe " CUSHMAN: CUSHMAN, 1937, p.36, p1.3, figs.27-28. " CUSHMAN: TEN MAXI 1950, p.14. ""--4--- CUSHMAN: MUGU, 1965, p.10, p1.2, fig.9. Remarks: This species was recorded by CHAPMAN (1892) from Beds 6 to 13 of the Copt Point Gault sequence. This distribution 101
(with Citharinella pinnaeformis (CHAPMAN)) has been consistent over the whole of southern Englanda In areas of "normal deposition" where zone 6a is missing there is a fairly sharp change to a population with the general shape of A.chanmani but possessing internal subdivisions. This form has been placed in Fhadvena (CUSHMAN) which will be described later. Remarks: Upper and Middle Albian sands and clays.
Arenobulimina courts. (MARIE) Plate 4 s Fig.6. ?Bulimina obesa REUSS(pars), 1851, p.40, pl.4, fig.12 only. Hagenowella courts MARIE, 1941, p.43, p1.7, fig.68a-b. se MARIE: BARNARD & BANNER, 1953, pp.202-3, t.fig.6j-o. Remarks: This species is now placed in Arenobulimina in accordance with LOEBLICH & TAPPAN (1964,Treatise). Hagenowella was initially described as having internal partitions, but this was subsequently shown by MARIE (1941, p.41) to be based on mis- identified material of the type species. The type species therefore, having a simple interior, makes Hagenowella a junior synonym of Arenobulimina. Occurrences Lower and Upper Cenomanian sands and chalk, including Division C of the Cenomanian Limestones.
Atenobuliminadepressa PERNER Plate 4 s Figs.718. Bulimina,depressa PERNER, 1892, p.55, (p.27), pl.3, fig.3a-b. Pernerina sp. aalleatIES, 1962, p1.78, fig.7a-b. Remarks: The generic position of this species is uncertain but it seems likely that it belongs in Arenobulimina. According 102
to CUSHMAN (1937, pp.195-6), the adult chambers of Pernerina depresses, (PERNER) show interseptal pillars. In his a000unt he figures two specimens, fig.5a-o showing external views while fig.6. is broken open to show the pillars. This specimen (fig.6) appears to be a coarser specimen and it may in fact belong to a different species. The British specimens lack any interseptal pillars but are externally very similar to CUSHMAN's fig.5a-c. If B.depressa is internally simple then Pernerina CUSHMAN is not a synonym of Ataxophragmium REUSS as LOEBLICH & TAPPAN (1964) suggested. If it is not worthy of generic status it should be placed in Arenobulimina. This species is probably that which has been described by many workers Ataxophragmium variabilis (D'ORBIGNY). This was initially a Senonian form and is possibly related to the present species by way of Bulimina jaekeli, FRANKE from the Upper Turonian. Occurrence: Cenomanian greensands, Lower and Upper Cenomanian chalk, and Lower Turonian.
Arenobulimina macfadyeni CUSHMAN Plate 4 s Buliminaorbignyi, CHAPMAN (not REUSS), 1892, p.754, p1.12, fig.2. Arenobulimina macfadyeni CUSHMAN, 1936, p.26, pl.4, fig.6a-c. CUSHMAN: CUSHMAN, 1937, p.35, P1.4, figs .13--14. CUSHMAN: TEN DO, 1950, p.14. CUSHMAN: NEAGU, 1965, p.10, p1.2, figs.7-8. CUSEMANs UGUZZONIecRADRIZZMI, 1967, p.1201, p1.88, figs.7,8. Remarks: This species is typically seen in the Lower Gault. Small forms are seen in Beds 1 - 6 with a maximum development in Beds 7 — 8. In the Upper Gault there are specimens that show coarser agglutination and which are usually larger in size. These 103 are rarely seen and only represent the final appearances of the species. Occurrence: Middle and Upper Albian clays and Foxmould sands.
Arenobulimina cf. obliques (D'ORBIGNY) Plate 4 : Fig.11. Bulimina obliqua D1 ORBIGNY, 1840, P.40, p1.4, ArenobuliMina,angliea CUSHMAN (part), 1937, p.37 p1.4, fig.33, (not figs.31,32,34) Remarks: Although initially a Senonian species it is possible that these small forms with a flat apertural face should be placed in this species. D'ORBIGNY's type figures are unsatisfactory but microfilm photographs of his specimens have been examined and used for comparative purposes. These show a great similarity to these Cenomanian specimens and because of this DIORBIGNY's specific name is tentatively used. Occurrence: Upper Albian clays and sands to Upper Cenomanian chalk.
Arenobulimina preslii Plate 4 : Fig.10. Bulimina preslii REUSS, 1846, p.38, p1.13, fig.72. Arenobulimina preslii (REUSS): CUSHMAN, 1937, p.39, p1.4, (REUSS): BUTT, 1966, p.172, p1.1, fig.5. Occurrence: Uppermost Cenomanian, Plenus Marls and Lower Turonian.
Arenobulimina satulosa (CHAPMAN) Plate 4 s Fig.12. 104
Bulimina preslii REUSS var, sabulosa CHAPMAN, 1892, p.755, p1.12, fig.5. Arenobulimina sabulosa (CHAPMAN): CUSHMAN & PARKER, 1934, p.32, p1.6, fig.6a-b. (CHAPMAN): CUSHMAN, 1937, p.36, p1.3, figs.29-30. Remarks: CHAPMAN (1898, appendix 3) states that this form is restricted to Beds 12 and 13 of the Copt Point succession, and this determination has been found to hold over the whole of south- east England. This quadriserial form is easily recognised by the very coarse agglutination of the test but can in some cases by confused with its triserial successor, F.intermedia TEN DAN. Occurrences Upper Albian clays and sands.
Arenobulimina sp. A sp. nov. Plate 4 t Fig.13. ?Arenobulimina truncate (REUSS): CUSHMAN, 1937, 13.4/ P1.4/ figs.15116. Determination: Test free, quadriserial, though may appear almost triserial; agglutinated with moderate amount of calcareous cement; chambers only slightly inflated, elongated, tapering very gradually to the distal end; the widest part of the test is the final whorl which normally contains four chambers: apertural face flattened, with a loop shaped aperture at the base of the final ohamber; interior of test simple. Remarks: CUSHMAN's species from the Cenomanian of Bohemia is very similar to this but are in general of smaller size. His specimens also appear triserial while the British ones are always quadriserial, giving a squarish cross section. The number of chambers in the whorl seems to be important as a generic character and it is because of this discrepancy that they have been separated. 105
Occurrences Middle and Upper Albian clays and sands to the Plenus Marls.
Arenobulimina sp. B sp. nov. Plate 4 : Determination: Test free, finely agglutinated; triserial, most specimens having a markedly triangular appearance in cross section; chambers slightly inflated with a simple interior; apertural face flat with a loop shaped aperture at the base of the final chamber. Remarks: CUSHMAN records a species, A.frankei, from the Cenomanian of Germany and while the two are superficially similar they are probably not the same species. The British specimens are much smaller - nearly half the size - and are only seen in zone 6a below the Glauconitic Marl. A few small juvenile forms are seen at lower levels in the Copt Point succession. Occurrences Upper Albian clay.
Evolutionary Trends within Arenobulimina and related genera The evolutionary trends within this group are relatively straightforward but the inter-relationships of these groups are more complex. Within any one group the sequences of shape and form appear to be continuous and can be followed with relative ease where the sampling is continuous. At some levels however there is rapid diversification and it is at these points that the evolutionary pattern becomes more obscure. Bearing these points in mind each of the main lineages is now outlined together with discussion of the connections between the groups. The evolutionary trends outlined in this section are illustrated in Pigs.6 and 7. 106
R. A. prestii TU 1
41P 1 4 IA N AN NOM CE
U. 111= . 1
3
ressa
. 4 m . m dep p ‘ A. 410.
+ tikik 4
6* NIAN 0 ? . - k OMA O - r
CEN w
rA .
L vi 0 1 1 1 4
LINEAGE CONTINUED ON OTHER T.FI a
8IAN A. sp.B --.--. N AL , -... A. chapmani U. -..-.. .-- i - -• 4: - ? - - - - .p AN BI A. macfadyeni AL
1 M.
FIG. 6 EVOLUTION OF ARENOBULIM/NA spp.
I 107
1) A.macfadyeni libeage: Appearing in the basal Gault A.macfadyent is the only member of the whole plexus at this level. Throughout this part of the succession there is very little change in this species apart from a slight increase in the size of the adult specimens. In the middle of the Gault succession (at Folkestone) the diversification of the genus begins. Three new forms appear quite suddenly without any indication of the species from which they arose. Aschammani is the most important of the new species while A.sp.A and A.spO are represented by only occasional specimens. In the Cenomanian some forms appear that are possibly referable to an A.macfadyeni ancestor but this relationship is only tentative. 2) A.sp.A lineage: This appears to originate in the Upper Gault as mentioned above. It is a small slender species at this level but rapidly attains a larger size in the basal Cenomanian. This size is maintained throughout the Cenomanian during which time the external shape hardly varies. 3) A.sp.B lineage: Originating with A.sp.A. in the Upper Gault this species has a very restricted range. It is mainly confined to zone 6a in the basal Cenomanian. 4) A.ohapmani lineage: This appears to be the source of most of the Cenomanian species as well as the dominant form in the Upper Albian. In the uppermost Albian some members of this group develop a coarser texture while others retain the same texture while increasing slightly in size. This is the first sign of the split that leads to the two lineages that are present in the basal Cenomanian.
Those that remain much as A.chammani in the uppermost Albian 108 irt 1-..
I
I
1
IAN I Flourensina sp. I AN I4 I
FM i I I EN
C - \
U. • \
_ \ 2 I "
111‘ kg
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V H. advena • AN INCREASING NI COMPLEXITY •
MA • OF PARTITIONS • F. intermedia
CENO lolir
A.anglica jJ L. t • • •• *
ki te% . 2' ‘? i •
c.. el,.' 412 A. sabutosa :-37;"- V* al ..• 'tor it A. chapmani NW/
FIG. 7 EVOLUTION OF ARENOBULIMINA spp. 109
continue across the Albian/Cenomanian boundary with very little change in their external morphology. There is however a marked difference in their internal structure across this boundary. Those from the Cenomanian - owing to generic determinations - have been placed in the species Hagenowina advena (CUSHMAN) on account of the development of internal partitions. This group continues to evolve throughout the Cenomanian as will be outlined in a later section. There can be no explanation of this change to forms with internal partitions, or as to why it should always occur at this stratigraphic level. It is seen a Dover where the change occurs across the Gault/Lower Chalk boundary. This is the only locality where it could be explained in terms of a faoies change as in the Isle of Wight the change occurs totally within the Upper Greensand facies. In this case there is no obvious environmental control.
Those forms in A.chapmank that develop a coarser test :;.n the uppermost Gault increase in rugosity until they are referable to A.sabulosa. This species is seen in Bed 13 of the Gault but above this level there are many rapid changes. At the base of the Glauconitic Marl at Folkestone this quadriserial species suddenly gives rise to the triserial F.intermedia TEN DAM. This species characterises the basal Cenomanian of south-east England but there is a strong possibility that this, unlike many of the other groups, is a facies controlled fauna. A.sabulosa at the same level may give rise to A.anglica which persists into the higher levels of the Cenomanian. 5). A.cf.obliqua lineage: In the uppermost Albian another group appears and this is again probably derived from A.macfadyeni 110
although there is no direct evidence for this hypothesis. In the basal Cenomanian A.cf.obliqua is accompanied by another - probably related - species and these two continue together throughout the Cenomanian. AlthoughA.cf.obliqua and A.depressa are closely related their position one to another cannot be ascertained and they appear to form a single group unrelated to any other. Also present throughout the whole of the Cenomanian are small rounded forms with no apparent relationship to any species. These are thought to be immature megalospheric individuals of all the various species discussed in this section.
Dorothia PLUMMER 1931 Type species: Gaudryina bulletta CARSEY 1926
Dorithia gradata (BERTHELIN) Plate 5 Figs.1,2. Gaudryina gradata BERrii/LIN, 1880, p.24, p1.1, figs.6a-b. ?Gaudryina spissa BERTHELIN, 1880, p.24, p1.1, figs.7a-d. Gaudryina pupoides CHAPMAN, (not D'ORBIGNY) 1892, p.752, p1.11, fig.8a-b. Gaudryina rugosa CHAPMAN, (not D'ORBIGNY) 1892, p.752, p1.11, fig.9a-b. Gaudryina gradata BERTHELIN: EGGER, 1899, p.38, p1.4, figs.4-6. Gaudryina gradata BERTHELIN: FRANKE, 1928, p.142, p1.13, fig.4, and fig.5a-c, (as G. spissa). Dorothia gradata BERTMLIN CUSHMAN, 1937, P.74, p1.8, fig.5a-b. BERTHELIN TEN DAM, 1950, p.16. " " BERTHELIN BARTENSTEIN, 1954, P.39. Gaudryina zradata BERTHELIN: UGUZZONI & RADRIZZAN, 1967, p.1190, p1.86, figs.1-5. Occurrence: Middle and Upper Albian Clays and. sands to Bed 3 Plenus Marls. 111
Dorothia gradata (BERPHELIN) var. dispansa (CHATHAM) Plate 5 Fig.3. Gaudryina dispansa CHAPMAN, 1892, p.753, p1.11, fig.10a—b. It ••••••111110.1•11•01.101100 CHAPMAN: CHAPMAN, 1926, p.34, p1.13, fig.8. Remarks: Although initially described by CHAPMAN as a separate species this form is very close to D. gradata, and so is reduced to a variety of this species. Occurrence: Middle and Upper Albian clays and sands to Lower Cenomanian
psx:s2Lai (BERTH0L1N) Plate 5 : Gaudryina filiformis BERTHELIN, p.25, p1.1, fig.8. Gaudryina filiformis BERTIANLINs CHAPMAN, 1892, p.752, p1.11, fig.7. Occurrence: Middle to Upper Albian clays.
Eggerellina MARIE 1941 Type s;ecies: Bulimina brevis D'ORBIGNY 1840
"Eggerellina gibbosa" MARIE Plate 5 s Fig.5. Eggerellina gibbosa MARIE, 1941, p.35, no figure. if sp. JE0VEHIES, 1962, (part), p1.79, Remarks: This is a tentative determination as the holotype of E.gibbosa was described from much higher in the chalk sequence. It appears to be distinct from E.mariae TEN DAM but it may just be a local variety of that species. Occurrence: Upper Albian Clay to Lower Turonian
112
Eggerellina mariae TEN DAM Plate 5 : Fig.6. Eggerellina me TEN DAM, 1950, pp.15-16, p1.1, fig.17. sp. azieSKIES, 1962, (part), p1.79, fig.5. Remarks: This is a very variable species which can range in shape from a short pyramidal form to a long narrow form. It is probably the anoestoral form of E.intermedia (REUSS) which is recorded from higher levels in the Cretaceous. Occurrences Upper Albian clay to Lower Turonian chalk.
Marssonella CUSHMAN 1933 Type species: Gaudryina oxycona REUSS 1860
garssonella ozawai CUSHMAN Plate 5 : Fig.7. Marseonella ozawai CUSHMAN, 1936, p.43, p1.4, fig.10a-b. CUSHMAN: CUSHMAN, 1937, p.59, p1.6, fig,18. " CUSHMAN: BARNARD in BARNARD & BANNER, 1953, P.205, p1.19, fig.2a-b. " CUSHMAN: BARNARD, 1963, PP.41-21 Occurrences Upper Albian clays and sands to Lower Cenomanian chalk and greensands.
Marssonella trochus (D'ORBIGNY) Plate 5 : Figs.8$9. Textularia trochus D'ORBIGNY, 1840, p.45, p1.4, figs.25-26. turris D'ORBIGNY, 1840, P.46, p1. 4, figs.27-28. Gaudryina oxycona REUSS, 1860, p.229, p1.12, fig.3. Marsonella trochus (D'ORBIGNY): BARNARD & BANNER, 1953, PP.204-5, t.fig.5o-s and synonymy. Marssonella turns (D'ORBIGNY)s BARNARD, 1963, pp.42-3, t.fig.2a-h. ft oxycona rUSS): NEAGU, 1965, p.8, p1.1, fig.13. trochus DIORBIGNY): NEAGU, 1965, p.8, p1.1, figs.14-16. msycea (REUSS): BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.144, plat figs.58-59. Marssonella oxycona (REUSS): UGUZZONI & RADRIZZ&NI, 1967, pp.1220-1, p1.88, figs.3-6. 113
Remarks: There has been a great deal of controvery as to which is the correct specific name for this species. D'OBIGNY's Textularia trochus and Textularia turns appear to be variants of the same species — with Totrochus taking priority. Gaudrtina oxycona REUSS was initially described as an older form, although still very closely related. Unfortunately misusage of these three specific names has rendered any stratigraphic value they had as useless and so it is thought best to place them all within the one species. A full synonymy would be vast and its compilation has not been attempted. Occurrence: Middle Albian clay to Lower Turonian chalk.
Marssonella sp. 21, sp. nov. Plate 5 : Piga°. Determination: Test free, initial stage trochospiral, adult stages biserial; wall finely agglutinated with large amounts of calcareous cement; chambers are slightly inflated and the sutures are horizontal, depressed; the final chamber is inflated out of proportion to the other chambers, and the aperture is a slit at the base of this final chamber. Occurrence: Lower to Upper Cenomanian chalk.
Subfamily VALVULININ10 BERTHELIN 1880
Plectina MARMON 1878 Type species: Gaudryina ruthenica REUSS 1851
Plna ruthenica (REUSS)
Plate 5 s Fig.11. 114
Gaudryina ruthenica REUSS, 1851, p.41, p1.5, fig.4a-c. Plectina ruthenica (REUSS): MARSSON, 1878, p.160. Plecanium ruthenicum (REUSS): EGGER, 1899, p.22, p1.15, figs.35-36. Gaudryina ruthenica(REUSS): FRANKE, 1928, p.687, p1.5, figs.3-15. it It (REUSS): FRANKE, 1928, p.145, p1.8, Plectina ruthenica (REUSS): WILLIAMS-MITCHELL, 1948, P.971 P1.81 fig.3. (REUSS): JEYFEHIES, 1962, p1.78, fig.12. Occurrence: Lower Cenomanian chalk and sands to Bed 3 of the Plenus Earls succession.
'Plectina' sp. 21, sp. nov. Plate 5 : Fig.12. Verneuillina 121,y2Impha (REUSS): JEFilBRIES, 1962, p1.78, fig.14. Determination: Test free, elongate, with many chambers per whorl in the early growth stages, reducing to three in the adult stages; wall agglutinated with a variable amount of cement; aperture interiomarginal - loop shaped at the base of the final chamber. Remarks: This species has many characters which relate it to the genus Mactinal while at the same time there are doubts as to this determination. Whatever the true identification of this species it is a useful zonal indicator for the Middle and Upper Cenomanian. Occurrence: Middle and Upper Cenomanian chalk (Zones lii, 11a, 13,), to Bed 1 of the Plenus Marls succession.
Subfamily ATAXOPHRAGUIINAE SCRAM 1877
Hagenowina LOIIBLICH &TAPPAN 1961 Type species: yalvulina quadribullata von HAGENOW 1842 115
Hagenowina of. advena (CUSHMAN)
Plate 5 : Fig.13. Hagenowella advena CUSHMAN, 1936, p.43, p1.6, fig.21. CUSHMAN: CUSHMAN, 1937, p.174, p1.21, figs.3-4. rsansabalinijjaranflje4— CUSHMAN, 1937, (part), p.37, p1.4, fig.34 (not 31,32,33). Remarks: Although initially described from the Senonian CUSHMAN's species must be closely related to these Cenomanian forms. Following LOEBLICH & TAPPAN (Treatise 1964) this internally subdivided species must be placed in Hagenowina, even though there is a complete transition to this species from A.chapmani. This distinction between the genera is thus seen to break down in detail, but a great deal of work will have to be done before an alternative can be suggested. The overall shape of this species is very variable and this range from the long and thin to the short and round may be due in some way to the two generations. Close examination has shown that the long slender specimens are probably the microspheric generation. In the region of the Albian/Cenomanian boundary there is a complete transition to this species from A.chapmani, and this has been observed in all the sections irrespective of the lithology. Although these early forms of Ladvena retain the ancestral external appearance they begin to show slight internal differences. In the basal Cenomanian these internal subdivisions are essentially simple but at higher levels more and more complex forms begin to appear. This is not a steady progression however, as examples of the simple forms occur at all levels. Thus in the base of the Plenus Marls all varieties from the very simple to the complex occur. Occurrence: Lower Cenomanian chalk and greensand to Bed 1 of the Plenus Marls succession. 11.6
Family PAVOTINIDAE LOEBLICH & TAPPAN 1961 Subfamily PFENDERININAE SNOUT & SUGDEN 1962
Pseudotextulariella BARNARD in BARNARD & BANNER 1953 Type species: Textulariella cretosa CUSHMAN 1932
Pseudotextulariella cretosa (CUSHMAN) Plate 5 : Fig.14,15. Textulariella cretosa CUSHMAN, 1926, p.97, p1.11, figs.17-49. CUSHMAN: CUSHMAN, 1937, p.61, p1.6, fige.26-28. CUSHMAN: WILLIAMS—MITCHELL, 1948, P.97, p1.8, fig.l. Pseudotextulariella cretosa (CUSHMAN): BARNARD (in BARNARD & BANNER), 1953, P.198, fig.6,b—i. Pseudotextulariella cretosa (CUSHMAN): BARNARD, 1963, P.48, p1.7, figs.1-6, t.figs.6a-d, 7a-f, 8a-c.
Occurrence: Lower to Upper Cenomanian chalk (usually only to Zone 11a).
Family ORBITOLINIDAE MARTIN 1890
Orbitolina D'ORBIGNY 1850 Type species: Orbitolites lenticulata LANARK 1816 Madreporites lenticularis BLUNENBACH 1805
Orbitolina lenticularis (BLUMENBACH) Plate 6 s figs.1 - 10, plate 7 s fig.l.
Madreporites lenticularis BLUMENBACH, 1805, p1.80, figs.1-6. Orbulites concava LANARK 1816, p.197. lenticulata LANARK, 1816, p.197. Orbitolina lenticulata (LANARK): D'ORBIGNY, 1850, p.143, no.342. concavaT.JAMARI D'ORBIGNY, 1850, p.185, no.745. Orbitolina concava (LANARK): EGGER, 1899, pe145, p1.22, fig.34, p1.24, figs.38-401 p1.26, figs.1-18. Orbitolina cf. concava (LANARK): HENSON, 1948, p.61, p1.4, figs.5-10, text figs.10j—r. 117
Orbitolina concava (UMW: DOUGLASS, 1960, p.32, pls.2,3. Orbitolina lenticularis (BLUMENBACH): HOFKER, 1963, pp.181-302, figs.1-24, charts 1 - 9, pls.1-23. Remarks: HOFKER (1963) has produced the most comprehensive study of this species and his work has been followed to a great extent. It has however been used with caution as many of the explanations forwarded in that account cannot be checked and verified in this present survey. The conclusions are somewhat sweeping and the author is cautious in using the evolutionary trends as precise indications of the age of any section of Cretaceous strata. The general pattern has been verified and this has allowed the use of some of HOFKER's data. The genus 'Orbitolina' has been studied and described in great detail and it has been shown to be represented by only one species - 0.1entioularis. Hofker has separated this into 'form groups', based on the characters of the megalospheric embryonic apparatus. The microspheric form begins with a strepto-spiral coil whereas the megalospheric form possess an embryonic apparatus consisting of a proloculus, a deuteroconch, and a varying number of epi-embryonic chambers. The embryonic apparatus is apparently the only consistent feature on which the age of a specimen can be determined. This embryonic apparatus has been separated into the following age units:- Form group I Up. Barremian - Up. Aptian. Form group II Up. Aptian - Lower Albian. Form group III Lwr. Albian - Up. Albian. Form group IV Up. Albian - Up. Cenomanian. Form group V Upper Cenomanian. The flat proloculus which typifies form group III, although maintained for some time, is later replaced by a proloculus which 118
in section resembles a rounded triangle. The epiembryonic chambers are complex and subdivided into small interconnected cellules by short partitions which are also attached to the walls of the proloculus or deuteroconch. This group is typified by the form commonly regarded as 0.concava (LANARK) from the type locality in the Sarthe region of France. Mr. D. Curry has kindly given the author some material from this locality and these are illustrated in Plate 6 (figs.l-8, & 10). This series shows the general variation in shape of the embryonic system throughout the Lower Cenomanian and this is seen to agree with the illustrations on Chart X (HOFKER, 1963). The same features are shown in an abbreviated form in Fig.8. It can be seen from this figure that the form illustrated in Plate 6, Fig.9 from the British Greensands would occur in the Lower Cenomanian part of the sequence. The figures on Plate 6, have been arranged in order of evolution (following HOFKER) from Fig.1 - 10. Hofker's illustration from the Upper Greensand of Devon (Plate 17, fig.14) is placed with those from the Type Lower Cenomanian and as HOFKER indicates, all his illustrations are in a general stratigraphic order. Although all the ages for every sample are given, Upper Albian, Middle Cenomanian, etc., he does not give the age for the British sample but only records the fact that it is from the Upper Greensand. As this is held to be Upper Albian in age this is probably the reason for not including this fact in his text - as it would appear to reduce the validity of the scheme as a whole. If however all the British specimens are from 'Cenomanian Upper Greensand', HOFKER's scheme would again seem to be plausible. The author is of the opinion that this in fact is the case and points to another occurrence of 119
HOFKER 1963 plate XVII fig .14
N specimen from U. Greensand of N1A
A DEVON M ENO C
specimen from the U. Greensand of the Haldon Hills p1.6 fig. 9
4=0m...ft .,•••• •//mii• specimen from type
FIG. 8 EVOLUTION OF 0. LENTICULARIS 120
this species within the region of the British Islands, The occurrence of 0.concava in the Hibernian Greensands of Northern Inland has long been known, and these are accepted as being of Cenomanian age. More than this they are probably better assigned to the Lower Cenomanian and would therefore appear to be synchronous with these occurrences in the south west of England, All the localities in the south west of England are essentially the same age and it is not surprising therefore that all the occurrencemin the British Isles are at about the same level. Orbitolina is known
to be very faoies controlled and it is only in these Lower Cenomanian greensands that one would expect to find this species at all. There will be reference to all these above points in the stratigraphio summary but it will suffice for the moment to say
that from the evolutionary trends within this species it seems almost certain that the upper levels of the Upper Greensand in the south west of England are of Lower Cenomanian age, and are comparable with the sands seen in the type Cenomanian succession of Sarthe in France. (JUKES-BROWNE (1896) in his attack on the work of BARROIS (1876) outlined the transition of the Rouen Chalk into the greensands of the type Cenomanian - and it should be no surprise therefore to find that this transition from an arenaceous to a chalky facies should also occur along the south coast of England in parallel to that seen only two hundred miles to the south in northern France.)
Suborder MILIOLINA DEIAGE & HEIROtTARD 1896 Superfamily MILIOLACFA EHRENBERG 1839 Family NUBECULARIIME • JONES 1875
Subfamily SNROLOCULININAE WIESNER 1920
121
Spiroloculina D'ORBIGNY 1826 Type species: Spiroloculina depressa CUSHMAN 1917
Spiroloculina papyracea BURROWS, SHERBORN & BAILEY Plate 7 : Fig.2. Spiroloculina papyracea BURROWS, SHERBORN & BAILEY, 1890, p.551, p1.8,
fig.l. It ft BURROWS, SHERBORN & BAILEY; TEN DAM, 1950,
P.18, p1.1, fig.19. ft ' It BURROWS, SHERBORN & BAILEY; FUCHS, 1967, p.277, p1.5, fig.8. Occurrence: Upper Albian clay, Lower and Upper Cenomanian chalk.
Subfamily NODOBACULARININAE CUSHMAN 1927
Nodobacularia RHUMBLER 1895 Type species: Nubecularia tibia JONES & PARKER 1860
Nodobacularia nodulosa (CHAPMAN) Plate 7 s Fig.3. Nubecularia nodulosa CHAPMAN, 1891, p.573, p1.9, fig.2. Nubeculina nodulosa (CHAPMAN): TEN DAM, 1948, p.177. Pseudonubeculina nodulosa (CHAPMAN): BARTENSTEIN & BRAND, 1949, p.670, figs.3-5. Pseudonubeculina nodulosa (CHAFMA TEN DAM, 1950, p.18, p1.1, fig.20. nodulosa ((CHAPMAN): BARTENSTEIN & BRAND, 1951, p.278, p1.4, figs.82-84. Pseudonubeculina nodulosa (CHAPMAN): NEAGU, 1965, p.10, p1.2, figs. 25-26. Nodobacularia nodulosa (CHAPMAN): FUCHS, 1967, p.278, p1.5, figs.1-2. Occurrence: Middle and Upper Albian clays.
Family MILIOLIDAE EHRENBERG 1839 Subfamily QUINQUELOCULININAE CUSHMAN 1917 122
Quinqueloculina D'ORBIGNI 1826 Type species: Sernula seminulum LINNE 1758
Quinqueloculina antiqua FRANKE Plate 7 : Figs.415. Miliolina venusta KARRERs CHAPMAN, 1891, p.9, p1.9, figs.5-6. ferussaci (D'ORBIGNY): CHAPMAN, 1891, p.10, p1.9, fig.8. (Quinqueloculina) antiqua FRANKE, 1928, p.126, p1.11, fig.26. Quinqueloculina antiqua FRANK'': TEN DAM, 1950, p.17, P1.1, fig.18. TT 40.~11"00,11 FRANKE: FUCHS, 1967, p.279, p1.5, fig.5a-b. Remarks: Although the true forms of this species are only found below the Middle Cenomanian non-sequence those seen above this level are so close as to be almost inseparable. They are however recorded on the range charts as g. of. antiqua. Occurrence: Middle and Upper Albian clays and sands, Lower and Upper Cenomanian Chalk, and basal Plenus Marls.
Suborder ROTALIINAE DELAGE & =GUARD 1896 Superfamily NODOSARIACEA EHRENBERG 1838 Family NODOSARIIDAE EHRENBERG 1838 Subfamily NODOSARIINAE EHRENBERG 1838
Nodosaria LANARK 1812 Type species: Nautilus radicula LINNE 1758
Nodosaria bambusa CHAPMAN Plate 7 s Fig.6. Nodosaria bambusa CHAPMAN, 1893, p.591, p1.9, fig.7. " " CHAPMAN; EGGER, 1899, p.71, p1.8, fig.23. " CHUM: NEAGU, 1965, p.21, p1.5, fig.21. Occurrences Middle and Upper Albian clays and sands, with a 123
sporadic occurrence throughout the Cenomanian chalk to the Flenus Marls (Bed 1).
Nodosaria lamelloso-oostata REUSS Plate 7 s Fig.7. Nodosaria lamelloso-costata REUSS, 1863, p.38, p1.2, fig.6. Occurrence: Middle and Upper Albian sands and clays to Lower Cenomanian chalk and greensand.
Nodosaria obscura REUSS Plate 7 : Fig.8. Nodosaria lgodosaria3 Cascara REUSS, 1845, p.26, p1.13, figs.7-9. 111 ° REUSS: REUSS, 1874, p.86, p1.20, figs .1-4. ,10 obscura REUSS: BERTHELIN, 1880, p.31, plat fig.17a-b. ? ,, (Dentalina) obscura REUSS: CHAPMAN, 1893, PP.593-41 P1.91 fig.16. II obscura REUSS: FRANKE, 1928, p.48, p1.4, fig.5. It ft REUSS: PLUMMER, 1931, p.156, p1.11, fig.3. , , ft REUSS: BROTZEN, 1936, p.84, P1.5, figs.24-25, taigs.26,27. ft It REUSS: CUSHMAN, 1940, p.90, p1.16, figs.11-12. It ft REUSS: TAPPAN, 1940, p.104, p1.16, figs.7-8. " " REUSS: TAPPAN, 1943, PP.496-7, p1.80, figs.1-2. " r "REUSS: CUSHMAN, 1946, P.731 P1.26, figs.15-16. ft " REUSS: TEN DAM, 1948, p.180. Nodosaria obscura REUSS: HAGN, 1953, p.50, p1.4, fig.24. ft REUSS: FUCHS, 1967, pp.280-1, p1.6, fig.2. Remarks: This species resembles N.proboscidea REUSS but can be distinguished by its smaller proloculus and less prominent neck. However, as both are very variable, there are naturally many occasions where a specimen cannot be placed conclusively and it is probable that N.obscura and :N.proboscidea represent the extreme forms of the one population. Occurrence: Middle and Upper Albian to the Plenus Marls. 124
Nodosaria orthopleura REUSS Plate 7 Fig.9. Nodosaria orthopleura REUSS, 1862, p.89, p1.12, 77 REUSS: CHAPMAN, 1893, p.595, p1.9, fig.22-23. non ft REUSS: EGGER, 18997 P.777 P1.24, fig.19. REUSS: FRANKE, 1928, p.48, p1.4, fig.5. ff ff REUSS: EICHENBERG, 19337 PP.4-5, P1.5, fig.5. 11 REUSS: EICHENBERG, 1935, p1.1, fig.27, p1.12, figs.5-6. REUSS: CUSHMAN, 1940, P.95, P1.16, fig.30. 11 chapmani TAPPAN, 1940, p.103, p1.16, figs.9-10. cf. chapmani TAPPAN: BARTENSTEIN, BETTENSTAEDT & BOLLI, 1957, p.36, p1.7, fig.152. orthopleura REUSS: TEN DAM, 1950, p.26, p1.2, fig.13. REUSS: NEAGU, 1965, p.21, p1.5, figs.8 -9. ft chapmani TAFTAN: FUCHS, p.279, p1.6, fig.10. Occurrence: Middle and Upper Albian to Lower and Upper Cenomanian.
Nodosaria orthopleura REUSS var tetragona REUSS Plate 7 : Fig.10. Nodosaria tetragona REUSS, 1860, p.181, p1.2, " REUSS: CHAPMAN, 1893, p.595, p1.9, fig.24. prismatica REUSS: JEFFERIES, 1962, p1.78,' fig.10a-b. Remarks: N.tetragona REUSS is an invalid name as there is a species listed as N.tetragona COSTA, 1855, from the Tertiary of Italy. Although this separation of the four sided variety of the species is totally artificial it has been found to be useful throughout the sequence under consideration. Occurrence: Upper Albian sands to Bed 1 Plenus Marls succession.
Nodosaria paupercula REUSS Plate 7 Figs.11,12. Nodosaria paupercula REUSS, 1845, p.26, p1.12, fig.12. " REUSS: REUSS, 18747 P.81, p1.20, figs.5-7. Dentalina (REUSS): BERTHELIN, 1880, p.43, p1.2, fig.17a-b. Nodosaria (Dentalina) paupercula REUSS: CHAPMAN, 1893, p.593, p1.97 figs.13-14. 125
Nodosaria (Dentalina) paupercula REUSS: CHAPMAN, 1917, p.27, P1.4, fig.41. ft REUSS: CHAPMAN, 1926, p.51, p1.3, fig.25a-f. paupercula REUSS: FRANKE, 1928, P.45, p1.8, fig.37. REUSS: CUSHMAN, 1940, p1.16, figs.32-341 P.96. ? ft REUSS: TAPPAN, 1940, p.104, p1.16, fig.11. ? REUSS: NEAGU, 1965, p.21, p1.4, fig.18. Occurrence: Middle and Upper Albian to Upper Cenomanian.
Nodosaria perpusilla CHAPMAN Plate 7 : Fig.13. Nodosaria perpusilla CHAPMAN, 1893, p.591, p1.9, fig.6. Remarks: This species is probably a part of a plexus which contains N.tubifera (REUSS). Occurrence: Middle and Upper Albian to Bed 4 of the Plenus Marls succession.
Nodosaria proboscidea REUSS Plate 7 : Fig.14. Nodosariaproboscidea REUSS, 1861, p.7, p1.1, fig.6. ? " (Dentalina) obscura REUSS: CHAPMAN, 1893, p.595, p1.9, fig.16. N.tenuicosta REUSS: CHAPMAN, 1893. 0.594, p1.9, figs.19-20. Nodosaria proboscidea REUSS: CUSHMAN, 1940, P.89, p1.18, figs.8-9. ,, 11 REUSS: CUSHMAN, 1944, P.8, p1.2, fig.3. ft ft ....'"... REUSS: CUSHMAN & DEADERICK, 1944, P.334, p1.51, fig.25p ft It REUSS: CUSHMAN, 1946, p.22, p1.26, figs.12-13. ft It REUSS: DIUMELL, 1954, P.91, p1.10, fig.33. ff It REUSS: NEAGU, 1965, p.21, p1.5, figs.6-7.
Occurrences MiddlE and Upper Albian to Lower Cenomanian chalk.
Nodosaria sceptrum REUSS Plate 7 : Fig.15. Nodosaria sceptrum REUSS, 1862, p.37, p1.2, fig.3. " REUSS: CHAPMAN, 1893, p.592, p1.9, 11 If REUSS: EICHENBERG, 1933, P.180, p1.19, fig.1. ft Ir REUSS: TEI DAM, 1948, p.180. 126
Nodosaria soeptrum REUSS: BARTENSTEM, BETTENSTAEDT&BOLLI, 1957, p.35, p1.7, fig.150. " REUSS: SZTEJN, 1957, p.52, p1.6, " REUSS: NEAGU, 1965, pp.21-2, p1.5, fig.10. Occurrences Middle and Upper Albian to Lower Turonian.
Nodosaria zippei REUSS Plate 7 : Fig.16. Nodosaria zippei REUSS, 1845, p.25, p1.8, (Dentalina) zippei REUSS: CHARM, 1893, p.593, p1.9, fig.12. zippei REUSS: MOO, 1898, P.451 P1.3, fig.l. " REUSS: SANDIDGE, 1932, pp.275 -8, p1.42, figs.13 -14. " REUSS: TEN DAM, 1950, p.27. Occurrence: Middle and Upper Albian to Upper Cenomanian.
Nodosaria sp. 41, sp. nov. Plate 7 : Fig.17. Determination: Test free, multilocular, rectilinear, with a rounded cross section; sutures horizontal, indistinct; surface of test smooth; aperture terminal, central, not produced in any
Way.
Occurrences Lower and Upper Cenomanian to Plenus Marls.
Nodosaria sp. 47, sp. nov. Plate 7 : Fig.18. Determination: Test free, multilocular, very slightly arcuate in some specimens; sutures horizontal, very indistinct - test having an almost smooth sided appearance; distal end drawn into a point; aperture central, at the end of a produced neck. Occurrence: Middle and Upper Albian clays to Lower and Upper Cenomanian chalks. 127
Nodosaria sp. 50, sp. nov. Plate 7 Fig.19. Determination: Test free, multilocular, rectilinear; sutures horizontal and markedly depressed giving the chambers an overall inflated appearance; distal end drawn into a point; aperture central, terminal, at the end of a very produced thin neck. Occurrence: Middle and Upper Albian clays, Lower Cenomanian chalk and greensand, through Upper Cenomanian chalk to Plenus Marls.
Citharina D'ORBIGNY in DE LA SAGRA 1839 Type species: Vaginulina (Citharina) strigillata REUSS 1846
Citharina arambourgi MARIE Plate 8 : Fig.l. Citharina arambourgi MARIE, 1938, pp.98-99, p1.8, figs.12-13. Occurrence: Seen throughout the Cenomanian, including greensands, with isolated occurrences in the Foxmould sands.
Citharinella MARIE 1938 Type species: Flabellina karreri BERTHELIN 1880
Citharinella chapmani MARIE Plate 8 : Fig.2. Prondicularia strigillata CHAPMAN (not REUSS), 1894, p.157, 131.3r figs.13-14. Citharinella chapmani MARIE, 1938, p.100, p1.7, ,figs.5-6. " MARIE: NEAGU, 1965, p.25, p1.6, fig.17. Remarks: This species is very close to C.pinnaeformis (CHAPMAN) and C.karreri (BERTHELIO from which it is differentiated by the lack of two or more continuous ribs. 128
Occurrences Middle & Upper Albian clays, Lower and. Upper Cenomanian chalk to Lower Turonian.
Citharinella didyma (BERTHELIN) Plate 8 Fig.3. Frondicularia di BERTHELIN, 1880, p.61, p1.2, fig.18a-b. Flabellina di BERTHELIN CHAPMAN, 1894, p.159, p1.4, fig.7. BERTHELIN : FRANKE, 1928, p.94, p1.8, fig.13. BERTHELIN EICHENBERG, 1933, p.12, p1.3, fig.5. BERTHELIN s EICHENBERG, 19330 p1.3, fig.12. Citharinella didyma (BERTHELIN): TEN DAM, 1950, p.38, p1.3, fig.7. Flabellinella didyma (BERTMLIN) BARTENSTEIN & BRAND, 1951, p.302, p1.8, fig.199. Citharinella didyma (BERTHELIN): FUCHS, 1967, p.283, p1.6, fig.11. Remarks: This is a transitional form between the Frondicularia group and the Citharinella group. The first three chambers are asymmetrical while the remainder follow the normal frondicularian pattern. Occurrence: Middle and Upper Albian clays to Lower Cenomanian chalk and greensand‘
Citharinella karreri (BERTHELIN) Plate 8 : Flabellina karreri BERTHELIN, 1880, p.52, p1.4, figs.1-3. Frondicularia karreri (BERTHELIN)sCHAFMAN, 1894, p.156, p1.3, fig.12. Occurrence: Middle and Upper Albian clays and sands, and Foxmould sands.
Citharinella laffittei MARIE Plate 8 : Figs.6,7. Citharinella laffittei MARIE, 1938, p.101, p1.8, fig.3. Occurrence: Gault Clay, particularly the level immediately below the Glauconite Marl. This species is particularly abundant in the Cambridge Greensand section at Arlesey. 129
Citharinella lemoinei MARIE Plate 8 : Fig.8. Frondicularia lanceola CHAPMAN, (not REUSS), 1893, p.157, p1.3, fig.15. Citharinella lemoinei MARIE, 1938, p.101, p1.8, fig.2a-b. Occurrence: Upper Cenomanian chalk (commonly Zone 11a) to Plenus Marls.
Citharinella4 pinnaeformis (CHAPMAN) Plate 8 Figs.9,10. Frondicularia pinnaeformis CHAPMAN, 1894, p.158, p1.3, figs.9-11. Citharinella pinnaeformis (CHAPMAN); MARIE, 1938, p.100, p1a, figs.7-9, p1.8, figs.4-6. Remarks: This species is an important zonal indicator in the Upper Albian (Zone 5) where it is seen to have very nearly the same range as Arenobulimina chapmani CUSHMAN. It is not very often seen in normal samples as it is usually broken - being such a very large species. Where it is missing A.chapmani can be used as an approximate zonal indicator, in the absence of A.sabulosa (the combination of A.sabulosa and A.chapmani indicating Zone 6). Occurrence: Found only in the Upper Albian, typically in the Gault Clay facies although many broken specimens are recorded from the Upper Greensand facies of the Isle of Wight.
Dentalina RISSO 1826 Type species: Nodosaria (Dentalina) ouvieri D'ORBIGNY 1826
Species of this genus have been found to be long ranging forms with very little, if any, stratigraphic use. Because of this the group has not been dealt with in any great detail. Dentalina appears to have been split into many species that on inspection are 130
no more than members of the same evolutionary trends. There has also been a complete disregard for the microspheric and megalospheric generations and this may account for some of this duplication. The compilation of full synonomies was therefore thought to be profitless in this present study.
Dentalina of. catenula REUSS Plate 8 s Fig.11. Dentalina catenula REUSS, 1860, p.185, p1.3, fig.6. Nodosaria (Dentalina) soluta CHAPMAN, (not REUSS), 1893, p.587, p1.8, fig.26. Dentalina soluta EICHENBERG, 1936, (not REUSS), p.14, p1.1, figs.3,21. Dentalina soluta BARTENSTEIN & BRAND, (not REUSS), 1951, p.309, p1.9, fig.237. Dentalina guttifera POZARYSKA, (not D'ORBIGNY), 1957, p.8, p1.7, fig.4. Dentalina guttifera NEAGUI (not D'ORBIGNY), 1965, p.20, p1.5, fig.33. " BARTENSTEIN, BETTANSTAEDT & BOLLI (not D'ORBIGNY), 1966, p.154, p1.3, figs.211-216. Dentalina solUta FUCHS, (not REUSS), 1967, p.289, p1.7, fig.10. Dentalina vetutissima UGUZZONI & RADRIZZANI, (not D'ORBIGNY), 1967, P.1207, p1.89, fig.5. Remarks: The types of REUSS were 1.9mm long while the British specimens are about 1.0mm long. This discrepancy however is not thought to be significant. Occurrence: Middle and Upper Albian clays and Lower Cenomanian chalk.
Dentalina deflexa REUSS Plate 8 : Fig.12. Dentalina deflexa REUSS, 18631 p.43, p1.2, fig.19. Remarks: This species is very close to, if not transitional with D.leguman (REUSS). Occurrence: Middle and Upper Albian clays and sands to Lower and Upper Cenomanian greensands and chalk. 131
Dentalina distincta REUSS Plate 8 : Fig.13. Dentalina distincta REUSS, 1860, p.184, p1.2, fig.5. REUSS: TEN DAM, 1950, p.28, p1.2, fig.15. " REUSS: BARTENSTEIN & BETTANSTAEDT, 1962, p.280, P1.39, fig.21. REUSS: BARTENSTEIN, BETTANSTAEDT & BOLLI, 1966, p.153, p1.3, figs.203-4,209,217. Nodosaria (Dentalina) cylindroides REUSS, 1860, p.185, p1.1, fig.8. Nodosaria (Dentalina) oli ste is REUSS, 1845, p.27, p1.13, fig.19-20. Dentalina oligpstegla REUSS : FRANKE, 1928, p.24, p1.2, figs.9-10. REUSS s BARTENSTEIN & BRAND, 1937, P.134. (REUSS): GANDOLFI, 1942, p.67. REUSS : HAGN, 1953, p.46, p1.4, fig.11. ff If REUSS BARBIERI, 1964, p.753, p1.41, figs.9-10. REUSS UOVZZONI&RADRIZZANI, 1967, P.1207, p1.89, fig.4. Remarks: This species typically consists of between two and four chambers. The first chamber is always inflated and is drawn out distally into a slight spine. The last chamber is almosit identical with this, being drawn out into the radiate aperture. The sutures are characteristically horizontal and almost flush with the surface of the test. D.cylindroides REUSS differs so slightly from this that the two are regarded as being conspecific. The type figure of D.oligostegia REUSS is unsatisfactory and it is suggested that this is also a variant of the present species. The British forms are identical with those figured by TEN DAM although he notes that his specimens were in fact larger than those of REUSS. Occurrence: Middle and Upper Albian to Plenus Marls.
? Dentalina fusiformis (KHAN) Plate 9 : Figs.1,2. Ramulina fusiformis KHAN, 1950, p.272, p1.2, figs.l-2 and synonymy. 132
Remarks: KHAN regards R.fusiformis from the Gault Clay as a single drawn out chamber with a thin neck at both ends. In many cases his description appears to be valid but occasionally two of these "chambers" are found in close proximity — thus giving the appearance of a very drawn out Dentalina. The generic position of this species is therefore in doubt. It is possible that KBAN's original was in fact part of a very fragile Dentalina, which owing to the processes of deposition, is usually only fragmentary. It may however be a trueRamulina which occasionally shows the develop— ment of a second complete chamber. Occurrence: Middle and Upper Albian clay to Lower and Upper Cenomanian chalk.
Dentalina cf. hammensis (FRANKE) Plate 9 s Fig.3. Marginulina hammensis FRANKE, 1928, p.77, p1.7, fig.9. Dentalina Ilan FRANKE): TAPFAN, 1940, p.102, p1.16, fig.3. Remarks: This quite distinctive species was initially recorded from the Upper Senonian of Germany while TAPPAN's records are from the Grayson Formation (Upper Albian) of the U.S.A. Occurrence: Middle and Upper Albian to Lower Turonian.
Dentalina intermedia (REUSS) Plate 9 : Fig.4. Dentalina intermedia REUSS, 1860, p.186, p1.2, fig.8. REUSS: FUCHS, 1967, p.287, p1.7, fig.3. Occurrence: Middle and. Upper Albian to Bed. 4 Pienus Marls succession. 133
Dentalina legumen (REUSS) Plate 9 : Fig.5. Nodosaria (Dentalina legumen REUSS, 1845, P.281 P1.13, figs.23-24. " " REUSS: REUSS, 1860, p.187, p1.3, fig.5. REUSS: CHAPMAN, 1893, p.589, p1.8, fig.37. ( ) " REUSS: FRANKE, 1925, p.32, p1.3, fig.6. Dentalina legumen rd7711KANKE, 1928, p.27, p1.2, fig.23. REUSS : EICHENBERG, 1933, p.5, p1.2, fig.18, p1.8, fig.3. REUSS EICHENBERG, 1935a, p.20, p1.2, fig.17. REUSS : EICHENBERG, 1935b, p1.5, fig.19. REUSS : BROTZEN, 1936, p.75, p1.5, fig.9. " REUSS : CUSHMAN, 1946, P.65, p1.23, figs.1 -2. (REUSS): BARTENSTEIN & BRAND, 1951, p.309, p1.9, fig.232. tt REUSS : MOTH, 1951, p.51, p1.2, fig.18. tt REUSS : SZTEJN, 1958, p.37, fig.83. it REUSS : NEAGU, 1965, p.20, p1.5, figs.32 —34. It REUSS : FUCHS, 1967, p.287, p1.8, fig.3. Remarks: This may not be the species of REUSS but a variety of D.deflexa REUSS. The only apparent difference is the slightly greater length of the chambers in the latter species. This is a very variable character in all species of Dentalina and because of this their separation may be invalid. Occurrence: Middle and Upper Albian to Bed 4 Plenus Marls succession.
Dentalina raristriata (CHAPMAN) Plate 9 : Fig.6. Nodosaria (Dentalina) raristriata CHAPMAN, 1893, p.591, p1.9, fig.4. Dentalina raristriata (CHAPMAN): FRANKE, 1928, p.37, p1.3, fig.22. (CHAPMAN): TEN DAM, 1950, p.29, p1.2, fig.17. (WOW): FUCHS, 1967, p.289, p1.8, fig.4. Remarks: According to CHAPMAN (1893) this species is restricted to Beds 11 - 13 of the Copt Point Gault succession. There is some variation in the coarseness of the ornamentation but it appears to have little or no stratigraphic significance. Occurrence: Middle and Upper Albian to Lower TUronian. 134
Dentalina strangulata REUSS
Plate 9 s Fig.7. Dentalina strangulata REUSS, 1860, p.185, p1.2, fig.6. It VI REUSS: EICHENBERG, 1935, p.163, p1.10, fig.6. If It REUSS: FUCHS, 1967, p.289, p1.7, fig.2. Remarks: Although the type specimens are from the Senonian of Germany typical forms can be seen in the Albian. The only variation seen in this species appears to be the degree of con- striction between the chambers. In overall shape it is very close to D.lorneiana D'ORBIGNY and only varies from it in being twice the size. Occurrences Middle and Upper Albian to Lower Turonian.
Dentalina strangulata REUSS var. nov. Plate 9 : Fig.8. Determination: Test free, elongate, arcuate, uniserial, sutures almost horizontal, depressed; chambers inflated - but not as much as in Dentalina strangulata REUSS; aperture radiate, terminal, excentric, on very slightly produced last chamber. Occurrence: Middle and Upper Albian to Lower and Upper Cenomanian.
Dentalina sp. 24, sp. nov. Plate 9 Fig.9. Determination: Test free, elongate, arcuate, uniserial, sutures horizontal, depressed; initial chamber drawn to slight
point; commonly only four chambers, all inflated to greater or lesser extent; terminal chamber drawn to slight excentric neck, with radiate terminal aperture; in overall form very close to
D.distincta REUSS, and this species may in fact belong to one of 135
the series described in that section. Occurrences Middle and Upper Albian to Lower and Upper Cenomanian (as far as Zone 11a).
Dentalina sp. 48, sp. nov. Plate 9 : Piga°. Determination: Test free, elongate, arcuate, uniserial, sutures horizontal, only slightly depressed; initial chamber drawn to very sharp point; chambers not inflated giving the test an overall smooth—sided appearance; none of the specimens were complete and no indication of the apertural end can be given. Occurrence: Middle and Upper Albian clays.
Frondicularia DEFRANCE in D'ORBIGNY 1826 Type species: Frondicularia inversa REUSS 1844 There are many species recorded in this genus which are, for varying reasons, unsatisfactory. The majority were described in the middle of the last century and the type figures are somewhat unreliable. The result is a great duplication of names for forms that are so similar as to make their separation virtually impossible. When one allows for changes in the population through periods of geologic time it becomes apparent that many of the recorded species are in fact stages in a continual evolutionary plexus. It is because of this confusion and their minimal strati— graphic usefulness that this group has not been treated in any great detail.
Frondicularia archiaciana D'ORBIGNY
136
Plate 9 Fig.l1. Frondicularia arohianiana D'ORBIGNY, 1840, p.20, p1.1, figs.34-36. D'ORBIGNY: REUSS, 1845, P.31, p1.13, fig.29. It D'ORBIGNY: BURROWS, SHERBORN & BAILEY, 1890, p.558, p1.10, fig.6a b. It D'ORBIGNY: CHAPMAN, 1893, P.155, p1.3, fig.6. 11 D'ORBIGNY: CUSHMAN, 1946, P.91, P1.37, fig.8-20. Pseudofrondicularia archiaciana (D'ORBIGNY): PRIZZELL, 1954, P.997 p1.13, figs.6-8. Occurrence: Middle and Upper Albian to Lower Turanian.
Frondicularia cordai REUSS Plate 9 Pig.12. There is a vast synonymy for this species in ELLIS & MESS INA (1940). Frondicularia cordai REUSS, 1844, p.302. It REUSS: REUSS, 1845, P.31, p1.8, figs.26-28, p1.13, fig.41. tt " REUSS: REUSS, 1854, P.66, p1.25, fig.3a-b. " REUSS: CHAPMAN, 1894, P.159, P1.4, fig.6. ►t " REUSS: EGGER, 1899, p.90, p1.13, tt " REUSS: FRANKE, 1925, p.48, p1.4, fig.2. " REUSS: FRANKE, 1928b, p.62, p1.5, " REUSS: CUSHMAN, 1930, P.34, P1.5, fig.12. VI " REUSS: CUSHMAN, 1931, p.307, p1.35, fig.8. 19 REUSS: CUSHMAN & JARVIS, 1932, p.39, p1.12, fig.4. tt REUSS: BROTZEN, 1936, pp.95-6, P1.6, fig.14. Included in this species are forms that have variously been described as:- Frondicularia microdisca REUSS, 1860, p.195, p1.5, fig.4. REUSS: CHAPMAN, 1894, P.158, p1.4, fig.3. tt REUSS: CUSHMAN, 1930, p.33, p1.5, fig.4. Frondicularia parkeri REUSS, 1862, p.91, p1.12, fig47. • " REUSS: CHAPMAN, 1894, P.157, p1.5, fig.17. Frondicularia perovata CHAPMAN, 1894, P.158, p1.4, fig.2. Frondicularai mediostriata TEN DAM, 1950, p.32, p1.2, fig.24a-b. Occurrence: Middle and Upper Albian to Lower Turanian.
Frondicularia gaultina REUSS Plate 9 Fig.13.
137
Frondicularia gaultina REUSS, 1860, p.194, p1.5, fig.5. tf " REUSS: BURROWS, SHERBORN & BAILEY, 1890, p1.10, fig.5. ?I REUSS: CHAPMAN, 1894, P.1559 p1.3, fig.7. ft REUSS: SHERLOCK, 1914, p.258, p1.19, fig.11. 99 t t REUSS: CHAPMAN, 1917, p.30, p1.6, figs.54-55. REUSS: EICHENBERG, 1933, P.8, p1.6, fig.4a-b. REUSS: EICHENBERG, 1935b, p1.1, fig.13. tip WIIIIII111~/WINNIMMII/1110.11•11* REUSS: TEN DAM, 1950, p.32, p1.2, fig.23. tIP REUSS: BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.156, p1.3, figs.265,270-2. tt tt REUSS: FUCHS, 1967, p.290, p1.8, fig.11. Remarks: This species appears to be slightly asymmetrical in the early growth stages and it is possible that it may be the microspheric form of Citharinella didyma (BERTHELIN). Occurrences Middle and Upper Albian Clays.
Frondicularia planifolium CHAPMAN Plate 9 : Fig.14.
Frondioularai planifolium CHAPMAN, 1894, p.158, p1.4, fig.la-b. tl 11 CHAPMAN: BROTZEN, 1934, p.41. Occurrence: Middle and Upper Albian clays to Lower Cenomanian chalk.
Frondicularia quadrata CHAPMAN Plate 9 : Fig.15. Frondicularia quadrata CHAPMAN, 1894, p.158, p1.4, fig.4. Remarks: CHAPMAN in erecting this species recorded only one specimen from Bed 10 at Copt Point, Folkestone. Occurrence: Upper Albian Clays.
Frondicularia striga CHAPMAN Plate 9 Fig.16. Frondicularia striga CHAPMAN, 1899, p.303, t.fig.l. 138
Remarks: CHUMAN's type specimen is from the Cambridge Greensand and although it was in fact broken the species seems to be distinct. In the present survey this species was only recorded in the region of the Cambridge Greensand in the Arlesey section. Occurrences Lower Cenomanian chalk and greensands.
Lenticulina LAMARK 1804 Type species: Lenticulina calcar LINNE 1758
(LOEBLICH & TAPPAN (1964, Treatise) regard Robulus de MONTFORT as a junior synonym of Lenticulina. All these forms show considerable variation in the length of the radial apertural slits and a generic separation appears to be unsatisfactory. In the present work the two are retained as they are in common usage.)
Lenticulina gaultina (BERTHELIN) This extremely variable form has been separated in the pas-% into many different species. The group occurs throughout the Gault, Lower Chalk, Upper Greensand, and Plenus Marl and in many cases the apparent variation is due only to differences of preservation. The most variable characters are the tightness of coiling and the size of the umbilical plug — combinations of these two providing most of the variants. Although treated as one large group three forms have been recognised.
Lenticulina gaultina (BERTHELIN) form gaultina Plate 10 : Figs. 1, 2. Cristellaria gaultina BERTHELIN, 1880, p.49, p1.3, figs.15-19. " BERTH:MN: CHAPMAN, 1896, pp.7-8, p1.1, figs.10a—b,11. 139
Cristellaria gaultina BERTHELIN: EG T:s.4-9.I 1899, p.121, p1.23, f it ft BERTHELIN: SHERLOCK, 1914, p.262, p1.18, fig.27. It ft BERTHELIN: CHAPMAN, 1917, p.38, p1.9, fig.85. ft washitensis OARSEY„ 1926, p.38, p1.7, fig.9. Lenticulina washitensis (CARSEY): !MUMMER, 1931, p.142, p1.11, fig.10. Robulus gaultinus (BERTELIN): EICHENBERG, 1935, p.156, p1.16, fig.6. Lenticulina gaultina BERTHELIN $ TAFTAN, 1943, P.494, P1.79, fig.13. ,, BERTHELIN t TAPPAN, 1940, p.101, p1.15, fig.11. III ft BERTHELIN s FRTz7PILL, 1954, P.82, p1.8, fig.15. ,, ft BERTHELIN s SZTEJN, 1958, p.20, fig.35. tt (Lenticulina) gaultina (BERTHELIN): FUCHS, 1967, P13.293-4, p1.11, figs.4a -b. Remarks: In this form the sutures are generally flush to the surface of the test and the umbilical plug is of only moderate prominence. The last few chaMbers are often seen to expand more rapidly in size giving a sub-circular appearance to the whole test. Occurrence: Middle and Upper Albian clays and sands, including Foxmould sands.
Lenticulina saultina (BERTHELIN) form ovalis Plate 10 : Fig.3. Cristellaria ovalis REUSS, 1844, p.213. ft It REUSS: REUSS, 1845, PP.34-5, p1.8, fig.49. ft ft REUSS: REUSS, 1875, PP.103 -4, p1.2, figs.6-11. II It REUSS: CHAPMAN, 1917, p.35, p1.8, fig.75. 1, 1, REUSS: FRANKE, 1928, pp.107 -8, p1.10, fig.lOa-b. Robulus aff. ovalis (REUSS): EICHENBERG, 1935, p.155, p1.16, fig.6. Remarks: This form displays a very large initial chamber which gives an overall globular appearance to the test. Occurrence: Middle and Upper Albian to Lower Turonian.
Lenticulina gaultina (BERTHELIN) form rotulata Plate 10 Fig.4. Lenticulina rotulata LANARK, 1804, p.188. Cristellaria rotulata LAMARK : BRADY, 1884, P.547, p1.69, fig.13a-b. ft tl LAMARK : CHAPMAN, 1896, pp.5-6, p1.1, fig.8a-b.. ft ft LAMARK : CUSHMAN, 1913, p.66, p1.33, fig.3a-b.
140
Cristellaria rotulata (LANARK): CUSHMAN, 1923, p.108, p1.22, fig.2, p1.28, figg.1-2. (LANARK): CARSEY, 1926, p.39, p1.6, fig.2. Lenticulina rotulata LANARK: MINOR, 1931, p.142, p1.11, fig.20. If ft LANARK: CUSHMAN, 1941, P.67, p1.16, fig.13. " " LANARK: FRIZZELL, 1954. P.82, p1.7, fig.15a-b. " " LANARK: ataiwatIDS, 1962, p1.79, fig.23. Remarks: The forms outlined above have smooth sutures but in the later examples of this form the sutures are raised above the general level of the test. Unlike 'form gaultina' the chambers increase steadily in size throughout the test. Occurrences Lower and Upper Cenomanian to Lower Turanian.
Lenticulina lepida (REUSS) Plate 10 : Fig.7. Robulus lepida REUSS, 1846, p.109, p1.24, fig.46. Occurrence: Middle and Upper Albian clays and sands, to Lower Cenomanian greensands and chalk.
Lenticulina nodosa (REUSS) Plate 10 : Fig.5. Cristellaria (Robulina) nodosa REUSS, 1862, p.78, p1.9, fig.6a-b. If nodosa REUSS: CHAPMAN, 1895, p.4, p1.1, fig.5a-b. Remarks: The angular periphery of this species separates it from the above group with which it is still intimately associated. Occurrence: Middle and Upper Albian to Plenus Marls.
Lenticulina secans (REUSS) Plate 10 : Fig.8. Cristellaria secans REUSS, 1860, p.214, p1.9, fig.7a-b. v. subalata REUSS, 1863, p.76, p1.8, fig.10. If REUSS: CHAPMAN, 1896, p.3, p1.1, fig.3a-b. 141
Occurrence: Middle and Upper Albian clays.
Lenticulina sp. 35, sp. nov. Plate 10 : Determination: Test free, planispiral, lenticular, biumbonate, periphery angled, chambers increasing fairly rapidly in size; sutures radial, slightly curved, elevated in the later growth stages; aperture radial, slightly produced at the peripheral angle.
Remarks: This species may be related to Robulus prominula (REUSS).
Occurrence: Middle and Upper Albian clays.
Marginulina D'ORBIGNY 1826 Type species: Marginulina raphanus D'ORBIGNY 18 26
Marginulina aevivoca (REUSS) Plate 10 : Fig.9. In the mid-Cretaceous there is an involved plexus of elongate ribbed Marginulinae. This group is totally intergradational and without a detailed study it would be impossible to assess the true values of the species included here. Most of the species were described by REUSS (1863) and as the figures are all of poor quality they could all be variants of the one group. In the Lower Chalk some forms appear that lack ribs in the final chambers but their general shape indicates that they also belong here. The name for this species 'group' has been chosen from the page priority in the 1863 publication.
The species included here are as follows:-
142
Cristellaria (Marginulina) aequivoca REUSS, 1863, p.60, p1.5, fig.17. Marginulina aequivoca REUSS CHAPMAN, 1894, p.162, p1.4, fig.20. REUSS : TEN DAM, 1950, p.23, p1.2, fig.6. ft 11 REUSS : NEAGU, 1965, p.17, p1.4, figs.36-37. Cristellaria (Narginulina) acutioostata REUSS, 1863, pp.62 -3, p1.6, fig.3.
Cristellaria costulata CHAPMAN, 1894, p.649, p1.9, fig.10. tt ft CHAPMAN: EGGER, 1899, P.115, p1.24, fig.42. striata CHAPMAN, 1894, p.646, p1.9, fig.2a-b. f6=11711astriata(CHAPMAls EICItENBERG, 1933, p.177, p1.18, fig.12. Cristellaria (Marginulina) stiatodostata REUSS, 1863, p.62, p1.6, fig.2. Marginulina stiatocostata (REUSS): CHAPMAN, 1894, P.1651 P1.4, fig.21. Cristellaria (Marginulina) tenuissima REUSS, 1863'1 p.61, p1.5, fig.18, p1.12, fig.12. Marginulina tenuissima REUSS s CHAPMAN, 1894, p.162, p1.4, fig.19. ft t f ••••••11.••••iNim•••••1•11. REUSS : EGGER, 1899, p.97, p1.10, fig.23. it REUSS : TAPPAN, 1940, Pp.101-2, p1.17, figs .9-10. It paucicosta TAPPAN, 1943, P.494, p1.79, figs.16a,17b. Cristellaria (Marginulina) turgida REUSS, 1863, p.63, p1.6, fig.?. Remarks: Although many of the species listed above appear to be distinct when studying individuals or even the type figures, a review of the overall populations give an altogether different picture. M.costulata, which commonly has a curved initial portion, is seen to be transitional with M.striata, which in turn is closely related to the longer M.striatocostata. Occurrence: Members of this group are seen throughout the Gault and lower Chalk, although only in the latter formation are the non-ribbed forms seen.
Marginulina bronni (ROEMER) Plate 10 s Figs.10-12.
143
Planularia bronni ROEMER, 1841, P*977p1.15, fig.14. Cristellaria bronni ROEMER REUSS, 1d62, p.70, p1.7, fig.13a-b. " ROEMER CHAPMAN, 1894, AP.659-60, p1.9, figs.12-13b. Cristellaria oligostegia REUSS: CHAPMAN, 1894, pp.651-2, p1.10, fig.5a-b. Cristellaria bronni (ROEMER): FRANKE, 1928, p.102, p1.9, fig.18a-b. Astacolus of bronni ROEMER : EICHENBERG, 1935, pp.11-12, p1.3, figsaa-c, 8a-c. Astacolus bronni (ROEMER): EICHENBERG, 1935, p1.5, fig.34. Marg:inulina sp.B. TAPPAN, 1940, p.101, p1.15, fig.13a-c. Lenticulina (VAGINULINOPSIS) bronni (ROEMER): NEAGU, 1965, p.14,16, p1.4, figs.17-23. Remarks: This species shows a great variation in external morphology but the occurrence of this variation in the succession suggests that it is all one lineage showing progressive uncoiling of the test. Occurrences The tight coiled C.oligostegia are commoner in the lower parts of the Gault succession while the uncoiled M bronni forms are dominant in the upper part of the Gault succession.
Marginulina jonesi (REUSS) Plate 10 : Figs. 13,14. Just as in the M.aequivoca group one has here a plexus of small partially, or totally ribbed forms. In this case the priority name is M.jonesi, and included with it are the following:- Cristellaria Mar•inulina ,jonesi REUSS, 1862, p.61, p1.5, fig.19. Marginulina jonesi REUSS : EGGER, 1899, p.100, p1.10, fig.11. f, REUSS : CHAPMAN, 1894, P.163, p1.4, fig.24. /1 11 REUSS : EICHENBERG, 1933, p.9, p1.7, fig.8a-b. 11 (REUSS :EICHENBERG, 1935, pp.160-1, p1.17, ••••••••••••••=1T• fig.5. 11 (REUSS): EICHENBERG, 1935, p1.9, fig.19, p1.11, fig.10. (REUSS): TEN DAM, 1950, p.22, p1.2, fig.4. Astacolus jonesi REUSS): SZTEJN, 1958, p.24, fig.45. Marginulinopsis jonesi (REUSS): TAPPAN, 1962, p.167, p1.42, figs.1-6. Marginulina jonesi ROSS): NEAGU, 1965, p.17, p1.5, figs.11-12. Lenticulina (Marginulinopsis) jonesi (REUSS): FUCHS, 1967, p.298, p1.11, figs.2-3,5. 144
Cristellaria (Marginulina) mulleri REUSS, 1863, p.61, p1.6, fig.l.
Marginulina punieri BERTHELINs CHAPMAN, 1894, p.163, p1.4, fig.22.
Cristellaria Mar nulina) Robus a REUSS, 1863, p.63, p1.6, fig.5-6. Marginulina robusta REUSS t WOMAN, 1894, p.163, p1.4, fig.23. Occurrences Middle and Upper Albian to Bed 2 Plenus Marls succession.
Marginulina sp. C, sp. nov. Plate 10 : Fig.15. Determination: Early portion of test showing slight signs of coiling, rest of chambers in a uniserial, slightly arcuate arrangement; test free, flattened giving a lens-shaped cross- section; sutures oblique, slightly depressed; chambers not inflated, thus giving a smooth sided appearance to the test; aperture terminal, radial, slightly raised on the produced last chamber. Occurrences Middle and Upper Albian clay and Lower Cenomanian chalk.
Marginulina sp. 25, sp. nov. Plate 11 s Fig.l. Determinations Early portion of the test showing slight signs of coiling, rest of chambers in a uniserial, slightly arcuate arrangement; test free, chambers inflated, sutures very oblique and depressed, giving a lobulate outline to the test; aperture terminal radial, excentrioally placed on the slightly produced final chamber. Occurrences Upper Cenomanian chalk. 145
Marginulina sp. 32, sp. nov• Plate 11 s Fig.2. Determination: Early portion of test showing slight signs of coiling, rest of chambers in a uniserial, slightly arcuate arrangement; test free, chambers inflated very slightly giving a faintly lobulate appearance to the last two chambers; sutures indistinct, slightly oblique, almost flush with the test in the early stages; aperture radial, terminal, excentrically
placed on the slightly produced final chamber.
Occurrence: Middle end. Upper Albian to Lower Turanian.
Marginulina sp. 36, sp. nov. Plate 11 : Fig.3.
?Marginulina glabra CRAPMAU (not D'ORBIGNY), 1894, p.160, p1.4, fig.11a b. Determinations Early portion of test showing slight signs of coiling, rest of chambers in a uniserial, slightly arcuate arrangement; test free, chambers markedly inflated, increasing in size rapidly; sutures oblique, depressed; aperture radial, terminal, almost central, raised on a very slight neck above the final chamber. Remarks: This form is very variable in the length of the
test and in the tightness of the initial coiling. Occurrence: Middle and Upper Albian to Lower Turanian.
Marginulina sp. 39, sp. nov. Plate 11 : Fig.4. Determination: Early portion of test showing slight signs
of coiling, remainder of chambers in a uniserial, arcuate 146
arrangement; test free, chambers not inflated, although sutures still slightly depressed; test flattened slightly giving a lens- shaped cross-section; aperture radial, terminal, only slightly produced at the end of the final chamber. Occurrence: Middle and Upper Albian clays and Lower
Cenomanian chalk.
Marginulina sp. 45, sp. nov. Plate 11 Fig.5. Determination: Early portion of the test coiled tightly; succeeding chambers added on top of each other, overlapping almost all the earlier growth stages; sutures only slightly depressed and hardly visible; aperture radial, terminal, at the produced end of the final chamber. Remarks: Small forms of this species are fairly common in the Lower Chalk while larger varieties are seen at higher levels. The form described as Cristellariatripleura REUSS by CHVAIM (1894) may be an earlier form of the same species seen occasionally in the Gault Clay. Occurrence: Middle and Upper Albian to Lower Turonian.
Marginulina sp. 47, sp. nov. Plate 11 : Fig.6. Determinations Early portion of the test slightly coiled; succeeding chambers arranged uniserially, only slightly arcuate; chambers inflated, sutures nearly horizontal, depressed; aperture radial, terminal, excentrically placed on moderately produced final chamber. 147
Occurrence: Middle and Upper Albian to Plenus Marls.
Neoflabellina BARTENSTEIN 1948 Type species: Flabellina rugosa D'ORBIGNY 1840
Neoflabellina ornata (REUSS) Plate 11 s Fig.7. Flabellina ornata REUSS, 1845, p.32, p1.24, fig.43. Occurrence: Upper Cenomanian chalk.
Palmula LEA 1833 Type species: Palmula sagittaria LEA 1833
Palmula cordata (REUSS) Plate 11 Fig.8.
Flabellina cordata REUSS, 1844, p.213. ft ft REUSS: REUSS, 1845, P.32, p1.8, figs.37-46. REUSS: REUSS, 1854, P.67, p1.25, figs.6a-b,7 -8. 77 " REUSS: REUSS, 1860, p.216. ft elliptica REUSS: 'Dr D' 1892, p.63, p1.8, figs.1-7. ?I cordata REUSS: EGGER, 1899, p.108, p1.10, fig21. " REUSS: EGGER, 1907, p.30, p1.1, fig.3. Remarks: This commonly smooth form may possess an ornamentation of small beads scattered over the proximal part of the test and along the earlier sutures. Occurrence: Foxmould sands, Cenomanian greensands and chalk, to uppermost Plenus MArls,
Planularia DEFRANCE in DE BLAINVILLE 1826 Type species: Peneroplis auris DEFRANCE in DE BLAINVILLE 1826 148
Planularia cenomana (SCHACKO) Plate 11 s Figs.9,10.
Cristellaria cenomana SCHACK°, 1897, p.162, p1.4, figs.1-2. bra ana CHAPMAN, 1894, p.654, p1.10, fig.13a-b. Planularia bradyana CHAPMAN): TEN DAM, 1950, p.24, p1.2, fig.8. '► cenomana SCHACK0): FRANKE, 1928, p.105, p1.18, fig.14a-b. Remarks: In the higher levels of the successions under consideration a strengthening of the striate ornament and a general elongation of the test produces a form that has been referred to P. cf. mariae TEN DAM. A more extensive study of the evolutionary trends of this group may show that they are both in fact the same species. Occurrence: Middle and Upper Albian to Bed 4 of the Plenus Marls succession.
Planularia cristellaroides (REUSS) Plate 11 : Fig.11. Vaginulina cristellaroides REUSS, 1863, p.48, p1.3, Vaginulina priceana CHAPMAN, 1894, p.427, p1.8, fig.15a-b. Occurrence: Middle and Upper Albian clays.
Planularia mariae TEN DAM Plate 11 : Fig.12. Planularia mariae TEN DAM, 1950, p.24, p1.2, fig.9a-b. Occurrence: Lower and Upper Cenomanian chalk.
Pseudonodosaria BOOKGAART 1949 Type species: Glandulina discreta REUSS 1850
149
Pseudonodosariapylindracea (REUSS) Plate 11 : Fig.13. Nodosaria (Glandulina) cylindracea REUSS, 1845, p.25, p1.13. Glandulina cylindracea (REUSS): REUSS, 1860, p.190, p1.4, fig.l. Nodosaria (Glandulina) cylindracea REUSS: BURROWS, SHERBORN & BAILEY, 1890, p.556, p1.9, fig.17. Nodosaria (Glandulina) cylindracea REUSS: CHAPMAN, 1893, pp.585-6, p1.8, fig.21. Nodosaria (Glandulina) cylindrica REUSS: EGGER, 1899, p.84, p105, figs. 19-20. REUSS: FRANKS, 1928, p.52, p1.4, figs. 22-3. Pseudoglandulina cylindracea (REUSS): CUSHMAN, 1946, p.76, p1.27, figs.33-4. Occurrence: Middle and Upper Albian clays and sands.
Pseudonodosaria humilis (ROEMER) Plate 11 : Figs.14,15. Nodosaria humilis ROEMER, 1841, P.95, p1.15, fig.6. Glandulina humilis (RO DI Mr ): REUSS, (in parts), 1862, p.58, p1.5, figs.9-11 (not 7,8). Nodosaria humilis ROEMER: CHAPMAN, 1893, p1.8, fig.18. Glandulina humilis ROEMER): EGGER, 1899, p.83, p1.22, figs.3-4. I, " RO Di He ): EICHENBERG, 1935, p.174, p1.16, fig.9a-b. " ROMER): EICHENBERG, 1935b, p1.9, fig.16. Pseudgglandulina humilis (ROEMER): TEN DAM, 1948, p.129. Occurrence: Middle and Upper Albian clays and sands, and Cenomanian greensands.
Pseudonodosaria mutabilis (REUSS) Plate 11 : Fig.16. Glandulina mutabilis REUSS, 1863, p.58, p.91, p1.5, figs.7-11. ft " REUSS: CHAPMAN, 1894, p.585, p1.8, figs.19-20. tt REUSS: EGGER, 1899, p.83, p1.5, figs.21,29. It REUSS: FRANKE, 1928, p.52, p1.4, fig.25. ft REUSS: BROTZEN, 1936, p.89, p1.4, fig.16. Occurrence: Lower and Upper Cenomanian chalk, to Plenus Marls.
Saracenaria DEFRANCE in DE BLAINVILLE 1824 Type species: Saracenaria italica DEFRANCE 1824 150
Saracenaria bononiensis (BERTHELIN) Plate 12 : Figs.1,2. Cristellaria bononiensis BERTHELIN, 1880, p.55, p1.3, fig.23a-c. ft ft BERTHELIN: CHAPMAN, 1894, pp.652-3, p1.10, fig.9a-b. ft ft BERTHELIN: BGGER, p.112, p1.25, figs.4-6. Saracenaria bononiensis (BERTHELIN): TAPPAN, 1940, pp.105-6, p1.16, fig.16a-b. ft ft (BERTHELIN): TEN DAN, 1950, p.24. Lenticulina (Saracenaria) bononiensis (BERTHELIN): BARTENSTEIN, 1954, p.46. (BERTHELIN): NEAGU, 1965, p.16, p1.4, figs.26 -27. Lenticulina (Saracenaria) of. bononiensis bononiensis (BERTHELIN): FUCHS, 1967, pp.300-01, p1.12, fig.2. Occurrences Middle and Upper Albian to Upper Cenomanian.
Saracenaria italics DEFRANCE Plate 12 : Fig.3. Saracenaria italica DEFRANCE, 1824, p.177. " DEFRANCE: DEFRANCE, 1827, p.334, p1.13, fig.6. Cristellaria italica (DEFRANCE): BRADY, 1884, p.544, p1.88, figs.??, 18,20-23. i, " (DEFRANCE): CHAPMAN, 1894, p.653, p1.10, fig.10a-b. 1, sulcifera CHAPMAN (not REUSS), 1894, P10.650-1, p1.10, fig.2a-b. II italica DEFRANCE: CUSHMAN, 1913, p.78, p1.33, fig.3a-b. ft ft DEFRANCE: CUSHMAN, 1923, p.125, p1.35, figs.5 -7. Saracenaria cushmani TAPPAN, 1940, p.106, p1.16, fig.17a-b. n " TAPPAN: TAPPAN, 1943, P.498, p1.80, fig.9a-b. Occurrence: Middle and Upper Albian to Lower Turonian.
Saracenaria jarvisi, (BROTZEN) Plate 12 : Fig.4.
Cristellaria trianularis D'ORBIGNY: BEISSEL, 1891, p.53, p1.10, fige.1 -9. I, navicula D'ORBIGNY: FRANKS, 1925, p.72, p1.5, fig.28. ,, italica (DEFRANCE): FRANKE, 1928a, p.680. I, navicula D'ORBIGNY: FRANKE, 1928b, p.104, p1.9, fig.25a-b. ft nuda REUSS: CUSHMAN & JARVIS, 1928, p.96, p1.14, fig.2. ,, " REUSS: CUSHMAN & JARVIS, 1932, p.24, p1.7, fig.6a-b. ft navicula D'ORBIGNY: BROTZEN, 1934, p.49. Astacolus jarvisi BROTZEN, 1936, pp.56 -7, p1.3, fig.5a-b, t.fig.17. 151
Occurrence: Lower Cenomanian chalk and greensand to Lower Turonian.
Saracenaria vestita (BERTHELIN) Plate 12 : Fig.5. Cristellaria vestita BERTHELIN, 1880, p.53, p1.3, fig.22. " BERTHELIN: CHAPMAN, 1894, 13.653, p1.10, fig. lla-b. Saracenaria vestita (BERTHELIN): TEN DAM, 1950, pp.25-6, fig.11. Occurrence: Middle and Upper Albian to Upper Cenomanian.
Saracenaria sp. 24, sp. nov. Plate 12 : Fig.6. Determination: Test free, planispiral in the early growth stages; later chambers uncoiling and becoming inflated; triangular in cross-section with rounded edges to the apertural face; sutures indistinct, flush with the surface and often indistinguishable; aperture radiate at the peripheral angle - only slightly prDduced. Occurrence: Middle and Upper Albian clays.
Vaginulina D'ORBIGNY 1826 Type species: Nautilus legumen LINNE 1758
Vaginulina Bicostulata REUSS Plate 12 Fig.7. Vaginulina bicostulata REUSS, 1860, p.202, p1.8, fig.5. Occurrences,. Lower and Upper Cenomanian chalk.
Vaginulina debilis (BERTHELIN) Plate 12 Fig.8. 152
Marginulina debilis BERTHELIN, 1880, p.35, p1.3, fig.28. " BERTHELIN: CHAPMAN, 1894, P.161, p1.4, fig.15. Dentalina debilis BERTHELIN): EI •10f :Or G, 1933, PP.183-4, P1.23, fig.10. ft (BERTHELIN): EICHENBERG, 1935, p.167, p1.12, fig.9. Vaginulina debilis (BERTHELIN): TAPPAN, 1940, pp.108-9, p1.16, fig.26a-b. ft " (BERTHELIN): TAPPAN, 1943, p.500, p1.80, fig.15. Dentalina debilis (BERTHELIN): FRIZZELL, 1954, P.88, p1.19, fig•5• " " (BERTHELIN): BARTENSTEIN, BETTENSTAEDT & BOLL', 1957, p.35, p1.7, fig.149. Dentalina debilis (BERTHELIN): NEAGU, 1965, p.21, p1.5, fig.19. Occurrence: Middle and Upper Albian to Bed. 1 of the Plenus Marls succession.
Vainulina kochii ROEMER Plate 12 : Fige.9,10,11. This is an extremely variable 'species group' and throughout the Albian and Oenomanian foris previously regarded as separate species are seen to intergrade. Variation occurs in the form and strength of the ornament as well as in the overall shape of the test. A large amount of work on total populations of this group will be necessary before any conclusive statements can be made. For the present, the group is divided into three forms - each with separate synonymies.
Vaginulina kochii ROEMER form gaultina Plate 12 : Fig.9.
Remarks: CHAPMAN, 1894, p1.8, fig.8a-b, illustrates a form with the typical V.kochii shape but the raised sutures are broken in an 'en echelon' pattern. This slight difference is not thought to be of great significance. Occurrence: Middle and Upper Albian clays and sands.
153
Vaginulina kochii ROEMER form kochii Plate 12 s Piga°. Vaginulina koohii ROEMER, 1840, p.96, p1.15, fig.10. Vaginulina arguta REUSS, 1860, p.20e, p1.8, fig.4. Vaginulina striolata REUSS, 1863, p.46, p1.3, fig.7. Vaginulina arguta REUSS: REUSS, 1863, p.47, p1.3, fig.13. Vaginulina curynota REUSS, 1863, p.90, p1.12, fig.9. Vaginulina truncata REUSS: BERTHELIN, 1880, P.39r P1.24, figs.25 -28. Vaginulina arguta REUSS: BERTHELIN, 1880, p.42, p1.25, fig.7a-b. " REUSS: BURROWS, SHERBORN & BAILEY, 1890, p.559, p1.10, figs.14-15. Vaginulina cenomana PERNER, 1892, p.62, p1.5, fig.18. Vaginulina truncata REUSS: CHAPMAN, 1894, PP.423 -4, p1.8, figs.5 -6. Vaginulina gaultina BERTHELIN: CHAPMAN, 1894, p.425, p1.8, fig.8. Vaginulina arguta REUSS: CHAPMAN, 1894, P.425, p1.8, fig.9a-b. n REUSS: FRANKE, 1928, p.83, p1.7, fig.29. Vaginulina koohii ROEMER: CUSHMAN & ALEXANDER, 1930, p.1, p1.1, figs.1 -9. Vaginulina arguta REUSS: EICHENBERG, 1933, p.10, p1.8, fig.5. Vaginulina uncata REUSS: EICHENBERG, 1933, p.187, p1.20, fig.6. " REUSS: EICHENBED1,1935, p.179, p1.16, fig.5. —Tr— REUSS: EICHENBERG, 1935, P.281 p1.5, fig.9. Vaginulina kochii ROEMER: TAPPAN, 1940, pp.109-110, p1.17, figs.2 -4. If " ROEMER: TAPPAN, 1943, pp.500-1, p1.80„ figs.17a-18. Vaginulina argots. REUSS: TEN DAM, 1950, p.34. 10 REUSS: BATENSTEM, BETTENSTAEDT & BOLLI, 1957, p.38, p1.6, fig.136. Vaginulina costulata ROEMER: JtrratIES, 1962, p1.79, fig.15, Vaginulina arguta REUSS: NEAGU, 1965, p.24, p1.5, fig.37. Remarks: Included in this group are all those forms that lack any form of ornament and are not included in the other two categories. Most specimens display the typical chamber arrange- ment, gradually expanding in size away from the proloculus. Occurrence: Middle and Upper Albian to Lower Turonian.
Vaginulina kochii ROEMER form recta Plate 12 : Fig.11. Vaginulina recta REUSS, 1863, p.48, p1.3, figs.14-15. " REUSS: BERTHELIN, 1880, p.41, p1.25, figs.5 -6. tt " REUSS: BURROWS, SHERBORN & BAILEY, 1890, p.559, p1.10, figs.l0-13. Vaginulina recta REUSS: PERNER, 1892, p.62, p1.5, fig.17. REUSS: CHAPMAN, 1894, p.422, p1.8, fig.'. 154
Vaginulina recta REUSS: FRANKE, 1928, pp.82-3, p1.7, figs.27-28. REUSS: CUSHMAN & ALEXANDER, 1930, p.4, p1.1, figs.17-22. " REUSS: TAPPAN, 1940, Pp.110-11, p1.17, figs.7a-8. ft " REUSS: TAPPAN, 1943, p.501, p1.80, fig.22a-b. ft ft REUSS: CUSHMAN, 1946, P.77, p1.28, fig.23. ft ft REUSS: TEN DAM, 1950, p.36. Citharina recta (REUSS): FRIZZELL, 1954, P.95, P1.11, figs.19-20. Vaginulina rectaREUSS: SZTEJN, 1958, p.28, fig.57. ft " REUSS: DRUSCHIZA & KUDRJAZEWA, 1960, p.99, p1.11, fig.l. ft ft REUSS: NEAGU, 1965, PP.24-5, P1.5, fig.31, p1.6, figs.1-2. ft " REUSS: BARTENSTEIN, BETTENSTAEDP & BOLLI, 1966, p.155, p1.3, figs.250-53. Vaginulina recta REUSS: mons, 1967, p.313, p1.13, fig.5, P1.14, fig.la-b. Remarks: Although V.recta has been regarded by many workers as a separate species, intermediate forms do exist which suggest that it does in fact belong in this general group. The name as used here, refers to almost parallel-sided forms lacking any strong ornamentation, although in some specimens fine ribs are recorded. Occurrence: Middle and Upper Albian to Lower Turonian.
Vaginulina mediocarinata TEN DAM Plate 12 Fig.14. Vaginulina strigillata REUSS: CHAPMAN, 1894, P.423, p1.8, figs.3-4. Vaginulina mediocarinata TEN DAM, 1950, pp.36-7, p1.3, fig.3. Occurrence: Lower Cenomanian chalk.
Vaginulina neocomiana CHAPMAN Plate 12 : Fig.13. Vaginulina neocomiana CHAPMAN, 1894, P.711, p1.34, fig.lOa-b. 1, CHAPMAN: TEN 11AM, 1948, p.180, p1.32, fig.14. Occurrence: Middle and Upper Albian clays and sands, Lower Cenomanian greensand and chalk. 155
Vaginulina truncata REUSS Plate 12 : Fig.12. Vaginulina truncata REUSS, 1863, p.47, P1.3, fig.9. REUSS, var. robusta BERTHELIN, 1880, p.39, p1.2, fig.4a-b. Vaginulina truncata REUSS, var. robusta BERTHELIN: CHAPMAN, 1894, PP.424-5, p1.8, fig.7a-b. Vaginulina truncata robusta BERTHELIN: EICHENBERG, 1933, pal, p1.6, fig.5a-b. Voginulinayobusta CHAPMAN: TEN DWI 1950, p.35, taig.3. Vaginulina truncata robusta BERTHELIN: FUCHS, 1967, pp.313-4, fig.6a-b. Occurrence: Middle and Upper Albian clays and sands, Lower Cenomanian greensands and chalk.
Vaginulina sp. B, sp. nov. Plate 12 : Fig.15. Determination: Test free, uniserial, slightly arcuate in the early growth stages, almost rectilinear in the adult stage; test oval in cross-section, chambers becoming more inflated in the later growth stages, sutures oblique, depressed; aperture terminal, radiate, on slightly produced final chamber. Occurrences Middle to Upper Albian clays.
Vaginulina sp. 21, sp. nov. Plate 12 :Fig.16. ?Cristellaria,crepidula (FITCHEL&WW: CHAPMAN, 1894, p.648, p1.9, fig.8a-b. ?Cristellaria planiscula REUSS: CHAPMAN, 1894, p.654, p1.10, fig.14a-b. Determination: Test free, uniserial, slightly arcuate in the early growth stages; test oval in cross-section, chambers inflated throughout with only slightly depressed sutures, which are markedly oblique; initial chamber very inflated and almost circular in appearance; aperture terminal, radiate, on slightly 156
produced final chamber. Occurrence: Middle and Upper Albian clays.
Va inulina sp. 30, sp. nov. Plate 12 : Fig.17. Determinations Test free, uniserial, slightly arcuate, markedly compressed, with rectangular cross-section; chambers increasing rapidly in width until adult stage is attained; proloculus spherical, ornamented with a single rib; chambers not inflated, separated by oblique raised sutures which in some individuals show a break up into a series of flecks as in V.kochii f.Raultina; aperture terminal, radiate, on slightly produced final chamber. Occurrence: Lower Cenomanian chalk.
Vaginulina sp. 36, sp. nov. Plate 13 s Figs.l, 2. Determination: Test free, uniserial, elongate, almost rectilinear; inflated proloculus lacks any ornament; chambers slightly inflated but margins still appear straight as sutures produce no depression; in the more advanced forms the sutures can become very thickened, and raised above the surface of the test; aperture radial, terminal on topmost surface of the final chamber. Remarks: This species occurs throughout the Gault clay and shows a sequence from small rounded forms to large, elongated, almost parallel sided ones. The latter are significant as they commonly occur in the Foxmould sands of south-east Devon, which 157
may indicate an Upper Albian age for these beds. The character— istic raised sutures are always seen both in the large or small specimens. Occurrence: Middle and Upper Albian clays and sands. ? Lower Cenomanian chalk.
Subfamily LINGULININAE LOEBLICH & TAPPAN 1961
Lingulonodosaria SILVESTRI 1903 Type species: Lingulina nodosaria REUSS 1863
Lingulonodosaria semiornata (REUSS) Plate 13 : Fig.3. Lingulina semiornata REUSS, 1863, p.91, p1.12, fig.l1. ye REUSS: CHAPMAN, 1894, p.154, p1.3, REUSS: TEN DAN, 1950, p.31. Occurrences Middle and Upper Albian to Plenus Marls.
Family POLYMORPHINIDAE D'ORBIGNY 1839 Subfamily POLYMORPHININAE D'ORBIGNY 1839
Glandulopleurostomella SILVESTRI 1903 Type species: Polymorphina subcylindrica HANTKEN 1875
•Glandulopleurostomella pleurostomelloides (FRANKE) Plate 13 : Fig.4. Polymorphina pleurostomelloides FRANK t 1928, p.121, p1.11, fig.l1. Palaeopolymorphina pleurostomelloides (FRANKE): CUSHMAN & OZAWA, 1930, p.112, p1.28, Glandulopleurostomella pleurostomelloides (FRANK): LOEBLICH & TAPPAN, 1964(Treatise), p.530, fig.415, 4a-b. 158
Occurrence: Middle Cenomanian chalk to Bed 2/4 of the Plenus Marls succession. Normally only seen above the mid- Cenomanian non-sequence.
Globulina D'ORBIGNY in DE Lk SAGRA 1839 Type species: Polymorphina (Giobuline) gibba D'ORBIGNY 1826
Globulina lacrima REUSS Plate 13 : Figs. 5, 6. Polymorphina (Globulina) lacrima REUSS, 1845, P.40, 131.12, fig.6, p1.13, fig.83. Globulina lam REUSS: REUSS, 1851, p.27, p1.4, fig.9. Polymorphina gibba CHUM, (not D'ORBIGNY), 1896, p.9, p1.2, fig.5. lactea CHAPMAN, (not WALKER 84.1.C37), 1896, p.9, p1.2, PolymorphinaAutta CHAPMAN, (not D'ORBIGNY), 1896, p.10, p1.2, fig.7. Globulina lacrima REUSS: CUSHMAN & OZAWA, 1930, pp.77-8, p1.19, figs .1-2, and full synonymy of previous work. Globulina lacrima REUSS: CUSHMAN, 1932, p.337, p1.51, fig.2. “ REUSS: FRi77ALL, 1954, P.348, p1.56, fig.27. REUSS: CUSHMAN & TODD, 1943, P.61, P1.11, fig.3. REUSS: CUSHMAN, 1944, p.9, P1.21 fig.5. REUSS: CUSHMAN, 1944a, p.89, p1.13, to REUSS: CUSHMAN, 1946, p.244, P1.20, fig.23. Remarks: Although very close to G.gibba D'ORBIGNY, CUSHMAN & OZANA (1930) concluded that most authors have been constant in describing G.lacrima as a Cretaceous species with a produced neck. Occurrence: Middle and Upper Albian to Plenus Marls (Bed 4).
Globulina lacrima REUSS var. ericia CUSHMAN & OZAWA Plate 13 : Figs. 7, 8.
Globulina horrida REUSS, 1845, p.110, p1.43, fig.14. Polymorphina Roemeri REUSS, 1870, p.35, P1.34, figs.4-12,14. gutta D'ORBIGNY: CHAPMAN, 1895, p.10, p1.2, fig.8. D'ORBIGNY: CHAPMAN & JONES, 1896, p.513, fig.29. Globulina lacrima REUSS var. ericia CUSHMAN & OZAWA, 1930, pp.78-9, p1.19, fig.4. 159
Remarks: This is a very typical form in which the fistulose outgrowths, commonly seen in the Polymorphinidae, have expanded over the whole surface of the test. Unlike the normal apical outgrowths, these take the form of stout blunt spines which are unequally distributed over the whole wall surface. Occurrences The holotypes were described from the Cambridge Greensand and all the specimens recorded in this survey were from strata immediately adjacent to the Albian/Cenomanian boundary.
Globulina lacrima REUSS var. subsphaerica (BERTHELIN) Plate 13 Fig.9. Polymorphina subs haetica BERTHELIN, 1880, p.58, p1.4, fig.18a-b. " gibba CHAPMAN & JONES, (not IPORBIGNY), 1896, p.509, fig.5. Globulina lacrima REUSS var. subsphaerica (BERTAELIN): CUSHMPN & OZAWA, 1930, 0.78, p1.19, figs.5-7. Globulina lacrima REUSS var. subsphaerica (BERTabIN): TAPPAN, 1940, PP.113-4, p1.17, fig.24a-b. Globulina lacrima REUSS Var. subsphaerica (BERTHELIN): CUSHMAN, 1946, pp.96-7, p1.40, Globulina lacrima REUSS var. subsphaerica (BERTHELIN): FRIMELL, 1954, P.104, p1.14, figs.22a-c,23. Remarks: This differs from the typical form in being flattened or more rounded at the base. Occurrence: Middle and Upper Albian clays and sands, and Lower Cenomanian greensands.
Globulina prisca REUSS Plate 13 Fig.10. Globulina prisca REUSS, 1862, p.79, p1.9, fig.8. Polymorphina acuta OLSZEWSKI, 1875, p.120, plat fig.13. Polymorphina prisca (REUSS): BERTHELIN, 1880, p.57, p1.4, figs.20a-b,21. ft lactea BURROWS, SHERBORN & BAILEY, 1890, p.561, p1.11, fig.10. It fusiformis CHAPMAN, (not ROEMER), 1896, p.11, p1.2, fig.9, (not fig.10). 160
Polymorphina prisca (REUSS): EGGER, 1899, p.124, p1.17, figs.30,31. Globulina prisca REUSS: CUSHMAN & OZAWA, 1930, p.73, p1.12, fig.6a-c. ft ' REUSS: CUSHMAN, 1932, p.337, p1.51, fig.1. REUSS: BROTZEN, 1936, p.114, P1.7, fig.11. INIMII.114•••• REUSS: CUSHMAN, 1946, P.971 P1.40, figs.15,16(?17). " " REUSS: TEN DAM, 1948, pp.185-6, p1.32, fig.15. " " REUSS: FRT7ARLL, 1954, P.1041 p1.14, fig.24. " REUSS: NEAGU, 1965, p.28, p1.7, figs.3-5. " REUSS: BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.158, p1.3, figs.286-292,308.
.pocurrefice: Middle and Upper Albian to Lower Turonian.
Globulina sp. A, sp. nov. Plate 13 : Fig.11.
Determination: Test free, varying from globular to ovate, chambers strongly overlapping, added in planes approximately 144° apart; sutures almost flush with the smooth surface; aperture terminal, radiate; distal end of test slightly drawn out from the circular but not pointed. Occurrence: Foxmould sands, Chert Beds, Upper Cenomanian and Lower Turonian chalk.
Guttulina DIORBIGNY in DE LA SAGRA 1839 Type species: Polymorphina (Guttuline) communis D'ORBIGNY 1826
Guttulina adhaerens (OLSZEWSKI) Plate 13 : Fig.12.
Polymorphina adhaerens OLSZEWSKI, 1875, p.119, p1.1, fig.11. Guttulina adhaerens OLSZEWSKI): CUSHMAN & OZAWA, 1930, p.36, p1.1, fig.9a-c. Guttulina adhaerens (OLSZEWSKI): CUSHMAN & TODD, 1943, P.61, p1.11, fig.l. Guttulina adhaerens (OLSZEWSKI): CUSHMAN, 1946, p.96, p1.40, figs .8--10.
Occurrence: Lower Cenomanian chalk and greensands to Bed 3 of the Plenus Marls succession.
161
Guttulina adhaerens (OLSZEWSKI) var. cuspidata CUSHMAN & OZAWA Plate 13 2 Figs. 13,14. Polymor;hina sp. BURROWS, SHERBORN & BAILEY, 1890, p.561, p1.11, fig.15. Guttulina adhaerens (OLSEWSKI) var. cuspidata CUSHMAN & OZAWA 1930, p.37, p1.6, fig.6. OuttulinaHsororia BARNARD (not REUSS), 1963, pp.721-2, Remarks: The type figures of CUSHMAN & OZAWA (1930) do not appear to illustrate really typical members of this species but the specimens found in this study are nearer those of OLSZEWSKI. This is possibly the form listed by BARNARD (1963) as G.sororia REUSS. In his description BARNARD comments on the characteristic spine seen on the initial chamber of this species. This feature is also quite prominent in his illustrations. However, examination of the original figures of REUSS has shown that G.sororia has a distinctly rounded distal end and so cannot be the same as BARNARDIs species. Occurrence: Lower and Upper Cenomanian, greensands and chalk.
Pyrulina DIORBIGNY in De La SAGRA 1839 Type species: Polymorphina (PYruline) gutta DIORBIOW 1826
Pyrulina cylindroides (ROEMER) Plate 13 : Fig.15. Polymorphina cylindroides ROEMER, 1838, p.385, p1.3, fig.26. it n ROEMER: BRADY, PARK & JONES, 1870, p.221, p1.39, fig.6a—c. Pyrulina cylindroides (ROEMER): CUSHMAN & OZAWA, 1930, pp.56-7, p1.14, figs.1-5. Pyrulina cylindroides (ROEMER): TAPPAN, 1940, p.114, p1.18, figs.la-c. (ROEMER): CUSHMAN, 1946, p.97, p1.40, figs.18,19. (ROEMER): TEN DAM, 1950, p.42. It (ROEMER): FRIZZELL, 1954, p.104, p1.14, figs.25-27. 162
PYrulina cylindroides 1•ROEMER1: BARNARD, 1962, p.723, fig.8a-c. ROEMER : BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, p.158, p1.3, figs.299-302. Occurrence: Middle and Upper Albian to Plenus Marls.
Subfamily EDITHAELLINAE FUCHS 1967
Edithaella FUCHS 1967 Type species: Edithaella sessilis FUCHS 1967
Edithaella sessilis FUCHS Plate 13 s Fig.16. Edithaella sessilis FUCHS, 1967, p.320, p1.16, figs.4a-b,5. Remarks: This species is very closely related to Cornusphaera grandis FUCHS, and their division into two separate genera is doubtful. However until larger populations can be studied their positions, as determined by FUCHS, are retained. Occurrences Middle and Upper Albian to Upper Cenomarian.
Cornusphaera FUCHS 1967 Type species: Cornusphaera grandis FUCHS 1967
Cornusphaera grandis FUCHS Plate 13 Fig.17. Cornusphaera grandis FUCHS, 1967, p.321, p1.16, figs.2a-b,3a.b. Occurrence: Middle and Upper Albian clay and Lower Cenomanian chalk; also occurs in Foxmould sands.
Subfamily WEBBINELLINAE RHUMBLER 1904 163
Bullopora QUENSTEDT 1856 Type species: Bullopora rostrata QUENSTEDT 1857
Bullopora laevis (SOMAS) Plate 14 Fig.l. Webbina laevis SOLLAS, 1877 p.103, p1.6, figs.1-3. Vitriwebbina laevis (SOLLAS): CHAPMAN, 1896, p.585, p1.12, fig.12. sollasi CHAPMAN, 1892, p.53, p1.2, " CHAPMAN: CHAPMAN, 1896, p.586, p1.13, fig.l. Bullopora laevis SOLLAS WICKENDON, 1932, p.206, p1.29, 1 " SOLLAS s CUSHMAN, 1940, p.64, p1.11, fig.12. " SOLLAS : TAPPAN, 1940, p.115, p1.18, fig.6. " SOLLAS s TEN DAM, 1948, p.186. Vitriwebbina laevis (SOLLAS): FRIZZELL, 1954, p.107, p1.15, fig.6. Bullopora sofiZrTCHAPMAN): BARNARD, 1958, p1.24, fig.2. " laevis (SOLLAS): ADAMS, 1962, p.158, p1.23, figs.6-8, p1.24, figs.9-11, and synonymy. Vitriwebbina laevis SOLLAS NEAGU, 1965, p.28, p1.7, fig.13. " SOLLAS t FUCHS, 1967, p.322, p1.16, figs.6a-b. Remarks: B.sollasi (CHAPMAN) was initially separated on the basis of having a pitted surface. BARNARD (1958) suggested that B.laevis may be the same as B.globulata BARNARD and if this is so then the latter would be a junior synonym. ADAMS (1962) agrees with this, the difference being, in his opinion, only one of stratigraphic position. He, however, advocated leaving the two species as separate units as they do have some stratigraphic value. Occurrence: Middle and Upper Albian to Lower Turonian.
Bullopora tuberculata (SOLLAS) Plate 14 : Fig.2. Webbina tuberculata SOLLAS, 1877y p.104, p1.6, figs.4-7,9. Vitriwebbina tuberoulata (SOLLAg): CHAPMAN, 1896, pp.586-7, p1.13, (SOLLAS): CHAPMAN, 1896a, p.332, t.fig.4. If ft (SOLLAS)t CHAPMAN, 1899, p.315, t.fig.3. Bullopora tuberoulata(SOLLAs): CUSHMAN, 1946, p.99, P1.42, figs.5-7. Bullopora (SOLTAS): ADAMS, 1962, p.159, p1.24, figs.12, 14,15, and synonymy. Occurrence: Middle and Upper Albian to Plenus Marls. 164
Subfamily RAMULINME BRADY 1884
Ramulina JONES in WRIGHT 1875 Type species: Ramulina laevis JONES in WRIGHT 1875
Ramulina aculeata WRIGHT Plate 14 : Fig.3. Ramulina aculeata WRIGHT, 1886, p.331, p1.27, fig.11. WRIGHT: CHAPMAN (part), 1896, p.583, p1.13, fig.7. WRIGHT: EGGER, 1899, p.135, p1.2, fig.3. dOMOMLIMPONN••••••• 411•11•1•40.0~1..00 WRIGHT: FRANKE, 1928, p.121, p1.11, figs.16,17. " WRIGHT: EICHENBERG, 1933, p.18, p1.6, 1 WRIGHT: EICHENBERG, 1935a, p.29, p1.6, fig.l. '11 WRIGHT: EICHENBERG, 1935b, p1.1, fig.15, p1.5, • fig.50. " WRIGHT: BROMISM, 1936, p.116, t.fig.38. 11, " WRIGHT* TAPPANi 1943, P.506, p1.81, ?7. pit " (D'ORBIGNY): CUSHMAN, 1946, p.100, p1.43, fig.11. novaculeata BULLARD, 1953, P.346, p1.46, fig.26. Ramulina7argErOPORBIGNY): HAGN, 1953, p.71, p1.6, fig.10. " novaculeata BULLARD: NEAGU, 1965, p.28, p1.7, figs.17,18. " aculeata D'ORBIGNY): BARTENSTEIN, BETTENSTAEDT & BOLLI, 1966, pp.159-60, p1.4, figs.315-324 (?325-339). Ramulina aculeata (D'ORBIGNY): FUCHS, 1967, p.324, p1.17, figs.6,9. Remarks: As can be seen from the vast synonymy (which is by no means complete) this species has had a chequered career. D.aculeata D'ORBIGNY (1840) was initially described from the Tertiary while R.aculeata WRIGHT (1886) came from the Upper Cretaceous of Northern Ireland. Most subsequent workers on the Cretaceous followed WRIGHT's determination until 1949 when LOEBLICH & TAPPAN noted the real similarity between the two sets of type figures. They agree quite closely in the outline, ornamentation and size, and this, claimed LOEBLICH & TAPPAN, rendered them synonymous. Since that time both species have been variously cited as ascribable either to D'ORBIGNY or WRIGHT and the initial meanings have been somewhat obscured. LOEBLICH & WPM claimed that as 165
D.aculeata looks like a 'Dentalina' the name MamulinalAs in error, "as in no publication was a new species of Ramulina described with the specific name aculeata, the references always citing DIORBIGNY or WRIGHT". They therefore concluded that a new name was needed and this was supplied four years later by BULLARD (1953) in Renovaculeata. Unfortunately her figure does not appear to be very like the normal Cretaceous R.aculeata as normally accepted. Recent examination of a microfilm of D'ORBIGNY's type specimens has shown that D.aouleata is a Dentalina, quite unlike his type figure. His determination is therefore invalid and WRIGHT's initial determination of R.aculeata is in fact the valid name for the Cretaceous species. Occurrence: Middle and Upper Albian to Lower Turonian.
? Ramulina fusiformis KHAN Plate 14 : Fig.4. This species has already been discussed under the secidon Dentalina fusiformis (KHAN).
Ramulina globotubulosa CUSHMAN Plate 14 Fig.5. Ramulina globotubulosa CUSHMAN, 1938, p.44, p1.7, fig.16. CUSHMAN: CUSHMAN, 1946, p.100, p1.43, fig.l0. CUSHMAN: TEN DAM, 1948, p.43, p1.4, fig.l. CUSHMAN: FHIZZELL, 1954, p.106, p1.14, fig.49. ti arkadelphiana CUSHMAN: NEAGU, 1965, p.29, p1.17, fig.14,?15. globotubulosa CUSHMAN: UGUZZONI & RADRIZZANI, 1967, PP.1215-6, p1.90, figs.5-6. Remarks: Although initially a Senonian species this is almost certainly the same as the specimens here recorded from the Gault and Lower Chalk. 166
Occurrence: Middle and Upper Albian clays and sands.
Ramulina muricatina LOEBLICH & TAPPAN Plate 14 : Fig.6. Ramulina muricatina LOEBLICH & TAPPAN, 1949, pp.261-2, p1.50, figs.5-61 and earlier synonymy. Ramulina muricatina LOEBLICH & TAPPAN: BARTENSTEIU & BRAND, 1951, P.3221 pl.11, fig.308. Ramulina muricatina LOEBLICH & TAPPAN: PRT77MLL, 1954. p.106i P1.14, figs.44.45. Ramulina muricatina LOEBLICH & TAPPANs SZTEJN, 1958, P.43, fig.104. arkadelphiana FUCHS, (not CUSHMAN), 1967, p.325, p1:171 fig.11. Occurrence: Middle and Upper Albian to Plenus Marls.
Ramulina sp. 2, sp. nov. Plate 14 t Fig.7. Determination: Test free, comprised of almost globular chambers loosely connected by short, stout tubes; aperture at the open end of the tube; surface covered in short, fine spines (almost hispid) while necks have a slightly coarser ornament. Remarks: This species possibly belongs to the same stock as ? Dentalina fusiformis (KHAN). Occurrence: Middle and Upper Albian clays to Lower Cenomanian chalk.
Ramulina sp. 3, sp. nov. Plate 14 Ramulina aculeata (D'ORBIGNY): JEFFNHIES, 1962, p1.79, fig.18. Determination: Test free, consisting of almost globular chambers connected loosely by stolon-like necks; aperture rounded at the open end of the tube; branching as in R.muricatina has been 167 observed, but unlike that species there is normally a subglobular chamber at the junction; surface is covered sparsely in short, stout spines. Occurrence: Middle and Upper Albian to Plenus Marls.
Ramulina sp. A, sp. nov. Plate 14 s Fig.10. Determinations Test free, spherical, covered in short, stout spines which appear to be hollow; no visible sign of an aperture. Remarks: This 'species' is of unknown affinities, and it is possible that it may not in fact belong in the foraminiferida. It is assigned to the genus Ramulina with some doubt. Occurrence: Middle and Upper Albian to Bed 4 of the Plenus Marls succession. Family GLANDULIMIDAE REUSS 1860 Subfamily GLANDULINIMAE REUSS 1860 Tristix MACFADIEN 1941 Type species: Rhabdogonium liasinum BERTHELIN 1879
Tristix excavatum (REUSS)
Plate 14 s Fig.11. Rhabdogonium excavatum REUSS, 1862, p.91, p1.12, fig.8a-c. ti minutum REUSS: BURROWS, SHERBORN & BAILEY, 1890, p.559, p1.10, fig.8. Rhabdogonium excavatum REUSS: CHAPMAN, 1894, p.160, p1.4, fig.9a-b. fl II REUSS: CHAPMAN, 1899, p.305, fig.2. st it REUSS: EGGER, 1899, p.92, p1.17, figs.23-24. vp ant REUSS: FRANKE, 1928, p.73, p1.6, fig.22a-b. Dentalinopsis excavata (REUSS): PLUMMER, 1931, p.187, p1.2, figs.11-12. n " (REUSS): TAPPAN, 1940, p.118, p1.18, fig.lOa-b. Tricarinella excavata (REUSS): TEN DAM & SOHIJFSMA, 19451 PP.233-4. Tristix excavates REUSS SCHIJFSKA, 1946, Pp.62-31 p1.2, fig.15. "" REUSS): VAN WORTHUYSEN, 1947, P1444-51 t.fige.1-2. II excavatum (REUSS): TEN DAM, 1950, p.46. 168
Rhabdogonivm excavatum REUSS: NOTH, 1951, p.81, p1.2, fig.41. Tristix excaZitrigEUSS): FRMALL, 1954, p.119, p1.17,
41.1NWINININNIMIN. excays/ta (REUSS): NEAGU, 1965, P.241 p1.5, figs.14-15. " REUSS : FUCHS, 1967, p.308, p1.10, fig.la-b. Occurrence: Middle and Upper Albian to Plenus Marls.
excavatum (REUSS) var. exile OILMAN Plate 14 Fig.12. Rhabdogonium excavatum REUSS var. exilis CHUM, 1899, p.305, t.fig.2. Occurrence: Middle and Upper Albian to Upper Cenomanian.
Ansigne (REUSS) Plate 14 : Fig.13. Rhabdogonium insigne REUSS, 1862, p.56, p1.5, fig.2a-b. Occurrence: Middle and Upper Albian to Plenus Marls.
Subfamily OOLININAE LOEBLICH & TAPPAN 1961
Oolina DiORBIGNY 1839
Type species: Oolina laevigata GALLOWAY & WISSLER 1927
Oolina op. 23 sp. nov. Plate 14 Figs.14,15.
Entosolenia sp. J ',MIES, 1962, p1.79, Determinations Test free, single globular to ovate chamber, occasionally asymetrical; aperture circular, provided with ento- solenian tube; surface of test smooth, lacking in any ornamentation. Remarks: This variable form has many anomalous features, the most striking of which is the variation in aperture from that 169
of fissurine to radiate. Most specimens also possess an entosolenian tube. As well as occurring as single chambers, they may occur joined together in two's and three's thus raising the possibility that this species should belong in either Nodosaria or Dentalina. Occurrence: Middle and Upper Albian to Lower Turonian.
Fissurina REUSS 1850 Type species: Fissurina laevigata REUSS 1850
Fissurina sp. 20, sp. nov. Plate 14 1`ig.16. Determination: Test free, ovate in outline, compressed, rectangular in cross section; surface rough (may be due to preservation); initial end with a small distal spine, asymetrically placed; aperture central, terminal, slit-like, bearing an entosolenian tube. Remarks: Initial inspection suggested that this was perhaps the proloculus of a species like Frondicularia cordai, but broken specimens have shown the presence of an entosolenian tube. fJocurrence: Middle and Upper Albian to Lower Turonian.
Fissurina sp. 24, sp. nov. Plate 14 : Fig.17. Determination: Test free, ovate in outline, slightly compressed, giving a lenticular cross-section; surface rough (may be due to preservation); distal end slightly drawn to a point 170
though not markedly so; aperture terminal on a flattened, slightly produced part of the chamber; aperture slit-like, bearing an entosolenian tube. Occurrence: Middle and Upper Albian to the Plenus Marls.
Superfamily BULIKINACEA JONES 1875 Family TURRILINIDAE CUSHMAN 1927 Subfamily TURRILININAE CUSHMAN 1927
Buliminella CUSHMAN 1911 Type species: Bulimina elegantissima D'ORBIGNY 1839
'Buliminella' sp. 21, sp. nov. Plate 15 : Figs.11 21 3. Determination: Test free, elongate, high spired, formed of about four chambers per whorl; wall calcareous, perforate, radial in structure; aperture loop-shaped with a broad upper end; appears to have internal tooth-plate although details obscured by preservation; distal end rounded, chambers slightly inflated, sutures slightly depressed in adult growth stages. Remarks: Although occurring in the Upper Cenomanian this form continues into the Turonian where large well-developed specimens can be found. Buliminella CUSHMAN is basically a post- Maastrichtian form and all earlier determinations should (according to LOEBLICH & TAPPAN, 1964, Treatise) be placed in the genus Praebulimina HOFKER. As the description of this latter genus does not agree with the specimens under discussion they have been placed in Buliminella for the purpose of this present work.
Occurrence: Upper Cenomanian to Lower Turonian. 171
'Buliminellat sp. 22, sp. nov. Plate 15 : Figs.4,5. Determination: Test free, in a low spiral formed of four chambers per whorl; chambers inflated, sutures depressed; wall calcareous perforate, radial in structure; aperture loop-shaped, preservation obscuring internal details. Occurrence: Lower Cehomanian to Lower Turonian.
Family BOLIVINITIDAE CUSHMAN 1927
Bolivina 1'ORBIGN! 1839 Type species: Boliviaplicata CUSHMAN 1911
Bolivina temillaroideR REUSS Plate 15 i Figs.6,74 Maxim „torkilarailes REUSS, 1862, pe81, p1.10, figil.. -": REUSS: BERTHEL/N, 1880,.p:28, p1.1, fig.5. REUSS: BURROWSi SHERBORN & BAILEY, 1890, P6554; P168, fig.23. ormr nmorom REUSS: CHAPMAN, 1892, p.757, p1.12, fig.12a-b. ff p1.16, figs.1-3. ••••=1.11MPWININIM REUSS: EGGER, 1899, p.44, If REUSS: =WU, 1937, pp.37-8, p1.5, fig.18. REUSS: TAPPAN, 1940, p.118, p1.18, fig.8a-c. Occurrence: Middle and Upper Albian to Bed 4 of the Flenus Marls succession,
Bolivinoides CUSHMAN 1927 Type species: Bolivdna draco MARSSON 1878
Bolivinoides sp. 10, sp. nov. Plate 15 s Fig.S. 172
Determination: Test free, rhomboidal, flaring, flattened; chambers low and broad, biserially arranged (investigation with stereoscan indicates that there may be an early coiled portion), septa thick, sutures oblique, obscured externally by strong ornamentation; wall calcareous, monolamellar, perforate; aperture basal on face of finil chamber, no details of aperture as specimens are generally poorly preserved. Remarks: Although this genus is only recorded from the Santonian or above this species is thought to be a very early representative of the group as a whole. It is a very small form with a sporadic occurrence throughout the Lower Chalk. Occurrence: Lower and Upper Cenomanian Chalk.
Tainenina NOTANARO GALLITELLI 1955 Type species: Bolivinita solmensis CUSH MAN 1933
Tappanima sp. 20 sp. nov. Plate 15 s Fig.9. Determination: Test biserial, flaring, compressed; almost rectangular in cross-section; chambers cuneiform, concave on broad sides, with well developed horizontal ribs across chambers and along zigzag suture; sutures depressed; wall calcareous, finely perforate; aperture narrow, at base of final chamber; final chamber inflated with rounded margin, lacking any ornamentation. Remarks: This is a species very close to Bolivinita eouvigeriniformis KELLER from the Cenomanian of Russia. It has however the typical Tappanina aperture and is definitely referable to that genus. 173
Occurrences Lower Cenomanian to Lower Turonian.
Tappanina sp. 25, sp. nov. Plate 15 s Fig.10. Determinations Test biserial, slightly flaring, compressed; almost rectangular in cross—section; chambers cuneiform, concave on broad sides with well developed horizontal ribs across chambers and along zig-zag suture; sutures depressed; wall calcareous, finely perforate; aperture narrow, at the base of the final chamber; final chambers not inflated, ornamented by strong rib along margin; adult growth stages of -test almost parallel sided with little expansion in width. Remarks,: This is a more regular and rectangular looking species than the above and it is commonly seen in the lower part of the S.varians zone of the Lower Chalk. Occurrence: Lower Cenomanian chalk and greensands.
Family EOUVIGERINIDAE CUSHMAN 1927
Eouv4erina CUSHMAN 1926 Type species: Loxostomum aculeatum EHRENBERG 1854
Eouvigerina regularis (KELLER) Plate 15 s Fig.11. Bifarina regularis KELLER, 1935, P.549, p1.3, figs.l5-18. Occurrences Lower and Upper Cenomanian chalk.
Family BULNINIM JONES 1875 174
Subfamily mann= Jams 1875
Bulimina D'ORBIGNY 1826 Type species: Bulimina marginata CUSHMAN 1911
'Bulimina' ap. 20 sp. nov. Plate 15 : Fig.12. Determination: Test triserial; wall calcareous, radial, finely to coarsely perforate; aperture extending up from the base of the apertural face, border bears slight trace of a rim although preservation mars other details; chambers inflated, sutures depressed, lacking any ornamentation. Remarks: The earliest forms of this species are seen in the lower levels of the Gault Clay, where adult tests characteristically possess three chambers in the final whorl. Specimens like this are also common in the Lower Chalk but in the higher levels of this formation there is a transition to the larger species, Buliminella sp. 21, sp. nov., which typically has four chambers in the final whorl. Occurrence: Middle and Upper Albian to Lower Turonian.
Family UVIGERINIDAE HAECKEL 1894
Orthokarstenia DIETRICH 1935 Type species: Orthocerina ewaldi KARSTEN 1856
Orthokarstenia ealcarata (BERTHELIN) Plate 15 : Fig.13. 175
Bigenerina calcarata BERTHELIN, 1880, p.27, p1.1, figs.14-16. Sagrina calM:TrIBERTHELIN): CHAPMAN, 1894 P.15, P1.2, fig.14a—b. Bifarinaoalcarata BERTHELIN BOTENSTEIN, 1954i -10,440. It BERTHELIN $ NEAGU, 1965, p.29, p1.7, figs.11-12. Remarks: This very rare form has been placed in various genera by many authors but the description of Orthokarstenia by LOEBLICH & TAPPAN (1964, Treatise) appears to agree very closely with the features observed on the few specimens available. In most the initial portion of the test is either broken or poorly preserved, thus rendering accurate determination impossible. Occurrence: Middle and Upper Albian clays, and Lower Cenomanian chalk.
Superfamily IaSCORBACE& EHRENBERG 1838 Family DISCORBIDAE EHRENBERG 1838 Subfamily DISCORBINAE EHRENBERG 1838
Discorbis LAMARK 1804 Type species: Idscorbis vesicularis MURK 1804
"Discorbis allomorphinoides" (REUSS): atairkatIES Plate 16 : Figs.1-3. Discorbis allomorphinoides (REUSS):aeratIES• 1962, p1.79, fig.24a—c. Remarks: This species is often squashed or distorted and this is probably due to the thin nature of the test. There is great variety in the angularity of the periphery and in some specimens the ventral surface of the test is almost flat. The forms from the Albian and Cenomanian are close to the type figures of REUSS and although his specimens were much younger the two forms are definitely related. The species recorded from the Plenus 176
Marl by aiteVERIES (1962) is certainly that under discus:I:ion here and so his determination has been followed. Rosalina nitens REUSS is a species from the Cenomanian which must also belong to this group and it may actually be the species under discussion. His type figure however makes a good comparison impossible. Occurrences Middle and Upper Albian to Lower Turonian.
Discorbis sp. A, sp, nov, Plate 15 : Figs.14,15. Determination: Test free, trochospiral, piano-convex, flattened on the umbilical side; periphery slightly angled; chambers of final whorl visible on umbilical side; flap (?) extends from base of each chamber into umbilicus but details are obscured by bad preservation; aperture appears to be an interio- marginal, extraumbilical arch. Occurrence: Middle and Upper Albian to Plenus Marls.
Superfamily SPIRILL1NACEA REUSS 1862 Family SPIRILLINIDAE REUSS 1862 Subfamily PATELLIN1NAE RHUMBLER 1906-
Patellina WILLIAMSON 1858 Type species: Patellina corrugata WILLIAMSON 1858
Patellina trochiformis (SCHACKO) Plate 16 : Fig.4. Spirillina trochiformis SCHACKO, 1892, p.159, plate , " SCHACKOs HUCKE, 1904, p.171, p1.23, fig. 25a-c. 177
Patellina subcretacea CUSHMAN &ALEXANDER, 1930, p.10, p1.3,
.1.9•••••••=0.101 CUSHMAN & ALEXANDER: TAPPAN, 1943, p.511, p1.82, fig.4. el CUSHMAN & ALEXANDER: LOEBLICH & TAPPAN, 1949, p.264, p1.51, fig.3. , CUSHMAN &ALEXANDER: BARTENSTEIN & BRAND, 1951, p.325, p1.11, fig.315. CUSHMAN & ALEXANDER: SZTEJN, 1958, p.46, fig.111. 1. CUSHMAN & ALEXANDER: FUCHS, errninommo rm•mmoim. 1967, pp.330-i, p1.18, fig.7a-c. Occurrence,: Lower Cenomanian chalk and greensands (including Chert Beds) to Upper Cenomanian and Plenus Marls.
Superfamily GLOBIGERINACEA CARPENTER, PARKER & JONES 1862 Family HETEROHELICIDAE CUSHMAN 1927 Subfamily GUEMBELITRIINAE MONTANARO GALLITELLI 1957
Guembelitria CUSHMAN 1933 Type species: Guembelitria cretacea CUSHMAN 1933
Guembelitria harrisi TAPPAN 1940 Plate 16 s Fig.5. Guembelitria harrisi TAPPAN, 1940, p.115, p1.19, fig.2a-b. TAPPAN: PESSAGNO, 1967, p.258, p1.48, figs. 12-13. Remarks: BANDY (1967) records only two species of Guembelitria; G.cretacea CUSHMAN in the Maestrichtian and G.harrisi TAPPAN in the Albian. G.harrisi, the larger form, has a lower aperture, is less rapidly flaring and has comparatively less breadth. BANDY (1967) derives G.cretacea from Heterohelix globulosa, (EHRENBERG) and it is possible that G.harrisi is a triserial off- shoot from Heterohelix moremani (CUSHMAN). There is a possibility that Goretacea is in fact derived from Gsharrisi but 178
this problem is beyond the scope of the present work. Occurrence: Sporadically present in the Albian, common in the Cenomanian and represented in the Lower Turonian.
Subfamily HETEROHELICINAE CUSHMAN 1927
Heterohelix EHRENBERG 1843 Type species: Snironlecta americana EHRENBERG 1844
Heterohelix more (CUSHMAN) Plate 16 : Fig.6. Guembelina moremani CUSHMAN, 1938, p.10, p1.2, figs.1-3. washitensis TAPPAN, 1940, p.115, p1.19, fig.l. t• moremani CUSHMAN: CUSHMAN, 1946, pp.103-4, p1.44, figs.15-16(not 17). Heterohelix sp. AYALA, 1962, p.11, p1.1, fig.la-c, p1.6, fig.la-c. moremani CUSHMAN: PESSAGNO, 1967, pp.260-11 p1.48, figs.10-111 p1.89, figs.1-2. Remarks: This species is very similar to H.washitensis (TAPPAN) of the Aptian to Cenomanian. TAPPAN notes the similarity to HomoreMani but claims that H.washitensis is smaller and has more nearly horizontal sutures. Her claim that it has more globular chambers is not thought to be significant as within a population of H.moremani in the Upper Cenomanian all the extremes are seen from nearly straight sided chambers to those that are quite globose. PESSAGNO (1967) noted that larger, gerontic specimens of H.moremani, such as the holotype, tend to show a more highly arched aperture whereas the smaller specimens (which he figures on p1.48, figs.10-11) show low arched apertures. This, he claims, makes TAPPAN's differentiation on the basis of the low aperture and small size invalid, and he therefore places H.washitensis as 179
an earlier form of Himoremani. BANDY (1967) leaves them as two distinct species though showing that they follow each other stratigraphically. He does make the suggestion that the two may be dimorphic forms of the same species . This, as he points out is unlikely as their ranges are different but he would be prepared to accept the fact that H.washitensis is the ancestral form of H.mo'emani. Occurrences Middle Albian to Lower Turonian.
Family HANTKENINIDAB CUSHMAN 1927 Subfamily ROTALIPORINAE SIGAL 1958
Rotalipora BROTZEN 1942 Type species: Rotalipora turonica BROTZEN 1942 Globorotalia cushmani MORROW 1934
Rotalipora aushmani (MORROW) Plate 16 Figs.7-10. Globorotalia cushmani MORROW, 1934, P.199, p1.31, figs.214, Rotalipora turonica BROTZEN, 1942, P.32, t.figs.10,11(4). Globotruncana (Rotalipora) montsalvensis MORNOD, 1950, P.584. t.figs.4(1)17(1,2). Rotalipora aushmani (MORROW): LOEBLICH & TAPPAN, 1961, pp.297 -8, p1.8, figs.1-10, and synonymy. Rotalipora turonica BR• AN s aftainUIES, 1962, p1.79, fig.31. flp BROTZEN: PESSAGNO, 1967, pp.292-3, p1.51, figs.6-9, p1.1011 figs,5 -71 and synonymy. (MORROW): DOUGLAS, pp.173 -4, p1.1, figs.1,21 1969. Remarks: This species is one of the most conspicuous Foraminiferida in the British Upper Cenomanian. It appears in flood abundance above the planktonic/benthonic break in the middle 180
of the Cenomanian, but below that level in zones 9 and 10 a smaller variety very like the juvenilia stages of later adult specimens is seen at occasional levels. This earlier member of the series has smooth, inflated chambers and some specimens show only the slightest trace of a keel. In many ways this form resembles R.evaluta SIGAL and this may be the ancestral form of the present species. It may however be only an ecological feature, the morphology being in response to unfavourable conditions. The development of R.oushmani from R.evluta is postulated by BANDY (1967, t.fig.7) and although the level at which this occurs is at variance with that indicated by BANDY this general principle is adopted. R.oushmani could develop from a form of
R.evaluta by the reduction of the number of chambers in the final whorl from seven to five; the loss of the beaded sutures on the spiral side; the accentuation of the sutures on the umbilical side, and the development of more prominent, secondary, sutural apertures; and the loss of the large, umbilical shoulder.
In the Upper Cenomanian R.cushmani attains a large size at certain levels while at some horizons this one species can constitute up to 40% of the total foraminiferal population in the 60/30 size fraction. It is last seen in Bed 4 of the Plenus Marls and, as far as the author can discover, has not been recorded in strata proved younger than this. Occurrences Middle and Upper Cenomanian to Bed 4 of the
Plenus Earls succession.
Rotalipora evoluta SIGAL
Plate 17 Figs.l-3. 181
Rotalipora cushmani MORROW var. evoluta SIGAL, 1948, p.100, p1.1, fig.3, p1.2, fig.2. Rotalipora almadenensis CUSHMAN & TODD, 1948, p.98, p1.16, fig.24. cf. R.appenninica (0.R NZ) BOLLI, LOEBLICH & TAPPAN, 1957, p.41, p1.6, fig.5. Rotalipora evpluta SIGAL: LOEBLICH & TAPPAN, 1961, pp.298-9, p1.7, figs.1-4, and synonymy. Rotalipora evpluta SIGAL: PESSAGNO, 1967, pp.294 -5, p1.49, figs.12 - 14, p1.53, figs.6 -8, p1.98, fig.12. Remarks: This species differs from R.appenninica (O.RENZ) in being about one half as large and in having more angular chambers. It also has a more prominent, umbilical shoulder than any other species in this group. Rsevoluta Characterises the lowest part of the Lower Chalk (where it is never abundant) and gives the impression of being the ancestral stock for the rest of the species recorded in this country. PESSAGNO (1967) also suggests that R.evoluta is the oldest Cenomanian species - probably giving rise to R.appenninica, and then R.cushbani and R.Ateenhornensis. R.appenninica is not represented in this country and this species may or may not be an integral part of the evolutionary sequence. As already noted above R.evoll...ta does appear to give rise to R.cushmani in the upper part of the Lower Cenomanian. The position of R.greenhornensis in the sequence is discussed below. Occurrence: Lower Cenomanian chalk.
Rotalipora greenhornensis (MORROW) Plate 17 : Globorotaliafreenhornensia MORROW, 1934, P.199, p1.31, flea. Planulina greenhornensis (MORROW): CUSHMAN, 1940, 13.37, p1.7, fig.l. Rotalipora globotruncanoides SIGAL, 1948, p.100, pla, fig.4, p1.2, figs.3 -5. Thalmaninella brotzeni SIGAL, 1948, p.102, p1.1, fig.5, p1.2, figs.6-7. Globorotalia decorate CUSHMAN & TODD, 1948, 13.97, p1.16, fig.21. Thalmaninella greenhornensis (MORROW): BRONNIMANN & BROWN, 1956, p.535, p1.20, figs.?-9. 182
Rotalipora brotzeni BOLLIX LOEBLITi ac TAPPAN,. 1957: P.419 p1.9, Rotalipora greenhornensis (MORROW): LOEBLICH& TAPPAN, 1961, pp.299-301, p1.7, figs.5-10, and synonymy. Thalmaninella deecki (FROKE)1 JEFVERIES, 1962, p1.79, fig.32. Rotalipora greenhornensis (MORROW): PESSAGNO, 1967, pp.295-7f p1.50, fig.3, p1.51, figs.13-21, p1.101, figs.3-4, and synonymy. Rotalipora greenhornensis (MORROW): DOUGLAS, 1969, p.174, p1.1, fig.3. Remarks: According to BANDY (1967, text Fig.7(5)) this species ranges through the Middle and Upper Cenomanian and possibly into the basal Turonian. In this country it first appears in the Middle Cenomanian above the non- sequence and is last seen in Bed 2 of the Plenus Marls sequence. It is a highly ornamented form with raised, beaded sutures on both the spiral and umbilical sides. The chambers of the final whorl do not increase so rapidly in size as in other members of the genus. However, the marked umbilical shoulders, together with the raised sutures relate this form to R.evoluta and it is likely that R.peenhorneneis is an Upper Cenomanian derivative of this species. Occurrences Middle and Upper Cenomanian to Bed 2 of the Plenus Marls sequence.
Praeglobotruncana BERMUDEZ 1952 Type species: Globorotalia delrioensis PLUMMER 1931
Subgenus Praeglobotruncana BERMUDEZ 1952 (emended BANNER & BLOW 1959)
Praeglobotruncana (Praeglobotruncana) delrioensis (PLUMMET) Plate 17 : Globorotalia delrioensis PLUMMER, 1931y p.199, p1.13, fig.2. Praeglobotruncana delrioensis (PLUMMER): BERMUDEZ, 1952, p.52, p1.7, fig.l. 183
Praeglobotruncana delrioensis (PLUMMER): BOLLI, LOEBLICH & TAPPAN, 1957, p.39, p1.9, riga. It (PLUMMER): LOEBLICH & TAPPAN, 1961, PP.280-4, p1.6, figs.9-12, and synonymy. ft ( • hmr): KLAUS, 1960, p.793, p1.6, fig.la-c. (PLUMMER): KLAUS, 1960, pp.300-1, fig.la. ft (PLUMMER): PESSAGNO, 1967, pp.286-7, p1.52, figs.3-5, P1.100, fig:// and synonymy. Remarks: There is a full account of this species and its affinities in the remarks on P.W.stephani. Although not in alphabetical order the members of this present group are studied in their evolutionary order. P.W.delrioensis P.().marginaculeata E.(p).stenhani P.W.stephani v. turbinata followed by the other two formssi- P.(t).roddai P.W.helvetica
Praeglobotruncana (Praeglobotruncana) marginaculeata, LOEBLICH & TAPPAN
Globorotalia marginaculeata LOEBLICH & TAPPAN, 1946, p.257, P1.37t fig.19a-b, t.fig.4a(P.257). Praeglobotruncana marginaculeata (LOEBLICH & TAPPAN): KLAUS, 1960, pp.301-2, t.fig.lb-d, and synonymy.
Praeglobotruncana (Praeglobotruncana) stenhani (GANDOLFI) Plate 18 s Figs.4-6. Globotruncana astenhani GANDOLFI, 1942, p.130, p1.3, figs.4-5, p1.4, figs.36-37, 41-45, p1.6, figs.4,6, P1.9, figs.518, p1.13, fig.5, p1.14, fig.2. 184
Praeglobotruncana. stephani (GANDOLFI): BOLLI, LOEBLICH & TAPPAN, 1957, p.39, p1.9, fig.2. Praeglobotruncana stephani (GANDOLFI): LOEBLICH & TAPPAN, 1961, pp.284-90, p1.6, fige.1-8„ and synonymy. Praeglobotruncana stephani (GANDOLFI): PESSAGNO, 1967, p.287, p1.50, figs,9-11. Praeglobotruncana stephani (GANDOLFI): EICHER, 1966, p.28, p1.6, fig.4. Praeglobotruncana stephani (GANDOLFI): DOUGLAS, 1969, p.173, p1.2, fig.l. Remarks: The three species listed above have been discussed for many years and their validity has often been questioned. They are quoted as separate species in this account purely as a formality and it is hoped to show that in fact they could all be referred to P.W.delrioensis s.l. 15.(11.delrioensis has been variously confused with P.W.stephani in the literature and was in fact regarded as synonymous with it by BRONNIMANN&BROWN (1956, p.531), ZEIGLER (1957, p.199), and BANNER & BLOW (1959, p.8). LOEBLICH & TAPPAN (1961) claim that the two are quite distinot morphologically if one studies the type specimens. They .also claim that there is great variation within P.(),delrioensis and include P.() .marginaculeata within its synonymy. However in studying complete sequences of strata, sampled at close regular intervals, it appears that none of these species can be truly separated. It is true that the type specimens are distinct - hence the retention of the specific names - but it is also clear that one is dealing with a vast evolutionary plexus beginning with P.W.delrioensis. This has also been recognised by KLAUS (1960, pp.285-308) and after an extensive biometric study he showed almost conclusively that the three forms are in fact one diverse plexus. The overlap of characters makes accurate differentiation impossible. It is because of 185
this that the C.F.P. graphs show only the numbers of Praeglobotruncana spp. This evolutionary sequence is shown in fig.9, and this also includes the possible origin of the group. Though there is no direct evidence of this evolution in this country it is thought from general relationships that the most likely source (in the Albian) was P.(,delrioensis (GAMEY). E.(E).ptephani var. turbinate,: is also a recognisable variety when considering type material but this also falls onto the evolution sequence of KLAUS (1960).
Praeglobotruncana (Praeglobotruncana) stephani (GANDOLFI) var. turbinata REIWEL Plate 18 3 Figs.1 -9. Globotruncana stephani GANDOLFI var. turbinata REICHML, 1950, p.609. Remarks: Although falling within the Praeglobotruncana evolutionary sequence as outlined by KLAUS (1960) this variety has been separated off whenever possible. In most cases it can be recognised by the greater degree of ornamentation on the spiral side.
Praeglobotruncana (Praeglobotruncana) roddai (WIANOS & ZINGULA) Plate 18 s Figs.1-3. Globotruncana (Praeglobotruncana) renzi THALMANN & GANDOLFI var. primitiva. KUPPER, 19567-1713, p1.8, figs.2a-c. Globotrunca.najcuepperk THALMANN, 1959, p.130. Praefllobotruncana sp. vitaortatIES, 1962, p1.79, fig.33a-o. Globotruncana roddai MARIANOS & ZINGULA, 1966, p.340, p1.39, fig. 5a-c. Globotruncana kueTTeri THALMANN: MARIAM & ZINGULA, 1966, p.340, p1.39, fig•60ar-c, Praeglobotruncana roddai NARTANOS & ZINGULA): DOUGLAS, 1969, PP.171-2, p1.2, fig.2. U . AL SIAN L . CENOMANIAN U. CENOMANIAN TUR. F I G . _ _ _ _ R (H) delrioo nsis 9 E V OLU ( ),.'1::.::::delrloensis -:,...: :, ',:, .1
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Remarks: THALMANN (1959) raised this variety to specific level and claimed that it was an intermediate form between the Praeglobotrunoana and Globotruncana groups. Evidence suggests that this is in fact the case. It appears in the Upper Cenomanian and the basal Turonian as a member of the P.(2). delrioensis plexus. Unfortunately the stratigraphic range of this study does not allow the completion of this series but it is very likely that it does lead to some of the Globotruncana's. BANDY (1967) derives the Globotruncana group from the Rotalipora axpenninioa (0.RENZ) group, and while this may in part be true there is strong evidence to suggest a derivation from this present plexus. This is seen in the Upper Cenomanian by the thickening of the peripheral band to a point where in fact it divides into two distinct bands as recorded in this species. P.W.kuepperi was included in the synonymy of P.(E)sstephani by LOEBLICH & TAPPAN (1961). There is also the possibility that this is not the species indicated by THALMANN in his diagnosis and it seems likely that it should really be referred to P.W.hagni SCHEIBNEROVA. However until illustrations of this species can be examined these twin keeled forms are placed in the present species. Many transitional forms between this and P.(P).stephani occur in the region of the Plenus Marls as shown on Fig.9. The recent work of DOUGLAS (1969) has confirmed the earlier suggestion of LOEBLICH & TAPPAN (1961) that P.(20.kuepperi is in fact a deformed P.W istephani (after examination of the type specimens). Since this invalidates the name P.W.kuepperi the only other described species to which all these specimens can be referred is P.W.roddai. 188
Praeglobotruncana (,Praeglobotruncana) helvetica (BOLLI) Plate 19 : Figs.11 2. Globotruncana helvetica BOLLI, 1945, p.226, p1.9, figs.6-8, text fig.l (9-12). BOLLI: BOLL; 1957, p.56, p1.13, fig.l. " BOLLI: TRUJILLO, 1960, p.341, p1.50, fig.2a-c. BOLLI: MARIANOS & ZINGULA, 1966, p.340t p139, fig.2a-c. Praeglobotruncana helvetica (BOLLI): DOUGLAS, 1969, pp.169-70, p1.4, figs.4-5. Remarks: Although a Lower and Middle Turonian index species rare specimens have been found in the Upper Cenomanian„ they are not typical in their development but they are certainly referable to this species. Occurrence of the Praeglobotruncana group: This is largely summarised on Fig.9 but some further comments are included here. P.(0.delrioensis is the first and most important member of the plexus as it is from this species that all the later forms are derived. In the Middle Cenomanian the other forms like P.(E).stephani and P.().stephani var. turbinata begin to appear. It is only in the uppermost Cenomanian and the Plenus Marls where P.(,9.roddai amd P.W.helvetica are seen to occur - forerunners of the species later to become so abundant in the Turonian.
Praeglobotruncana BERMUDEZ 1952 Type species: Globorotalia delrioensis PLUMMER 1931
Subgenus Hedbergella BRONNIMANN & BROWN 1958 Type species: Anomalind lorneiana DIORBIGNY var. trochoidea GANDOLFI 1942 (emended BANNER & BLOW 1959) 189
This is a very involved group whose inter-relationships cannot be fully appreciated on the basis of so short a study. The present account records the species encountered - many for the first time in this country - and sets out a rough evolutionary sequence based on known species. No new species are listed because each species has been treated as an evolutionary group which could therefore include variations that would undoubtedly have been placed in new species had only spot samples been taken. Regularly taken samples through thick sequences of strata has enabled the author to appreciate the evolutionary trends within the subgenus. There are remarks after most of the species but a more complete summary will be found at the end of the section.
Praegiobotruncana (Hedbergella) amabilis LOEBLICH & TAPPAN Plate 19 a Figs .4-6. Globierina cretacea D'ORBIGNY: MOREMAN, 1927, p.100, p1.16, figs.14-15. D'ORBIGNY: BRONNIMANN, 1952, pp.14-161 t.fig.3a-m. Hedbergella amabilis LOEBLICH & TAPPAN, 1961, p.274, p1.3, figs.l-10. Clavihedbergella simplex LOEBLICH & TAPPAN, 1961, pp.279-80, p1.3, fig.11a-c, (not figs.12-140 Clavihedbergella,simple2s LOEBLICH & TAPPAN: AYALA, 1962, pp.25-6, p1.4, figs.2a-c,3a-c, (not la-0), p1.5, figs.la-c. Hedbergella amabilis LOEBLICH & TAPPAN: BENZ, LUTERB&CHER & SCHNEIDER, 1963, p.1084, P1.9, figs.4a-o,6a-c. Clavihedbergella simplex LOEBLICH & TAPPAN: TODD & LOW, 1964, PP.403-4, p1.1, fig.l. Hedbergella amabilis LOEBLICH & TAPPAN: PESSAGNO, 1967, pp.281-2, p1.52, figs.6-8. Hedbergella amabilis LOEBLICH & TAPPAN: DOUGLAS, 1969, p.165, p1.4, fig.8. Remarks: This species appears to be the forerunner - or a stunted variety - of Clavihedbergella BANNER & BLOW. p.(g). planispira TAPPAN has many more chambers in each whorl and the sutures are also much less constricted. The spire is very low 190
in most specimens and they appear almost flat. This fact separates it from the P.W.delrioensis (GARREY) and P.(0.infracretacea (GUESSNER) lineages. Occurrences Lower Cenomanian to Lower Turonian.
Praeglobotruncana (Hedbergella) cretacea (D'ORBIGNY) Plate 19 : Fig.3. Remarks: Globigerina cretacea D'ORBIGNY was initially described from the Senonian chalk of France and Britain and the author has been reluctant to use this name after the misuse that has been made of it up to the present day. However there is some justification for its use as it is hoped to outline in the following paragraphs. No attempt has been made at the deter- mination of a synonymy as this is a task beyond the scope of this present work. The references laid out shortly would enable such a synonymy to be compiled if this was desired. Globigerina cretacea D'CtBIGNY has variously been cite by many authors for any planktonic foraminifera seen in the Upper Cretaceous. The synonymy is vast and the species has been so misused that it is now virtually impossible to know what these workers were really referring to in their accounts. No attempt has been made at synthesising this synonymy but the most suitable point from which to commence such a work would be:-
BANNER & BLOW, 1960, pp.8-10. BANNER & BLOW, realising the confusion over this species, attempted to examine D'ORBIGNY's specimens in 1960. They found six specimens in one phial of which two were broken, three were covered in chalk, and only one was suitable as a type specimen. 191
This was then figured as a lectotype and redeeoribed. This description was very like that for P.(0.delrioensis but for the fact that the aperture possessed a porticus and the specimen in general displayed two weak widely spaced carinae. On this determination it was placed in Globotruncana by
BANNER & BLOW but this has never been satisfactory and PESSAGNO (1967) has now erected another new genus (Archaeglobigerina PESSAGNO) to contain this species. He claims that BANNER & BLOW's lectotype
is unfortunate as the chambers increase less rapidly than in the type figure of D'ORBIGNY. On this evidence he erects a new species, A.blowi PESSAGNO to cover specimens resembling D'ORBIGNY's figure and leaves forms referable to BANNER & BLOW's lectotype as A.cretacea (WORBIGNY). In fact he derives A.cretacea from A.blowi and even records the presence of many transitional forms. It is possible that this is the end of the lineage that begins in the Upper Cenomanian with the 'species' under discussion. The name 'cretacea' has been tentatively used to avoid burdening the literature with further names. The occurrence of some form of lineage from a form like P.W.infracretacea (GLAESSNER) through P.(2).delrioensis (=SET) to A.cretacea PESSAGNO would possibly account for the many references to 1G.cretacea, from all stratigraphic levels between the Albian and the Senonian. As the present account only covers the Albian and the Cenomanian
very little more can be said about the true taxomic position of this 'species'. HOFKER (1961) was troubled by the same feature and in his paper on the "Globigerina cretacea gene" he showed a similar evolution pattern to that which has been postulated here. 192
He included in his work a series of measurements which it is claimed substantiated the pure palaeontological deductions. Unfortunately at that time G.cretacea was not known to possess keels and his sequence ran from P.W.infracretacea through a form very like P.LH).delrioensis and on to the keel—less G.cretacea. Allowing for the fact that we now know that the end member did possess keels, this sequence could still hold in the manner outlined above. Occurrences Very rare in the uppermost Cenomanian chalk and the Plenus Marls sequence.
Praeglobotruncana (Hedbergella) delrioensis (CARSEY) Plate 19 Globigerina cretacea D'ORBIGNY var. delrioensis GARREY; 1926, p.43. . " " WORBIGNY: TAPPAN; 1940, p.121, p1.19, fig.11. " " D'ORBIGNY: TAPPAN, 1943, p.5121 p1.82, figs.16-174 gautierensis BRONNIMANN, 1952, p.11, p1.1, figs.1-3, t.fig.2. Globigerina delrioensis CARSEY: PRTMILL, 1954, p.127, p1.20, Praeglobotrunconana gautierensis (BRONNIMANN): BOLL', 1959, p.265, p1.21, figs.3-6. P (Hedbergella) delrioensis (GAMY): BANNER & BLOW, 1959, p.8. Hedbergella del=g-TaIRSEY): LOEBLICH & TAPPAN, 1961, p.275, p1.2, figs.11-13. (CARSEY): BUTT, 1966, pp.173-4, p1.2, figs.1-8. Rarks Included in this species are the large Hedbergella spp. with a moderate to low spire seen in the Albian and Cenomanian. There is in fact a range in this group from forms with an almost flat spire to those that have a high spire, which according to some authors may be placed in a distinct species. The variation, in the author's opinion, is continuous, and no real division can be drawn between the two groups. BUTT (1966) observed that in some specimens from the basal type Ttronian the later chambers have shifted somewhat towards the umbilicus, giving the specimen the 193
appearance of possessing a high spire. Although this plexus is difficult to separate into species two have been delimited and this present form covers all the low spired forms while the following group covers those with the markedly higher spires. Occurrence: Middle Albian to Lower Turonian.
Praeglobotruncana (Hedbergella) delrioensis (CARSEY) (High spired form) Plate 20 : Remarks: There are many examples in the literature where various workers have attempted to name this particular group of individuals. One of the attempts was that of WILLIAMS—MITCHELL (1948) who introduced the name of Globiperina portedownensis, after the PortedOwn Borehole in which it was first found. The type specimen of this species has been examined and this has shown that in fact it is not as high spired as originally understood. The specimen in the British Museum (Natural History) is no more than a normal P.(1).delrioensis. There is an added complication in that various workers have examined this specimen and some have come to the conclusion that it does possess two very faint keels — which would therefore place it in the species P.W.cretacea. The form illustrated by LOEBLICH&TAPPO (1961, p1.5, fig.3) is therefore not representative of the species and thus their determination of Hedbergella brittonensis (1961, pp.274-5, figs.1-8) would seem to be the best name for these high spired forms. Their illustrations of Hoortsdownensis and H.brittonensis are so similar that this comparison can be readily accepted. (BANDY (1967) also grouped these two species under the earlier name, 194
Goortsdownensis WILLIAMS-MITCHELL). LOEBLICH & TAPPAN's determination has not been followed in this present work and the species is retained as a high spired variant of P.(H).delrioensis. However as there are so many references to this form in the literature it was thought necessary to summarise these under the heading of the most likely determination of the species - namely P.(.brittonensis LOEBLICH &TAPPAN.
Globigerina bulloides D'ORBIGNY, CHAPMAN, 1896, p.587, p1.13, fig.4a-b. Globigerina cretacea D'ORBIGNY: MORROW, 1934, p.198, p1.30, figs.7-8110%-b. tt cf.G.cretacea D'ORBIGNY: APPLIN, 1955, p.196, p1.48, fige.23-24. ft sp. KUPPER, 1955, p.117, p1.18, fig.9a—c. Hedbergella brittonensis LOEBLICH & TAPPAN, 1961, pp.274-5, p1.4, fige.1-8. 11 portsdownensis LOEBLICH & TAPPAN (non WILLIAMS-MITCHELL): 1961, p.277, p1.5, fig.3. brittonensis LOEBLICH & TAPPAN: FUCHS, 1967, p.331, p1.18, fig.la-c. GlobiFerina portsdownensis (non WILLIAMS-MITCHELL): BANDY, 1967, p.8, t.fig.3(6). •
Occurrences Upper Albian to Lower Turonian.
Praeglobotruncana (Hedbergella) infracretacea (GLAESSNER) Plate 20 : Figs.4-6, Globigerina cretacea BURROWS, SHERBORN & BAILEY, (not D'ORBIGNY), 1890, p.561, p1.11, fig.18. Globigerina cretacea CHAPMAN, (not D'ORBIGNY), 1894, P•5 p1.13, figs.5-6. infracretacea GLAESSNER, 1937, p.28, t.fig.l. Praeglobotruncana infracretacea (GLAESSNER): BOLLI, 1959, p.266, p1.21, fige.9-10, (not p1.22, fig.1.) Globigerina infracretacea GLAESSNER: NEAGU, 1965, p.36, p1.10, fige.10-12. Hedbergella " GLAESSNER (emended), 1966, ppe179-83, p1,1, figs.1-3. 195
Hedbergella infracretacea GLAESSNER: FUCHS, 1967, p.331, p1.17, fig.13a-o. GLAESSNER: UGUZZONI & RAIBIZZOI, 1967, p.1226, p1.92, figs.70-0,8a-c. Remarks: This species has recently been emended by GLAESSNER and in this he notes the great variation both in the spire and in the position of the aperture. In 1961 LOEBLICH & TAPPAN regarded P.W.infracretacea as similar to P.(g).delrioensis differing only in being half the size and because of this they suggest that the two may in fact be synonymous. GLAESSNER has studied the type specimens and concluded that. P.(g).infracretacea oan be differentiated by the higher spire as well as the smaller size. P.().infracretacea is now regarded as a morphologically primitive member of the genus Hedbergella. Occurrence: Middle and Upper Albian.
Praeglobotruncana(Hedber/v1la) planispira (TAPPAN) Plate 19 : Figs.10-12. Globigerina planispira WEAN, 1940, p.122, p1.19, fig.12. Anomalina lorneiana D'ORBIGNY var. trochoidea GANDOLFI, 1942, p.98, p1.2, fig.1, p1.4, figs.2-3, p1.13, figs.2,5. Globigerina p.lobigerinelloides SUBBOTINA, 1949, P•32,131.2, figs.11 -16. Praeglobotrunoana planispira (TAPPAN): BOLLI, LOEBLICH & TAPPAN, 1957, P.401 p1.9, fig.3. Hedbergella trochoidea (GANDOLFI): BRONNIMANN & BROWN, 1958, p.16, fig.l. Praeglobotruncana planispira (TAPPAN): BOLLI, 1959, p.267, p1.22, figs.3-4. modesta BOLLI, 1959, p.267, p1.22, fig.2. Hedbergella planispira TAPPAN): LOEBLICH & TAPPAN, 1961, pp.267-8, p1.5, figs.4-111 and synonymy. Bedbergella trochoidea (GANDOLFI): LOEBLICH&TAPPAN, 1961, PP.277-8, p1.5, figs.1 -2, and synonymy. Hedbergella planispira (TAPPAN): PESSAGNO, 1967, Pp.283-4, p1.51, fig.1, p1.53, figs.1-4, and synonymy. Remarks: The size has always been quoted as the main difference between these species (planispira and trochoidea) but 196
this is not bourne out by the type descriptions. The diameter of P.LH).planispira is listed as 0.11 mm.- 0.26 mm. while that for P.W.trochoidea as 0.26 mm. - 0.39 mm. The division on a size range between 0.11 mm. and 0.39 mm. is purely artificial and in many ways, unjustified. The surface ornamentation varies with size from smooth to spinose and so is also unsuitable grounds for a separation. The size difference is not totally evolutionary and may be ecologically controlled. In the Lower Gault P.(g).olanispira is usually very small while some of the specimens encountered in the Upper Gault are very large. These, however, are only rare and the bulk Of the population remains very small. In the Lower Chalk they are again small but in the Plenus Marl a few extremely large specimens have been recorded. Occurrence: Middle and Upper Albian to Lower Turonian.
Praeglobotruncana (Hedbergella) washitensis (CARSEY) Plate 20 Figs.7-10. Globigerina washitensis CARSEY, 1926, p.44, p1.7, fig.10, p1.8, fig.2. Hedbergella washitensis (CARSEY): LOEBLICH & TAPPAN, 1961, p.278, p1.41 figs.9-11, and synonymy. Remarks: In the early growth stages this species appears to be a true Hedbergella but in more adult speoimens the final chambers encroach over the aperture and in fully developed specimens the aperture appears to be almost umbilical. The fine honey-comb ornamentation is unusual for this group and because of its very characteristic appearance this species is a useful indicator. As only a few specimens have been seen the inter-relationships between this species and P.Wshiltermanni LOEBLICH & TAPPAN have 197
not been determined, although it is thought that BANDY (1967) has oversimplified their evolutionary positions. Occurrence: In the south east of England this species can be found immediately below the non-sequence in most of the important sections, while in the south west it has been recorded from the uppermost Upper Greensand as well as from within the calcareous sand facies of the Upper Cenomanian. The total range is therefore from the Middle/Upper Albian to the Middle Cenomanian.
Evolutionary trends within Hedbergella spp, These trends and inter-relationships are shown in Fig.10. Basically there are four main groups based on the species described above:- 1. P.W.amabilis 2. P.(1a).washitensis 3. P.(g).planispira 4. P.(g).infracretacea
1, P,(g).amabilis Very little has been seen of the origin of this species but it is possible that it developed quite early from the flat spired P.().planispira plexus. There are also relationships with the Clavihedbergella spp. group which are not obvious at the present time.
2. P.().washitensis - As noted above very little can be said about the origins and development of this particular group of individuals.
3. P.(g).planispira - This species appears to have been derived from the P.W.infracretacea lineage at the beginning or very early in the Albian. Once developed in the basal U. AL ®IAN L. CEN'MANIAN U. CENOMAN1AN TUR. R
6 ?Clavihedbergella
.10 7 E P. CH). air's-bilis VO LUT v I
ON OF , --...,r...... P. (H). planispira T
HE P. (H.) delrioensi§
61 .„. ... P. (H), cretacea . * I ...------11: — .08I .. ., ... P. (H). infracreta ea P.(H). de ensis ( high spired farts I ...., .....
6ERI I i N ACEA
P. (H). washltensis 1 I 1 I i 199
Albian there was very little change in this group before the Senonian. The only variation recorded in this project, as noted earlier, is the increase in size at certain levels. This has been indicated in Fig.10, and although this is a simplification much more work is required before a more accurate account can be presented.
4. P.W.infracretacea — This is the major group represented in the Albian and Cenomanian of this country.
Members of this plexus are present in all the samples studied and in many oases they form a very large percentage of the total population. An account of this series is now presented beginning with the origin of the group. The basic form appears to originate in the Aptian and could possibly be Globigerina kugleri BOLLI as suggested by BAWDY (1967). However there is no evidence for this in the present survey and so this origin is omitted from Fig.10. Unfortunately BANDY (op. cit.) separated the Globigerina and Hedbersella lineages as he thought that G.portsdownensis, G.washitensis and G.hiltermanni were better placed in Globigerina. In the present work all these have been studied together because the author felt that there can be no valid separation. In this plexus there are two main trneds and it is suggested that they first began diverging in the Aptian or basal Albian. Whenever this occurred, one has at the base of the Gault Clay representatives of the P.W.delrioensis s.l. group and the P.03).infracretacea s.l. group. In the Lower Gault the latter is represented by many small high spired forms characterised by the overlapping of the final chamber over the umbilicus. 200
P.W.delrioensis is much rarer in the Gault and only a few specimens occur that possess the characteristic low spire. In the upper most Albian and Lower Cenomanian this latter form becomes increasingly abundant and in fact is the dominant plank— tonic foraminifer in many of the later samples. Throughout the Albian the specimens of P.(0.infracretacea tend to increase in size and in the Upper Albian it is very difficult to differentiate this species from the high spired forms of P.(H).delrioensis. GLAESSNER (1966) records p.(). infracretacea from the chalk but these are probably juvenille
specimens of P.W.delrioensis (high spire form), the transition between the two being so complete. During the same period of time P.W.delrioensis increased in prominence and some of the specimens began to attain a greater overall size. However these two 'species' are nothing more than the extremes of a complete sequence from the high spired to the low spired forms. Inter— mediates between them are very common and all the determini.tions are of necessity a little arbitrary. It is for this reason that the C.F.P. graphs show only the total percentage of Hedbergella spp. It is in the Upper Cenomanian, when both groups are at their maximum development, that variations from both these trends begin to appear. As in the whole of this sequence this varietal element affects both extremities of the plexus and it is because of this that we have the forms referable to:—
P.().delrioensis — P.().cretacea P.().delrioensis (high spire) (not named but is probably best represented by the 201
holotype specimen of G.portsdownensis WILLIAMS MITCHELL although as observed earlier this specimen is not so high spired as initially thought).
This development of the faint twin keels has already been mentioned in some detail, and its evolutionary significance has yet to be grasped. As the Plenus Marls are the upper limit of this present work these sequences cannot be followed any further up the succession although it is known that they do persist into the Lower Turonian. This is only a very brief account of this complex group but it is hoped that the basic principles outlined here can be expanded by further work. It must be emphasised again that the concept of a species within this group breaks down as species become impossible to define. However, 'palaeontologically incorrect' this may be the author wishes to demonstrate the futility of splitting these groups into innumerable new species. As -Vey are, these sequences can be used stratigraphically without the burden of a vast taxonomy, which would be inevitable if every worker erected his own artificial divisions for this complex evolving group.
Subfamily PLANOMALININAE BOLTZ, LOEBLICH & TAPPAN 1957
Planomalina LOEBLICH & TAPPAN 1946 Type species: Planomalina apsidostroba LOEBLICH & TAPPAN 1946
Subgenus GlobkEerinelloides CUSHMAN & TEN DAM 1948
Type species: Clobigerinelloides algeriana CUSHMAN & TEN DAM 1948 202
Planomalina (Globigerinelloides) caseyi BOLLI, LOEBLICH & TAPPAN 1957 Plate 20 s Pigs.11-13. not Anomalina eaglefordensis MOREMAN, 1927, p.99, p1.16, fig.9. not Planulina (MOREMAN): CUSHMAN, 1940, p.32, p1.6, figs.4 & 5. not " (MOREMAN)s CUSHMAN, 1946, p.156, p1.64, figs.8a-c19. Planomalina ,caseyi BOLLI, LOEBLICH & TAPPAN, 1957, p.24, p1.1, figs.4a-5b. Globigerinelloides eaglefordensis (MOREMAN): LOEBLICH & TAPPAN, 1961, p.268, p1.2, figs.3a-7b. f t (WRENS): AYALA, 1962, pp.15-16, p1.1, fig.2a-c, p1.6, figs.2a-b, 3a-b. If (MOREMAN): LOEBLICH & TAPPAN; (Treatise), 1964, pp.C657-8, fig.526(7a-b). I I caseyi (BOLLI, LOEBLICH & TAPPAN): LOW, 1964, pp.122-3. t " (BOLLI, LOEBLICH & TAPPAN): PESSAGNO, 1967, p.276, p1.49, figs.2-5. Remarks: PlanomalinaHoasevi BOLLI, LOEBLICH & TAPPAN was first described from the Gault Clay of Ariesey, England, its generic position being based on the presence of relict apertures. However it lacks the keel of the true Planomalina group and following the classification of BANNER & BLOW (1959) this species is now placed in the non carinate subgenus, Globigerinelloides. PESSAGNO (1967) confirmed the belief of LOW (1964) that Anomalina eaglefordensis MOREMAN was a benthonio species and because of this all the planktonic individuals referred to this species ought to be placed in P.W.casevi. Occurrence: Middle and Upper Albian, rare in the Cenomanian. There is a marked level in Bed XIII of the Gault Clay at which very abundant large specimens can be obtained.
Schackoina THALMANN 1932 Type species: Siderolina cenomana SCHACKO 1897 203
Subgenus Schackoina THALMANN 1932
Schaokoina (Schackoina) cenomana (SCHACKO) Plate 21 : Figs.1-2. Siderolina cenomana SCHACKO, 1897, p.166, p1.4, figs.3-5. •1 SCHACKO: EGGER, 1899, P.174, p1.21, fig.42. I, 1, SCUM: FRANKE, 1928, p.193, p1.18, figollap-c. Hantkenina " (SCRAM): CUSHMAN & WICKENDEN, 1930, p.40, p1.6, figs.4-6. le (Schackoina) cenomana (SCHACKO): THALMANN, 1932, p.288. Schackoina gandolfi REICHEL, 1947, P.397, t.fig.3a—g, 6(3), 7(3), 8a, 10(1,3,4,): p1.8, fig.l. Schackoina cenomana (SCHACKO): NOTE, 1951, p.74, p1.5, fig.9. Hastigerinoides rohri BRONNIMANN, 1952, p.55, t.fig.29, p1.1, figs.8-9. Schackoina gandolfi HEMEL: AUROUZE, & DE KLASZ, 1954, p.99, taiga°. cenomana SCHACKO MONTANARO & GALLITELLI, 1955, PP.143-4. It It SCHACKO BOLLI, LOEBLICH & TAPPAN, 1957, p.26, P1.2, figs.1-2. ....A __,_,i,__ gandolfi REICHEL: BOLLI, 1959, p.263, p1.20, figs.12-18. n cenomana (SCHACK0): LOEBLICH & TAPPAN, 1961, pp.270-1, p1.1, figs.2-7. ft ...... ft.— (SCHACK0): AYALA, 1962, pp.20-i, p1.2, figs. 2a-c,3a-c, p1.7, fig.3a-b, p1.8, fig.la-o. (SCHACKO): LOEBLICH & TAPPAN (Treatise); 1964, p.C658, fig.526,(8a-c,9). ft (SCHACKO): PESSAGNO, 1967, pp.279-80, p1.48, fig.6. Remarks: This species appears to be very rare but this may in part be due to the processing techniques. All the samples from the south-west of England were crushed under water - a method which may destroy most of the specimens of a species as fragile as this. However in the south-east of England where the chalk is softer and processing is thus less foroeful it was still extremely rare. Occurrence: Middle and Upper Cenomanian, to Lower Turonian.
Family GLOBOTRUNCANIDAE BROTZEN 1942
204
Globotruncana CUSHMAN 1927 Type species: Pulvinulina arca CUSHMAN 1926
Subgenus Globotruncana CUSHMAN 1927
Globotruncana (Globotruncana) linneiana linneiana (D'ORBIGNY) Plate 21 t Figs.3,4. Rbsalina linneiana D'ORBIGNY in DE LA SAGRA, 1839, p.110, p145, figs.10-12. Globotruncana lapparenti BROTZEN, 1936, p.175. linneiana (D'ORBIGNY): RENZ, 1936, p1.6, figs.32-34. D'ORBIGNY s GANDOLFI, 1942, pp.125 -130, p1.3, fig.3, p1.4, figs.18,32,33. lapparenti lapparenti BROTZEN: BOLLI, 1945, P.230, p1.9, fig.11, t.fig.1(15-16). 11 U " . BROTZEN: HAGN, 1953, p.96, p1.8, fig.12, t.fig.16,17. It // BROTZEN: HAGN & MIL, 1954, •••••••••••••••• •••••••111111.01110016
1430 3942 i p1.3, fig.3. linneiana linneiana (D'ORBIGNY): BARR, 1961, pp.571-, 572, p1.69, fig.7a-c, p1.72, fig.5. lapparenti BROTZEN lapparenti BROTZEN: JErratIES, 1962, p1.79, fig.30• linneiana linneiana (D'ORBIGNY): BANDY, 1967, p.19, t.fig.6(11). Remarks: Although only rare specimens have been encountered in the upper part of the Plenus Marls and the Lower Turonian they are almost certainly assignable to this variety. Occurrence: Upper Plenus Marls and Lower Turonian.
Superfamily ORBITOIDACEA SCHWAGER 1876 Family EPONIDIDLE HOFKER 1951
Eponides DE MONTFORT 1808 Type species: Nautilus repandus FITCHEL & MOLL 1798
"Eponides" sp. 20 sp. nov. 205
Plate 21 : Fig.5. Determination: Test free, trochospiral, slightly bi—convex; periphery angled; sutures curved on spiral side, radial on umbilical side; wall calcareous, finely perforate, radial bilamellar; aperture an interiomarginal arch; all whorls visible on the slightly domed spiral side; details of aperture obscured by bad preservation of this very small species. Remarks: Very small representatives of this typically
Turonian form are seen occasionally in the Lower Chalk. Occurrence: Upper Cenomanian and Plenus Marls.
Superfamily CASSIDULINACEA D'ORBIGNY 1839 Family PLEUROSTOMELLIDAE REUSS 1860 Subfamily PLEUROSTOMELLINAE REUSS 1860
Pleurostomella REUSS 1860 Type species: Dentalina subnodosa REUSS 1851
Pleurostomella barroisi BERTHELIN Plate 21 : Figs.6,7.
Pleurostomella barroisi BERTHELIN, 1880, p.30, p1.1, fig.13a—b. " BERTHELIN: LOEBLICH & TAPPAN, 1964 (Treatise), pp.C725-7, fig.5941 2a—b.
Remarks: This well developed species is recognised by the prominent hook over the aperture and is seen in the Upper Gault immediately below its junction with the Cenomanian.
Occurrence: Upper Albian clays and (?) Lower Cenomanian greensands. 206
Pleurostomella reussi BERTHELIN Plate 21 s Figs.8,9. Pleurostomella reussi BERTHELIN, 1880, p.28, p1.1, figs.lOa-b,11,12. tt obtusa BERTHELIN, 1880, p.29, plat fig.9a-b. t• alternans BURROWS, SHERBORN & BAILEY (not SCHWAGER), 1890, p.555, p1.8, fig.30. CHAPMAN (not SCHWAGER), 1892, p.758, p1.12, fig.14a-b. obtusa BERTHELIN: CHAPMAN, 1893, p.9, p1.12, fig. 13a-b. BERTHELINs EGGER, 1899, P.481 p1.16, fig.29. reussi BERTHELIN: TEN DAM, 1950, p.44, P1.2, fig.15. obtusa BERTHNLIN: NEAGU, 1965, p.29, p1.7, figs.29-32. reussi BERTHELIN: NEAGU,1965, p.30, p1.7, fige.27-28. of. obtusa BERTHELIN: UGUZZONI & BORMAN', 1967, P.1216, p1.90, fig.7. Pleurostomella of. reussi BERTHELINIUGUZZONI & RADRIZZANI, 1967, Pleurostomella reussi BER=Ig-IPUCHS, 1967, pp.332-3, p1,18, figs.516a-b. Remarks: The two main species listed in the synonymy have been shown to be no more than the megalospheric and microspheric generations of the same species. This being the case P.reussi takes Page priority over P.obtusa. Occurrences Middle and Upper Albian clays and sands, and Lower Cenomanian greensands.
Pleurostomella sp. 23 sp. nov. Plate 21 s Fige.10,11. Determinations Test free, small, elongate; chambers euneate, altering in position; sutures in early stages oblique, later becoming more nearly horizontal; wall calcareous, finely perforate; aperture terminal with projecting hood on one side, occasionally two small teeth are seen within the aperture; chambers in this species do not become uniserial; the rounded proloculus seems to suggest that only megalospheric forms have so far been found. Occurrences Lower Cenomanian to Lower Turonian. 207
Ellipsoidella HERON-ALLEN & EARLAND 1910 Type species: Ellipsoidella pl9urpstomelloidut HERON-ALLEN & EARLAND 1910
Ellipsoidella cf. austinana (CUSHMAN) Plate 21 : Figs. 12,13. Pleurostomella austinana CUSHMAN, 1933, p.64, p1.7, fig.13. Remarks: This form appears to be very close to E.pleurostomelloides HERON-ALLEN & EARLAND. Occurrence: Upper Albian to Lower Turonian.
Family NONIONIDAE SOULTZE 1854 Subfamily CHILOSTOMELLINAE BRADY 1881
Quadrimorphina. FINLAY 1939 Type species: Valvulina allomorphinoides REUSS 1860
QAadrimorphina cf. allomorphinoides (REUSS) Plate 22 : Figs.11 2. Valvulina allomorphinoides REUSS, 1860, p.223, plait fig.6. QuAdrimorphina allomorphinoides MUSS): FINLAY, 1939, p.325. Remarks: This small species is usually encountered in the Turonian and Senonian but primitive forms are found in the strata under consideration. Occurrences Middle and Upper Albian to the Plenus Marls.
Family OSANGULARIIDAE LOEBLICH & TAPPAN 1964
Globorotalites BROTZEN 1942 Type species: Globorotalia multisepta BROTZEN 1936 208
Globorotalites of. minuta GOEL Plate 22 : Figs.3,4. Globorotalites minuta GOEL, 1965, p.127, p1.8, fig.4a-c. Remarks: GOEL claims that typical forms of this species are restricted to the Middle Turonian but forms that are closely related to it can be found througout the Cenomanian in small numbers. This occurrence may be significant in that small forms are seen in the chert beds of south-east Devon. Occurrence: Lower Cenomanian chalk and greensands (including upper levels of Foxmauld sands), and up to the level of the Plenus Marls.
Gyroidinoides BROTZEN 1942 Type species: Rotalina nitida REUSS 1844
Gyroidinoides narva (KHAN) Plate 22 : Rotalia soldanii DIORBIGNT var. nitida REUSS: CHUM, 1898, pp.9-10, p1.2, fig.2a-c. Valvulineria parva KHAN, 1950, p.275, p1.2, figs.12-14,19. Gyroidinoides nitida (REUSS): JEFFEHIES, 1962, p1.79, fig.26a-c. Valvulineria,parva KHAN: JANNIN, 1967, pp.156-8, plat figs.1-5, p1.3, figs.1-3,6-9, p1.4, fig.l. Remarks: KHAN (1950) initially described this species from the Gault of Copt Point. It is a small form with 6 - 7 chambers in the final whorl. The dorsal side is slightly domed, while the ventral side is more so, giving the test an overall biconvex appearance. Throughout the Gault the size increases gradually and in the Cenomanian specimens may attain a diameter of 0.4mm. During this interval the number of chambers in the final whorl increases to an average of eight. 209
U.nitida (REUSS) s.s. is more highly domed ventrally and is not thought to be this British species. It must certainly be related to G.parva but REUSS' form is not normally seen below the Turonian. JANNIN (1967) has studied this group in great detail and has shown a complete sequence from forms attributable to Gyroidina loetterlei TAPPAN, through G.parva,and a new species (Valvulineria bethelini JANNIN), to a form beginning to resemble G.nitida.
Her sequence has been found to hold but it is felt that one name is all that is necessary and that oversplitting of the lineage is unnecessary. G.parva is retained as the Albian/Cenomanian species - although it is actually ancestor of the earlier described G.nitida. Occurrences Middle and Upper Albian to Lower Turonian.
Family ANOMALINIDAE CUSHMAN 1927 Subfamily ANOMALININAE CUSHMAN 1927
Biorostella gen. nov. Type speciess Biorostella sp. 1, sp. nov. Determination: Test free, nearly planispiral, with broadly
rounded periphery, both sides involute, with convex chamber elongations covering the central areas of both sides; prolongations of chambers bordered by a lip, in later chambers these elongated flaps cover those of the preceeding chambers; slit-like interio-
marginal aperture, usually obscured by the chamber outgrowths.
Biorostella sp. 1, sp. nov. 210
Plate 22 : Pigs,8,9,10. Determination: Test free, nearly planispiral, periphery slightly lobulate; both spiral and umbilical sides convex; chambers inflated on both sides, sutures appearing slightly depressed; commonly seven chambers in the final whorl; extended flaps on all chambers on both sides obscuring details of aperture; wall structure unknown as all specimens are recrystallised. Remarks: The validity of this species (and genus) is some— what doubtful as its appearance seems to coincide with that of sediments laid down during periods of disturbance, erosion, etc. It may prove eventually to be an ecopbenotype of Lingulogavelinella Alobosa (BROTZEN). Occurrence: Cenomanian chalk, and Plenus Marls. More abundant at levels like Zone 11a, and in the Glauconitic Marl of the Isle of Wight (Compton Bay).
Gavelinella BROTZEN 1942 Type species: Discorbina pertusa MARSSON 1878 Included in this genus are many species that are strati— graphically useful. Although the group is based on one lineage many others develop at intervals during the Albian and Cenomanian. Throughout these stages members of this group form a large percentage of the population in all size fractions. It is because of their numbers and diversity that it has been possible to determine a vague evolutionary sequence and although this is by no means a complete account it is a basic outline which further work could expand. A complete synopsis of this group is to be found after the account of G.rudis (REUSS). 211
Gavelinella baltica BROTZEN Plate 22 : Figs.11,12,13. Gavelinella baltica BROTZEN, 1942, p.50, p1.1, " BROTZEN: JEFFERIES, 1962, p1.78, fig.9a—c. Remarks: This species is very similar to Gtintermedia (BERTHELIN) from which it differs in the inflation of the last three chambers. Occurrence: Restricted to the Cenomanian.
Gavelinella cenomanica (BROTZEN) Plate 23 : Figs.1,21 3. Cibicidoides (Gibicides) cenomanica BROTZEN, 1942, p.54, p1.2, fig.2ar-d. Anomalina (Pseudovalvulineria) cenomanica (BROTZEN): var. cenomanica WASSILENKO 1954, p.87, p1.9, fig.2. Gavelinopsis cenomanica 11:ROTZEIli HOFKER, 1957, p.321, fig.370. It It BROTZEN 1 HILTERMANN & KOCH, 1962, p.318, p1.48, fig.l. 1, f, (BROTZEN): MICHAEL, 1966, p.436, p1.50, figs.16„17. Remarks: This differs from G.intermedia in the possession of a more or less marked rim round the edge of the umbilicus. There has been some confusion as to the generic position of this species, and this can in some ways be attributed to the initial description by BROTZEN. In his 1942 account he refers to the species as Cibicidoides (Cibicides) cenomanica on page 54, and then as Cibicides cenomanica in the plate explanation. HOFKER (1957) then placed this species in Gavelinopsis and his determination has been followed since that date. However an examination of the wall structure has shown that there is a double septal wall which is in agreement with the generic description of Gavelinella. G.cenomanica can be shown, by a series of transitional forms, to be developed from G.intermedia 212
in the uppermost Albian. It is because of the wall structure and also this close relationship with the rest of the Gavelinella group that BROTZEN's species is placed in the present genus. FUCHS (1967) records Gointermedia from the Albian of Holland but figures a specimen that shows a slight trace of an umbilical rim. It seems possible that this in fact is one of the trans- itional forms from G.intermedia to this species. Occurrence: Upper Albian to Bed 3 of the Plenus Marls succession.
Gavelinella intermedia (BERTHELIN) Plate 23 Fige.4,516. nAno Minna interMedia BERTHELIN, 1880, p.67, p1.4, fig.14a-b. ammonoides REUSS: CHAPMAN, 1898, p.3, p1.1, fig44. Gavelinella intermedia (BERTHELIN): MOMENT 1942, p.52, t.fig.18. (BERTHELIN): BARTENSTEIN, 1954, p.49, p1.1, figs.21-28. Anomalina (Anomalina) suturalis MJATLIUK: WASSILENKO, 1954, p.51, plat fig.l. hostaensis MOROSOWA: WASSILENKO, 1954, p.52, play fig.3. infracomplanata WATLIUK: WASSILENKO, 1954, P.53, p1.1, fig.4. Gavelinella intermedia (BERTHELIN): HOFKER, 1957, pp.285-6, taigs.336-7. (BERTHELIN): MOULLADE, 1960, p.138, p1.2, figs.15-17. flandrini MOULLAME, 1960, p.137, p1.2, figs.10-14. cf. barremiana BETTENSTAEDT: BARTENSTEIN & BETTENSTODT, 1962, p.289, p1.39, figs.9-10. Gavelinella intermedia (BERTHELIN): MAGI], 1965, p.32, p1.8, figs.l-2. (BERTHELINA) intermedia (BERTHELIN): MUM, 1965, pp.138-9, pls.l,2, and p1.5, including forms placed in G.reussi (KHAN). Remarks: BERTHELINIs specimens were from the Gault of Montcley but this species has been seen to range through both the Albian and the Cenomanian. It is a very variable form and in the upper most Gault gives rise to three of the other species listed here. 213
Occurrence: Middle Albian to Lower Turonian.
Gavelinella reussi (KHAN) Plate 23 : Figs.7,8,9.
Rosanna ,complanata, REUSS var* REUSS, 1863, p.86, p1.11, fig.3a-c. Anomalina complanata (REUSS)s BERTHELIN, 1880, p.66, p1.4,
figs.12-13. ft ft (REUSS): CHAPMAN, 1898, 04,3-4, p1.1, fig.4a-c. ft ammonoides (REUSS): CHAPMAN, 1898, pp.4-5, play fig.5a-o. complanata (REUSS): EICRENBERG, 1933, p.23, p1.2, fig.17. not berthelini KELLER, 1935, p.552, p1.2, figs.25,27. ft berthelini TEN DAM (nom. nov. for A.complanata BERTHELIN non REUSS), 1944, P.105. Anom:linaberthelini TEN DAM: THALMANN, 1947, p.391. TEN DAM: TEN DAM, 1950, pp.56-7,58,59161, p1.4, fig.9. " complanata REUSS var, reussi KHAN, 1950, p.2771 p1.2, figs.17,18. Gavelinopsis infracretacea HOFKER, 1957, pp.320-1. ft simionescui NEAGU, 1965, p.32, p1.8, Gavelinopsis berthelini (KELLER) MICHAEL, figs.18,19. Gavelinella intermedia (BERTHELIN) MICHAEL, 1966, p.432, p1.50, figs.10-13. Gavelinella berthelini (KELLER) FUCHS, 1967, p.336, p1.18, fig.8a-c. Remarks: There has been great confUsion about this species and the long discussion here is an attempt at sorting out the many references made to this form in the literature. BERthanit s specimens were from the Gault clay of France while those of TEN DO are from the Albian of Holland. KHAN's types are from the Gault of Folkestone and in his synonymy are references to mainly Albian occurrences. This species was first recorded as 11.complanata var." by REUSS. The second was that of BERTHELIN, who placed his Gault form in A.complanata REUSS 1851, a Senonian species, 214
which is fairly distinct from "Roomplanata vart". CHAPMAN in following BERTHELIN's description figured yet another form. KELLER (1935) realised that BERTHELIN's specimens were not the same as those described by REUSS (1851) as A.comolanata, and so he proposed a new name, A.berthelini, for BERTHELIN's specimens from the Albian. Unfortunately the specimen selected as a holo- type came from the Cenomanian, and while it is superficially similar, is in fact a later development of the same lineage. The identification A.berthelini KELLER cannot therefore be applied to the Albian forms with any certainty. In 1944 TEN DIM also noticed the initial nomenclatural mistakes and proposed a new name for BERTHELIN's specimens from the Gault. Unaware of KELLER's work he chose A.berthelini which was immediately an objective homonym of KELLER's species. Thus TEN DAM's attempt at reducing the confusion failed. KHAN (1950), unaware of both these attempts, also realised that CHAPRAN's figures did not resemble the figures given by REUSS in 1851 for A.complanata. He erected a new variety - A.complanats4 var. reussi - designating one of his own Gault specimens as a holotype. These have subsequently been shown to be immature specimens of the form erroneously identified by CHAPMAN and KHAN as R.ammonoides REUSS (as A.ammonoides (REUSS)) and identical with BERTHsLINIs A.complanata REUSS (= TEN DAM's invalid A.berthelini). Immaturity however is not grounds for invalidation of the name and as this is quite a distinct species KHAN's variety has been elevated to specific rank. In 1956 MAORIS showed that in the M.AlbianA.complanata REUSS: BERTHELIN and AL.intermedia BERTHELIN are in fact variants 215
of a single species. As "A.complanate" was not a valid name for these forms she placed them all in A.intermedia and erected a new subgenus, Berthelina, of Gavelinella. If these conclusions are correct then G.reussi (KHAN) may have to be degraded to a variety of G.intermedia (BERTHELIN). Occurrence: Middle and Upper Albian to Lower Turanian.
Gavelinella reussi (KHAN) var. A.
Plate 23 Fige.10,11,12. Determination; Test free, trochospiral, piano-convex, periphery slightly angled; only chambers of final whorl seen around umbilicus, large, calcareous, umbilical boss obscuring details of earlier whorls; wall calcareous perforate; aperture low interiomarginal slit. Remarks: The lineage beginning with G.reussi in the Gault is continuous through the Cenomanian. Separation into many varieties is possible but their delimitation would be difficult. One separation is proposed here and it is perhaps the most obvious. G.reussi is characterised by a central umbilical boss and while at the type levels there is a depression around this forms appear in the Cenomanian that have no depression. This sequence, running parallel to the group based on G.intermedia, persists throughout the Cenomanian and into the Turanian. Specimens included in this variety could possible be referred to KELLER's species of A.berthelini. In higher levels of the lineage forms appear that are very close to Cibicides voltziana (D'ORBIGNY) and it is possible that this Senomian species is the end member of this present lineage.
Occurrence: Upper Albian to Lower Turanian. 216
Gavelinella rudis (REUSS) Plate 23 : Fig.13. Anomalina rudis REUSS, 1863, p.87, p1.11, fig.7. " REUSS: BERTHELIN, 1880, p.68, p1.4, fig.15. " REUSS: CHAPMAN, 1898, p.5, plat fig.6. " REUSS: TEN DAM, 1950, p.56, p1.4, fig.8. Gavelinella rudis (REUSS): NEAGU, 1965, p.32, p1.8, fig.8. 0 " (REUSS): FUCHS, 1967, p.335, p1.19, Remarks: CHAPMAN records A.rudis as a separate species occurring in the Upper Gault. This has been followed by the later workers without exception. It appears however to be nothing more than transitional form between G.intermedia and G.baltica and should therefore not be regarded as a distinct species. MICHAEL (1966) records this species as a junior synonym of Rosalina ammonoides REUSS, and at the same time also suppresses Rosalina moniliformis REUSS. These two species however were described from the chalk while A.rudis is a Gault form. If A.rudis is sufficiently close to these species to warrant its suppression then it seems likely that R.ammonoides and. R.moniliformis could be senior synonyms of G.baltica — which would then be invalid. Occurrence: Middle and Upper Albian clays and sands.
Gavelinella tormarpensis BROTZEN Plate 24 : Figs.1,2,3. Gavelinella tormarpensis BROTZEN, 1942, p.52, p1.1, fig.6. BROTZEN: MAWR'S, 1965, p.148, p1.3,
Remarks: Most specimens of this species appear to be rather coarsely perforate and, unlike some of BROTZEN's type figures, have a deep distinct umbilicus. 217
Occurrence: Middle and Upper Albian clays and sands.
Evolutionary trends within Gavelinella In the basal Gault one finds two forms that are very closely related but which, above this level, appear to produce very different lineages (see Fig.11). G.reussi develops in the Upper Albian through a series of varieties to a form described here as G.reussi var. A. Between this species and its variety there is a whole spectrum of forms, all of which have been included in G.reussi 5.1. This plexus continues with little change into the Turonian and, as noted earlier, is probably the lineage that gives rise to the Senonian form, C.voltziana.
The other lineage begins with G.intermedia in the Albian which, in Bed 13 of the Copt Point sequence, gives rise to forms that have been described as G.rudis and Gaff. cenomanioa. These are restricted to the uppermost Albian and the basal Cenomanian and within a few feet of the base of the Cenomanian these species are totally referrable to G.baltica and G.cenomanica. It must be emphasised that this transition from one species to three species over the Albian/Cenomanian boundary occurs in all the sections studied, and including those like that at Compton Bay where this change occurs totally in the Upper Greensand facies. Gebaltica and G.cenomanicaaverestricted to the Cenomanian — both dying out in the Plenus Marl — while G.intermedia continues into the Turonian.
Lingulogavelinella MALAPRIS 1965 Type species: Lingulogavelinella albiensis MALAPRIS 1965 [ M. ALBIAN U. ALLMAN L . CENOMANIAN U. CENOMANIAN TUR F
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Lingulogavelinella albiensis MAL&PRIS Plate 24 : Figs.4,5,6. Lingulogavelinella albiensis MALLPRIS, 1965, p.140, p1.4, figs.5-8, P1.5. Remarks: The figures of MAL&PRIS (1965) suggest that in her French material the ventral surface is usually flat or concave. The British specimens, although undoubtedly the same species, have slightly convex ventral surfaoes but this is possibly due to the fact that her specimens are from lower levels than those encountered in this survey. Occurrence: Middle and Upper Albian clays and sands.
Lingulogavelinella globosa (BROTZEN) Plate 24 : Figs.7,8,9. Anomalinoidesd2bosa BROTZEN, 1945, p.58, p1.2, " BROTZEN: JmerPIRIES, 1962, p1.78, fig.19a-c. non Orostella turonica BUTT, 1966, p.180, p1.3, fig.6, p1.4, Remarks: For notes on the generic position of this species refer to the section following the synonymy of L.turonica (BUTT). Occurrence: Rare in Upper Cenomanian, continues up into the Turonian. Lingulogavelinella jarzevae (VASILENKO) Plate 24 s Figs.10,11,12. ?Cibieides formosa BROTZEN, 1945, P.55, p1.2, fig.3a-c. Cibicides (Cibicides) jarzevae VASILENKO, 1954, P.121, p1.17, fig.3a-c. Remarks: This distinctive form with a totally flat spiral side and strongly elevated umbilical side is seen only at certain levels in the Cenomanian succession. At these levels it is present in large numbers indicating what may be the optimum conditions for the species. These usually occur in the region of non-sequences, due to shallowing or even periods of
220
penecontemporaneous erosion. Occurrence: Lower Cenomanian chalk and greensand.
LinFulogavelinella cf, jarzevae (VASILENKO) Plate 24 s Fig.13. Remarks: This form is very closely related to the above species from which it differs in having no prominent keel on the final chambersi Apart from this there is no real discernable difference, the only other slight variation being in the height of elevation of the umbilical side. This particular form, while not occurring in the main part of the Cenomanian succession, occurs in the sandy facies at the margin of the basin where shallow conditions must have prevailed. Occurrence: Upper Cenomanian and Lower Turonian chalk, Upper Cenomanian calcareous sands facies of the south west of England.
Lingulogavelinella turonica (BUTT) Plate 25 s Figs.1,213. Anomalinoides globose BROTZENs Pa/AMU, 1954, p.268, t.fig.28. ” " BROTZENs WITWICKA 1958, p.228, p1.19, fig.38. Lingulogavelinella aff. frankei (BYKOVA)s MALAFRIS, 1965, Pp.140-2, p1.4, figs.1-4, p1.5. Orostella turonica BUTT, 1966, p.180, p1.3, fig.6, p1.4, fig.4. Remarks: Although very similar to L.globosa this species can be distinguished by the tightness of the spiral — resulting in the lack of a distinct umbilicus. The chambers, which are generally fewer in number, are also less inflated than in BROTZEN's species. Material from the type Turonian has shown that BUTT'S new species of 1966 is identical with that described as L.affefrankei 221
by MAWR'S. The genus erected by BUTT to cover this species (and L.globosa) has been seen to fall within the definition of Lingulogavelinella MALAPRIS and therefore Orostella BUTT (1966) has been suppressed as a junior synonym.
Occurrence: Lower Cenomanian chalk and greensand to the Plenus Marls.
Linguloavelinella sp. nov. Plate 25 : Figs.415,6. Pseudovalvulineria sp. .ThittITRIMS7 19627 p1.78, fig.15a-o. Determination: Test free, nearly planispiral, piano-convex, periphery angled; umbilical side almost flat, with only shallow umbilicus; interiomarginal aperture usually obscured by poor preservation; spiral side chambers more inflated and bearing the chamber elongations giving the star shaped pattern so character- istic of the group as a whole.
Remarks: This species is very similar to A.globosa but is sufficiently distinguishable to suggest that there are specific differences. The restricted occurrence of this species however indicates that it may be no more than an ecophenotypic variant of the basic L.turonica/L.globosa stock. Occurrence: Rarely seen in the uppermost Cenomanian chalk, abundant in the Bed 1 of the Plenus Marls sequence, being rare in Bed 2 immediately above.
Notes on the Lingulogavelinella group The evolutionary trends and distribution of this group are summarised in figure 12. In the British Albian (Gault Clay) 222 ct L.globosa
RELATED L . cf. jarzevae SEEN IN UPPERMOST CENOMANIAN , MAINLY IN THE ARENACEOUS FACIES OF SOUTH WEST ENGLAND
. jar zevae L. turonica
L. albiensts
FIG. 12 EVOLUTION OF LINGULOGAVELINELLA spp. 223
small forms of L.albiensis are abundant, and although the transition to L.turonica is by no means clear some intermediate forms are seen. At about this level L.jarzevas appears to be developed and this ecologically controlled species then appears at various levels throughout the Cenomanian. Above the mid- Cenomanian non-sequence the new genus Biorostella gen. nov. appears in some numbers although some earlier occurrences have been recorded. The final two species in the group both appear in the uppermost Cenomanian and while L.globosa continues in large numbers into the Turonian Lingulogavelinella sp. nov. only extends as far as the base of the Plenus Marl where it occurs abundantly in Bed 1. This species again, like L.jarzevae, appears to be a facies variant.
Superfamily ROBERTINACEA REUSS 1850 Family CERATOBULDIINIDAE CUSHMAN 1927 Subfamily hiJibTOMININAE WEDEKIND 1937
Epistomina TERQUEIM 1883 Type species: Epistomina regularis TERQUEM 1833
Epistomina spinulifera (REUSS) Plate 25 : Figs.7,8. Rotalia,spinulifera REUSS, 1862, p.93, figs.3a-5c. Epistomina spinulifera (REUSS): UHLIG, 1893, p.768, p1.7, figs.5-7. Pulvinulina,spinulifera (REUSS): CHAPMAN, 1896, p.9, p1.2, Rotaliapolypoides EICHENBERGI 1933, p.21, p1.3, fig.la-o. EPistomina,spinulifera MUSS): EICHENBERG, 1933a, p.192, p1.22, fig.la-d. Rotalia polzpoides EICHENBERG: EICHENBERG, 1933b, p1.3, figs.7-9, p1.4, figs.15-16. 224
(REUSS): TEN DAM, 1947, pp.28-29, figs.7a-c. ft It rEUSI: TEN DAM, 1948, p.170, p1.2, fig.5. Hrotzenla REUSS :HOFKER, 1954, pp.182-3,t.fig.9-12. REUSS : CORDEY, 1963, pp.655-656. Remarks: This easily recognisable species typifies one of the zones of the Albian. The ornamentation is very variable and using it one has an indication of any samples position within the zone. This, together with the restricted range, make it invaluable for sub-dividing the Gault Clay. Occurrence: This species first appears in Bed 1 of Copt Point; it is present in Bed's 2,5, & 6 with increasing ornamentation; in Bed's 7 & 8 if appears in flood abundance (very ornate forms); and finally moderately ornamented forms are encountered in the base of Bed 10.
Hoeglundina BROTZEN 1948 Type species: Rotalia elegans D'ORBIGNY 1826
Hoeglundina carpenteri (REUSS) Plate 25 s Figs.9,10. Rotalia carpenteri REUSS, 1862, p.94, p1.13, fig.6a-c. Pulvinulina carpenteri (REUSS): CHAPMAN, 1898, p.8, p1.1, fig.11a,c. Epistomina carpenteri (REUSS): TEN DU, 1948, p.165, p1.1, fig.4. ' (REUSS): TEN DAM, 1950, p.50, p1.4, fig.3. Hoeglundina oarpenteri (REUSS): HOFKER, 1954, pp.104-5, Epistomina carpenteri (REUSS): NEAGU, 1965, p.34, p1.9, figs.3-4. Remarks: This is a very variable species with a full range from those with a smooth test to those with a completely spinose test. Intermediate forms with small spines on the chamber faces of both the dorsal and ventral sides are more abundant in the Gault Clay. Occurrence: Middle and Upper Albian. 225
Hoeglundina chapmani (TEN DAM) Plate 25 : Figs.11,12. Rotalia elegans D'ORBIGNY: JONES & PARKER, 1860, p1.20, fig,46. Pulvinulina carcolla (ROEMER): CHAPMAN, 1898, p.7, plat fig.9. ft elegans rORBIGNis CHAPMAN, 1898, p.6, plat fig.8. Epistomina D'ORBIGNY EICHENBERG, 1933, p.22, p1.7, fig.l. chapmani TEN DAM, 1948, p.166, plat fig.5a-c. " TEN DAM: TEN Dom, 1950, p.453, P1.4, fig.6. Hiltermannia chapmani (TEN DAM): HOFKER, 1954. PP.191-931 t.fig. 27-32. Epistomina, chapmani (TEN DAM): NEAGUI 1965, P.341 p1.9, fig.5• Remarks: HOFKER (1954) separated Hiltermannia (Type species, H.chapmani (TEN DAM)) from Hoeglundina on the basis of the smaller internal partitions of the former. LOEBLICH & TAPPAN (1964, Treatise) suggest that the relative size of these features is worthy only of specific differentiation. This agrees with the work of CORDEY (1963) who for the same reasons rejects HOFKER's separation of Epistomina and Voorthuysenia. Occurrence: Middle and Upper Albian. 226
CHAPTER 6
Stratigraphic Summary
This summary is not intended to be a dogmatic attempt at a revision of British mid-Cretaceous stratigraphy. However many of the suggestions forwarded here are new and some — although described before — are re-•interpreted in the light of this present research. It must be stated at once that although the evidence for these theories is sound too few localities have been studied to make the acceptance of all these theories possible at the present time. In some regions (e.g. the Beer district of Devon) sufficient data is available to allow an almost certain correlation while over the south coast from Dorset to Kent far more data is required from intermediate sections to prove the worthiness of the present suggestions. However suggestions there are, and it is hoped that many will be of some use in future years when the progress of research may elaborate on the present studies. The enclosed sheets, with the suggested final correlations, display one important feature that has been described already in a previous chapter. After the work of JEFFPIRIES (1962, 1963) the author felt that here was possible proof of a moderately 'time limited' horizon. It is because of this that the main sections have all been plotted using the Plenus Marls as a datum and with this in mind it has been decided to begin with this horizon in this summary. These marl bands at the top of the Lower Chalk contain within them a complex series of erosion surfaces and/Or periods of marked non—deposition, However variable the succession may initially appear one cannot fail to be impressed by the lateral extent of 227
many of the constituent members. JBoratIES (1963) regards the A.plenue subzone as the uppermost member of the Lower Chalk sequence, but probably the lowest subzone of the I.labiatus zone of the Turonian (following WRIGHT & WRIGHT 1951), As one can appreciate from this statement it is not abundantly clear as to the exact stratigraphic position of this marl horizon. Litho- logically, and in many ways faunally, they appear (as suggested by JEFFERIES) to belong within the Lower Chalk and yet they are still placed as a subzone of the lowest Turonian. HANCOCK (discussion in atairERIES 1963) would prefer them to be a zone in their own right but he did not make it completely clear to which stage they should be assigned. This of course is only the latest attempt at resolving a problem begun by PHILIPS (1818, pp.46-47) when he first described the "bed of merle" at the base of Shakespeare Cliff, Dover. Since that time the matter has been discussed by HEBERT (1874, p.420), BARROIS (1876, pp.15, 154), PENNING & JUKES-BROWNE (1881), HILL&JUKES-MOWNE (1886), JUKES- BROWNE&HILL (1903, p.21), SPATH (1926) and in the last few years JLIeleZRIES (op. cit) and KENNEDY (1969, in press). On the continent there are three further usages of the Ni4slenus zone' and these are briefly described by JEVYNHIES. In the more central parts of the Anglo-Paris Basin the Menus Marls are fairly thick and usually display a series of eight separate beds, while towards the margins this pattern is somewhat modified as will be demonstrated shortly. JAWTUHIES showed, by way of a very hazy isopachyte map, that there are regional variations in this sequence and he suggests that the work of WOOLDRIDGE & LINTON (1938, pp.274-5) indicates that it reflects a Turonian other than 228
a Cenomanian pattern of deposition. In the discussion of the paper HANCOCK disagreed with this statement and his objections have been bourne out by this present research. The microfauna of this sequence is described in detail by JEbielItIES (1962) and this obviates the need for any lengthy repetition. For most practical purposes the following have been used with some success for the identification of the various horizons. 1. extinction of R.greenhornensis (MORROW) in bed 2. 2.abundance of Lingulogavelinella sp., sp. nov.0 in the vicinity of the bed 1 / bed 2 boundary.
3. extinction of R.cushmani (MORROW) in bed 4. 4. abundance of 114globosa (BROTZEN) and Praeglobotruncana spp. in beds 5 — 8. Although these are only brief extracts from the whole of JterEHIES/ data they are regarded by the author as being the most significant, and together with the C.F.P. graphs (especially in the south west of England) have facilitated all the neceosr.ry correlations. In most of the sections from the south east of England the correlation followed is that devised by JtabEHIES — which follows consistently with the present work. The most constant feature has been shown to be the abrupt disappearance of R.cushmani (MORROW) in Bed 4. This has immediate international implications in the light of BANDY's (1967) work on planktonic foraminiferal zonation. In this account he claims that for most large scale geological work the Cretaceous can be divided into three basic miorofaunal units. Upper Cretaceous — Globotruncana spp. fauna Middle Cretaceous Rotalipora spp. fauna 229
Lower Cretaceous — primitive globigerinid fauna In this scheme the Middle Cretaceous would be represented by the Cenomanian stage. This scheme, claims BANDY, agrees with the time scale developed by KULP (1961) which provides a division of the Cretaceous into roughly three 20,000,000 year periods. From this scheme it follows that the Cenomanian/Turonian boundary should be characterised by the disappearance of the Rotalipora spp. fauna. This agrees with the work of JErratIES as he records the extinction of Roushmani (MORROW) in Bed 4 of the Plenus Marls in every section he has studied. Although he does not mention this fact it is about this level where forms like P.(g).stephani (GANDOLPI), P.W.roddai (URIANOS & ZINGULA) and P.W.helvetica (BOLLI) become more abundant. Thus Bed 4 can be regarded as the best horizon at which to place the Cenomanian/Turonian boundary. This fact is well displayed in Enclosure 15 which shows the detailed correlations of the Cenomanian sections of south east Devon. Here one can se - clearly the normal pattern of events with the drop in the numbers of R cushmani (together with the extinction of R.Areenhornensis (MORROW)) followed almost immediately b a slight increase in the population before the final extinction. This pattern, as outlined above, can also be seen at Dover, Eastbourne, Culver Cliff, Compton Bay, Bincombe, Maiden Newton, and Buckland Newton as well as the sections described in such detail by JriersHIES. This fact coupled with the change in the benthonio fauna also seen at these levels in the disappearance of many typically Cenomanian forms (E.ruthenica (REUSS), Plectina sp. 21, sp. nov., Degradata (BERTHELIN), H.advena (CUSHMAN), L.turonica (BUTT), 230
G.baltica BROTZEN, and G.cenomanica (BROTZEN), etc.,) indicates that perhaps this is the best place at which to draw this major stratigraphic boundary. This agrees with many of the macrc:7q,unal observations and also provides the reason for the many years of bitter controversy as to the true stratigraphic position of this horizon.
This suggestion can be verified by CLARKE & VERDIER (1967) who have studied the microplankton assemblages from the chalk of the Isle of Wight. They have produced a final zonation scheme in which they tentatively suggest that the top of the Cenomanian (top of the Hystrichosnhaeridium huguonioti VALENSI zone) falls within the Plenus Marls sequence. Although the exact horizon of this faunal change is not known it is in such a position in their figure that it is in all certainty about the level of Bed 4. Six species become extinct at this level - a fact which must have prompted CLARKE & VERDIER into placing the Cenomaniannuronian boundary where they did, contrary to all previous stratigrdphic determinations. As indicated earlier the Plenus Marls, while remaining moderately constant within the more central areas of the Anglo- Paris Basin, do show some variation towards the margins. In the area under discussion one is able to follow the changes that occur as one approaches the presumed shoreline of the south west of England. The normal lithology is maintained as far as Maiden Newton and Buckland Newton but after this area of central Dorset the next exposure is that of Membury in Devon. As already mentioned this quarry has in many ways been a thorn in the side of many 231
stratigraphers and because of this it has been studied in some detail. The result of all the excavations has been to expose fully the beds described recently by KENNEDY (1969, in press). The basal surface of the excavations was the glauconitised upper surface of a bed of very hard calcareous sandstone. This contains abundant, heavily phosphatised Scaohites aeaualis (J. SOWERBY), which is characteristically seen in Division B of the Cenomanian limestone succession of the coastal sections. Resting on this surface there is a thin basement bed containing phosphatised pebbles, phosphatised Seaequalis SOWERBY), as well as a rich Middle Cenomanian phosphatised fauna and a green stained Lower Cenomanian ammonite fauna. These would all tend to indicate a variety of levels from the normal south eastern Cenomanian sections. It is this 'basement bed' that has been (erroneously?) correlated with the Lower Chalk Basement Bed of the Dorset Coast, thus suggesting that the chalk at Membury is the equivalent of some part of the Cenomanian (Lower Chalk) sequence. SMITH & DRUMMOND (1962, p.346) record a Schloenbachia sp. of Upper Cenomanian aspect from this seotion but KENNEDY (1969, in press and pers. com.) now believes that this is a Lower Turonian Watinoceras sp. The only macrofossils obtained from the chalk at Membury by the author are referable to Inoceramus labiatus (SCHLOTHEIM). Above this 'basement bed' are two to three feet of glauconitic chalk containing large quartz grains and small fragments of light brown phosphate. The microfauna from this glauconitic bed is comparable to that of the typical Plenus Marls sequence. The extinctions of ft.greenhornensis and Roushmani are 232
readily identifiable and the benthonic fauna also allows an immediate correlation with the changes in the fauna throughout the Plenus Marls. From this evidence it is clear that the forty five feet of chalk above this level is automatically referable to the Lower Turonian and samples studied from this section compare favourably with samples collected from the Type Turonian and also agree to a great extent with the work of BUTT (1966). Enclosure 15 shows the accurate correlation of the • Membury Plenus Marls section with the other sequences within the south western area. These diagrams show at once the value of detailed work in resolving major problems. The Pinnacles section of Division C of the Cenomanian Limestones (see Text plate 8), as noted earlier, has been sampled every three inches and one can immediately see the similarity of the resulting graph with the one produced for Membury. The Bovey Lane section, while still moderately accurate, appears to be slightly different but this is only a symptom of the greater sampling interval employed at the latter locality. The three sections, using the Bed numbers and the C.P.P. graphs, are readily compared indicating that Division C is completely referable to the Plenus Marls at all localities, whether in the limestone or in the glauconiticsand facies. The planktonic foraminiferida are not affected in any, way by these facies changes, and this fact will be put to good use in some of the later sections. As a result of these correlations all the sections of the Cenomanian Limestones can be plotted using the Bed 4 (Plenus Marls) datum, and thus one is therefore able to construct sections for 233
correlative purposes across the whole of southern England. Having now defined the datum level one is able to turn one's attention to the strata immediately below, in the main mass of the Lower Chalk. Enclosure 14 gives the C.F.P. graphs for the main sections of south east and south central England as well as the outline zonal schemes for some of the sections. There has already been some discussion as to the nature of these graphs and only brief comments will be added at the present time.
The main feature is the marked change in the population at the level of the mid-Cenomanian non-sequence. This change occurs immediately above a band of abundant Orbirhynchiapantelliana (J. SOWERBY) iescribed by KENNEDY (1969, in press). The marked change in the microfauna is also reflected in a complete change in the nature of the benthonic macrofauna and this appears to be the result of the change to a more pelagic type of deposition. The use of these graphs as well as the significance of the non- sequence, have already been discussed and only the stratigraphic implications will be mentioned at the present time. The faunal Changes associated with this non-sequence can be seen by studying any of the faunal distribution charts for Eastbourne, Culver Cliff and Compton Bay. The main features of this change are now outlined. 1. a change from less than 10% planktonic individuals to a figure which is usually more than 40%. 2. a general change from a P.W.delrioensisik.evoluta fauna to that of P.(19.stephani/R.cushmani,
3. a sudden reduction of the arenaceous benthonic fauna across the break. 234
4. the presence of P.(g).washitensis (CARSEY). immediately below the non—sequence -• as seen in the sections for Dover, Eastbourne, Culver Cliff, and Wilmington (?). As one can see from the main sections (Enclosure 14) the non—sequence does not maintain its position in the strata and in fact appears to cut across, as though it were an erosion surface. This is true and a study of the strata immediately underneath the surface indicates that it is in fact an erosion surface following a previously forted structure. The stratigraphic variation of its position is therefore a reflection of a period of folding in Middle Cenomanian times which apparently affected the whole of southern England. The sections of Dover, Eastbourne and Culver Cliff reflect the position of a downfold into a very broad syncline which is followed by a marked upfolding of the succession between Culver Cliff and Compton Bay. It is suggested that this upfold is even more pronounced between Compton Bay and Punfield Cove over the extension of the mid—Dorset Swell, which wheu produced south eastwards from Central Dorset would appear to pass between these two sections. The axes of all these folds are plotted on Pig.5, although most of these can only be positioned very approximately. Passing westwards from Swanage one can see (Enclosure 6) that there is a series of small folds evident along the Dorset coast but unfortunately most of these have been obscured by Alpine tectonics and there is very little in the way of visible field evidence. In the south west of England SMITH (1957, etc.) has described in detail the structures associated with the Cenomanian Limestones. In this work he has succeeded in plotting a whole 235
series of folds with the various periclinal axes as indicated in Fig.5. =RANCE 8:HAMBLIN (1969) have recently demonstrated by geophysical means that the Haldon Hills, near Exeter, are affected by folding along periclinal east west axes. They indicate that these may be the same feature recorded by SMITH near Beer and suggest that the folding is post- the deposition of the greensand and yet probably pre-Senonian. Although the evidence is slight the author believes that all these periods of known folding can be correlated into the one system by micro- palaeontological means. This being so one is afforded an explanation for a great many of the stratigraphic anomalies at present in our interpretation of these deposits. The presence of this non-sequence can be detected in the borehole at Liddington (Enclosure1) at approximately the same stratigraphic level as in the Culver Cliff section. Although the lithological description of the borehole is not as precise as would be liked it can be readily correlated with the old railway cutting between Chilton and Upton. Thisseqpience displays the full succession across the Totternhoe Stone which is seen, by this means, to correspond to the level of the non-sequence. Thus the Totternhoe Stone is in the same stratigraphic position as the O.mantelliana band in the south east of England, immediately below the marked change in the microfauna. The section at the Totternhoe Lime Kilns is in the same stratigraphic position and from this point the configuration of the non-sequence can be followed using any previous lithological descriptions. At Barrington therefore, described in detail by BURNABY (1962), the 236
'Burwell Rook (Totternhoe Stone) can be seen in its expected position dividing Zone 11 into divisions 11i and llii. The full correlation of this level into Yorkshire has not yet been attempted but even at Speeton the position of the non-sequence can be located using the equivalent horizon of the Totternhoe Stone. There now remains the task of assessing the configuration and the correlation of the strata above and below this major unconformity. This summary now begins in the following order:- 1. Post-folding deposits (Upper Cenomanian Chalk, Cenomanian sands and limestones) 2. Pre-folding deposits (Lower Cenomanian Chalk, Upper Greensand and the Gault Clay)
Section 1. The Post-Folding Deposits This sequence of strata includes /coma) zones liii, lla, and 13 as well as the Plenus Marls (already discussed in detail). It is immediately noticeable (Enolosure 14) that the thickness of the Plenus Marls is directly controlled by the configuration of the non-sequence. This is well shown at Eastbourne (20 ft.) and at the Pinnacles (5 ft. 6 ins.) where one is dealing with slight depressions of the non-sequence. However at Eastbourne the great thickness is made up largely of Bed 1, and by the time Bed 4 is attained most of the sections have been evened up to the previously described datum line. This variation in the thickness of the basal part of the Plenus Marls demonstrates how the deposition of these beds follows the pattern imposed upon it by the Cenomanian, and in many ways disagrees with the conclusions 237
of 4.wrieBRIES (1963). The palaeontological markers of these horizons are as follows:— Zone 13 — Abundant R.aushmani, P.W.delrioensis, P.W.stephani, with abundant Plectina sp. 21, Gavelinella app., and O.pleurostomelloides (FRANKE).
Zone lla — Abundant R.aushmani, P.W.delrioensis, P.(0.stephani, with Flourensina sp., Biorostella sp. 1, and the disappearance of P.cretosa.
Zone liii — Abundant Rtoushmani, P.01).delrioensist P.(0.stephani, with Plectina sp. 21, P.cretosa, and Gavelinella spp.
One can see by the uniformity of the zones in the south eastern sections that deposition was constant of the whole area, beginning to some extent in the lower parts of the troughs, as would normally be expected. On the swells however, deposition did not begin again until a much later time and at Buokland Newton (astride the Mid—Dorset Swell) sedimentation did not begin until Zone lla times. In the south west of England one does not have chalk deposition over the whole of the area after the non—sequence but instead one has a transition from a chalky to a limestone facies. The Basement Bed of the Dorset coast sections belongs to the base of Zone liii and this stratigraphio horizon can be traced from this area towards the south east of England. It is important 238
to observe at this point that to the west of the Mid-Dorset Swell the base of the chalk coincides with the non-sequence while to the east there is some (Lower Cenomanian) Lower Chalk below this level. This is summarised in Fig.l3. The Basement Bed of the Dorset Coast is suggested by WRIGHT (in MIMI 1947) as being of Middle Cenomanian age which agrees with the present Zone llii determination. Towards the south west the age for the commencement of deposition above the non-sequence becomes later and later, as outlined by KENNEDY (1969, in press). At Buckland Newton, as noted above, deposition did not begin until Zone 11a while the Divisions A and B of the Cenomanian Limestone succession indicate a Zone 13 age. This clearly requires a little more discussion as such an age determination is against all the evidence of SMITH (1957, etc.), DRUMMOND (1967, Thesis) and KENNEDY (1969, in press) as well as all the earlier accounts of authors like JUKES-BROWNE, MEYER, etc. This discussion of the age of these sections in south east Devon will therefore form a large section of this present chapter as it is in this area that, at present, accurate correlations are lacking. The disturbances of SMITH (1957, etc.) and KENNEDY (1969, in press) have always been regarded as transitional between the Albian and the Cenomanian and it is largely because of this that the deposits immediately above the non-sequence should be thought to be of Lower Cenomanian age. There are four important sections to be considered in some detail before one can attempt to produce an overall analysis of the situation. These are, in order, Chardstock, the Pinnacles, Bovey Lane and Wilmington. Membury DEVON DOVER BED 4 PLENUS MARLS
13 a
•••••• Ve.• ••••• +— ••••,••• ••••• •••I••• •••••• ••••• •••••• ••••m•••• lSl 1M. ••••• ei •••• ••• 11ii ...... ------• I • • nel Oil
•
• ••••• •.•••••••••• GAuLr CLAY
M. D. • CHEAT BEDS S WELL • .•. • FOXMOULO & U. GREENSAND .%;
MID-CENOMANIAN NON - SEQUENCE 240
also fits into this category but this has already been analysed in great detail and little more will be added to the previous comments.
Chardstock This succession of the Upper Greensand/A2 Limestone/Basement Bed/? Lower Chalk has been described in detail by KENNEDY (1969,
in press) and only the salient features of the microfauna need be
considered at the present time. The Upper Greensand and A2 have produced no microfauna although samples from both levels have been exhaustively studied. Pebble in the Basement Beds— Flourensina sp., which indicates a level in either lla or the basal part of 13. Basement Bed matrix:— abundant planktonic foraminiferida, including P.(1).stenhani with Flourensina sp. and Plectinq sp. 21 — indicating a Zone 13 age. Sandy chalk above the Basement Beds— abundant Zone 13 planktonic foraminiferida (including R.cushmani) with Plectina sp. 21, G.quadrans, A.preslii and G.pleurostomelloides — all of
Which indicate a high Zone 13 age. From this data one can immediately place the chalk matrix of the pebble bed accurately and this age agrees with the slightly younger age expected for the chalk immediately above. The phosphatised pebble (after dissolving in acid) indicates a Zone lla age which is itself very high in the Cenomanian succession.
The Pinnacles The succession of A2/B/C has already been illustrated and 241
described in some detail and the stratigraphic horizon of Division C has been determined beyond doubt as the equivalent of the Plenus Marls in the south eastern sections. Div. B:— abundant R.oushmani and R.greenhornensis with the rare planktonic species, S.cenomana (SCHACK0); also abundant are Lingulogavelinella sp., L.globosso L. cf. jarzevae and Buliminella sp. 21 and 22. Div. A2:— abundant R,aushmani, P.W.stephani and Plectina sp. 21. These two groups of individuals indicate, both by benthonic content and by the high percentage of planktonic individuals, that both these Divisions are referable to the higher levels (Zones lla — 13) of the Cenomanian.
Bovey Lane Sandpit The three Divisions A(?)/B/C are again represented in this section and although they all fall within the calcareous sand facies, and not the limestone facies (as at the Pinnacles) the faunas are almost identical. Div. C:— already correlated with Plenus Marls. Div. Bs— abundant R.cushmani (8% — 13%), P.(g).stephani (4% — 20V), and P.(.delrioensis in association with Aoreslii, Ltglobosa, Plectina sp. 21, and L. of. jarzevae. Div. As— abundant R.aushmani and occasional R.greenhornensis with A.cf.preslii, L. cf. jarzevae and G.pleurostomelloides. These faunal lists, as for those at the Pinnacles, indicate that the Divisions of the Cenomanian Limestones are at least partial equivalents of Zones lla and 13 of the south east of England. 242
FatiadaL(White Hart Sand it This major section is also in the calcareous sand facies and with its extension down to the Upper Greensand it is one of the most important sections in southern England. Limestone:— P.W.delrioensis, P.(2),,stenhani with Ltglobosa. Upper Calcareous sandst— P.().stenhani with L,globosa. Middle Calcareous sands:— moderate numbers of R.greenhornensis and P.(g),washitensis with occasional P.().helvetica in association with Biorostella sp. 1, A.preslii, L.cf,jarsevael and Buliminella sp. 21. Top Upper Greensand:— P.CH).washitensis. Laminated Upper Greensand:— 0.1enticularis (BLUMENBACH) The faunal assemblages associated with the various lithologies contained within this section are complex, although still readily explained, Considering firstly the main sequence of sands one finds a fauna very similar to the sands of Division B of the Bovey Lane section. The combination of the Upper Cenomanian benthonic species (Buliminella sp.21, Buliminella sp. 22, L.cf.jarzevae) with early forms of many Turonian species (tpreslii and P.().helvetica) indicate a high Zone 13 level. The presence of P4g).washitensis is somewhat discouraging as this form is only recorded from the Upper Albian to Lower Cenomanian in the south east of England. In all these more easterly sections (Dover, Eastbourne, Culver) the final appearance of the species (as noted earlier) is immediately below the mid—Cenomanian non-.sequence. However the forms present in these sands are not typical (see Plate 20, Fig.10) of the species as a whole and they are regarded as facies variants of 243
either the true P.W.washitensis or possibly another P,(Hedbergella). sp. stock. Their presence in this very littoral facies places some doubt as to the validity of P.W.washitensis as a species in its own right. If these forms described here are facies variants then perhaps there are similar controls operating in the overall distribution of P.W.washitensis s.l. (These comments may also apply to the closely related form P.(0.hiltermanni LOEBLICH & TAPPAN). These views are further enhanced by the other levels at which this species occurs. These are primarily the strata immediately- below the mid— Cenomanian non—sequence, and the few feet of clay immediately below a suspected non—sequence in the Upper Gault succession. This clearly requires further investigation but this restricted occurrence of the species enables its use in determining these horizons and its presence at Wilmington in the Upper Greensand (immediately below the non—sequence ?) allows — together with other evidence — a correlation with the main non—sequence of the south east of England. The occurrence of 0.1enticularis (BLUMENBACH) below this level agrees with its recorded occurrence a few feet below the
Cenomanian Limestones on the coast at Dunscombe.
Analysis of the south western area This section must of necessity be the resolution of an apparent conflict of dating between the macrofauna and the miorofauna. This matter has been discussed freely (see Acknowledgements) with many workers in this field and as yet there is no immediate solution. The author feels that at the present time there must 244
be a complete analysis of all the evidence at hand before any categoric statements can be forthcoming. The presently held views placed the Cenomanian Limestones and the Cenomanian sands as lateral equivalents of one another, of Lower Cenomanian age. This view is basically that of the early workers in the area who equated these limestones with the Glauconitic Marls of the south east of England. The correlations between the sections along the Devon coast — as well as inland to Bovey and Wilmington — are not in dispute and the author feels that in some ways he may have clarified previously inadequate correlations. Membury has now been satisfactorily explained and this once prbblematical section is now in accord with the regional synthesis. The reasons for the presently held correlative views are well documented in SUM (1957, etc.) and KENNEDY (1969, in press) and these accounts will not be repeated here. The basic objections and inadequacies will now be outlined. 1. The correlation of the Cenomanian Limestones with the lower part of the Lower Chalk is fraught with the difficulty of condensing 100 ft, of chalk into about 6 ft. (or less) of sandy limestone, 2. KENNEDY agrees with the basic correlations of SMITH while at the same time equating Division C with the Plenus Marls (approx.). This necessitates a break of some 10,000,000 years between Divisions B and C (if one follows the time scale of KULP 1961) which is certainly not bourne out by the field relationships. Text plate 8 illustrates this feature very clearly and it is apparent to any casual observer that although 245
there are breaks between each of the documented Divisions they are by no means of that magnitude. SMITH (1961, pp.303-332) has given a detailed account of the detrital mineralogy of the Cenomanian Limestones, of which the following is an abstract.
Div. C 92.0% 77.0% Div. B 92.0% 95.0% 83.0% Div, A2 92.0% 83.0% 81.0% Div. Al 89.0% 87.0% 81.0% W. of Little Humble Branscombe Beach Rocks (These figures are for the occurrence of detrital tourmaline)
These figures indicate the close similarity of these beds, and the difference between B and C is not sufficient enough to reflect the palaeogeographical changes that would surely be associated with a lapse of 10,000,000 years. The field observations indicate that the major break — if any — occurs at the base of the limestone sequence and not at these intermediate levels. 3. The fossils used in the dating of these deposits can be criticised in the following ways. A. Many of the well preserved specimens are impregnated with brown phosphate and for these initially limestone casts to have been phosphatised they must have been exhumed from their original place of deposition. B. Many of the fossils are 'green—coated', and this process of glauconitisation would require a similar exhumation as that indicated above. C. Some of the fossils, especially in the limestones, occur 246
in pebbles that often have phosphatised margins, although the fossil in the centre of the pebble may be unaffected. D. The fauna of the sandy facies is basically made up of long ranging forms with little, if any, stratigraphic value, although the abundance of H.subglobosus (LESKE) would seem to be more indicative of an Upper Cenomanian age. However ammonites are quite abundant and these have been used to demonstrate the age of the deposit but enquiry has indicated that their dating is by no means conclusive and it is basically a fauna of Lower Cenomanian
'aspect'. As already noted above there are peculiarities in the microfauna from this section and in fact the author has already mentioned the presence of one previously determined Lower Cenomanian species and it is tentatively suggested that perhaps the aspect of the fauna is somewhat controlled by this peculiar facies.
E. Most of the fossils collected by the author in the course of over three years work have not given any indication of the age of these deposits and in many of the recent papers on these areas lengthy reference is made to specimens collected many years ago — Some of which are thought to be from doubtfully identified horizons F. The most abundant ammonite in the limestone facies is S.equalia (3. SOWERHY) which usually occurs in a highly phosphatised condition. This species, although long ranging, is more abundant in the Middle and Upper Cenomanian and it is this abundance which again oasts doubts on the dating of this deposit. The above six points have received a great deal of attention in this present work and the author does not wish to question the determinations of these fossils nor their suggested occurrences. 247
The main query in the mind of even the casual observer is that of the overall depositional conditions. Most of the points raised above only cast doubts on the validity of the use of these ammonites as indicators of the age of the deposit, BROMLEY (1965, thesis) has demonstrated how ultra-violet radiation can be used for the detection of phosphate horizons in the chalk and this technique has been put to good use by the author. The Basement Bed of the Snowdon Hill Quarry, Chard was chosen as a standard reference as the fauna of this horizon is proved
(and accepted) as derived from Middle Cenomanian and Lower Cenomanian sources. Upon radiation in a dark room the phosphatised fossils and pebbles were seen to flouresce bright yellow while the calcareous matrix produced a deep purple flourescence. The former is largely due to the uranium absorbed by the phosphate while the latter is due to the presence of organic calcium carbonate. These standard colours were then used in the inspection of many samples from these south western deposits. The results of these investigations are now documented. a. all the brown stained fossils flouresced bright yellow indicating heavy phosphatisation. b. all the green stained fossils flouresced pale cream/yellow indicating some phosphatisation as well as the expected glauconitisation. c. all the brown stained pebbles (even those with unstained fossils) flouresced pale yellow indicating some effect of phosphatisation. d. some fossils, apparently free of any phosphatisation or pebbles were seen to be enclosed by phosphatised rims — often some 248
distance from the actual fossils, indicating that in fact they were only a part of a larger phosphatised unit. It is because of these investigations that the author has been able to inspect the fauna of the pebbles and the fauna of the matrix in some of the south western sections. This has necessitated the tedious removal of matrix from the outside of some pebbles but the evidence obtained from this labour has justified the time involved. At this point it is perhaps necessary to mention some of the objections that could be raised against these methods. Bioturba— tion is seen to be quite extensive in these deposits and care has to be taken to ensure that obviously reworked and burrowed material was not used in these analyses. EVen if one accepts intensive burrowing of material from Division C to Division B, there was already a hardground between Divisions B and A thus arresting the progress of this contaminating material. It is also unlikely that burrows in the top limestone of the Wilmington section could completely penetrate the limestone, and that they certainly could not, after that, penetrate up to thirty feet of calcareous sands. 4. All the previous correlations of the Cenomanian Limestones indicated that there was a period of disturbance at about the Albian/Cenomanian boundary but this has now been shown to be an invalid assumption. There is however strong evidence to suggest that this disturbance was in the Middle Cenomanian„ which would of necessity place all the later deposits in the Upper Cenomanian. These, then, are the main disagreements with the present correlations held by the majority of workers. The present synthesis can be dealt with rapidly as all the relevant descriptive work is contained in the above paragraphs or the 249
references quoted in the introduction to the study as a whole.
The mid—Cenomanian non—sequence can be traced from Dover across country to Buckland Newton and the Dorset coast from which it is only a short distance to the disturbances of SMITH (1957, etc.)* the fauna, as already documented, indicates an Upper Cenomanian age and the overall stratigraphic position of the sequence suggests that these limestones are no more than a condensed, arenaceous, version of Zone 13 of the more normal chalky sequence. Division C, equated as it is with the Plenus Marls, is present only above the depressions and is missing over the zones of uplift. This agrees with the thickenings and thinnings of the Plenus Marls already observed in the south east of England. The figures of the detrital minerals (SMITH 1961) show a general reduction towards the east, which would be expected if there was a west to east direction of transport. The troughs contain Division Al, which in many ways appears to be a basal conglomerate to the sequence, which would be formed of detritus worn off the swells and deposited in the depressions. The discussion of these folds is already complete but it is worth mentioning the Wilmington trough at this time. This is perhaps the largest feature of the coastal section and as shown in Enclosure 11 this is reflected in the thickness of the strata at the Pinnacles as well as the great thicknesses of sand seen further inland. This is probably one of the largest synforms, although not of course on the scale of the Mid—Dorset Swell, to which it is intimately related. It is hoped that this short explanation will suffice at the present time, and only when the beds below the non—sequence have been discussed in detail will the final appraisal of the stratigraphy be possible. 250
Section 2. The Pre—Folding Deposits Those sequences covered by this division are the lower part of the Lower Chalk of south east England, the Glauconitic Marl, the Upper Greensand (including the Chert Beds and the Foxmould Sands) and the Gault Clay. To save lengthy description of all these units there will be extensive reference to the Enclosures at the rear of the Thesis. These will obviate the need for tedious repetition of already well known sequences. The Glauconitic Marl, which forms the basal member of the Lower Chalk over most of southern England, occupying Zone 7 of the present scheme in the Dover section, displays a remarkably variable sequence of beds which have led to much confusion as regards their true stratigraphic interpretation. In the majority of works up to the present day it has been taken as a datum line, and even as late as 1961 TRE1SISE used the base of the chalk as a datum for all his correlations. It has already been demonstrated that the Basement Bed of south west England is a remarkably diachronous unit and it is not surprising therefore to find that this is also the case in the south east. In the four main sections covered by this research the Glauconitic Marl is found at the following levelss—
Compton Culver Eastb'ne Dover Bay Cliff Zone ...9 Zone ...8/9 Zone...9/10 Zone 7
The correlation of the chalk immediately above this bed is relatively simple as can be seen by the figures above. The bed is, in general, becoming older as one progresses eastwards — as one would expect after the example of the south west of England. 251
There is however a slight complication at Eastbourne which will be expanded in a later section. At Dover, as already stated, the base of the Glauconitic Marl is piped into the Gault Clay and at this locality this forms the boundary between the Aabian and the Cenomanian. The different characters associated with this transition are now documented (Enclosure 2):— Cenomanian:— appearance of the keeled planktonic foraminiferida (e.g. P.(E)Idelrioensis, R.evoluta) and many new species of agglutinated benthonic foraminiferida (e.g. P.cretosa, A.anglica, F.intermedio and G.quadrans). This level also shows the transition from L.albiensis to L turonica as well as the appearance of another related species, L..przevae. Albian:— final disappearance of A.chapmani (to H.advena) and A.sabulosa (to (?) F.intermedia). There is also a level of abundant G.caseyi immediately below the main faunal change.
This change in the fauna is well seen in the coastal section between Dover and Folkestone, as well as at the top of the Gault Succession of Copt PointtEast Wear Bay. An identical change is recorded between the Gault Clay and the Upper Greensand on the foreshore near Beachy Head, Eastbourne. This point is about thirty feet below the Glauconitic Marl, and the implications of this statement will be discussed in a later section. At Arlesey (Enclosure 5) the same faunal sequence can be observed — this time between the Gault Clay and the base of the Cambridge Greensand, The details of this correlation is quite amazing in that the G,caseyi recorded at Folkestone and Dover also occurs at a similar level below the Cambridge Greensand. This seems to suggest that the dating of the Cambridge Greensand could 252
be resolved by this reasoning and there now follows a more prolonged discussion about this stratum, For many years the Cambridge Greensand has become entrenched in the literature as one of the problems of the time, Various comments about the age have been forwarded during the course of the last century and it is worth discussing them in some detail. COWPER REED (1879) included with his descriptions of this bed a suggestion that it was a part of the S,varians zone — now basal
Cenomanian — but his work was criticised that it was only based on the evidence of the unconformity and not on the basis of any determinitive cephalopods. JUKES—BROWNE (1903) believed that this bed was the equivalent of the Glauconitic Marl horizon of the south east of England and he therefore included it within the S.varians zone. SPATH (1943) was of the opinion that this deposit was formed during S.dispar zone times, with the gradually rising sea floor leading to the erosion of the underlying A.substuderi and M.inflatum subzones — fossils from the latter forming the bulk of the fossils preserved within the bed. COOKSON & HICamS (1964) in their account of the microplankton from this horizon described the succession briefly and from the evidence of their work gave a brief account of the stratigraphy. Their views on this matter were coloured by their possession of three specimens (?) of Schloenbachia spp, from the greensand. SPATH had already discussed two of these (SPATS 1928, p.245) with some distrust. Their smaller specimen was identified by
A.G. Brighton as S.of.sUbplana (MANTELL) — found in the Barrington Cement works by N.F. Hughes in 1954. CASEY (in EDMONDS & =MN 1965) appeared doubtful as to its exact stratigraphic position, 253
but if it was in place, he discounts this as evidence of Cenomanian age, by noting the occurrence of Schloenbachia spp. from several localities on the continent of Upper Albian age. These are well documented by BREISTROFFEH (1936, pp.65-7; 1940, p.96; 1947, pp.63-6) who records the occurrence of Schloenbachia sp. nov. (varians group) with S.dispar (D'ORBIGNY) and. M.rostratus (J•SOwERBY) and many other dispar zone ammonites. This genus has also been recorded from the dispar-perinflatum subzone of the
Dorset coast (WRIGHT in ARKELL, 1947) but in this case the specimens are all reported from cracks in the surface of the Upper Greensand.
In his review of the Cambridge Greensand BREISTROWElt (1947) assigns this bed to the uppermost Albian which in terms of English stratigraphy implies the substuderi and dispar-perinflatum subzones. CASEY (in EDMONDS & DINHAM 1965) agrees with this assessment of the phosphatised fauna but allows for the fact that the deposit might finally have been laid down in Cenomanian times. He; in many ways, excuses this conclusion by adding that the suggestion is based on 'non-palaeontological grounds*. KEEN (in SYLVESTER-BRADLEY & FORD 1969) summarises some of the above contributions and concludes that until firm faunal evidence is available the presence of the unconformity and the gradation of the greensand into the chalk marl tends to support the view that the deposit is of basal Cenomanian age. The author feels that this evidence is now available and that the age of this deposit is basal Cenomanian, Zone 7. This is indicated by its overall stratigraphic position (outlined above) and a fauna of F.intermedia, H.advena, S.annectens, U.moesiana,
0.calcarata, and E.austinana •- none of which occur below the 254
Cenomanianv as well as abundant specimens of M.ozawail G.intermediav G.cenomanica and 'D.allomorphinoidest, which also indicate a Cenomanian age.
Having now considered the change in the fauna from an Albian to a Cenomanian aspect at three localities (one of which still remains to be discussed in detail) it is necessary to mention two other sections where the Albian/Cenomanian boundary can be located. The section at Compton Bay (Enclosure 4) displays a full succession of the Lower Chalk, Upper Greensand and the Gault Clay but even
sot the Albian/Cenomanian boundary has been found difficult to localise. None of the usual zonal indicators (Zones 7 & 8) are present in this section and many of the minor changes associated with this level occur at various horizons within this sequence. The boundary is therefore so diffuse that it cannot be placed exactly. The first changes appear thirty feet below the top of the Upper Greensand with the development of large specimens of Vaginulina sp. 36. This species is recorded from many Upper Albian sequences where the trend from short to elongate forms (shown in Plate 13, Figs.l&2) can be followed up through the succession. The larger forms are usually found immediately below the Cenomanian but in this case the overlying fauna (with F.intermedia) is not developed. A.chapmani shows transitional forms with H.advena at about this level and occasional specimens of L.jarzevae are seen. In the higher levels of the Upper Greensand forms of ,k.sabulosa very close to F.intermedia occur but true specimens of the latter species do not occur. In the Lower Chalk the zones continue as in the normal sequence with the chalk immediately above the Upper Greensand belonging to Zone 9. There is no available ammonite evidence for these levels and the 255
author suggests that the upper twenty to thirty feet of the Upper Greensand could be of Cenomanian age, although the evidence is by no means clear* This view is supported by the situations at Eastbourne and Betchworth (Surrey). Eastbourne (as already indicated) displays the Albian/ Cenomanian boundary at the junction between the Gault Clay and the Upper Greensand, which places the thirty feet of Upper Greensand at this locality within the Cenomanian. The faunal evidence for this is quite substantial (Enclosure 2) and there is no contra— dictory macrofossil evidence. The sections at Betchworth have been studied by Al—KASSAB (1968, thesis), BIGG (1968, thesis), CANN (1968, thesis), DIVER (1968, thesis) and JAWORSKI (1968, thesis), and their results indicate a situation very similar to that at Compton Bay and in some ways, Eastbourne. The Glauconitic Marl occurs in Zones 8/9 which leaves Zones 7/8 in the Upper Greensand facies. There has been some dispute at this deter— mination as the Geological Survey have produced a detailed account of their borehole at Fetcham Mill (GRAY et al. 1965) which is only a few miles away from the Betchworth quarries. The appropriate data from this log is summarised below.
Plenus Marls 643' 9" — 646' 5" Lower Chalk 646' 5" — 836' 0" Glauc. Marl 836' 0" — 841' 11" Up. Gsnd 841' 11" — 894' 3" Gault Clay 894' 3" onwards.
The succession of the Plenus Marls and the Lower Chalk is seen to correlate precisely with the work of DIVER (1968, thesis) and the thickness of the Glauconitic Marl is almost the same as that recorded by JAWORSKI (1968, thesis). The zonal position of this marl 256
has already been stated above but there is really no objection to this dating when the Fetcham Mill log is studied in detail. CASEY (in GRAY et al,, 1965, Appendix B, pp.105) states that the first identifiable ammonite of Albian age is Pleurohoplites of. subvarians SPATH at a depth of 883' 1" (with Lephoplites cf. pseudoplanus SPAM at 883' 2" and Callihoplites cf. tetragonus (SEEDY) at 895' 2"). This fauna appears to belong to the dispar zone, although not he comments, from the higher dispar- perinflatum subzone, but rather from the lower substuderi subzone. This suggests (to cASEY) that the top of the Albian is immediately below the last Schloenbachia sp. - at 840' 11". This data is summarised in Fig.14, -which contains the Eastbourne section for comparison. The sample from 754' 0" contained a fauna with Plectina sp. 21 and abundant planktonic foraminiferida which indicated an age of Zone liii on the present sequence. The 'Orbirhynchia band' - and hence the mid-Cenomanian non-sequence - has been located by the Geological Survey at 779' 0" to 783' 0". The sample from 834' 0" - 835' 0" has been inspected by the author, and the fauna from this basal Lower Chalk sample indicates without doubt a Zone 9 stratigraphic level. This is based on the occurrence of N.ozawai, P.ruthenica, Marssonella sp. 21, P.cretosal A.anglical H.adVena, A.courta, S.jarvisi, G.baltica, D.gradata, S.rectangularis, Gaudryina sp. 25, L.turonica, 2.antictua, L.gaultina f. rotulata, Pt2).delrioensis and P.().delrioensis and many other typically Cenomanian species. Sample 854' 0" - 855' 0" contains a transitional fauna between A.chapmani and H.advena and this suggests a proximity to the true Albian/Cenomanian boundary. If the boundary was drawn here - approximately 14' below the Glauconitic Marl there is no contradiction between the evidence 257
FETCHAM MILL
EASTBOURNE
B ETC HWORTH
10 10
- 836i 0" GLAUCONITIC MARL 9 841' 11" last recorded 9 8 Schloenbachia sp.
No identifiable cephalopods.
Lammelibranch fauna is virtually the same as that found in the basal part of the chalk.
CENOMANIAN 7 AL B/AN 6
883' 1" Pleurohoplites cf. subvarians SPA TH 883' Lephoplites cf pseudoplanus 894' 3" SPA TH 895' 2" Callihoplites cf. tetragenus (SEELEY)
FIG 14. FETCHAM MILL BOREHOLE 258
forwarded here and the evidence of CASEY (in GRAY, et al., 1965). This also allows 28' of Upper Greensand for the dispar-perinflatum subzone - which does not seem unreasonable to the author. The succession of Beachy Head is also included on Fig.14. for comparison and one can see at once the relationships between the two sections, In both sequences there is a substantial amount of Cenomanian Upper Greensand. The author hopes that this correlation of the macro. and micropalaeontologioal data will provide a basis for the future understanding of this apparent annomaly. The conclusion that one is forced to accept from all this is the fact that there is definitely some evidence for a part of the Upper Greensand being of Lower Cenomanian age. This position bears a close similarity to JUKES-BROWNE's (1896) objections to the theories of BARROIS (1876) which insisted that the Albian/Cenomanian boundary was in fact contained within the Upper Greensand sequence, There is another way in which these conclusions can be tested and this has been attempted using the sections of the Gault Clay at Folkestone (Enclosure 5) and Compton Bay (Enclosure 4). The zonal scheme developed for the Gault Clay at Folkestone can be identified in the Compton Bay section although Zone 4 cannot be located. This is due to the arenaceous nature of the clay in the lower part of the sequence. Zones 5 (.chapmani & C.pinnaeformis)and 6 (A.chapmani & A.sabulosa) can be recognised and this correlation indicates quite clearly the diachronous nature of the Gault and the Upper Greensand. At Compton Bay Zone 5 occurs astride the Passage Beds with no change in the fauna recognisable, even though there is a complete change in the 259
overall facies. Zone 6 continues up into the upper levels of the Upper Greensand, only to petre out into a Cenomanian fauna during the last thirty feet below the Glauconitic Marl. One is therefore left with the conclusion that of the 130' of Upper Greensand at Compton Bay 100' should probably be assigned to the Albian while about 301 may be referable to the Cenomanian. Intermediate sections of the Gault Clay at Buckland (Surrey) and Small Dole (Sussex) have confirmed the westward continuence of the Gault Clay zones from the Folkestone area and the author has no hesitation in accepting the evidence as outlined above.
This loss of the lower zones of the Gault Clay westwards is due to increasing amounts of arenaceous material coming in as a westward increasing wedge at the base of the clay unit. This is only to be expected as the Middle Albian sea must have been advancing westwards at this time, actively eroding the Jurassic and Triassic deposits of south west England. It is now hoped to follow this clay/sand unit westwards with a view to completing this survey of the pre-folding successions. Between Compton Bay and Punfield Cove there is a drastic change in the appearance of these deposits as these two sections are on the opposite flanks of the Mid-Dorset Swell. The sections of the Dorset Coast (Enclosures 6 & 14) are complicated by the structure imposed on that area at a later date and the determination of the depositional features is rendered more complicated. One of the most interesting features of the Lulworth section is the 'ammonite bed' which contains a large fauna of Upper Albian ammonites - all in an abraded and phosphatised condition. This precise level with its microfauna 260
of li.advena, Lejarzevae, S.allomorphinoides and P.trochiformis is of Lower Cenomanian age although an exact zonal determination is impossible. Samples from above this level - still in the Upper Greensand facies - also indicate a Lower Cenomanian age. Those samples from the base of the chalk, as at Durdle Door, indicate an Upper Cenomanian age for the beds above the non- sequence. The correlation problems involved with these determinations are illUstrated in Enclosure 14 which shows the position of these sections with respect to the Mid-Dorset Swell.
On the east side of the Swell there is direct evidence that some of the upperthost Greensand is of Cenomanian age, while on the western flank of the same structure there is yet more evidence to suggest a Cenomanian age for this part of the green- sand sequence. The lithological correlations produced for the Upper Greensand of the Dorset Coast demonstrate a thickening of the Upper Greensand, as though the various horizons were coming out in seqUence from below the non-sequence. One would er4pect therefore, that this would begin with Zones 7/8/9, and only in the more westerly regions would higher zones appear. This pattern can be detected between the swell and the sections at Compton Bay and Culver Cliff. All the zones between these last two localities are angled up in such a way that Zone lli has almost disappeared under the erosion surface of the non-sequence in the Compton Bay section. This is shown on Enclosure 14. DRUMMOND (1967, thesis) outlines a similar feature when studying the ammonite faunas and he suggests that in mid-Dorset the non-sequence is resting directly on aequatorialis subzone greensands. This feature has been confirmed by the present 261
research and the vast amount of erosion that must have accompanied this uplift gives a ready explanation as to the source of the abundant phosphatised Upper Albian and Lower Cenomanian ammonites found along the Dorset and Devon coast and also in the Glauconitic Marl of the Compton Bay section. An accurate study of the position of all these 'faunas' would probably indicate that move— ment on the swell was initiated quite early in the Cenomanian and was only terminated in the Middle Cenomanian. This work has not been possible at the present time but the data which is now available may be sufficient to produce an outline of the timing of these movements. The details of the flanks of the swell can also be seen in some of the inland sections of Dorset, the sections at Buokland Newton, Stoke Wake, Mere and Maiden Bradley demonstrating this feature remarkably well. The base of the chalk at Buokland Newton belongs to zone lla and this indicates the time at which deposition was restarted on the crest of the swell — which would be the last place for this to occur, Stoke Wake (Enclosure 8) shows a similar section above the top of the Upper Greensand but at this locality the non—sequence lies above the base of the chalk sequence. At Mere (Enclosure 8) the succession is again very similar, with Zone 10 Lower Cenomanian chalk being present just above the contact with the Upper Greensand. The section at Maiden Bradley (Enclosure 8) shows Zone lli (basal) chalk only four feet above the cornstones at the top of the Upper Greensand and while this observation fits in with the overall regional pattern being suggested here there are obviously some local variations (at Mere and Maiden Bradley) which the present work has not been able to resolve in any detail. 262
Following the pre—folding strata westwards from the crest of the swell one finds that the succession provides yet another complication in the appearance of the Eggardon Grit. The chalk immediately above this belongs to Zones 11a/13 (above the non— sequence) but the bed itself (with a fauna of S.oanyracea, L.jarzevael etc.) appears to be that associated with Zones 8/9. The greensand with doggers immediately below the grit has also provided an indication of a Zone 8/9 fauna. Many workers, notably DRUMMOND (1967, thesis), have suggested the equation of the
Eggardon Grit with the Al Limestone of the coastal sections. This is clearly not possible in the present scheme as one occurs above, and the other below, the level of the mid—Oenomanian non— sequence. The Upper Greensand succession developing below the chalk along the Dorset coast (Enclosure 12) is readily correlated (lithologically) with the succession seen in south west Dorset and southern Devon. The succession at Branscombe and Beer (tclosuie 12) can be taken as typical of the area and illustrates the basic separation of the Foxmould Sands and the overlying Chert Beds. The Gault Clay is only represented at Branscombe by a thin succession of blue/green sands resting on an irregular Triassic surface. KITCHIN & PRINGLE (1922) suggested that no Lower Gault ammonites were present in any of the south western successions and SPATH (1923-1943) agrees with these conclusions. In his opinion the oldest identifiable horizon is that of the varicosum/orbignyi. subzones. The Foxinould sands have yielded a small microfauna with Upper Albian affinities. Vaginulina sp. 36 appears in 263
these levels and is seen to develop the same characteristics observed in the Compton Bay sequence. This species is not seen in the overlying Chert Beds where the fauna takes on a very non—descript appearance, although a few specimens of Globorotalites minuta may indicate a Cenomanian age. This evidence is not totally reliable and the extinction of Vaginulina sp. 36 just below the Chert beds is of dubious value. There is however another line of attack to this problem of the Foxmould/Chert Bed relationships. SMITH (1962), in his heavy mineral analysis of the south west of England Cretaceous, also studied the Upper Greensand and some of his figures may have a bearing on the present discussion.
Branscombe Little Humble Beach Rocks
Div, C 92.0% 77.0%
Div, B 92.0% 95.0% 83.0%
Div. A2 92.0% 83.0% 81.0%
Div. Al 89.0% 87.0% 81.0%
Top sst. 95.0% 79.0% 76.0%
Chert Bd. 89.0% 86.0% 11•••
Chert 69.0% 50.0%
Coarse Gsd, 9.1% 14.1% Foxmould 9.5% 11.6% 14,6%
Figures for the total percentage of tourmaline in acid reductions. 264
These figures indicate conclusively that the major sedimentological break occurs between the Chert Beds and the underlying Foxmould. The faunal evidence from the south west is very slender but if one interpolates the data from the Dorset coast westwards onto the present problem it becomes apparent that the lower part of the Upper Greensand (Foxmould sands) could be of Upper Albian age and the upper part of the Upper Greensand (Chert Beds) would then be of Lower Cenomanian age, The author therefore suggests that perhaps the Albian/Cenomanian boundary in the south west of England should be drawn at this level. This suggestion would seem to reduce the large hiatus produced by the elevation of the Cenomanian Limestones to a position in the uppermost Cenomanian. One therefore has the following distribution:—
Division C Plenus Marls Divisions B & A • Zones 11a/13 Mid—Cenomanian non—sequence Chert Beds Zones 1100/9/8/7 (?) Foxmould sands Zones 6/5 (?)
There remains yet two more pieces of evidence to be considered, both of which may help to clarify these new suggestions. a. As already discussed in Chapter 4 the rhythmic deposition of the Lower Chalk and the Chert Beds can be regarded as forming under similar sedimentary controls. This present scheme, equating the Lower Cenomanian with the Chert Beds, implies that not only were these similar controls, but that they were basically the same controls. 265
b, Approximately five feet below the Cenomanian Limestones at Dunscombe Cliff JUKES-BROWNE (1900) records the occurrence of 0.1enticularis (BLUMENBACH) 0.concava LANARK of previous workers. These are in the same stratigraphic position as those recorded in this present work below the Cenomanian sands at Wilmington and it is tentatively suggested that these are in fact the same level. Mr. R. Edwards of Exeter University has kindly provided the author with a magnificent specimen of O.lenticularis rich greensand from the upper levels of the Haldon Hills. Some of these specimens have been sectioned by the author (Plate 6, Fig.9) and compared with a specimen that has been sectioned and Illustrated by HONOR (plate XVII, fig.14) from the Dunscombe locality. The degree of similarity between these two sections is striking and those from Wilmington, while lacking the Pull embryonic apparatus, have a similar overall form. The evolutionary trends of this spebies and the discussion arising from this are outlined fully in the taxonomic section of this account and only the implicationu will be discussed here. After comparison with material from the type Lower Cenomanian provided by Mr. D. Curry, and by the position of HOFKER4s (plate XVII, fig.14) illustration in a series of plates arranged in stratigraphic order, it is suggested that these date the upper sandstones of the Chert Beds series as Lower - Middle Cenomanian. This dating of these specimens from the Haldon Hills indicates that these sands are probably of Upper Albian to Middle Cenomanian age but although the author has processed large quantities of these sands no other microfossils have been found. 266
The evidence is therefore slender, but it is aided by the work of DURRANCE & HAMBLIN (1969). If their period of folding can be correlated with the mid—Cenomanian non—sequence of the author (a not too difficult step) then this dating seems to be quite reasonable, especially when one considers that Orbitolines only occur at three localities in England, all of which would then be at about the one stratigraphic level. This then concludes this rapid survey of the stratigraphy and although this is not intended as a full scheme of revision it is hoped that this has at least provided a basis for a new appraisal of the whole situation. The palaeogeographical implications are not too difficult to comprehend, and the present work agrees with many of the theories of SMITH (1962) in his work on the heavy mineral distribution. Dartmoor and the surrounding area must have been a landmass over which the Albian sea advanced in Middle/upper Albian times, The Gault Clay (in a non—arenaceous state) would have formed in relatively sheltered water away from the supply of detritus. With the completion of the advance and the subsequent deepening of the sea chalk formation must have begun (in rhythmic manner) in the more off—shore areas while arenaceous deposition persisted well into the Cenomanian nearer to the landmass. There was then the period of disturbance which produced the non—sequence when all the structures described in the text were formed. This was accompanied and/or followed by a period of erosion during which time many of the so—formed swells were planed down to the level they have today. It is quite possible that these disturbances were initiated early in the Cenomanian and that much of the 267
arenaceous material of Cenomanian age was formed during the early stages of the uplift. After this was complete open sea conditions must have prevailed over most of the Anglo—Paris Basin, thus allowing the more settled deposition of the Upper Cenomanian chalk. Nearer the remnants of the landmasses there were still shallow water conditions and it is in these regions where one had the formation of the deposits seen so well along the south east Devon coast. These more littoral deposits of the Upper Cenomanian must have been localised in the more positive areas as in the western approaches to the English Channel there are many records of chalk of Cenomanian age (Curry et al 1962). It would therefore seem quite reasonable to suppose that all the features described in this stratigraphic account have their mirror image to the west of the Devon/Cornwall massif. This is very similar to the position in France where the Rouen Chalk is seen to pass westwards into the typical Cenomanian facies which in turn peters out against the Brittany massifs. The disturbance associated with the faunal changes of Division C and the Plenus Marls heralded the beginning of a semi— quiescent period during which time the Turonian chalk was deposited over the whole area — including those areas which had previously been suffering active erosion. This had the effect of completely removing the source of all the detrital elements that had been so characteristic of the Albian and Cenomanian deposits. 268
CHAPTER?
Conclusions
It is apparent from the above discussion that there is a marked discrepancy between the accepted ideas of the stratigraphy and those proposed in this account. There are many reasons for this, the most important of which has been the dogmatic retention of theories based on the early days of geology. Until the recent research of KENNEDY there has been no attempt at questioning any of these important theories although many minor details have obviously been fully described and documented. The main reason for this has been the continued use of the same fossils in attempting this stratigraphic work. In some cases a revision of the stratigraphy has merely resulted in a revision of some generic names to bring the determinations in line with modern taxonomy.
The author has therefore attempted to produce a stratigraphic synthesis based on a group which, up to the present time, has not been used for any stratigraphic work. There is naturally a need to consult all fossil groups before a firm theory can be presented but this survey should allow future workers to at least take some notice of the Foraminiferida.
The differences between this work and some of the others in the same field can be resolved by combined research in areas where discrepancies occur. The main difficulty appears to be the stratigraphic position of the Upper Greensand, and this conflict was forecast in Chapter 2, where the following quotes from JUKES—BROWNE & HILL (1896) were presented. They are repeated here to emphasise the importance of their position in the whole problem of stratigraphic nomenclature. 269
'The result of British investigation, therefore, has been to tell us that our subdivisions into Gault, Upper Greensand, and Lower Chalk do not tally in any way with their Albien and Cenomanien stages and that if we wished to adopt the French nomenclature we should have to draw a hard and fast line in the middle of the Upper Greensand.;
'The work of English geologists has therefore tended to consolidate the Gault and Greensand, and to separate them as a whole from the overlying Lower Chalk, which has generally a bed of glauconitic marl at its base, and is often marked off from the Upper Greensand by a very clear plane of division. The faunal assemblages agree with this method of classification and no modern English geologist would imagine that a more natural division could be made by grouping a part of the Upper Greensand with the Lower Chalk.;
Most workers on the Upper Greensand sequence have experienced difficulties and this present piece of research has not been an exception to this rule. Some evidence however is available and in places this has been enough to allow the author to make some
predictions as to the age relationships of the various bedso These suggestions do not agree with the older and more accepted tIleories
but the author feels that the evidence for them is enough to warrant
their inclusion in this account. The main points of dissention have already been outlined but the following four sections will serve as a summary.
1. The Chert Beds — no conflicting macrofossil evidence to the suggestion that these are of Lower Cenomanian age.
2. The Upper Greensand at Eastbourne — again there is no
evidence to oppose a Lower Cenomanian age.
3. The Upper Greensand at Compton Bay contains no macrofauna that opposes a Lower Cenomanian age although the Upper Greensand at the southern end of the Island would seem to contradict this
idea. The section from the Undercliff, where the macrofauna has
been collected, has not been sampled by the author and as a result
the conflict cannot be resolved at the present time. 270
4. The Upper Greensand of the Fetcham Mill borehole has been shown (Fig.14) to contain no evidence against the suggestion that the upper part of the greensand sequence is of Lower Cenomanian age.
These four instances seem to suggest we have a choice in this country of either following a lithological set of subdivisions or following the bio—stratigraphic units of the Continental geologists. This matter raises the whole question of suitable type sequences for geological correlation, and the Cretaceous is perhaps one of the worst cases in the geological record. The sequences of Aube, Sarthe, and Touraine etc., are by no means suitable for correlation but during the past few years their usefulness has been somewhat overshadowed by the development of International planktonic foraminiferal zonation. The total fauna of these stages has been shown (BANDY 1967) to agree with the assemblages found in this work and they are summarised as follows: — Albian abundant fauna characterised by Nodosariacea, moderately abundant arenaceous benthonic forms! large numbers of small planktonic individuals of the non—keeled type (E.(Hedbergella)
Cenomanian typified by the single—keeled planktonic individuals of the Rotalipora spp. and P.(Prae—, globotruncana) spp. groups.
Turonian typified by the double—keeled planktonic individuals of the Globotruncana spp. group.
The Albian/Cenomanian boundary can usually be recognised as a 271
faunal change wherever it occurs but it cannot be placed in a lithological sequence as a marker horizon, except at specific localities. The Cenomanian/Turonian boundary can be placed with some confidence within the Plenus Marls (Beds 1-4 Cenomanian: Beds 5-8 Turonian) and this horizon can be followed in the field. The overall effect of these two stages is to produce a trans- gression/regression/transgression stratigraphy very like that which is seen in the Palaecgene of the Hampshire Basin. This produces in fact a threefold cycle that can be outlined as follows:- 1. 'Transgression' greensand or sandy clay on the advance and at the margins of the basin with clay deposition away from the border- ing landmass.
2. 'Regression' greensand deposition over the whole area. (This of course is not necessarily an actual regression and the effect is probably produced by an increase in the detrital material entering the area from the margins where the Albian/Cenomanian sea was actively eroding the Jurassic and Triassic strata exposed at the surface.
3. 'Transgression' greensand deposition is gradually replaced by chalk deposition, although this remained rich in detritus nearer the margins. The period of folding
which complicates this part of the 272
record successfully divided the basin of
the Upper Cenomanian into two provinces —
an eastern and a western — and it is
the correlation between these two that
has largely obscured the more important
relationships of correlation at this
stratigraphic level. Thus the world wide transgression of the Cenomanian often quoted in the literature is in fact (in this Country) a complex set of advances initiated in the Middle Albian. This was more or less at its maximum extent in the Turonian but even during this stage deposition did not proceed in a settled manner and SMITH has reported erosion surfaces and unconformable relationships within the Turonian from the Beer area. In the same way the Senonian chalk di7plays a series of hard grounds and phosphatised levels which may -turn out to be features very like that found in the mid—Cenomanian. These problems could possibly be resolved if these stages were given the same treatment as the Cenomanian has now undergone.
All these points provide tremendous opportunitites for a re— assessment of the whole question of chalk deposition. Recent work by CURRY et al (1962) has shown the presence of 'normal chalk' of Turonian/Cenomanian age in the western approaches of the Channel and there are also extensive tracts of undersea chalk in the Irish Sea and English Channel. From these occurrences it can be postulated with some degree of confidence that the changes observed in this research when passing from east to west are repeated further to the west in the reverse direction. The same pattern appears to occur in France as one approaches the Brittany area from the east. In this situation one can see the position of the type Cenomanian 273
as being roughly analogous to the Dorset/Devon coast where the Cenomanian is almost totally represented by the greensand facies. The larger expanses of sand in the French successions are probably due to the larger amount of detritus available from the Brittany massif, when compared to that supplied from the Cornish massifs. This seems to suggest that the Cenomanian sea was a moderately shallow basin, open to the ocean, but containing marginal islands in the form of the older Hercynian massifs. While calcareous deposition continued in the centres of these basins arenaoeous sediments were being laid down nearer the margins, gradually merging off—shore into the more calcareous sediments. With the advance over the Cretaceous land surface marginal deposits were laid down all round the British Islands as witnessed by the Cenomanian sands in the Ulster and Hebridean provinces. These probably formed in basins, marginal to the main areas of sedimentation.
These are all possible suggestions for further thoughts on the palaeogeography of the Cenomanian as a whole and from these considerations may spring new thoughts on the formation of the chalk — a matter which is still not satisfactorily explained. These are beyond the scope of this present research but this new appreciation of mid—Cretaceous stratigraphy may provide a new outlook on one of the most intriguing problems of the geological record — the purity of the chalk. 274
General Bibliography Archiac, 1847 Etudes sur la formation Cretace. Mem, Soc. geol. F—. A, ser. 2, v.11, pp.1 —148 (1946). Arkell, W.J. 1947 The Geology of the Country around Weymouth, Swanage, Corfe, and Lulworth. Mem. geol, Surv. U.X4 Barrois, C. 1876 Recherches sur le terrain Cretace superieur de l'Angleterre et l'Irlande. Iem. Soc. geol. DI. Berger, W.H. 1968 & Heath, G.E. Vertical mixing in pelagic sediments. J, mar. Res., v.26, no.21 pp.134-43. Breistroffer, M. 1936 Les subdivisions du Vraconien dans le Sud-Est de la France. Bull. Soc. geol. Fr., (5). 6, pp.63-8. 1947 Sur les zones diammonites de l'Albien de France et d'Angleterre. Tray. Lab. poll Grenoble, v.26, PP.17 —104. Bromley, R.G. 1965 Studies in the Lithology and conditions of Sedimentation of the Chalk Rock and comparable Horizons. University of London Thesit (Ph.D.). Bruckshaw, J. 1961 et al, Work of the Channel Study Group. Proc. Instn. civi.Engra., v.18, pp.149.-178. Curry, D. 1962 et al, The Geology of the Western Approaches of the English Channel. 1. Chalky Rocks from the Upper Reaches of the Continental Slope. Phil. Trans. R. Soo. (B), no.724, v.245, pp.267-290. Davidson, T. 1852 A monograph of the British Fossil Brachiopods, Pt.11. ralaeontFr. Soc. (Monogr.), no,l, pp.1 —54. 275
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Gandolfi, R. (contd.) 1942 (Canton Ticino). Riv. ital. Paleont. Stratigr., v.48, mem.4, Ppo1-160. Glaessner, M.F. 1937 Planktonforaminiferen aus der Kreide and dem Eozan and ihre stratigraphische Bedeutung. Studies in Micropaleontologv, Univ. Moscow, Lab. Paleont., v.1, pt.l, pp.27 -46. Goel, R.K. 1965 Contribution a l'etude des Foraminiferes du Cretace superieur de la Basse-Seine. Bull, Bur. Rech. peol. min., no.5, PP.49-157. Gorbenko, V.F. 1957 Pseudospiroplectinata - Novyy rod Foraminifer iz Verkhnemelovykh otlozheniy severo-zapadnogo Dombassa. Dokl.Akad. Nauk. SSSR., v.117, no.5, pp.879-80. Grimsdale, T.F. 1955 & Van Morkhoven, F.P.C.M. The ratio between Pelagic and Benthonic Foraminifera as a means of estimating depth of deposition of sedimentary rocks. Proc. 4th Wld. petrol. Con r., sec.l/D, Pap.4, PP•473-91. Hagn, H. 1953 Die Foraminiferen der Pinswanger Schichten (Unteres Obercampan) Ein Beitrag zur Nikropalaontologie der Belvetischen Oberkreide Sudbayerns. Palaeontosraphical v.104, Abt.A, p.1. 1954 & Zeil, W. Globotruncanen aus dem Ober- Cenoman and Unter-Turon der Bayerischen Alpen. Eclog. geol. Helv., v.47, no.1, pp.1.60. Henson, P.B.S. 1948 Larger imperforate Foraminifera of southwestern Asia, Families Lituolidae, Orbitolinidae and Meandropsinidae. Monogr. Br. Mus. nat. Hist. (Geology), 127p. 291
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Plate 1 (Ammodiscacea, Lituolacea)
1. Pelosina sp. 20 sp. nov., (x95), Bed VII Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. Ammodiscus cretaceus REUSS, (x95), Bed XIII Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Glomospira gaultina (BERTHELIN), (x100), Bed II Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Hormosina lagenarium (BERTHELIN), (x68), Bed XIII Copt Point, Fokestone, Type succession of the Gault Clay, Middle to Upper Albian. 5. Reophax sp. 23, sp. nov., (x105), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 6. Cribratina cylindracea (CHAYMAN), (x34), Bed XIII Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Haplophragmoides concava (CHAPMAN), (x112), Lower Gault Clay (Middle Albian), Compton Bay, Isle of Wight. 8. Labrospira latidorsata (BORNEMAN), (x100), oblique apertural view, Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 9. Labrospira latidorsata (BORNEMAN), (x100), view of spiral side, Bed IX Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Labrospira nonioninoides (REUSS), (x100), Bed 1 Copt Point,
303
Plate 1 (contd.)
10, Folkestone, Type succession of the Gault Clay, Middle to (contd.) Upper Albian. 11. Bulbophragmium aeauale (MA:MC), (x24), Upper Gault Clay, Upper Albian, Compton Bay, Isle of Wight. 12. Ammobaculites subcretaceus CUSHMAN a:ALEXANDER, (x65), Bed 1 Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Ammobaculites subcretaceus CUSHMAN & ALEXANDER, (x72), Bed 1, Copt Point, Type succession of the Gault Clay, Middle to Upper Albian. 14. Ammobaculites parvispira TEN DAM, (x66), Bed 1, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 15. Flabellamminopsis sp. 1, sp. nov., (x80), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
Plate 2 (Lituolacea)
1. Placopsilina cenomana D'ORBIGNY, (x45), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 2. Spiroplectammina rectangularis TEN DAM, (x95), megalospheric form, Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 3. Spiroplectammina rectangularis TEN DAM, (x95), microspheric form, Zone 10, Lower Chalk, near Beachy Head, Eastbourne. 304
Plate 2 (contd.)
4. apiroplectammina sp. A, sp. nov., (x100), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
5. Acruliammina folkestoniensis (CHAPMAN), (x20), Glauconitic Marl, Copt Point, Folkestone. (Zone 7 of the Cenomanian).
6. Textulariachapmani LALICKER, (x72), basal Plenus Marl, near Beachy Head, Eastbourne. 7. Textularia,chapmani LALICKER, (x95), basal Plenus Marl, near Beachy Head, Eastbourne. 8. Textularia minuta BERTHELIN, (x150), Lower Gault Clay, Middle Albian, Compton Bay, Isle of Wight.
9. Textularka sp. 20, sp. novil (x98), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne:
10. Textularia sp. 21, sp. nov., (x98), Cambridge Greensand, Cenomanian zone 7, Arlesey. 11. Textularia sp. 22, sp. nov., (x98), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
12. Textularia sp. 24, sp. nov., (x84), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper
Albian. 13. Trochammina sp. 23, sp. nov., (x120), Gault/Upper Greensand transition, (Albian/Cenomanian Boundary), near Beachy Head,
Eastbourne. 14. Trochammina sp. 20, sp. nov., (x145), Bed VII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper
Albian.
306
Plate 3 (Lituolacea)
1. Tritaxis fusca (CHAPMAN, non WILLIAMSON), (x48), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. Flourensina intermedia TEN DAM, (x54), Glauconitic Marl, basal Cenomanian, Zone 7, Copt Point Folkestone. 3. Flourensina sp. A, sp. nov., (x46), Zone lla, Lower Chalk, Upper Cenomanian, near Beachy Head, Eastbourne.
4. Gaudryina quadrans CUSHMAN, (x70), Bed 1, Plenus Marls, Compton Bay, Isle of Wight. 5. Gaudrvina quadrans CUSHMAN, (x49), Bed 1, Plenus Marls, Compton Bay, Isle of Wight. 6. Gaudryiria sp. 25, spa. nov., (X64), Zone 100 Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 7. Gaudryina sp., adiTTEIES, (x64), Bed 2, Plenus Marls, Betchworth, Surrey. 8. Spiroplectinata annectens (PARKER & JONES), (x95), Plenus Marls, Compton Bay, Isle of Wight. 9. Spiroplectinata annectens (PARKER & JONES), (x74), Plenus Marls, Compton Bay, Isle of Wight. 10. Spiroplectinata annectens (PARKER & JONES), (x46), Plenus Marls, Compton Bay, Isle of Wight. 11. Tritaxia macfadyeni CUSHMAN, (x41), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 12. Tritaxia macfadyeni CUSHMAN var. subrotunda TEN DAM, (x44), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
308
,Plate 3 (contd.)
13. Tritaxia pvramidata REUSS, (x38), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 14. Tritaxia pyramidata REUSS, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 15. Tritaxia tricarinata (REUSS), (x84), basal Type Turonian, (Fretevou Chalk), Touraine, France. 16. Tritaxia sp. 20, sp. nov., (x80), basal Gault Clay, Middle Albian, Compton Bay, Isle of Wight.
Plate 4 (Lituolacea)
1. Uvigerammina moesiana NEAGUI (x110), Cambridge Greensand, Zone 7, basal Cenomanian, Arlesey. 2. Uvigerammina moesiana NEAGU, (x110), Cambridge Greensand, Zone 7, basal Cenomanian, Arlesey. 3. Arenobulimina r anglica CUSHMAN, (x34), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 4. Arenobulimina chapmani CUSHMAN, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 5. Arenobulimina chapmani CUSHMAN, (x72), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. i 310
Plate 4 (contd.)
6. Arenobulimina courta (MARIE), (x156), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 7. Arenobulimina depressa (MINER), (x140), Bed 1, Plenus Marls, Compton Bay, Isle of Wight. 8. Arenobulimina depressa (PERNER), (x140), apertural view of an adult specimen, Bed 1, Plenus Marls, Compton Bay, Isle of Wight. 9. Arenobulimina macfadyeni (CUSHMAN), (x80), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Arenobulimina preslii (RETJSS), (x120), basal type Turanian, (Fretevou Chalk), Touraine, France. 11. Arenobulimina cf. obliqua (D'ORBIGNY), (x100), Zone it, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 12. Arenobulimina sabulosa (CHAPMAN), (x70), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Arenobulimina sp. A, sp. nov., (x95), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 14. Arenobulimina sp. B, sp. nov., (x70), Bed XIII, immediately below the Glauconitic Marl, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
Plate (Lituolacea) 1. Dorothia gradata (BERTHELIN), (x50), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 311
Plate 5 ,(contd.)
2. Dorothia gradata (BERTHELIN), (x60), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Dorothia gradata (BERTHELIN),var. dispansa CHAPMAN,' (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Dorothia filiformis (BERTHELIN), (x180), Lower Gault Clay, Middle Albian, Compton Bay, Isle of Wight. 5. Eggerellina gibbosa MARIE, (x100), Zone 10, Lower Chalk, Cenothanian, near Beachy Head, Eastbourne. 6* EggeFellina mariae TEN DAM, (x150), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle ..co Upper Albian. 7. Marssonella ozawai CUSHMAN, (x55), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. Marssonella trochus (D,ORBIGNY), (x95), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 9. Marssonella trochus (D'ORBIONY)„ (x50), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Marssonella sp. 21, sp. nov., (x50), Zone lli, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 11. Plectina ruthenica (REUSS), (x85)„ Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 12. Plectina sp. 21, sp. nov., (x70), Zone llii, Lower Chalk, near Beachy Head, Eastbourne. - 313
Plate 5 (contd.)
13. Hagpnowina advena (CUSHMAN), (x70), Zone 10, Lower Chalk, Cenomanian, Compton Bay, Isle of Wight. 14. Pseudotextulariella cretosa (CUSHMAN), (x50), apertural view, Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 15. Psaudotextulariella cretosa (CUSHMAN), (x50), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
Plate 6 (Lituolacea)
1. 2.
3. 4. Orbitolina lenticularis (BLUMENBACH), (x100), Lower Cenomanian 5. Greensand, Type Lower Cenomanian, Sarthe, France. 6.
7. 8. 9. Orbitolina lenticularis (BLUMENBACH), (x100), Upper Greensand, Haldon Hills, Devon. 10. Orbitolina lenticularis (BLUMENBACH), (x100), Lower Cenomanian Greensand, Sarthe, France.
Plate 7 (Lituolacea, Miliolacea, Nodosariacea)
1. Orbitolina lenticularis (BLUMENBACH), (x20), Upper Greensand, - 315
,Plate 7 ,(contd.)
1. Haldon Hills, Devon. (contd.) 2. Spiroloculinaaacea wr BURROWS, SHERBORN & BAILEY, (x60), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbournei 3. Nodobacularia nodulosa (CHAPMAN), (x60), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. gyinqueloculina anticcia FRANKE, (x70), apertural view, Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 5. Quinqueloculina antiqua FRANKE, (x70), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 6. Nodosaria bambusa CHAPMAN, (x45), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Nodosaria lamello—costata REUSS, (x50), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. Nodosaria obscura REUSS, (x45), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
9. Nodosaria orthopleura REUSS, (x30), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Nodosaria orthopleura REUSS var. ,tetragona REUSS, (x60), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 11. Nodosariamapercula REUSS, (x65), Bed XIII, Copt Point,
317
Plate 7, (contd.)
11. Folkestone, Type succession of the Gault Clay, Middle to Upper (contd.) Albian. 12. Nodosaria of, paupercula REUSS, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Nodosaria perpusilla CHAPMAN, (x95), Totternhoe Stone (Lower Chalk), Cenomanian, Chilton/Upton section. 14. Nodosaria proboscidea REUSS, (x95), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 15. Nodosaria sceptrum REUSS, (x60), Bed III, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 16. Nodosaria zippei REUSS, (x60), Bed IX, Copt Point, Folhestone, Type succession of the Gault Clay, Middle to Upper Albian. 17. Nodosaria sp, 41, sp. nov., (x60), Basal Lower Chalk, Zone 10, Cenomanian, near Beachy Head, Eastbourne. 18. Nodosaria sp. 47, sp. nov., (x30), Bed VII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian, 19. Nodosaria sp. 50, sp. nov., Zone lli, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
Plate 8 (Nodosariacea)
1. Citharina axambourgi MARIE, (x34), Foxmould sands, Upper Albian?, Little Beach, Branscombe, Devon. 318
Plate 8 (contd.)
2. Citharinella chapmani MARIE, (x20), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 3. Citharinella didyma (BERTHELIN), (x70), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 4. Citharinella karreri (BERTHELIN), (x30), Bed XIII, Copt Point, Folkestone, Type succession of the Gault dliy, Middle to Upper Albian. 5. Citharinella karreri (BERTHELIN), (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 6. Citharinella laffitei MARIE, (x40), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Citharinella laffitei MARIE, (x30), uppermost Gault Clay, Upper Albian, (immediately below the Cambridge Greensand), Arlesey. 8. Citharinella lemoinei MARIE, (x45), Zone lla, Lower Chalk, Upper Cenomanian, near Beachy Head, Eastbourne. 9. Citharinella pinnaeformis (CHAPMAN), (x26), Bed XI, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Citharinella pinnaeformis (CHAPMAN), (x30), Bed XI, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 11. Dentalina catenula REUSS, (x50), Bed XIII, Copt Point, - 320
Plate 8 (contd.)
11. Folkestone, Type succession of the Gault Clay, Middle to (contd.) Upper Albian. 12. Dentalina deflexa REUSS, (x40), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Dentalina distincta REUSS, (x35), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
Plate 9 (Nociosariacea)
1. Dentalina fusiformis (KHAN), (x40), Zone 10, Lower Gna.lk, Cenomanian, near Beachy Head, Eastbourne. 2. Dentalina fusiformis (KHAN), (x55), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Dentalina cf. hammensis (FRANKE), (x35), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Dentalina intermedia REUSS, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 5. Dentalina legumen (OUSS), (x55), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 321
Plate 9 (contd.)
o. Dentalina raristriata (CHAPMAN), (x33), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Dentalina strangulata REUSS, (x50), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. Dentalinastrangulata REUSS var., var. nov., (x32), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 9. Dentalina sp. 24, sp. nov., (x45), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Dentalina sp. 48, sp. nov., (x45), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 11. Frondicularia archiaciana D'ORBIGNY, (x28), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 12. Frondicularia cordai REUSS, (x43), Zone 10, Lower Chalk,
Cenomanian, near Beachy Head, Eastbourne. 13. Frondicularia gaultina REUSS, (x30), Bed IV, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 14. Frondicularia planifolium CHAPMAN, (x55), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 15. Frondicularia quadrata CHAPMAN, (x73), Bed XI, Copt Pointy
323
Plate 9 ,(contdi)
15. Folkestone, Type succession of the Gault Clay, Middle to (contd.) Upper Albian. 16. Frondicularia striga CHAPMAN, (x65), Cambridge Greensand, basal Cenomanian, Zone 7, Arlesey.
Plate 10 (Nodosariacea)
1. Lenticulina gaultina (BERVWZIET) f.gaultina (BERTHELIN), (x80), apertural view, Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. Lenticulina gaultina (BERTHELIN) f.gaultina (PERTHELM), (x80), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 34 Lenticulina gaultina (BERTHELIN) f. ovalis (REUSS), (x40), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Lenticulina gaultina (BERTiaLIN) f. rotulata LANARK, (x40), Zone 10, Lower Chalk, Cenomanian„ near Beachy Head, Eastbourne. 5. Lenticulina nodosa (REUSS), (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 6. Lenticulina sp. 35, sp. nov., (x75), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 324
Plate 10 (oontd.)
7. Lenticulina lepida (REUSS), (x60), Upper Gault Clay, Middle (?Upper) Albian, Compton Bay, Isle of Wight. 8. Lenticulina secans (?FUSS), (x70), Upper Gault Clay, Middle (?Upper) Albian, Compton Bay, Isle of Wight. 9. Marginulina aeguivbca (REUSS), (x60), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10.11.12. Series of specimens showing the transition from a form referable to Lenticulina oligoategia (REUSS), to an uncoiled form more akin to Marginulina bronni (ROEMER). Magnification (x70) is the same for all three specimens and all are from* Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Margiouline. jonesi (REUSS), (x70), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 14. Marginulina jonesk (REUSS), (x70), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 15. Marginulina sp. C, sp. nov., (x55), Zone 10, Lower Chalk, Cenomanian, Compton Bay, Isle of Wight.
Plate 11 (Nodosariacea)
1. Mar4nulina sp. 25, sp. nov., (x65), Totternhoe Stone, Lower Chalk, Cenomanian, Chilton/Upton section.
326
Plate 11 (contd.)
2. Marginulina sp. 32, sp. nov., (x60), Glauconitic Marl, basal Cenomanian (Zone 7), Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Marginulina sp. 36, sp. nov., (x75)? Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Marginulina sp. 39, sp. nov., (x55), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 5. Marginulina sp. 45, sp. nov., (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 6. Marginulina sp. 47, sp. nov., (x50), Bed VIII, Copt iJint, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Fpoflabellina oFnata (REUSS), (x55), Zone 13, tower Chalk, Upper Cenomanian, Culver Cliff, Isle of Wight. 8. Palmula cordata (REUSS), (x15), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 9. Planularia cenomana (SCHACK0), (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Planularia cenomana (SCHACKO), abherrent form, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 11. Planularia cristellaroides (REUSS), (x60), Glauconitic Marl, Zone 7, Cenomanian, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
328
Plate 11 (contd.)
12. Planularia mariae TEN DAM, (x75), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 13. Pseudonodosaria cylihdracea (REUSS), (x7), Plenus Marls, Betchworth, Surrey. 14. Pseudonodosaria humilis (ROEMER), (x46), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
15. Pseudonodosaria humilis (ROEMER), (x46), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 16. Pseudonodosaria mutabilis (REUSS), (x70), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
Plate 12 (Nodosariacea)
1. Saracenaria bononiensis (BERTHELIN), (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. Saracenaria bononiensis (BERTfthLIN), (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Saracenaria italica DEFRANCE„ (x200), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
4. Saracenaria jarvisi (BROTZEN), (x70), Zone 10, Lower Chalk, 329
Plate 12 (contd.)
4. Cenomanian, near Beachy Head, Eastbourne. (contd.) 5. Saracenaria vestita (BERTHELIN), (x150), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 6. Saracenaria sp. 24, sp. nov., (x70), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Vaginulina bicostulata REUSS, (x60), Zone 11, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 8. Vaginulina debilis (BERTHELIN), (x45), Zone 11, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 9. Vaginulina kochii ROEMER f. gaultina BERTHELIN, (x50'2, Gault/ Upper Greensand boundary, Uppermost Albian, near Beachy Head, Eastbourne. 10. Vaginulina kochii ROEMER f. kochii ROEMER, (x50), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 11. Vaginulina kochii ROEMER f. recta REUSS, (x75), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 12. Vaginulina truncata REUSS, (x35)„ Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 13. Vaginulina neocomiana CHAPMAN, (x100), Plenus Marls, Maiden Newton, Dorset. 14. Vaginulina mediocarinata TEN DAM, (x25), Bed IX, Copt Point,
331
Plate 12 (contd.)
14. Folkestone, Type succession of the Gault Clay, Middle to (contd.) Upper Albian. 15. Vaginulina sp. B, sp. nov., (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 16. Vaginulina sp. 21, sp. nov., (x60), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 17. Vaginulina sp. 30, sp. nov., (x35), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
Plate 13 (Nodosariacea)
1. Vaginulina sp. 36, sp. nov., (x55), small form, Foxmould Sands, Upper Albian (?), Little Beach, Devon. 2. Vaginulina sp. 36, sp. nov., (x50), large form, Foxmould sands, Upper Albian (?), Little Beach, Devon. 3. Lingulonodosaria semiornata (REUSS), (x85), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 4. Glandulopleurostomella pleurostomelloides (FRANKE), (x100), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 5. Globulina lacrima REUSS, (x55), Bed XIII, Copt Point, Folke— stone, Type succession of the Gault Clay, Middle to Upper Albian. 332
y1211.11 (contd.)
6. Globulina lacrima REUSS, fistulose form, (x85), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Globulina lacrima REUSS var. ericia CUSHMAN & OZAWA, partial form, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. Globulina lacriMa REUSS var. ericia CUSHMAN & OZAWA, complete form, (x25), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Biddle to Upper Albian. 9. Globulina lacrima REUSS var. subsphaerica (BERTHELIN), fistulose form, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clayi Middle to Upper Albian. 10. Globulina prisca REUSS, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 11. Globulina sp. A, sp. nov., (x125), Foxmould sands, Upper Albian (?), Little Beach, Devon. 12. Guttulina adherens (OLSZEWSKI), (x85), Gault/Upper Greensand boundary, Uppermost Albian, near Beachy Head, Eastbourne. 13. Guttulina adherens (OLSZEWSKI) var. cuspidata CUSHMAN & OZAWA, fistulose form, (x80), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 14. Guttulina adherens (OLSZEWSKI) var. ,cuspidata CUSHMAN & OZAWA, (x80), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 15. Fyrulina cylindroides (ROEMER), (x70), Bed VIII, Copt Point,
334
Plate 13 (contd.)
15. Folkestone, Type succession of the Gault Clay, Middle to (contd.) Upper Albian. 16. Edithaella sessilis FUCHS, (x120), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 17. Cornusphaera grandis FUCHS, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
Plate 14 (Nodosariacea)
1. Bullopora laevis (SOLLAS), (x60), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. Bullopora tuberculata (SOLLAS), (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. Ramulina aculeata WRIGHT, (x45), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 4. Ramulina fusiformis KHAN, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 5. Ramulina cf. globotubulosa CUSHMAN, (x50), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 335
Plate 14 (contd.)
6. Ramulina muricatina LOEBLICH & TAPPW, (x50), Bed I, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7. Ramulina sp. 2, sp. nov., (x85), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. Ramulina sp. 3, sp. nov., (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albion. 9. Ramulina sp. 3, sp. nov., (x60), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10. Ramulina sp. A, sp. nov., (x95), Zone 11, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 11. Tristix exoavatm (REUSS), (x60), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 12. Tristix excavatum (REUSS) var. exilis CHAPMAN, (x95), Plenus Marls, Betchworth, Surrey. 13. Tristix insigne (REUSS), (x75), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 14. Oolina sp. 23, sp. nov., (x120), Zone 11, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 15. Oolina sp. 23, sp. nov., specimen deliberately broken to allow illustration of the entosolenian tube, (x250), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
337
Plate 14 (contd.)
16. Fissurina sp. 20, sp. nov., (x230)„ Zone 131 Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset.
17. Fissuring sp. 24, sp. nov., (x200), Zone llii, Lower Chalk, (immediately above the Totternhoe Stone), Cenomanian, Totternhoe Lime Works.
Plate 15 (Buliminacea, Discorbacea)
1. Buliminella sp. 21, sp. nov., (x240), Plenus Marls, Maiden Newton, Dorset.
2. Buliminella sp. 21, sp. nov., (x100), Plenus Marls, Juckland Newton, Dorset.
3. Buliminella sp. 21i sp. nov., apertural view, (x900), Plenus Marls, Maiden Newton, Dorset.
4. Buliminella sp. 22, sp. nov., (x270), Plenus Marls, Maiden Newton, Dorset.
5. Buliminella sp. 22, sp. nov., (x300), Plenus Marls, Maiden Newton, Dorset.
6. Bolivina textilaroides REUSS, (x160), Plenus Marls, Maiden Newton, Dorset.
7. Bolivina textilaroides REUSS, (x220), Plenus Marls, Maiden Newton, Dorset.
8. Bolivinoides sp. 10, sp. nov., (x130), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset.
9. Tappanina sp. 20, sp. nov., (x225), Plenus Marls, Maiden Newton, Dorset.
339
Plate 15 (contd.)
10. Tappanina sp. 25, sp. nov., (x250), Glauconitic Marl, Zone 7, Basal Cenomanian, Copt Point, Folkestone, Type Succession of the Gault Clay, Middle to Upper Albian. 11. Eouvigerina regularis (KELLER), (x265), Bed I, Plenus Marls, near Beachy Head, Eastbourne. 12. Bulimina sp. 20, sp. nov., (x240), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 13. Orthokarstenia calcarata (BERMUIN), (x265) , Bed I, Plenus Marls, near Beachy Head, Eastbourne. 14. Discorbis sp. A, sp. nov., (x320), Foxmould sands, Upper Albian (?), Little Beach, Devon. 15. Discorbis sp. A, sp. nov., (x320), Foxmould sands, t)per Albian (?), Little Beach, Devon.
Plate 16 (Discorbacea, Spirillinacea, Globigerinacea)
1. 'Discorbis allomorphinoides' (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 2. 'Discorbis allomorphinoides' aeKERIES, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 3. 'Discorbis allomorphinoides' JEFARIES, (x100), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
341
Plate 16 (contd.)
4. Patellina trochiformis(SCUCKO), (x70), Zone lli, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 5. Guembilitria harrisi TAPPAN, (x380), Division C, Bovey Lane Sandpit, Devon. 6. Heterohelix moremani (CUSHMAN), (x230), Division C, Bovey Lane Sandpit, Devon. 7. Rotalipora aushman' (MORROW), internal glauconite cast, dissolved out of limestone using HC1, (x150), Division B, Bovey Lane Sandpit, Devon. 8.9.10. Rotalipora aushmani (MORROW), (x150), Division B, Bovey Lane Sandpit, Devon.
Plate 17 (Globigerinacea)
1.2.3. Rotalipora evoluta SIGAL, (x75), Zone 10, Lower Chalk, Lower Cenomanian, near Beachy Head, Eastbourne. 4.5.6. Rotalipora greenhornensis (MORROW), (x115), basal Plenus Marls, Bincombe, Dorset. 7.8.9. Praeglobotruncana (Praeglobotruncana) delrioensis (PLUMMER), (x180), Zone 10, Lower Chalk, Lower Cenomanian, near Beachy Head, Eastbourne.
Plate 18 (Globigerinacea) 1.2.3. Praeglobotruncana (Praeglobotruncana) roddai OURIANOS &
- 344
Plate 18 (contd.)
1.2.3. ZINGUL&), (x75), Division C, Bovey Lane Sandpit, Devon. (contd.) 4.5.6. Praeglobotruncana (Eraeglobotruncan) stephani (UNDOLFI), (x150), Zone Mil Lower Chalk, Cenomanian, Buckland Newton, Dorset. 7.8.9. Praeglobotruncana (Praeglobotruncana) stephani (G&NDOLFI), var. turbinata REICHEL, (x160), Bed I, Plenus Marls, Maiden Newton, Dorset.
Plate 19 (Globigerinacea)
1.2. Praeglobotruncana (Praeglobotruncana) helvetica (BC;LI)„ (x200), Zone 13, Upper Cenomanian„ Lower Chalk, near Beachy Head, Eastbourne. 3. Praeglobotruncana (Hedbergella) cretacea (D,ORBIGNY), (x150), Plenus Marls, Buckland Newton, Dorset. 4.5.64 Praeglobotruncana (Hedbergella) amabilis LOEBLICH & TAPPAS, (x150), Zone 13, Upper Cenomanian, Lower Chalk, Buckand Newton, Dorset. 7.8.9. Praeglobotruncana (Hedbergella) delrioens4 (CARSEY), (x160), Bed C, Bovey Lane Sandpit, Beer, Devon. 10.11.12. Praeglobotruncana (Hedbergella) planispira (TUNS), (x150), uppermost Gault Clay, Upper Albian, immediately below the Cambridge Greensand, Arlesey.
346
Plate 20 (Globigerinacea)
1.2.3. Praeglobotruncana (Hedbergella) delrioensis (CARSEY), high spired form, (x185), Bed I, Plenus Marls section, Membury, Devon. 4.5.6. Praeglobotruncana (Hedbergella) infracretacea (GLAESSNER), (x130), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7.8.9.10. Praeglobotruncana (Hedbergella) washitensis (CARSEY). 7. (x100), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8. (x115), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Uppe: Albian. 9.(x90), from immediately below the mid—Cenomanian non—sequence, Middle Cenomanian, foot of Ackers Steps, Dover, Kent. 10.(x90), from immediately below the mid—Cenomanian non—sequence, Middle Cenomanian, uppermost Upper Greensand, Wilmington White Hart Sandpit, Devon. 11.12.13. Planomalina (Globigerinelloides) caseyi BOLLI, LOEBLICH & TAPPAN, (x150), Globigerinelloides band, uppermost Gault Clay, Upper Albian, immediately below the Cambridge Greensand, Arlesey.
Plate 21. (Globigerinacea, Orbitoidacea, Cassidulinacea) 1.2. Schackoina (Schackoina) cenomana (SCHACK0), (x350), Division B, Cenomanian Limestone, Upper Cenomanian, the
348
Plate 21 (contd.)
1.2. Pinnacles, Little Beach, Beer, Devon. (contd.) 3.4. Globotruncana (Globotruncana) linneiana linneiana (D'ORBIGNY), (x150), Lower Turonian, Membury, Devon.' 5. Eponides sp. 20, sp. nov., (x20), Plenus Marls, Maiden Newton, Dorset. 6. Pleurostomella barroisi BERTHELIN, megalospheric form, (x74), uppermost Gault Clay, Upper Albian, immediately below the Cambridge Greensand, Arlesey. 7. Pleurostomella barroisi BERTHELIN, microspheric form, (x80), uppermost Gault Clay, Upper Albian, immediatiy below the Cambridge Greensand, Arlesey. 8. Pleurostomella reussi BERTHELIN, megalospheric fprm, (x65), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 9. Pleurostomella reussi BERTHELIN, microspheric form, (x55), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10.11. Pleurostomella sp. 23, sp. nov., (x135), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 12, Ellipsoidella cf. austinana (CUSHMAN), (x70), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 13. Ellipsoidella cf. austinana (CUSHMAN), (x130), specimen broken to show internal tube extending downward from just beneath the aperture, Zone 10, Lower Chalk, Cenomanian near Beachy Head, Eastbourne.
350
Plate 22 (Cassidulinacea)
1.2. Quadrimorphina cf. allomorphinoides (REUSS), (x265), Zone 13, Lower Chalk, Upper Cenomanian, Buckland Newton, Dorset. 3.4. Globorotalites cf. minuta GOEL, (x175), Foxmauld Sands, Little Beach, Beer, Devon.
5.6.7. Gyroidinoides parva (KHAN), (x125), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 8.9.10. Biorostella sp. 1, sp. nov., (x130), Zone lla, Lower Chalk, Upper Cenomanian, near Beachy Head, Eastbourne. 11.12.13. Gavelinella baltica BROTZEN, (x85), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
Plate 23 (Cassidulinacea)
1.2.3. Gavelinella cenomanics, (BROTZEN), (x82 ), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 4.5.6. Gavelinella intermedia (BERTHELIN), (x105), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 7.8.9. Gavelinella reussi (KHAN), (x115), Bed IX, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 10.11.12. Gavelinella reussi (KHAN) var. Al var, nov., (x95), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne.
353
Plate 23 (contd.)
13. Gavelinella rudis (REUSS), (x105), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.
Plate 24 (Cassidulinacea)
1,2.3, Gavelinella tormarpensis BROTZEN, (x185), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 4.5.6. Lingulogavelinella albiensis MitLkPRIS, (x175), Bed XIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 7.8.9. Lingulogavelinella,globosa (BROTZEN), (x100), Bed 4, Plenus Marls, Maiden Newton, Dorset. 10.11.12, Lingulogavelinella,jarzevae (USILENK0), (x115), Zone 9, Lower Chalk, Cenomanian, Culver Cliff.
13. Lingulogavelinella cf. ,jarzevael (x150), Division B, Cenomanian sands, Bovey Lane Sandpit, Beer, Devon.
Plate 25 (Cassidulinacea, Robertinacea)
1.2.3. Lingulogavelinella turonica (BUTT), (x180), Zone 10, Lower Chalk, Cenomanian, near Beachy Head, Eastbourne. 4.5.6• Lingulogavelinella sp., sp. nov., (x120), Bed I, Plenus Marls, Compton Bay, Isle of Wight. - - 356
12114.25 (contd.)
7.8. Epistomina spinulifera (REUSS), (x64), Bed VIII, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian. 9.10. Hoeglundinacarpenteri (REUSS), (x120), Bed III, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Aibian. 11.12. Hoeglundina chapmani, (TEN DAM), (x110), Bed II, Copt Point, Folkestone, Type succession of the Gault Clay, Middle to Upper Albian.