© Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 4‘>3

Zitteliana 10 493-500 München, I. Juli 1983 ISSN 0373 9627

The Valanginian to Aptian stages - current definitions and outstanding problems

Compiled by

PETER FRANKLIN RAWSON»)

Willi 3 tables

ABSTRACT

Current definitions of the Valanginian to Aptian Stages are tion potential. The I’re-Albian Stages Working Croup is in­ reviewed and some of the outstanding problems outlined. Fi­ stigating study of selected sections in various parts of the nal recommendations on stage boundaries can be made only world to provide an integrated framework ol biostraligraphy after much more strat¡(graphical work has been completed, as and event stratigraphy. the eventual boundaries must have good international correla­

KURZFASSUNG

Lin Überblick über die gängigen Definitionen der Stufen barsein. Die Prc-Albian Stagcs Working Group regt an, ms vom Valangin bis zum Apt wird gegeben und einige wichtige gewählte Profile in verschiedenen Peilen der Welt zu unterst! Probleme hervorgehoben. Lndgülligc Empfehlungen zu Stu­ ehen, um so den allgemeinen Rahmen liii eine Ncudelinition fengrenzen sind z. Zt. noch nicht möglich. Dazu sind noch der Stufen auf der Grundlage der Biostraligraphie und der weitere stratigraphische Untersuchungen erforderlich, denn Lvenl-Straiigraphic zu schaffen. die fcstzulcgendcn Grenzen müssen international korrelier­

I. INTRODUCTION

This review has been compiled on behalf of the Prc-Albian boundaries and to improve the usage of stage names in re­ Stages Working Group of the Subcommission on Cretaceous gions away from stratotype sections." Stratigraphy. The primary role of the working group is to cla ­ Thus our fundamental philosophy is first to make objective rify, and to improve where necessary, the definition and correlations between regions and only then to redefine stages boundaries of the Valanginian to Aptian Stages. This cannot and their boundaries. be achieved simply by describing a stratotype and selecting As a first step towards priority I, several key sections were boundaries because such a procedure takes no account of the identified in western Rumpe. At its second meeting (Münster international correlation potential of the stages so defined. 1978, see Newsletter 3), the group agreed to concentrate ini ­ Hence at its first meeting in 1 lannover in 1977 (see the group’s tially on investigating correlation of I lautcrivian strata across Newsletter 2), the working group agreed on the following Europe, in collaboration with the re-investigation of the Jura priorities: Hautcrivian by a research group co-ordinated by Dr. J. Ri-: 1. “To establish inter-regional correlation more precisely mank. It is intended that first results on the investigation of than before, using all possible methods (macro- and mi­ key sections will be given at a meeting of the Subcommission crofossils, event stratigraphy, etc.)” on Cretaceous Stratigraphy in Copenhagen in 1983. In the 2. “As a result of more accurate correlation, to clarify (and if meantime it seems appropriate to summarise current de-fini necessary to improve) the definition of stages and stage tions of the Valanginian to Aptian Stages and to demonstrate some of the outstanding problems. For the sake of using a

*) P. P. Rawson, Department of Geological Sciences, Queen Mary common “language”, we hope that fellow workers will conti­ College, Mile P.nd Road, London Pd 4NS, P.ngland. nue to use stage names in the current sense ('Table I) until im- © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 494 proved definitions are agreed. Specialists who insist on using nardo (Lyon), R. C ombemorfl (Lyon), P. D onze (Lyon), T. them in a different sense are urged to explain their different N. G orbatchik (Moscow), J. E. van H inte (Amsterdam), usages. Ph . Hoedemaeker (Leiden), L. M emmi (Tunis), F. A. M idd- The following members of the working group assisted in lemiss (London), J. Remane (Neuchátel), J.-P. T hieuloy this compilation, though final responsibility for the wording (Grenoble) and M. R. A. T homson (Cambridge). rests with the compiler: D. J. Batten (Aberdeen), R. Bus-

II. EARLY CRETACEOUS BIOGEOGRAPHY AND THE STRATOTYPE AREAS

STAGE ZONE

FRANCE ENGLAND/NORTH GERMANY

Colchidites sp. Parancyloceras bidentatum & P. scalare

Simancyloceras stolleyi UPPER Heteroceras astieri "Ancyloceras" innexum & BARREMIAN Hemihoplites feraudi Simancyloceras pingue Emericiceras barremense P aracrioceras denckmanni

Paracrioceras elegans LOWER Moutoniceras sp. "Hoplocrioceras" fissioostatum BARREMIAN Pulchellia compressissima Paracrioceras raricostatum Spitidiscus hugii S. (C.) variabilis / Simbirskites „ \ . . (Craspedodiscus) Pseudothurmannia angulicostata S. (S.) marginatus ^ / discofalcatus UPPER Plesiospitidiscus ligatus S. (Craspedodiscus) gottschei

HAUTERIVIAN Subsaynella sayni S. (Kilanov;skia)_ speetonensis /sta ffi __

Lyticoceras nodosoplicatus Simbirskites (Speetonioeras) inversum

Olcostephanus .jeannoti LOWER Endemoceras regale Crioceratites loryi HAUTERIVIAN Endemoceras noricum Acanthodiscus radiatus Endemoceras amblv°-onium Neocomites (Teschenites) Olcostephanus spp. callidiscus Dicostella tuberculata UPPER Dichotomites bidichotomoides Himantooeras trinodosum VALANGINIAN Dichotomites triptychoides Dichotomites orassus Saynoceras verrucosum D. (Prodichotomites) polytomus ,D. (Prodichotomites) hollwedensis Polyptyohites sphaeroidalis Thurmanniceras campylotoxus Polyptychites clarkei Poljrptychites multicostatus Polyptychites pavlowi ilatylenticeras involutum Thurmanniceras pertran sien s Platylenticeras heteropleurum LOVER P la ty le n tic e ra s robustura Thurmanniceras otopeta VALANGINIAN

Table I . Valanginian to Barremian standard zones of south-east France, and the approximate correlation with the north-west European “boreal” Valanginian and Hauterivian. (Correlation afterKEMPER et al., 1981). No correlation between Barremian zones is intended. © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 495

During the Early Cretaceous there were two distinct faunal The historical type areas of the Valanginian to Aptian Sta­ realms in the northern hemisphere, the Tethyan and Boreal. It ges are in the Swiss Jura and south-east France, and are cha­ is difficult to attempt a global summary of Early Cretaceous racterised predominantly by Tethyan ammonites. Thus the biogeography because many taxonomic groups have not been main problem in Early Cretaceous stage definition lies in try­ investigated adequately, but K auffman (1979) has given a ge­ ing to correlate with the Boreal Realm. Primary clues come neral review, and for bivalves (K auffman, 1973) and ammoni­ from areas of faunal overlap (e. g. parts of Europe). The bio­ tes (Rawson, 1981) subdivision of the realms can be attempt­ stratigraphy of areas outside the type regions of the stages is ed. Valanginian to Aptian biostratigraphy is based primarily beyond the scope of this paper, but in Table 1 we give the ap­ on ammonites. As in the Tithonian and Berriasian, the Va­ proximate correlation of the Valanginian to Barremian Te­ langinian to earliest Barremian boreal ammonites are clearly thyan zones with the north-west European “boreal” zones to distinct from Tethyan ones, but during most of the Barremian illustrate the nature of the problem. The correlations achieved and Aptian there were no distinctively boreal subfamilies and so far suggest that some of the classic stage boundaries are of in the rare marine sections the northerly faunas were only de­ no inter-regional correlative value and therefore need to be al­ pauperated versions of the Tethyan ones. tered if they are to be equally applicable to both realms.

III. DEFINITION OF STAGES

THE VALANGINIAN STAGE b) Le calcaire compact ou marbre bâtard. c) Les marnes et brèches marneuses grises et bitumineuses. Author: D esor 1854 The “Marnes à A stieria” were explicitly placed in the Stratotype: The Seyon Gorge near Valangin, Neuchâtel, “Neocomian” (which became the Hauterivian of R ene- Switzerland. vier, 1874) by D esor and Gressly (1859, p. 36). It is also interesting to note that the first detailed descrip­ H ypostratotype: Roadside section near Angles (Al- tion of the succession at the type locality did not appear pes-de-Haute Provence, south-east France); Barret-le-Bas until the end of the century (Baumberger and M oulin, (Hautes-Alpes, south-east France) provides a complementary 1899). reference for the Lower Valanginian (Busnardo et al., 3. Logically, Renevier therefore included the “Marnes à 1979). A stieria” in his Hauterivian Stage. It is only since Baum­ Original definition: D esor (1854, p. 175) regarded all berger (1901, p. 21) that it has become general usage to the “Neocomian” beds beneath the “Marnes de Hauterive” as place them in the Valanginian. corresponding with Campiche’s “Neocomien inférieur”, and for this subdivision proposed (p. 177) the stage name “Valan- Development of the concept of the Valanginian gien” (“Valanginien” in the title of the paper). Thus the Va­ Stage: The early Cretaceous sediments of the Jura Moun­ langinian embraced all the post-Jurassic rocks to the base of tains accumulated on a shallow shelf. Some lithological units are thin, condensed and laterally discontinuous, especially the “Marnes de Hauterive”. those lying between the “Calcaire Roux” and the “Marnes de There are three important points to note with reference to Hauterive” . Early biostratigraphic correlation was based the definition of the boundary between the Valanginian and primarily on echinoids, and ammonites are generally rare. Hauterivian Stages: This, coupled with the incompleteness of the sequence, means that both the Valanginian and the Hauterivian stratotypes 1. In terms of local lithostratigraphic units, D esor’s defini­ tion is very vague. He indicated (p. 174) that the “calcaires have a very limited correlation potential. Because of the rarity jaunes à Ammonites astierianus” lay beneath the “marnes of ammonites K ilian and other French workers preferred to bleues de Haute-Rive” and hence by defining the Valangi­ define both stages according to the succession of ammonite nian stage to include all the units beneath the “marnes de zones established in the vocontian facies of south-east France. Hauterive” apparently implied that beds containing It should be noted that K ilian paid little attention to the cor­ “Ammonites astierianus” (= Olcostepbanus) were Va­ relation between the French zones and the original stratotype langinian. Unfortunately it is impossible to decide whet­ successions when drawing his boundaries. her the “calcaires jaunes à Ammonites astierianus” are In 1871, C oquand proposed the Berriasian for the limesto­ equivalent to the “Marnes à A stieria” (= “Astieriamer- nes of Berrias, regarding it as a substage for the lower part of g el”), a critical bed at the Valanginian-Hauterivian boun­ the Valanginian. Lory (1898) and Paquier (1900) then dary which was first described by df. T ribolet (1859). restricted the Valanginian to exclude the Berriasian and re­ Hence one cannot say how far the phrase “un étage à part, cognised lower and upper divisions of the restricted Valangi­ inférieur aux marnes de Hauterive” (Desor, 1854, p. 175) nian. Kilian (1910) reverted to an extended Valanginian, his has to be taken literally. lower Valanginian corresponding to the Berriasian and his 2. The first clear definition of the Valanginian was only given middle Valanginian to the lower Valanginian of Lory and Pa­ by D fsor and G ressly (1859, p. 40). From top to bottom, quier. A similar tripartite division was applied in north the stage was intended to include: Germany (e. g. Stolley , 1925). a) La limonite ou calcaire ferrugineux Mainly because of M azenot’s (1939) work, the Berriasian (= “calcaire roux” in actual usage) began to be used as a stage, and this was ratified by the 1963 496 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

I .yon colloquium, when the overlying Valanginian was divid­ and TuiEui oy (in Busnakdo el ah, 1979)suggested that faunas ed into: of the lower part ol Li H i carat’s pertransiens Subzone re­ substage zone presented a mixture of Berriasian and Valanginian forms, ge­ Upper Valanginian Saynoccras vcrrucosiim nerally poorly known species. This intermediate fauna be­ Lower Valanginian Kilianella roiibaudiana tween the “classic” Berriasian and Valanginian was known to M azi not. Lor this fauna the ntopeta Zone was proposed. The At the Colloquium, the principle of establishing a new stra- lower part of the overlying pertransiens Zone coincides with lolype in the vocuntian facies was approved. A hypostrato­ the remainder of Lr H i.g arai’s pertransiens Subzone (see type was formally proposed in 1979by Busnakdo et al. The Busnakdo and T emeuioy’s table 3, p. 62). As the distinctive Angles section anti a complementary section for the Lower Kilnmclld species of the old rmtbauduina Zone first appear Valanginian at Barrel-le-Bas were measured and sampled within the pertransiens Zone, Busnakdo and T iiieuioy have bed-by-bed and the ranges of ammonites, belemnites, ostra- effectively lowered the base of the Valanginian compared with cods, nannolossils, calpionellids and foraminilcra were esta­ previous definitions. blished. Some new zones were proposed (Tabie 2). "The am­ monite zones proposed by Busnakdo and Tim m ov (in Bus From the Caravaca region of south-east Spain, I Ioedemae NARiio et ah, 1979)represent the culmination of many years of ker (1982) has proposed a subzone of Tirnovella alpillcnsis, work on all the main ITcncli sections and are traceable across which he correlates with the callisto Subzone of Lt H ecarat the whole voeontian trough. The zones (Tables 1, 2) are as­ and Ri mani (1968). However, while the French callisto Sub­ semblage hiozones, in which the index species reached ns zone contains Berriasian ammonites, its Spanish equivalent acme within the nominate zone. Some ol the zones have been contains Valanginian forms too, and thus H oidemaekir pla­ recognised in Tunisia (Ml mm I, 1981) but still require testing in ces the alpillcnsis Subzone in the Valanginian. If the correla­ other Tethyan areas. tions are correct, this would suggest that the French callisto Subzone should be placed in the Valanginian. Base of the Valanginian: The boundary between the Berriasian and the Valanginian has been placed between the While further work is clearly required, neither definition boissieri and roitbaitdiana Zones since these were introduced allows the base of the Valanginian to be recognised in the Bo­ by Kit ian (1888). The base of the Valanginian was effectively real Realm. In the West F.uropcan Province the first appea­ marked by the appearance ol KilhinclLt. The palaeontological rance of Platylcnticeras is taken to mark the base of the Va­ boundary was believed to coincide with the lithological langinian (Ki meek, 1973), because early species occur also in boundary between the “Calcaires tie Benias” and the “Mar­ France, at approximately the base of the old roitbaudiana nes valanginiennes”. However, Le H i carat (1965) showed Zone. In the modern /.»nation this horizon is at about the base that the highest part of the ‘‘Calcaires dc Berrias” contained a of the pertransiens Zone, and thus the otopeta Zone may cor­ distinctive early Valanginian fauna, lor which he later (in Li relate with the highest Ryazanian of the boreal sequence. I Ii-oarat and Remane, 1968) introduced the pertransiens Base of the Upper Valanginian: The old Saynoccras Subzone. This subzone has priority over the litcensis Zone, vcrrucosiim Zone spanned the whole of the Upper Valangi­ introduced by W iedmann (1968) for the same fauna in the nian. However, M oui i adi and T iiii uioy (1967) showed that same beds. the index species had a very short range, and restricted the Li 1 11.carat (1973, p. 295) believed the faunal change from zone to embrace only the lowest part of the Upper Valangi­ Berriasian to Valanginian was abrupt. However, Busnakdo nian. The sudden appearance of Saynoccras vcrrucosiim and

AMMONITES FORAMINIFERA OSTHACODS CALITONELLIDs NANNOFLORA

Neocomités Hapiophragmoides (Teschenites) vocontianus callidiscus

Thetysia Himantoceras Lenticulina trinodosum chabrensin ft u eichenbergi in f la ta s Laynoceras Calcicalathina verrucosum Lenticulina hauteriviana oblongata Thu rmann i ce ra s Lenticulina campylotoxum busnardoi Calpionellites Thetysia darderi ...... Thurmanniceras chabreneir, u petransiens Lenticulina chabrensis Cretarhabdus nodoaa TiofehzTella- Thurmanniceras crenulatus 5 nodona hungarica ...... otopeta Calpionellopsls- o b lo n g a...... « • T

Table 2. Biostratigraphic subdivision of the French Valanginian (after IiUSNAKDO et al., 1979). © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 497 some associated species (e. g. Valanginites nucleus, N eoho- The base of the Upper Hauterivian: The separation ploccras submartini and Karakascbiceras spp.) in north-west of the Hauterivian into two substages, defined by the disap­ Europe marks a major faunal migration horizon (and trans­ pearance of the Neocomitinae and the appearance of Subsay- gression) which can be traced in the Polish Furrow, nortli nclla sayni, is very clear, especially in Ardeche where the hc- Germany and eastern England (Kemper, R awson and T hieu- mipclagic sequence is very expanded (Busnaruo, herein). loy, 1981, p. 259). The same fauna occurs also in Tunisia Thus the base of the Upper Hauterivian is defined by the base (Memmi, 1981). ol the Subsaynella sayni Zone. The boreal Upper Hauterivian is characterised by Simbirs- kites (with several subgenera) which occurs from California THE HAUTERIVIAN STAGE and Arctic Canada to north-west Europe and the So­ viet-Union. Faunal mixing in north-west Europe shows that Author: Renevier 1874. the base of thcTcthyan Upper Hauterivian correlates with the Stratotype: “Hauterive” (actually in Neuchatel), Swit­ upper part of the Simbirskites (Spcctoniccras) inversion Zone zerland. (Kemper ct ah, 1981, p. 307). Original definition: R enevier included the “mames a Asticria", the “mames bleue dc f lautcrive” and the “Pierre Jaunc de Neuchatel”. THE BARREMIAN STAGE Discussion: By including the “Mames a Astierui” (= “Astieriamergcl”) in the Hauterivian Stage, R enevier Author: C oquand 1861. placed the base of the Hauterivian to agree with D esor and Stratotype: Angles, Basses-Alpes, France (designated G ressly’s (1859) definition of the top of the Valanginian (see Valanginian discussion, above). by Busnardo, 1965 b). Development of the concept of the Hauterivian Original definiton: C oquand proposed the stage for Stage: Eor reasons discussed above (see “Valanginian Sta­ beds characterised by “lielemuitcs minaret, Ammonites liga- ge”) the Hauterivian of the type area proved to be of limited tus, Scapbitesyvanni, etc.”. Angles was one of the cited loca­ lities. correlation potential. Hence Kilian and others again turned to the French sequence for a better standard, and here propos­ Development of the concept of the Barremian ed four ammonite zones. The lowest was that of Acantbodis- Stage: Although C oquand’s original definition was not very cus radiatus, which most subsequent workers (including precise, Busnardo (1965a) pointed out that it embraces both Baumbergir ) accepted as marking the lowest Hauterivian. the Barremian and Upper Hauterivian of current usage. Pre­ However, in the Jura A. radiatus occurs in the “Mames de sent usage effectively dates from K ii.ian’s (1888) work on the I lautcrive” but not in the “Marnes a Astieria" beneath. Thus montagne dc Lure: Busnardo (1965b) summarised subse­ common usage has modified the Valanginian/Hauterivian quent ideas and tabulated the evolution of zonal schemes. We boundary as defined by R enevier . It should also be noted that agree with him that despite historical priority it is best in the in the French scheme the Hauterivian Stage was extended up interest of stability to follow customary usage and limit the wards so that both the “Marnes dc Hauterive” and the “Pierre Barremian in Kn.ian’s sense. jaune” are now Early Hauterivian. Busnardo (1965 b) designated the Angles roadside section T hieuloy (in M oullade and T hif.ueoy, 1967) has modified as stratotype because it is complete, readily accessible, suffi­ the zonation of the French successions (see Table 1), though ciently rich in ammonites and tectonically undisturbed. It is further revision is in progress (by Busnardo and T hieuloy) part of the same long exposure that has been selected as hy­ and the sequence has still to be described in detail. No hypo­ postratotype of the Valanginian. Busnardo gave a detailed li- stratotype section has been described. D ebelmas and T hifu- thic log and ammonite ranges, retained Kilian’s division into loy (1965) recommended that one should be chosen in the Sa Lower and Upper Barremian and proposed a zone for each lérans region (Hautes-Alpcs), but T hieuloy (herein) now be­ substage. He also suggested a subzonal scheme, though that lieves that this alone would not be sufficient: several sections was incomplete because of gaps in the faunal sequence. Bus are useful, including La Charce, Sallcrans, Bárreme and Ca- nardo (1965 a, p. 115) regarded his work as a first step in stcllanc. achieving a geographically widespread zonation, and indicat­ ed the problem of selecting suitable zonal and subzonal indi­ The base of the Hauterivian: T hieuloy (1977, p. 125) has formally defined the base of the radiatus Zone at La ces. Recently he has put forward a more detailed zonation Charce as the base of the Hauterivian. The base of the rad'ux- (Busnardo in Roger, 1980, table) which is shown, with slight tus Zone itself is defined by the first appearance of A cantho- modification (Busnardo, herein) in Table 1. The zonation discus. The use of A. radiatus as a zone fossil has been critici­ has yet to be formally described. sed because it is so rare in the vocontian facies, but despite this Elsewhere in the Tcthyan Realm, the best-known faunas it is very useful because it allows an inter-realm correlation. are probably in Colombia, where a detailed pulchelliid zona­ Early Hauterivian strata are poorly known in the Boreal Re­ tion has been established, and the Barremian divided into alm (Rawson, 1981) but occurin north-west Europe. In north “lower”, "middle” and “upper”. In the Boreal Realm, Bar­ Germany, rare Acantbodiscus occur near the base of the En- remian faunas occur mainly in north-west Europe, where dcmoccras beds and hence these are placed conventionally in they arc represented predominantly by hctcromorphs and, in the Hauterivian. In theory, the lowest beds could be latest Va­ the basal Barremian, by the last Simbirskites. Some of the he- langinian, but the area of uncertainty is small. teromorphs may be identical with Tethyan species, other are 49S © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

endemic. Stolley (1925) recognised a tripartite division into This limit differs slightly from that published in Roger (1980, “lower” , “middle” and “upper” and proposed a zonal table). However, it remains difficult to define in the stratoty­ scheme which has been modified only slightly since (see Im- pe, for want of sufficiently numerous fossils. mel , 1979, table 5). The base of the Barremian : At the stratotype section the passage from Hauterivian to Barremian was hidden by fal­ THE APTIAN STAGE len rock, though faunas can now be collected. Species of Pul- chellia, Ho/codiscus and “Enienciceras” (= Paracrioceras) Author: d’O rbigny 1840. have been used by various authors to define the lowest zone. Stratotyp es: The stage was named after Apt (Vaucluse) At present, Busnardo (herein) takes the appearance of Ra- in south-east France. However, there is no single stratotype spailiceras and Barremites to mark the base of the stage, section: La Bedoule, Gargas (near Apt) and Clansayes are all though this limit will be refined eventually. There is a slight reference sections for subdivisions of the Aptian though not overlap between these forms and the last representatives of all are satisfactory for correlation purposes. Pseitdothurmanma (especially P. gr. edoitardi). Spitidiscits Original definition: The stage was proposed rather (gr. kiluini-hugii) and Nicklesui appear several beds higher in loosely for strata containing an “Upper Neocomian” fauna, the sequence. but d’O rbigny' later modified his definition several times. In the Boreal Realm, the base of the north-west European Development of the concept of the Aptian Stage: Barremian lies approximately at the base of the English varia- F landrin (1965) and Moullade , T axy and T ronchetti biln Zone and in the middle of the German discofalcatus (1980a) have summarised the history of interpretation of the Zone (K emper et ah, 1981, p. 307). Aptian Stage and its subdivisions in France, and Casey (1961) The base of the Upper Barremian: Busnardo (here­ reviewed its interpretation in other European areas too. The in) defines the base of the Upper Barremian by the appearance 1963 Lyon Colloquium adopted the following division of the of Heinzia and of “Emericiceras” of the barrem ense group. French Aptian (Anonymous, 1965):

Clansayesian Diadochoceras nodosocostatum Upper Aptian Epicbeloniceras subnodosocostatian Gargasian { { Aconecerus nisns Lower Aptian Bedoulian Deshayesites desbayesi

Moullade et al. (1980a, p. 113) pointed out that in terms of The ammonite sequence in the French Aptian is still inade­ both stratigraphical nomenclature and logic a division into quately documented (see Moullade et ah, 1980a) and at pre­ Lower and Upper Aptian was less satisfactory than Brei- sent the zonal division of the English (C asey, 1961) and north stroffer’s (1947) tripartite division into Lower Aptian or Be­ German (Kemper , 1976) sequences is much more detailed. Al­ doulian, Middle Aptian or Gargasian and Upper Aptian or though there was still some faunal differentiation between the Clansayesian Substages. north-west European and French areas, it was not as well-

South-east France Oouthpm England North Germany

Hypacanthopiite s jacob i Diadochoceras Hypacanthopli tes nodosocos ta turn jncobi Acanthohoplites nolani UPPER Epicheloniceras Parahoplites Parahoplites APTIAN subnodosocostatura nutf ieldiensis nutfieldiensis

Epicheloniceras Epicheloniceras tschemyschewi Aconeceras nisus martinioides Tropaeum drewi

Tropaeum Tropaeum bowerbanki bowerbanki

Deshayesites LOWER deshayesi Deshayesites Deshayesites deshayesi APT UN deshayesi Deshayesites fo rb esi

Prodeshayesites Prodeshayesites f issicostatus tenuicostatus

Table 3. Correlation of French, English and north German Aptian zonal schemes. © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at 499

marked as earlier in the Cretaceous and broad correlation can The Gargasian “SubstageThe Gargasian was pro­ be made (Table 3). posed by Kilian (1887) for marls with Aconeceras near Gar­ Rich ammonite faunas occur also in parts of the Soviet gas, but is now used in a more limited sense (see Moullade , Union. Here, some recent workers have abandoned the long­ 1980 a). The Gargas section is of limited value for correlation -established division into Lower and Upper Aptian in favour and several sections have been investigated for selection as a of a tripartite division. parastratotype; nothing has yet been published (Moullade , 1980a, p. 122). The base of the Aptian : The appearance of the earliest deshayesitid ammonite, Prodesbayesites, marks the base of The Clansayesian “ Substage” : The Clansayesian the north-west European Aptian, and this genus is now was proposed by Breistroffer (1947) for about 5 metres of known from south-east France. It appears there immediately cross-bedded sands with beds of phosphatic nodules yielding above latest Barremian Colcbidites, as for example at La Be- a Diadocboceras nodosocostatum Zone fauna. Again the stra­ doule (Busnardo, herein). Thus it appears to be a good mar­ totype is poor, and a working group has chosen the Lioux sec­ ker over a wide area. tion (Alpes-de-Haute-Provence) as a parastratotype though the decision is not yet published. The Bedoulian “ Substage” : TheBedoulian was pro­ posed by T oucas (1888) for the upper part of the limestones of Moullade (1980 b) has pointed out that of the three Aptian La Bedoule, near Marseilles. The Lyon Colloquium recom­ “substages” the Clansayesian is the thinnest and is often diffi­ mended that the name be used in a broader sense, following cult to separate palaeontologically. It is thus often included in K ilian (1907-13). M oullade , T axy and T ronchetti (1980 b) an enlarged Gargasian, or referred to informally as the “Clan- reviewed the sequence in the stratotype area, and a “Bedouli- sayes horizon”. At present the name is not used outside the en” volume is to be published in the CNRS series “Les strato­ south of France: in most other areas there is a two-fold divi­ types français”. This will include 7 ammonite zones, which sion into Lower and Upper Aptian. Thus one of the outstand­ can be correlated with C asey’s (1961) English scheme. At pre­ ing problems to be resolved by the working group is whether sent, only a single zone of Desbayesites deshayesi is recognis­ the Clansayesian should be retained, and if so what status it ed (Table 3). should have.

IV. CONCLUSIONS

Research over the last 150 years has resulted in a broad un­ 1. Lithological/palaeontological logging of the remaining derstanding of the world-wide distribution and correlation of type sections. rocks of Valanginian to Aptian age. For the stratotype areas of 2. Comparable logging of other key reference sections (some France and Switzerland the 1963 Lyon Colloquium (publish­ of which will serve as regional stratotypes) around the ed 1965) summarised much useful information and stimulated world. further research, some now published. However, even in 3. Magnetostratigraphic logging of stratotypes and other key these areas few sections have been described in detail and most reference sections. stage/substage boundaries are open to dispute. The present 4. Chronostratigraphic logging of stratotypes and other key review shows a strong bias towards ammonite biostratigraphy reference sections (O and C stable isotopes, rare elements, because ammonites have been the main tools of correlation so organic matter). far; yet many ammonite ranges are still poorly known and few other taxon ranges are adequately documented. 5. Search for radiometrically datable material in stratotypes and key reference sections. Most of the problems outlined in this brief review can be re­ 6. Synthesis of all available data to provide: solved only after much more field work. For the Valanginian a) A definition of stage and substage boundaries that is Stage, and to some extent for the Barremian and Aptian Sta­ valid for as broad an area as possible, ideally globally. ges, detailed lithological/palaeontological logs have been b) A series of standard zonal schemes for individual fau- produced for the stratotype sections, and these provide a star­ nal/floral regions. ting point for the next phase of research. This will concentrate on: 500 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

V. LITERATURE CITED

Anonymous (1965): Conclusions generales du Colloque. - Mém. C asey & P. F. R a w so n (Eds), 327-344. Geol. Jb ., Spec. Iss. Bur. Rés. Geol. Minier., 34: 827-834. 5. BAUMBERGER, E. (1901): Über Facies und Transgressionen der unte­ ------(1976): Geologischer Führer durch die Grafschaft Bentheim ren Kreide am Nordrande der Mediterrano-helvetischen und die angrenzenden Gebiete. — 206 pp., 34 pis; Bentheim Bucht. - Wiss. Beil. Ber. Töchterschule Basel, 1900/1901. (Nordhorn). -----& MOULIN, H. (1899): La Serie néocomienne à Valangin. — — , R a w so n , P. F. & T h ie u l o y , J.-P . (1981): Ammonites of Bull. Soc. Sei. nat. Neuchâtel, 26. T ethyan ancestry in the early Lower Cretaceous of north-west Br e i STROFFER, M. (1947): Sur les zones d’Ammonites dans l’Albien Europe. - Palaeontology, 24: 251-311. de France et d’Angleterre. -T rav. Lab. Géol. Grenoble, 26, Kilian , W. (1888): Description géologique de la Montagne de Lure 88 pp. (Basses-Alpes). - Ann. Sei. Géol., 19-20: 458 pp. BUSNARDO, R. (1965 a): Le Stratotype de Barrémien. 1. - Lithologie ------1907-1913. Unterkreide (Palaeocretacicum). - in: Letbaea et Macrofaune. — Mém. Bur. Res. Géol. Minièr., 34: 101-116. Geognostica. IL Mesozoic., Vol. III, Kreide, 398 pp., 14 pl. ------(1965 b): Rapport sur l’étage Barrémien. - Mém. Bur. Res. Stuttgart (Schweitzerbart). ' Géol. Minier., 34: 161-169. Lo r y , P. (1898): Sur le Crétacé inférieur du Dévoluy et des régions ------, Thieuloy , J.-P . & Moullade , M. (1979): Hypostratotype voisines. - Bull. Soc. géol. Fr., (3) 26: 132-138. mesogéen de l’étage Valanginien (sud-est de la France). - Les M a z e n o t , G. (1939): Les Palaeohoplitidae tithoniques et berriasiens stratotypes français, 6, 143 pp. du Sud-Est de la France. — Mém. Soc. géol. Fr., 18: 303 pp., CASEY, R. (1961): The stratigraphical palaeontology of the Lower 40 pis. Greensand. - Palaeontology, 3: 487-621. M em MI, L. (1981 ): Biostratigraphie du Crétacé inférieur de la Tunisie COQUAND, H. (1861): Sur la convenance d’établir dans le groupe in­ nord-orientale. - Bull. Soc. géol. Fr., 7 (23): 175-183. férieur de la formation crétacée un nouvel étage entre le Néo­ M o u l l a d e , M. (1980a): Gargasien. — Mém. Bur. Res. Géol. Mi­ comien proprement dit (couches à Toxaster complanatus et à nièr., 109: 120-122. Ostrea coulom) et le Néocomien supérieur (étage Urgonien de ^------(1980b): Clansayésien. -M ém . Bur. Res. Géol. Minièr., 109: D’O r b ig n y ). - Mém. Soc. Emul. Provence, 1: 127-139. 123-125. ------(1871): Sur le Klippenkalk du département du Var et des Al­ ------, T axy, S., & T ronchetti, G. (1980a). Aptien. -M ém . Bur. pes-Maritimes. - Bull. Soc. géol. Fr., 28: 232-233. Res. Géol. Minier., 109: 112-115. Debelmas , J. & Thieuloy , J.-P . (1965): Étage Hauterivien. - Mém. ------, ------& ------(1980b): Bédoulien. — Mém. Bur. Res. Bur. Res. Géol. Minier., 34: 85-96. Géol. Minièr., 109: 116-119. Desor, E. (1854): Quelques mots sur l'étage inferieur du groupe néo­ ----- 6c T h ie u l o y , J.-P. (1967): Les zones d’Ammonites du Va­ comien (étage Valanginien). - Bull. Soc. Sei. nat. Neuchâtel, langinien supérieur et de l’Hauterivien vocontien. - C. R. 3: 172-180. somm. Séancs. Soc. géol. Fr., 6: 228-229. ------& Gressly , A. (1859): Études géologiques sur le Jura neuchâ- D’ORBIGNY, A. (1840): Paléontologie française. Terrains crétacés. 1. telois. - Mem. Soc. Sei. nat. Neuchâtel. 4: 1-159. Céphalopodes. 662 pp. Paris. Flandrin, J. (1965): Rapport sur l’étage Aptien. - Mém. Bur. Res. PAQUIER, V. (1900): Recherches géologiques dans le Diois et les Ba­ Géol. Minièr., 34: 227-234. ronnies orientales. — Ann. Univ. Grenoble, 12: 373-516, Le Hé GARAT, G. (1965): Le Stratotype du Bernasien. 11. Stratigra­ 551-806, 8 pis. phie et macrofaune. — Mém. Bur. Res. Géol. Minièr., 34: Rawson, P. F. (1981): Early Cretaceous ammonite biostratigraphy 9-16. and biogeography. - in: The Ammonoidea. -M . R. HOUSE & ------(1973): Le Berriasien du Sud-Est de la France. — Doc. Lab. J. R. Senior (Eds): p. 499-529. Syst. Ass. Spec. Vol. 18. Géol. Fac. Sei. Lyon, 43: 575 pp., 55 pl. RENEVIER, E. (1874): Tableau des terrains sedimentaires. — Bull. Soc. ------6C Rf.MANE, J. (1968): Tithonique supérieur et Berriasien delà vaud. Sei. nat., 13: 218-252. bordure cévenole. Corrélation des ammonites et des calpio- R o g e r , J. (1980): Barrémien. - Mém. Bur. Res. Géol. Minièr., 109: nelles. - Geobios, 1: 7-70. 106-111. HOFDEMAFKER, Ph. J. (1982): Ammonite biostratigraphy of the up­ St o l l e y , E. (1925): Die leitenden Belemniten des norddeutschen permost Tithonian, Berriasian and lower Valanginian along Neokoms. - 17. Jber. Niedersâchs. Geol. Ver.: 112-126. the Rio Argos (Caravaca, SE Spain). - Scripta Geol., 65: 1-81. THIEULOY’, J.-P. (1977): La zone à Callidiscus du Valanginien supé­ Immel , H. (1979): Die Ammonitengliederung des mediterranen und rieur vocontien (Sud-Est de la France) Lithostratigraphie, borealen Hauterive und Barreme unter besonderer Berück­ ammonitofauna, limite Valanginien-Hauterivien, corréla­ sichtigung heteromorpher Ammoniten der Gattung Criocera- tions. - Géol. Alpine, 53: 83-143. tites Leveille . - Newsl. Stratigr., 7: 121-141. TouCAS, A. (1888): Note sur le Jurassique supérieur et le Crétacé in­ Kauffmann, E. G. (1973): Cretaceous Bivalvia., in: Atlas of Palaeo- férieur de la vallée du Rhône. - Bull. Soc. géol. Fr., 3 (16): biogeography. - A. Hallam (Ed.), 353-383. Elsevier, Am­ 903-927. sterdam. T r ib OLET, G. (1859): Sur l’Ammonites Astieri de la base des marnes ------(1979): Cretaceous, in: Treatiseon Invertebrate Paleontology, néocomiennes. - Bull. Soc. Sei. nat. Neuchâtel, 5. Part A. Introduction. - A418-A487. University of Kansas WIEDMANN, J. (1968): Das Problem stratigraphischer Grenzziehung Press. und die Jura/Kreide-Grenze. — Eclog. geol. Helv., 61: KEMPER, E. (1973): The Valanginian and Flauterivian Stages in 321-386. northwest Germany, in: The Boreal Lower Cretaceous. - R .