GENY of UNISERIAL UVIGERINA from the MEDITERRANEAN REGION in the Same Series Has Appeared: Bulletin 1: FREUDENTHAL, T
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STRATIGRAPHY OF NEOGENE DEPOSITS I NTH ERE THY M NON PRO V I NeE, eRE T E, WIT H S PEe I A L REF ERE NeE TOT H E P H Y L 0- GENY OF UNISERIAL UVIGERINA FROM THE MEDITERRANEAN REGION In the same series has appeared: Bulletin 1: FREUDENTHAL, T. - Stratigraphy of Neogene deposits in the Khania Province, Crete, with special reference to Foraminifera of the family Planorbulinidae and the genus Heterostegina. (Statistical analysis, evolu- tion and stratigraphic application of Planorbulinella, Linderina, Helleno- cyclina and others. Material from localities in Europe, America and the Indopacific is included). 208 pages, 15 plates, 53 text figs., 10 tables. In the same series will appear: Bulletin 3: VERDENIUS, J. G. - Neogene stratigraphy of the western Guadalquivir Basin (S. Spain). (Mainly planktonic and benthonic smaller foraminifera). (In the press). The following titles are planned to appear in the near future: TJALSMA, R. C. - Stratigraphy and Foraminifera of the Neogene of the eastern Guadalquivir Basin (S. Spain). (Planktonic and larger fora- minifera). DROOGER, C. W., P. MARKS, A. PAPP et al. - Nummulites from the Upper Eocene and Lower Oligocene of the North Sea Basin. (Statistical analysis of Nummulites variolarius, N. orbignyi and related species). HARDENBOL, J. - Stratigraphy and Foraminifera of the Type Pria- bonian, Northern Italy. Subscribers to the entire series will have the benefit of a 20 % reduction. Subscriptions can be made to: Messrs Schotanus & J ens Lange Nieuwstraat 20 Utrecht The Netherlands STRATIGRAPHY OF NEOGENE DEPOSITS IN THE RETHYMNON PROVINCE, CRETE, WITH SPECIAL REFERENCE TO THE PHYLOGENY OF UNISERIAL UVIGERINA FROM THE MEDITERRANEAN REGION 1969 SCHOTANUS & ]ENS INC. UTRECHT - THE NETHERLANDS SUMMARY 7 I. INTRODUCTION 11 II. LITHOSTRATIGRAPHY 17 II. 1. Introduction 17 II. 2. Description of the formations . 18 2.1. Pandanassa Formation 18 2.2. Apostoli Formation 24 2.3. Rethymnon Formation 27 2.4. Gallou FormatiOn 32 2.5. Mylopotamou Formation 34 2.6. Dhramia Formation 38 2.7. Asteri Formation 41 2.8. Francocastello Formation 44 II. 3. Lithostratigraphic correlation 46 III. THE UVIGERINA MELITENSIS GROUP AND THE U. CRETENSIS GROUP IN THE MEDITERRANEAN NEOGENE 51 III. 2. Review of material studied 2.1. Crete 2.2. Italy 2.3. Spain 2.4. France 2.5. Malta III. 3. Counts and measurements 3.1. Parameters 3.2. Statistical approach of counts and measurements 3.3. The value of the parameters for classification. 3.4. The designation of species m. 4. Results of counts and measurements 66 4.1. Crete. 66 4.1.1. Section Exopolis- Vryses 66 4.1.2. Section Apostoli 71 4.1.3. Section Viglotopi-Apelaki . 75 4.1.4. Section Selli 79 4.1.5. Section Prasses 82 4.1.6. Section Moundhros 83 4.1.7. Section Asteri . 85 4.1.8. Section Stavromenos 89 4.1.9. Section Viran Episkopi 91 4.1.10. Section Dhramia 91 4.1.11. Scattered samples from the Rethymnon area 94 4.2. Italy 94 4.2.1. Section Rio Castellanfa 95 4.2.2. Section Tabiano Bagni 100 4.2.3. Section Lugagnano-Castell' Arquato 103 4.2.4. Section Borzano 107 4.3. Spain 108 4.3.1. Section Carmona 109 4.4. France 110 4.5. Malta. 111 4.5.1. Section 437 (Gozo) 111 4.5.2. Section 356/357 (Malta) 116 4.5.3. Section 110 (Malta) 120 III. 5. Conclusions 120 5.1. Two successive lineages 120 5.2. Summary of evolutionary trends in the U. melitensis group and the U. cretensis group . 120 5.2.1. Trends found in the single parameters 120 5.2.2. Relation between characteristics 123 5.3. General conclusions 128 III. 6. Taxonomy 129 6.1. Review of taxa reported earlier from the Mediterranean Neogene. 129 6.2. Species concepts 131 6.3. Taxonomic description 132 6.3.1. Introduction 132 6.3.2. Description of species 135 IV. BIOSTRATIGRAPHY. 145 IV. 1. Introduction . 145 IV. 2. Stratigraphic correlations 145 2.1. Crete 145 2.2. Italy. 149 2.3. Spain 150 2.4. Malta 150 PLATES 1-6 154 REFERENCES 166 Stratigraphical and micropaleontological investigations were performed on Neogene deposits of the Rethymnon Province, Western Crete. The Neogene succession includes marine as well as brackish and fresh-water sediments. Eight formations are recognized, several of which have to be regarded as lateral equivalents. From the sediment types and their distribution along the north coast it is concluded that to-day's topography still reflects the paleogeogra- phic conditions existing during the Neogene. The micropaleontological part of the paper deals with the phylogeny of two groups of Uvigerinids, the U. melitensis group and the U. cretensis group, both showing a main trend to uniserial chamber arrangement. Apart from our Cretan material samples are studied from localities elsewhere in the Mediterranean region. These samples are derived from Italy, Spain, France and Malta, and are partly taken from the stratotypes of the Late Neogene stages. The representatives of the U. melitensis and the U. cretensis groups can be distinguished by external characters such as the presence or absence of a distinct, regular, biserial stage in between the triserial and uniserial parts of the test, the more or less recurved character of the sutures, and the regular or irregular ar- rangement of the early uniserial chambers. The U. cretensis group corresponds to the U. gaudryinoides group in the literature, whose phylogeny was first emphasized by PAPP (1963). Representa- tives of this group are common in younger Neogene deposits throughout the Mediterranean region. So far the U. melitensis group is restricted to the Maltese Neogene and to the basal part of the Cretan Neogene succession. The evolutionary trend is the same in both lineages and comprises among other things an increase in the average number of uniserial chambers, an increase in the relative length of the uniserial part of the test, and the development toward an arrangement of the uniserial chambers in more regular series. Besides, a general trend is observed to relatively more slender tests. No development is found in the length or in the breadth of the test. The striate ornamentation ap- pears to be strongly environment controlled; specimens from deposits close to evaporites show an aberrant ornamentation. Since a typological approach of the observed features proves to give unsatis- factory results, counts and measurements are made on a number of parameters. The latter are based on the number of uniseral chambers, the character of the uniserial chambers, the length of the uniserial part of the test, and the length and the breadth of the test. The uniserial chambers can be divided into primitive uniserial chambers and fully developed ones, depending on the angle between the upper and lower sutural planes. In fully developed uniserial chambers these planes are more or less parallel, whereas they form an angle of 20° and more in primitive uniserial chambers. In ontogeny, the fully developed uniserial chambers are the younger ones. In the course of time the relative number of primitive uniserial chambers decreases, i.e., the uniserial chambers become arranged in more regular series. By comparing the number of primitive unserial chambers present at the same growth stage - for instance in all individuals with two uniserial cham- bers, or in those with three, or with four - parameters become available that are independent of the final ontogenetic stage the specimens reached. Appa- rently these parameters show the most constant development, evidently not influenced by external circumstances. In the course of phylogeny, most of the parameters and their means become more strongly correlated. In the higher part of the phylogenetic sequences random fluctuations in test size thus cause significant set-backs of the means in all other parameters, except in those based on the number of primitive uni- serial chambers in specimens at the same ontogenetic stage. Both lineages are not synchronous. The melitensis lineage starts approximate- ly at the Orbulina surface (base Serravallian?). Uvigerina (Hopkinsina) bono- niensis compressa is considered to be the forerunner. The last representatives of the lineage are found in deposits of Early-Middle Tortonian Age. The cretensis lineage probably starts in the Early Tortonian, and it ranges up into the Pleistocene. Its ancestor is as yet unknown. By statistical methods four morphologically adjoining species, successive in time, could be distinguished within each lineage. Seven of our eight species are new, because no meaningful contents could be given in terms of our biometri- cal analysis to the existing species names. Biostratigraphic correlations of our Cretan marine formations with the Late Neogene stratotypes indicate that marine sedimentation in the Rethymnon region started in the Early-Middle Tortonian and that it persisted up into the Pliocene without interruption. An interval of less than one Uvigerina Range zone, if any, seems to be present between the uppermost part of the type Tortonian (sensu GIANOTTI 1953, not CITA et aI1965) and the base of the Tabianian stratotype. If we accept GIANOTTI'Sdefinition of the upper limit of the Tortonian stratotype, there seems to be no need of a separate stage between the Tortonian and the Pliocene. The Andalusian stratotype is younger than the type Tortonian; actually it can be correlated with the Tabianian and Piacenzian stratotypes, which corre- lation points to its Pliocene Age. The Maltese Blue Clay and Greensand are considered older than the Cretan Neogene; the Upper Coralline Limestone may be contemporaneous with the basal marine deposits of Crete. PROVINCE \ IRAKLION I \, I "- ( -- SCHEMATIC MAP OF RETHYMNON PROVINCE CRETE AND ADJACENT AREAS Town, Village Monastery Castle Road Province boundary Dl!ltrlct boundary A Mountain Neogene deposits are common all over the island of Crete. This paper deals with the lithostratigraphy and some micropaleontological aspects of similar deposits in the Rethymnon Province and adjacent areas in the western part of the island.