IChlor « Nikoiov THE MEDITERRANEAN LOWER CRETACEOUS (§[l®[y®(§D(g^ Су) §@[FÛ@g ®[р@[?Ш[]Ш gÛDûgQOD®[?0fl0ïïù Todor G. Nikolov LE CRETACE INFERIEUR MESOGEEN EDITIONS DE L'ACADEMIE BULGARE DES SCIENCES. SOFIA. 1987 Тодор Г. Николов СРЕДИЗЕМНОМОРСКИЙ НИЖНИЙ МЕЛ ИЗДАТЕЛЬСТВО БОЛГАРСКОЙ АКАДЕМИИ НАУК. СОФИЯ. 1987 BULGARIAN ACADEMY OF SCIENCES SOFIA UNIVERSITY "KLIMENT OHRIDSKI" Todor G. Nikolov THE MEDITERRANEAN LOWER CRETACEOUS Sofia.1987 PUBLISHING HOUSE OF THE BULGARIAN ACADEMY OF SCIENCES In this monograph the Lower Cretaceous of the Mediterranean palaeogeographic Region is considered. The Lower Cretaceous sediments in this large area are developed in varions faciès and are rich in fossils. On the background of a broad, almost global panorama the author considers the foundation of stratigraphy of the Lower Creta­ ceous in the Mediterranean Region, the regional stratigraphie features of the development of the Series In local areas, the evolution and palaeobiogeography of the Early Cretaceous marine organisms in the Mediterranean, as well as the basic features of the geological evolu­ tion of these areas during Early Cretaceous. The book is the first synthesis of this kind on the Lower Cre­ taceous of such a large area and represents a long-term research of the author in Bulgaria and in many other countries as well. The monograph is designed to be of interest for a broad circle of specialists — geologists, geophysicists and students of corresponding professional fields. Тодор Георгиев Няколов Превод от български език Нсдялка Гочсва Чакалова 1987 с/о Jusautor, Sofia 55 PREFACE The idea for this study arose several years ago, when the author had to investigate the Bulgarian Lower Cretaceous in a wide (almost global) stratigraphie and pa- laeographic panorama. Even at that time a picture emerged, representing — figuratively speaking — an "Alpian-Himalayan" mixing of various processes and phenomena, with different interferences in the concrete regions and provinces. Parallel with this, there appeared the contours of definite trends of great signific­ ance for the Early Cretaceous geological evolution of one of the most dynamic areas in the Earth's crust. In view of the level of present-day knowledge on the Lower Cretaceous in Bul­ garia, it may be assumed that its investigation over a wider area would contribute to the further development of the theory and practice of Lower Cretaceous stra­ tigraphy. Another impetus for this difficult work is the practical lack of a generalization of the Lower Cretaceous in world literature. After Kilian's synthesis in Lethaea Geognostica (K i 1 i a n, 1907-1913) concerning the Lower Cretaceous in Southern France, only Eristavi ( Эристави, 1962) has made an attempt at a generali­ zation of the Lower Cretaceous in the Alpine Zone, though his work is rather sche­ matic. The Mediterranean Region is part of the Tethys Ocean (Tethys Belt in palaeo- biogeographic sense of the term). The Tethys is known to have comprised vast an­ cient marine aquatoria which crossed theMegagea from the Proto-Atlantic to the west, to the Proto-Pacific to the east (S t i 11 e, 1946). It covered vast areas of North­ western Africa, Southern Europe, the Caucasus, Asia Minor, Iran, Afghanistan, the Himalayas and Indo-China to the Caroline corner in the Proto-Pacific. The Tethys Ocean was the conflict space between several lithospheric plates. It gener­ ated tto Alpian-Himalayan Mountain Belt, while its fragments are the Mediter- raneansea, the Black Sea, the Caspian Sea, the Persian Gulf and the seas of the Malayan Archipelago (B i j u-D u v a 1, 1974; В i j u-D u v a 1 et al., 1976). The Mediterranean Region comprises Northern Africa, Southern Europe, the Caucasus and Asia Minor. It is characterized by specific development of the Lower Cretaceous, in contrast to the other adjacent regions and provinces (Volgian, Boreal, Himalayan, Malgash, Andian). Various facies are developed in this region: from deep-sea to continental. Rich fossil associations belonging to different groups of organisms are found. The present monograph is based on the results of the studies on the Lower Cretaceous in Bulgaria, carried out by the author since 1957. In addition, between 1960 and 1984 the author had the opportunity to investigate and collect materials from different countries in the Mediterranean Region (Algeria, France, Switzer­ land, Italy, Yugoslavia, Greece, Hungary, Romania, Czechoslovakia, Poland and the Soviet Union). The study of the Lower Cretaceous over such a vast area came' up against many difficulties, especially with respect to some countries where the series has been insuf- 5 ficiently investigated. On the other hand, generalizations always conceal the poten­ tial danger of a superficial survey. This is why, the author's intention has been to comprise as fully as possible the general trends in the development of the Lower Cretaceous, by presenting the factual material serving as a starting point. In an attempt at concise presentation of the material, detailed characterization of the series in the individual countries has been avoided. The interpretations reflect the author's theoretical views and his concept about the stratigraphy of the Lower Cretaceous. When examining the Lower Cretaceous in such a vast area, considerably more attention has been devoted to the Lower Cretaceous in Bulgaria. With this the author's aim has been to offer a better opportunity to foreign readers to become familiar with the stratigraphie investigations of the Lower Cretaceous in this coun­ try, because the relevant literature published so far is mainly in Bulgarian. On the other hand, the monograph also contains relatively brief information about Greece, Turkey and the Middle East, both due to the limited Lower Cretaceous outcrops there and to the small number of specialized studies. The area to the east of the Caspian Sea and Iran manifests faunistic (and mainly ammonite) elements, which are alien to the Mediterranean Lower Cretaceous. The author is indebted to a number of colleagues and friends who have helped him in different ways and who have contributed to the successful outcome of the present studies. Profound gratitude is due to the author's teacher, Academician Ekim Bon- cev, who suggested the investigation of the Lower Cretaceous. The author has carried out joint studies of the Lower Cretaceous according to different groups of organisms, joint stratigraphie and lithological studies, or studies of stratigraphically related (transitional) levels together with a number of colleagues over different periods. In this connection the author would like to acknow­ ledge gratefully the cooperation with Mrs. D. Bakalova, Prof. M. Stojanova-Vergi- lova, Dr. A. Goranov, Mrs. L. Dodekova, Mrs. P. Jovôeva, Dr. T. Kovatcheva, Dr. B. Monov, Dr. I. Nachev and Dr. Kh. Khrischev. Special gratitude is due to Dr. N. Ruskova for the lithological studies of the Lower Cretaceous rocks used in the present study, as well as for the joint investi­ gations of the Lower Cretaceous in Northern Bulgaria. Most cordial thanks also to the colleagues Dr. G. Mandov, Dr. I. Sapunov and Dr. J. Tencov for the discussions and valuable suggestions in connection with the present work. The author is closely linked with Dr. I. Sapunov and Dr. G. Man­ dov by years of joint fruitful work, which is highly appreciated. In the course of his work over many years, the author has had the opportunity and the privilege to discuss various problems concerning Lower Cretaceous stra­ tigraphy with many colleagues from abroad. Many of them kindly provided litera­ ture not available in Bulgaria, as well as plaster casts or original ammonites from the collections of various institutes and/or museums abroad. Therefore it is a pleas­ ant duty to acknowledge the cooperation of Dr. V. P. Egoyan (Krasnodar), Prof. G. Y. Krimholz (Leningrad), Dr. I. A. Mihaylova (Moscow), Dr. В. T. Yanin (Mos­ cow), Dr. I. G. Sazanova (Moscow), Academician J. Fiilôp (Budapest), Dr. R. Bus- nardo (Lyon), Prof. M. Durand Delga (Toulouse), Prof. Ch. Pomerol (Paris), Dr. J.-P. Thieuloy (Grenoble), Dr. R. Casey (London), Dr. P. Rawson (London) and Prof. J. Wiedmann (Tubingen). The author also remembers with gratitude the joint work on Lower Cre­ taceous terrains in Algeria with the colleagues Dr. D. Kozuharov, Dr. Tz. Tzan- kov, Dr. P. Tchoumatchenco, Dr. Z. Nikolov, Dr. N. Zidarov and Mr. I. Slavov. Research in France was facilitated by the colleagues Prof. M. Durand Delga, Prof. P. Rat, Dr. R. Busnardo, Dr. J.-P. Thieuloy, Dr. G. le Hégarat, Dr. G. Thomel, Dr. J.-P. Masse, Prof. S. Fabre-Taxy, Prof. J. Sornay, Prof. Ch. Pomerol; in Switzer- 6 land — by Prof. J. Rcmane, Dr. H.-P. Funk, Mr. M. Gazay, Mr. M. Lanterno; in Hungary — by Academician J. Fiilôp: in Czechoslovakia — by Dr. Z. Roth; in Poland — by Dr. F. Szymakowska; in Romania — by Prof. L. Contescu, Prof. D. Patrulius and Prof. G. Raileanu. The author is particularly obliged to many Soviet specialists who not only shared their knowledge and experience, but also provided the opportunity for him to work on Lower Cretaceous sections in the southern regions of the USSR. In 1960 the author had the privilege of being member for six months of the Complex Southern Geological Expedition of the Academy of Sciences of the USSR, which worked in the Crimea, in the Caucasus and in the southern periphery of the Russian Plat­ form. Deep gratitude and respect is due to the late Prof. V. P. Rentgarten, to Prof. N. P. Luppov and Prof. V. V. Drushchitz for providing information on the prob­ lems of Lower Cretaceous stratigraphy in the USSR. The author is grateful especially to Dr. N. Ruskova and Dr. I. Sapunov for read­ ing the manuscript of the book and for many good suggestions. The completion of the present work would have been impossible without the assistance of my colleagues from the Department of Palaeontology at Sofia Uni­ versity.