The Mediterranean Lower Cretaceous. Sofia: Publishing house of the Bulgaria Acad.of Sciences

275 Pages·1987·16.398 MB·English

by  Nikolov T.G.

IChlor « Nikoiov
THE MEDITERRANEAN
LOWER CRETACEOUS
(§[l®[y®(§D(g^ у)С
§@[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. ов локиН
СРЕДИЗЕМНОМОРСКИЙ НИЖНИЙ МЕЛ
ИЗДАТЕЛЬСТВО БОЛГАРСКОЙ АКАДЕМИИ НАУК. СОФИЯ. 1987
BULGARIAN ACADEMY OF S C I E N C ES
SOFIA UNIVERSITY "KLIMENT O H R I D S K I"
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-
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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. Mrs. N. Motekova and Mrs. M. Kehajova offered valuable assistance in
compiling the bibliography. Mrs. E. Dzonzurova has drawn most of the figures,
Mrs. C. DuSkova has typed parts of the manuscript. Mr. A. Vitanov facilitated the
settlement of a number of technical matters.
Many thanks to all institutions and persons not mentioned, whose various
contributions to the present work are highly appreciated. The shortcomings and
ommissions are entirely the author's own responsibity.
Sofia, October 1984

Part One
INTRODUCTION
I. GENERAL REMARKS ABOUT THE LOWER CRETACEOUS
1. NOMENCLATURE
The Cretaceous System was differentiated for the first time by О m a 1 i u s d'H a 1-
1 о y in 1822, in order to unify a complex of beds situated in the upper part of the
Mesozoic Erathem in the Paris Basin. These beds are formed of chalk with tuffs,
sandstones, marls and clays, and they comprise a section of the continental equi­
valents of the Berriasian Stage to the white chalk of the Senonian inclusive.
Later this Cretaceous ensemble was subdivided into a number of stages from
which, if we exclude the various synonyms and homonyms, the following stage terms
are in current use today: Berriasian, Valanginian, Hauterivian, Barremian, Aptian,
Albian, Cenomanian, Turonian, Coniasian, Santonian, Campanian, Maastrichtian
and Danian. At the end of the 19th and at the beginning of the 20th century different
authors proposed these stages to be grouped in two or three series. Thus, De Lap-
p a r e nt (1883, 1906) divided the Cretaceous System into two: Lower or Infra-
Cretaceous which comprises the ensemble from the Berriasian to the Albian
Stages included, and Upper Cretaceous or Cretaceous sensu stricto for the sequence
from the Cenomanian to the Senonian included. This subdivision of the Cretaceous
System has been accepted by most specialists, because it corresponds best to the law-
governed regularities in the vertical distribution of ammonite faunas in Cretaceous
rocks. The division was officially recognized by the Third International Congress
of Geology in Berlin (1885).
In 1911 E. H a u g proposed a new subdivision of the Cretaceous System into
three series: Eocretaceous or Neocomian (Eocrétacé ou Néocomien) comprising
from the Valanginian to the Aptian included; Mesocretaceous (Mésocrétacé) com­
prising the Albian, Cenomanian and Turonian; Neocretaceous (Néocrétacé ou Sé-
nonien) for the sequence from the Coniasian to the Danian included (in modern clas­
sifications of the Phanerozoic Danian beds are included in the Tertiary). This classi­
fication, however, has few adherents and it is currently very seldom used. There also
exists another grouping of the stages in the Mesocretaceous, to which some authors
attribute only the Albian and the Cenomanian.
Terms such as "Mesocretaceous stratigraphy", "Mesocretaceous events", etc.,
are often used in recent literature, although there is no conventionally accepted con­
cept of Mesocretaceous.
2- BOUNDARIES OF THE LOWER CRETACEOUS
*n the present monograph the Lower Cretaceous is considered t о be the series which
3omprises approximately the lower half of the Cretaceous Sys tern. It includes the
9