Geochemistry and Sedimentology of the Mediterranean Sea

SEDIMENTOLOGY AND PETROLEUM GEOLOGY

Geochemistry and Sedimentology of the Mediterranean Sea

by

E. M. EMELYANOV

and

K. M. SHIMKUS

P. P. Shirshov Institute of Oceanography, Academy of Sciences of the U.S.S.R.

D. Reidel Publishing Company

A MEMBER OF THE KLUWER ACADEMIC PUBLISHERS GROUP

Dordrecht / Boston / Lancaster / Tokyo

Library of Congress Cataloging in Publication Data

Emelyanov, E. M. Geochemistry and Sedimentology of the Mediterranean Sea.

(Sedimentology and petroleum geology) Bibliography: p. Includes index. I. Marine sediments- Mediterranean Sea. 2. Geochemistry-

Mediterranean Sea. 3. Geology, Stratigraphic- Cenozoic. 4. Geology - Mediterranean Sea. L Shimkus, K. M. (Kazimeras Mikolavich) II. Title. Ill. Series. GC389.E53 1986 551.3'6 ISBN-13: 978-94-010-8500-7 001: 10.1007/978-94-009-4490-9

85-28118

Published by D. Reidel Publishing Company P.O. Box 17, 3300 AA Dordrecht, Holland

Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers,

e-ISBN-13: 978-94-009-4490-9

190 Old Derby Street, Hingham, MA 02043, U.S.A .

In all other countries, sold and distributed by K1uwer Academic Publishers Group, P.O. Box 322, 3300 AH Dordrecht, Holland

All Rights Reserved © 1986 by D. Reidel Publishing Company, Dordrecht, Holland Reprint of the original edition 1986 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner

The Russian edition of this book was prepared under the Editorship of A.P. Lisitzin, Associate Member of the Academy of Sciences of the USSR.

The book has been trans­lated into English by T. I. Anosova.

The English edition has been edited by Graham Evans and Peter Ronald Bush, Imperial College, London.

Foreword

The monograph presented to foreign readers has been prepared by the famous Soviet investigators of processes of geochemistry and sedimentation in the Mediterranean Sea. For more than 20 years E.M. Emelyanov has examined the recent sedimentation of the Mediterranean Sea and K.M. Shimkus has studied the Quaternary and the earlier sedi­mentation of the area.

The authors, scientific workers from the P.P. Shirshov Institute of Oceanology, USSR Academy of Sciences (Atlantic and Southern Depart­ments), took part not only in numerous cruises on oceanographic vessels of the USSR, but in the study of cores of the deep-sea drilling on R/V "Glomar Challenger". A great number of scientific papers and some books devoted to the processes of sedimentation and geochemistry of the Mediterranean Sea were written by them.

Although the scientific interests of the authors are not only limited to these questions, I should like to emphasise these aspects of their scientific activity when introducing this book.

The Mediterranean Sea is a suitable natural laboratory for solving a number of principal problems of marine sedimentation and lithogenesis. That is why the problems of geochemistry and sedimentation are so interesting. A number of outstanding scientists and large scientific institutions in the countries around the Mediterranean Sea, particularly in France, Italy, Spain, Algeria, Egypt, Greece and Yugoslavia work in this sphere. The two legs of "Glomar Challenger" in the Mediterranean Sea were a remarkable phenomenon. They gave interesting results and formed the basis of the study of the peculiarities of Neogene sedimentation and the diagenesis of these sediments. I should like to mention the books "The Mediterranean Sea: a natural sedimentation laboratory" edited by D.J. Stanley (1972), "Sedimentary basins of the Mediterranean Sea continental margins" published by F.C. Wezel, "The Pelagian Sea" edited by G. Bellaiche and the dissertation by E. Shamley on clay minerals as being among the fundamental works of foreign scientists on sedimentation.

The numerous data obtained has made it possible to solve many important questions of geochemistry, sedimentation and diagenesis, but require a certain approach to the interpretation of results.

The authors of this book attempt to show a common picture of sedimentary and geochemical processes during the Holocene, Pleistocene and Neogene in the whole basin considering its peculiarities gradually from the most studied upper part of the stratigraphic section downwards towards deep historical horizons. Such a comparative geochemical approach proves its value, though it is the opposite to the course of geological events. It gives an opportunity to approximate to the truth on the basis of known facts.

The abundant information on the geochemistry of the Recent and Late Quaternary sedimentation is used effectively in this way to reveal

vii

viii FOREWORD

the peculiarities of sedimentary processes at more ancient stages for which there are scanty data.

I should like to draw attention also to the fact that new ideas, without which the profound study of sedimentation is not effective, are also developed in this monograph. In particular the value of geo­chemical barrier-zones is shown both in sedimentation and in the diagenesis of sediments. The areas where "avalanche" sedimentation is widespread in the Mediterranean Sea is also considered.

A first attempt of lithological-geochemical zoning of the Mediterranean Sea sediments is presented in this book. The large volume of data presented by the authors as tables and numerous maps is of primary importance. We hope that these data obtained over many years and verified thoroughly will be used by many investigators, and that they will make up a lot of deficiencies in our ideas about geochemistry and sedimentation processes in seas.

The monograph, as any large original work, is not free of defects. We hope however that foreign readers will kindly help the authors to eliminate them in future publications.

A. P. Lisitzin Associate Member of USSR Academy of Sciences

CONTENTS

Foreword

Abbreviations

Preface

Part I THE GEOCHEMISTRY OF THE RECENT SEDIMENTS

1.1 CONDITIONS OF RECENT SEDIMENTATION 1.1.1 A summary of the physio-geographical

characteristics of the basins of recent sedimentation

1.1.2 Origin and supply of sediments

1.2 RECENT SEDIMENTATION

1.3

Part II

1.2.1

1.2.2

1.2.3

Quantitative distribution and compo­sition of suspended matter in sea water Distribution and composition of sedi-ments Accumulation and composition of terri-genous material

THE INDIVIDUAL COMPONENTS, ELEMENTS AND GEO­CHEMISTRY OF SEDIMENTATION 1.3.1 Carbonate formation 1.3.2 Organic matter 1.3.3 Amorphous Silica 1.3.4 Phosphorus 1.3.5 Terrigenous Si02 and hydrolysate

elements 1.3.6 1.3.7 1.3.8 1.3.9

~lements of the iron group Alkaline elements Heavy metals Other trace elements

THE GEOCHEMISTRY OF QUATERNARY SEDIMENTOGENESIS AND DIAGENESIS

11.1 LITHOLOGICAL COMPOSITION OF THE DEEP­WATER QUATERNARY SEDIMENTS

11.1.1 Upper Quaternary sediments 11.1.2 Middle and Lower Quaternary sediments

11.2 TERRIGENOUS AND VOLCANOGENIC SEDIMENTATION 11.2.1 Sedimentation rates 11.2.2 Terrigenous sedimentation 11.2.3 Accumulation of volcanogenic material

11.3 GEOCHEMISTRY OF QUATERNARY SEDIMENTATION

vii

xii

xiii

1 7

15

15

24

55

63 63 91

102 106

118 137 176 188 203

228

228 229 244 275 275 281 291 299

x

II.3.1 11.3.2

II.3.3

11.3.4

11.3.5

Carbonate content Organic matter accumulation and concentration Amorphous silica accumulation and concentration Accumulation and concentration of iron, manganese, titanium and phosphorus in sediments Trace elements

Part III GEOCHEMISTRY OF THE LATE CENOZOIC SEDIMEN­TATION AND DIAGENESIS OF THE SEDIMENTS

111.1 LITHOLOGICAL AND GEOCHEMICAL CHARACTERISTIC OF NEOGENE SEDIMENTS AND PECULIARITIES OF SEDIMENTATION 111.1.1 Pliocene 111.1.2 Messinian 111.1.3 Tortonian 111.1.4 Burdigalian, Langian and Serravalian

111.2 SEPARATE COMPONENTS AND ELEMENTS AND THE GEO-CHEMISTRY OF SEDIMENTATION III.2.1 Carbonates IIL2.2 Organic matter IIL2.3 Phosphorus IIL2.4 Hydrolysate elements IIL2.5 Elements of the iron group (Fe, Mn

Cr and Ni) III .2.6 Alkaline elements (K, Na, Li, Rb) IIL2.7 Group of heavy metals (Cu and Zn)

Part IV MAIN FEATURES OF THE GEOCHEMISTRY AND SEDI­MENTOLOGY OF THE MEDITERRANEAN SEA

IV.l MAIN FACTORS CONTROLLING SEDIMENTATION AND THE TRANSFORMATION OF SEDIMENTARY MATERIAL IV.l.l Transformation of sedimentary material

during sedimentation and early diagenesis of the sediments

IV.l.2 Lithification and diagenesis of Neogene-Quaternary sediments

IV.l.3 Tectonics and Volcanism IV.l.4 River loads IV.l.5 Hydrodynamic conditions and hydrogen

sulphide contamination IV.l.6 Climate

IV.2 LITHOLOGICAL-GEOCHEMICAL ZONES OF SEDIMENTA­TION

IV.3 SOME FEATURES OF THE HISTORY AND GEOCHEMICAL EVOLUTION OF THE MEDITERRANEAN SEA IN THE NEOCENE AND THE PLEISTOCENE

CONTENTS

294

320

344

347 367

379

379 379 384 387 396

400 400 404 416 416

418 425 428

431

431

431

452 454 463

466 476

481

495

CONTENTS xi

IV.4 ABNORMALITIES OF THE GEOCHEMISTRY OF THE SEDIMENTARY PROCESSES IN THE MEDITERRANEAN SEA IN COMPARISON WITH OTHER BASINS

References

Index

500

507

533

lOAN

am

CFB

terr

nat

K.k.

OM

GBZ

LGA

LGR

LGP

Q

Fp

ex

g

t

St.

V

Va

Vy

A

Abbreviations Adopted in this Book

Institute of Oceanology, USSR Academy of Sciences

amorphous

contents calculated on a carbonate-free basis

terrigeneous

natural sediments

correlation coefficient

organic matter

Geochemical barrier zone

Lithological-geochemical area

Lithological-geochemical region

Lithological-geochemical province

quartz

feldspars

exemplar

gramme

tonne

station

"Vema"

"Akademik S. Vavilov"

"Vityaz"

"Albatross"

xu

Preface

The Mediterranean Sea lies between Europe, Asia and Africa in an area famous for its ancient civilizations and cultural developments. It was an area where marine navigation was developed and where many trade routes intersected. The publication of one of the first monographs on marine geology and geography by Marsilli in 1725 suggests that the Mediterranean Sea was the cradle of marine geology. However, the systematic study of this great marine basin did not really begin until 1946 when investigations were carried out mainly by French, Swedish, Italian, American and German scientists. More than a thousand scientific papers, maps and monographs have been published on different problems of the geology of the Mediterranean Sea. Particular attention was paid to the geology of this basin after the discovery, during the Leg 13 of the Deep Sea Drilling proj ect, of the peculiar natural phenomenon of a thick accumulation of evaporite.

Soviet scientists started systematic geological investigations of the Mediterranean Sea in 1959 during the first expedition on R/V Akademik S. Vavilov (Eme1yanov, 1961). Since that time thousands of samples of suspended material, Recent and Quaternary sediments have been collected and studied by Soviet scientists. This work was done mainly by the representatives of the Southern and Atlantic Departments of the P.P. Shirshov Institute of Oceanology, U.S.S.R. Academy of Sciences (Ge1enc1gik ana Kaliningrad). Expeditions were made on R/V Akademik S Vavilov, Akademik Kova1esky, Michael Lomonosov, Akademik Vernadsky, Moscow University, Vityaz (both old and new and on other vessels) . Geological investigations were carried out in three main subject areas: (1) lithology and geochemistry (2) geomorphology and (3) geophysics. This book is based on the data obtained from the lithological and geochemical studies made of the Mediterranean Sea sediments. This study contributed to the understanding of the pattern of Recent sedimentation, the diagenesis of the sediments, and the Late Quaternary stratigraphy and palaeogeography of the area. More than 200 scientific papers, including the monographs "Geochemistry of the Mediterranean Sea" (Eme1yanov et al., 1979) and "Sedimentation of the Mediterranean Sea in Late Quaternary time" ( Shimkus, 1981), have been published on these subjects in the USSR. In addition, the various authors studied the grain size, mineralogical and chemical composition of 250 samples of cores taken during Legs 13 and 42A of the DSDP. Thus the authors had at their disposal two to three thousand sediment samples, all of which have been analyzed by identical methods in the same laboratory by the same investigators. This allowed not only the presentation of a detailed uniform description of Recent, Quaternary and Neogene sediments but also the solution of some litho1ogica1-geochemical problems which had not been given sufficient consideration in the works of West European and American scientists. In particular this work led to: (1) the production of various maps showing the

xiii

xiv PREFACE

distribution of chemical elements, various grain size fractions and the distribution of minerals in present day sediments as well as for various stages in the Holocene and Pleistocene. (2) the revelation of the main patterns of sedimentation during recent and Quaternary times as well as the solution of some questions on Palaeogeographic environ­ments in the post-Miocene period and on the geochemical evolution of the Mediterranean Sea over the last 10-15 m.yrs. The approach. adopted by the authors involved the method of actualism (Strakhov et al., 1954) and that of comparative lithology (Strakhov, 1945). ----

The methods of collection and study of suspended matter, Recent and Late Quaternary sediments have been described in the books 'Sedi­mentation in the Atlantic Ocean' (1975) and (Sedimentation of the Mediterranean Sea in Late Quaternary time' (1981), and in two papers in English (Emelyanov, 1972; Emelyanov and Shimkus, 1972). The essence of these methods is that suspended matter was collected by separation and filtration. Soviet biological filters with 0.8 and 0.5 /.lm pores were used. The filters were weighed on a torsion balance with ±0.1 mg accuracy. A portion of the suspended matter was taken by using power­ful separators (Lisitzin, 1964). The chemical composition of the filtered suspended matter was analyzed by kinetic, calorimetric and atomic absorption methods. Bottom sediments were taken with an 'Ocean' 50 grab (recovering 0.25 mS ) and with gravity and piston corers (the core length was up to 11m). The grain size of the samples was per­formed on fresh wet samples. The following grain size fractions were determined: >1.0 mm; 1.0-0.5 mm; 0.5-0.25 mm; 0.25-0.1 mm; 0.1-0.05 mm; 0.05-0.01 mm; 0.01-0.005 mm; 0.005-0.001; and <0.001 mm. The 0.1-0.05 mm fraction (more rarely also the 0.25-0.1 mm fraction) was used for mineralogical analysis using an immersion technique and the <0.001 mm fraction was used for studying clays. The total mineral composition of the sediments was determined using a Sovlft di3~ract~eter DRO~+1.5 and DRON 2.0. Mobile or labile elements (Fe , Fe ,Mn and Mn , sulphate S and pyritic S) as well as pH and Eh were determined on board on fresh sediment samples. All the remaining chemical analyses were carried out in a land-based laboratory on samples dried at 50-70°C. CaC03 , CO2 , MgC03 , total Si02 amorphous Si02 and Al, Ti and P were determ~ned 15y wet chemical mel:hods which are standard analytical techniques in the U.S.S.R (The methods of studying sedimentary rocks, 1957; Ponomarev, 1961). Fe, Mn, K, Na, Li, Rb, Ni, Cr, Cu, and Zn were determined by atomic absorption techniques (Khandros and Shaidurov, 1980); U was determined by a fluorimetric method: B, Zr, Sn, Pb and V were assessed by quantitative spectro­metry; Mo, Se and W were determined mainly by wet chemical methods; and Si and Al (within the sediments) were determined by X-ray spectral analysis. The details of these methods may be found in the references quoted in this book.

The mathematical treatment of data with the calculation of average contents of chemical elements (given by the authors in Clarkes of concentration), as well as that of correlation coefficients has been carried out according to the 'Geokhimik' programme (Emelyanov et al., 1981).

The stratigraphic separation of Quaternary sediments is based on

PREFACE xv

14C dating, planktonic and benthonic foraminifera and detailed lithological-geochemical composition of cores. In general more than two thousand sediment samples were studied by the authors (about 600 were surface samples and about 1200 were from cores as well as 250 from the D.S.D.P. drilling).

The book is divided into four parts: the first of which is devoted to the problems of recent sedimentation; the second to the problems of Late Quaternary sedimentation and diagenesis; the third concerns Neogene and Early Pleistocene sedimentation and diagenesis; and the fourth discusses the patterns of sedimentation and the evolution of the Mediterranean Sea. The first part of the book is based on Russian editions: 'Geochemistry of the Mediterranean Sea' (Eme1yanov et a1., 1979), 'Bottom Sediments of the Mediterranean Sea' (Eme1yanov,:L975); the second part is based on the book 'Sedimentation of the Mediterranean Sea in Late Quaternary time' (Shimkus, 1981); the third part has its origins in the Initial Reports of the D.S.D.P. (Legs 13 and 42A of the 'Glomar Challenger') (Ryan, Hsu et a1., 1973; Hsu, Montardet et a1." 1978) as well as the results of the studies on the 250 sediment Samples f'rom these D.S.D.P. cores studied by the authors; and the fourth part is a synthesis of the data presented in the first three parts.

Since the results of work on the geology of the Mediterranean Sea produced in U.S.S.R. are unavailable to scientists that have no knowledge of the Russian language, the authors have added a supplementary list of papers by Soviet scientists (not used in writing this book) at the end of the volume. The new chemical data on the cores of the D.S.D.P. (Leg 13 and 42A). Initial Reports are also included at the end of the book as an appendix. Some of the data on chemical and grain-size composition of present day sediments (together with their description and station coordinates may be found in an appendix of the book 'Sedimentation in the Atlantic Ocean' (Joint Geophysical Committee, Moscow, 1973, pp.239-321».

The bulk of the data used by the authors was derived from samples collected and analyzed by the personnel of the laboratory of the Southern Sea Geology of the Southern Department of the Institute of Oceanology, U.S.S.R. Academy of Sciences (Ge1endgik) under the guidance of K.M. Shimkus, and by that of the laboratory of Atlantic Geology of the Atlantic Department of the same Institute (Kalingrad) headed by E.M. Eme1yanov. The authors express their deep gratitude to the personnel of these laboratories and particularly to: Yu. O. Shairdurov, Ts. Kh. Yab1unovskaya, L.A. Aku1enko, T.I. Anisimova, A.S. Khozheunikov, F.D. Stukanog, S.B. Chabashvi1i, V.S. Soko10v, E.G. Soko1ova and V.F. Bekhterer. The cooperation with A. Yu. Mitropo1sky and A.A. Moussa who 'were coauthors of the book 'Geochemistry of the Mediterranean Sea' was fruitful. The authors are very grateful to A.P. Lisitzin, who was an idea10gica1 leader in the geological work in the Mediterranean Sea. The authors are very thankful to the Heads of the Southern and Atlantic Departments and to the Head of the"P.P. Shirshov Institute of Oceanology, U.S.S.R. Academy of Sciences. A.S. Monin for constant support in carrying out lithological-geochemical investigat­ions of the Mediterranean Sea.

xvi PREFACE

The authors express their sincere gratitude to N.D. Shibkova, who designed the bulk of the drawings and to T.!. Anosova who compiled the manuscript of the book and who translated it into English. Finally, the authors are very grateful to various foreign reviewers who rendered assistance in improving both the book itself and its English version.