Indian Ocean Geology and Biostratigraphy

611 Pages·1977·11.206 MB·English

Ocear
Ge
Botrat
Studies Following Deep-Sea Drilling Legs 22-29
Edited by
J. R. Heirtzler, H. M. Bolli,
T. A. Davies, J. B. Saunders,
and J. G. Sclater
American Geophysical Union
Washington, D.C. 20006
Published under the aegis of the AGU Geophysical Monograph Board; Bruce
Bolt, Chairman; Thomas E. Graedel, Rolland L. Hardy, Pearn P. Niiler,
Barry E. Parsons, George R. Tilton, and William R. Winkler, members.
Sponsoredb y the Joint Oceanographic Institutions for Deep Earth Sampling
(JOIDES) and Supported by the National Science Foundation.
Copyright¸ 1977 by the American Geophysical Union, 1909 K Street, N.W.,
Washington, D.C. 20006
ISBN 0-87590-208-1
Library of Congress Card Number 77-88320
Printed in the United States of America by LithoCrafters, Inc.,
Chelsea, Michigan 48118
Preface
The Drilling Vessel GLOMARC HALLENGERe ntered the Indian Ocean
when she left Darwin, Australia on January 13, 1972. She traveled
around that Ocean in a counterclockwise fashion drilling 72 holes
at 64 sites during 7 cruises over all the major ridges and basins
from the Red Sea to the Antarctic continent. She finished her work
there when she eventually arrived at Christchurch, New Zealand on
February 27, 1973. During this time nearly 30 km of seafloor was
penetrated and much of that material was recovered and studied and
is archived at the Deep Sea Drilling Project core depository.
In the Indian Ocean CHALLENGER had several notable achievements.
On Leg 22 she drilled in a water depth of 6243 meters - the deepest
at that time. On Leg 23 she had a single hole penetration of 1300
meters and at another hole had a penetration into basaltic basement
of 81 meters for two new records at that time. She drilled in the
Red Sea, which is a new spreading center, and in the Argo Abyssal
Plain where some of the oldest seafloor in the world is found. She
spent 69 days at sea traveling 7400 miles on Leg 28 working into the
ice south of Australia. On Ninetyeast Ridge lignite was found indi-
cating major subsidence. There, and at other sites, the northward
drift of India and the opening of the Indian Ocean was in evidence
in the recovered seafloor materials.
The plans of the IPOD Project do not call for any further drilling
in the Indian Ocean in the forseeable future and so the work completed
four years ago may not be rivalled for some time. This fact prompted
the editors to organize this synthesis of all the work published in
the Initial Reports and in other related publications. Within a
manageable sized single book it is not possible to give sufficient
coverage to all geographic areas or to all disciplines or subdisci-
plines. Some of these shortcomings will be evident here.
Each of the articles is a synthesis and then in two introductions -
one to the geology and one to the paleontology and biostratigraphy -
a brief further synthesis of the articles is attempted. We feel that
as a result of these articles a complete history of the Indian Ocean
is established and rests upon a solid factual basis.
We wish to thank the authors for their patience with us during the
editing and publication of this work and to thank J. Beckman, D. Bukry,
C. Caron, J. Curray, H. Dick, R. Douglas, R. Heath, J. Kennett,
R. Kidd, B. Luyendyk, E. Martini, D. Ninkovitch, J. Peirce, K. Perch-
Nielson, I. Primola-Silva, E. Schreibner, J. Thiede, G. Thompson,
T. Vallier, and Tj. van Andel for reviewing manuscripts. We also
thank Mrs. Florence Mellor who typed and edited the entire manuscript.
The Editors
iii
Foreword
Certain human efforts produce a curious mixture of humility and
pride; humility -- in that truly important matters are addressed;
pride -- in that we are capable, collectively, of addressing them.
Now in its ninth year of operation, the Deep Sea Drilling Project
is an excellent example of such an effort. The Project is a
uniquely successful attempt to increase man's knowledge of the
Earth, the age, history and processes of development of the ocean
basins and the structure and composition of the oceanic crust. An
equally important aspect is the significant information DSDP has
made available to the world's scientific community -- and, ulti-
mately, to the public at large -- concerning the resource potential
either directly or indirectly related to oceanic realms.
Begun as an 18-month program of ocean drilling in August, 1968,
its levels of high achievement earned four successive extensions;
thus, the Project will now operationally continue until at least
the Fall of 1979.
Its current phase is called IPOD, the International Phase of Ocean
Drilling. Although initially the Project was financed entirely by
the United States, scientists from more than two dozen nations par-
ticipated in its work. In 1970, the first tentative discussions
were begun with the USSR Academy of Sciences. These led to the
signing of a Memorandum of Understanding between our two countries
by which the Soviet Union became a participating member of DSDP for
a period of five years, beginning on 1 January 1974.
Since then, similar Memorandums of Understanding have been
executed between the United States and Germany, England, France
and Japan.
Each of these nations, together with nine U.S. oceanographic
institutions, is represented on the Executive and Planning Com-
mittees of the Joint Oceanographic Institutions for Deep Earth
Sampling (JOIDES); it is JOIDES which provides the scientific
guidance for DSDP. Indeed, it was JOIDES, formed in mid-1964 by
four U.S. oceanographic institutions, which can truly be regarded
as the scientific wellspring from which the Project evolved.
Principal operational tool of the Deep Sea Drilling Project is
the research vessel GLOMARC HALLENGER. The University of California,
in its capacity as principal contractor with the National Science
Foundation for the Project, sub-contracts with Global Marine Inc.
of Los Angeles to accomplish the actual drilling and coring opera-
tions using the CHALLENGER.
CHALLENGERi s a scientific ship created especially to meet the
goals of the Project and has never been used by anyone else.
Launched in Galveston, Texas, in March 1968, she is 400 feet long,
displaces 10,500 tons and bears a 142-foot high drilling tower
amidships. In her service to science, she has traveled over a
quarter-of-a-million miles across the world's oceans and marginal
seas -- with the exception of the ice-bound Arctic Ocean.
iv
In these past nine years, the Project has developed a priceless
legacy of information, principal among which is a library of over
30 miles of sediment cores collected from drill holes in every
major ocean basin. These cores are kept in two repositories; at
Scripps Institution of Oceanography in California and at Lamont-
Doherty Geological Observatory in New York. This carefully preserved
resource provides the basis for study of the past history of the
oceans, the rifting and separation of continents, generation and
destruction of ocean basins, interaction of changing ocean currents
and climate and the evolution of flora and fauna. The cumulative
effect of the Project's findings has been to provide the basis for
a continuing revolution in thinking concerning the history of the
entire Earth, the origins of every resource for which we mine or
drill, and our self appreciation as inhabitants of this planet.
DSDP successes have not been entirely scientific in nature. Among
breakthroughs achieved is computer-controlled dynamic positioning
which system keeps the CHALLENGERo ver the bore hole in full oceanic
water depths. By the end of 1970, a re-entry system had been de-
veloped by which worn bits could be brought to the surface, replaced
and then re-entry gained to the same hole for yet deeper penetration
into the seabed.
The Deep Sea Drilling Project stands at the doorstep of bold and
vital exploration. The results of what its scientists will learn
can have significant impact on the future of all who live on this
planet.
Those of us who have stood central to the management of the Deep
Sea Drilling Project have been privileged to serve that community
of scholars, engineers, seamen and drillers who have truly forged
its purposes into realities.
M. N. A. Peterson
Project Manager
Principal Investigator
Deep Sea Drilling Project
Contents
Preface iii
Foreword iv
Chapter 1. An Introduction to Deep Sea Drilling in the
Indian Ocean by John G. Sclater and James R.
Heirtzler
Chapter 2. Paleobathymetry and sediments of the Indian 25
Ocean by John G. Sclater, Dallas Abbott and
J(cid:127)rn Thiede
Chapter 3. Sedimentation in the Indian Ocean through time 61
by Thomas A. Davies and Robert B. Kidd
Chapter 4. Volcanogenic sediments in the Indian Ocean 87
by Tracy L. Vallier and Robert B. Kidd
Chapter 5. Mesozoic-Cenozoic sediments of the Eastern 119
Indian Ocean by Peter J. Cook
Chapter 6. Models of the Evolution of the Eastern Indian 151
Ocean by J. J. Veevers
Chapter 7. Deep sea drilling on the Ninetyeast Ridge: 165
Synthesis and a tectonic model by Bruce P.
Luyendyk
Chapter 8. Eastern Indian Ocean DSDP sites: Correlations 189
between petrography, geochemistry and tectonic
setting by Fred A. Frey, John S. Dickey, Jr.,
Geoffrey Thompson and Wilfred B. Bryan
Chapter 9. Large ion lithophile elements and Sr and Pb 259
isotopic variations in volcanic rocks from the
Indian Ocean by K. V. Subbarao, R. Hekinian
and D. Chandresekharam
Chapter 10. Seismic velocities and elastic moduli of ig- 279
neous and metamorphic rocks from the Indian
Ocean by Nikolas I. Christensen
Chapter 11. The magnetic properties of Indian Ocean basalts 301
by M. W. McElhinny
Chapter 12. Introduction to stratigraphy and paleontology 311
by Hans M. Bolli and John B. Saunders
vi
Chapter 13. Paleontological-biostratigraphical investi- 325
gations, Indian Ocean sites 211-269 and 280-
282, DSDP Legs 22-29 by Hans M. Bolli
Chapter 14. Mesozoic calcareous nannofossi!s from the 339
Indian Ocean, DSDP legs 22 to 27 by Hans R.
Thierstein
Chapter 15. Paleocene to Eocene calcareous nannoplankton 353
of the Indian Ocean by Franca Proto Decima
Chapter 16. Distribution of calcareous nannoplankton in 371
Oligocene to Holocene sediments of the Red
Sea and the Indian Ocean reflecting paleo-
environmentb y Carla M(cid:127)ller
Chapter 17. Synopsis of cretaceous planktonic foraminifera 399
from the Indian Ocean by Rene Herb
Chapter 18. Maastrichtian to Eocene foraminiferal assem- 417
blages in the northern and eastern Indian
Ocean region: Correlations and historical
patterns by Brian McGowran
Chapter 19. 01igocene plankton foraminiferal assemblages 459
from Deep Sea Drilling Project sites in the
Indian Ocean by Robert L. Fleisher
Chapter 20. Indian Ocean Neogene planktonic foraminiferal 469
biostratigraphy and its paleoceanographic impli-
cations by Edith Vincent
Chapter 21. Synthesis of the cretaceous benthonic foramini- 585
fera recovered by the Deep Sea Drilling Project
in the Indian Ocean by Viera Scheibnerova
Chapter 22. Neogene deep water benthonic foraminifera of 599
the Indian Ocean by E. Boltovskoy
vii
Special Publications Indian Ocean Geology and Biostratigraphy: Studies Following Deep-Sea Drilling Legs Vol. 9
CHAPTER 1. AN INTRODUCTION TO DEEP SEA DRILLING IN THE INDIAN OCEAN
John G. Sclater
Department of Earth and Planetary Sciences
Massachusetts Institute of Technology
Cambridge, Massachusetts 02139
James R. Heirtzler
Department of Geology and Geophysics
Woods Hole Oceanographic Institution
Woods Hole, Massachusetts 02543
Introduction
The Indian Ocean is the most complex of the three major oceans.
It has structures which are peculiar to this ocean as well as a
large assortment of features which are found elsewhere. The early
work in the ocean was carried out aboard the DANA, SNELLIUS, MABAHISS,
CHALLENGER,A LBATROSS, and OB (Yentsch, 1962) and the results were
published by Wiseman and Seymour-Sewell (1939), Seymour-Sewell (1925)
and Fairbridge (1948, 1955). The first really substantial investiga-
tion of the ocean came with the International Indian Ocean Expedition
which extended from 1959 to 1966. During the course of this ex-
pedition ten countries and forty-six ships took part in loosely co-
ordinated cruises to the ocean. A compilation of the data from these
cruises has been completed in Atlas form (Udintsev et al., 1975) and
we present a chart of the general bathymetry from this Atlas as
Figure 1. The International Indian Ocean Expedition resulted in the
publication of much scientific work and led directly to a series of
expeditions to undertake specific objectives. Perhaps the most
successful of these was the drilling program carried out between
1971 through 1972 by the D/V GLOMARC HALLENGER. The purpose of this
paper is to present a simple description of the morphology and struc-
ture of the Indian Ocean, to review the problems presented to the
D/V CHALLENGERb efore drilling commenceda nd to present, within this
general context, the highlights of the findings of the drilling
program.
Morphology of the Indian Ocean
Many bathymetric charts of the Indian Ocean have been published.
The most detailed of these, Laughton et al. (1970) for the Arabian
Sea and Carlsberg Ridge, Fisher et al. (1968) for the Somali Basin,
Fisher et al. (1971) for the Central Indian Ridge and portions of
Sclater and Fisher (1974) have been compiled by Udintsev et al.
(1975) to produce a bathymetric chart of the whole ocean. Our
modification of this chart (Figure 1) shows the principal
Copyright American Geophysical Union
Special Publications Indian Ocean Geology and Biostratigraphy: Studies Following Deep-Sea Drilling Legs Vol. 9
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Copyright American Geophysical Union
Special Publications Indian Ocean Geology and Biostratigraphy: Studies Following Deep-Sea Drilling Legs Vol. 9
INTRODUCTION
Mid Ocean Ridge System
The major topographic feature in the Indian Ocean is the broad
active mid-ocean ridge system which starts in the Gulf of Aden
(Laughton et al., 1970) and trends southwest as the Carlsberg Ridge
into an en echelon pattern of transform faults and spreading centers
(Fisher et al., 1971) called the Central Indian Ridge. At 25øS,
70øE this ridge bifurcates into the Southeast Indian and Southwest
Indian Ridges. The Southwest Indian Ridge eventually joins the mid-
Atlantic Ridge at the Bouvet Triple Junction. The Southeast Indian
Ridge, a broad swell with less rough topography than the other
ridges, trends southeast to the Amsterdam and St. Paul Islands and
then almost due east between Australia and Antarctica joining up
with East Pacific Rise after some major offsets at the Macquarie
Triple Junction.
The Aseismic Ridges and Plateaus
Characteristic of the Indian Ocean is the abundance of relatively
shallow ridges and plateaus that are free from earthquake activity.
The most prominent of these features are the Chagos-Laccadive and
Ninetyeast Ridges both of which are thought to be oceanic and the
Seychelles Bank which is attached to the Mascarene Plateau. The
Seychelles Bank is known to be continental (Matthews and Davies,
1966) and is thought to be a micro-continent split from India during
the northward movement of that continent. The origin of the Mas-
carene Plateau is unknown. Other aseismic ridges of considerable
morphological importance are the Mozambique and Madagascar Ridges,
the Crozet and Kerguelen Plateaus, Broken Ridge and the Wallaby and
Naturaliste Plateaus (Figure 1).
Further aseismic ridges and islands which show up as morphologi-
cal features but are less extensive in size are the Rodriquez Ridge,
the Ob Seamount Province and the Cocos-Keeling, Christmas group of
islands in the Wharton Basin. Because all these features are rela-
tively small and appear of secondary importance they are not dis-
cussed either in this introduction or in the papers presented in
the volume.
The Ocean Basins
The mid-ocean ridges, the aseismic ridges and the continental shelves
divide the Indian Ocean into a number of more or less isolated basins
(Figure 1). These ridges and the continental edges have a very large
effect upon the distribution of sediments. Seismic reflection data
have enabled an isopach map of sediment thickness (Figure 2) to be
constructed which shows that 40 percent of the total sediment present
is to be found in the Arabian Sea and in the Bay of Bengal, probably
from Himalayan erosion (Ewing et al., 1969). More recent seismic
studies in the Bay of Bengal by Curray and Moore (1971) suggest that
sediment thickness may exceed 12 km and that Himalayan denudation may
be proceeding at an average rate of 70 cm/1000 years. Other thick
terrigenous sediments are found off East Africa and in the Mozambique
Channel. South of the polar front, high biological productivity has
given rise to thick accumulations of siliceous ooze. Elsewhere the
sediments are relatively thin and on the crestal area, 100 km on either
side of the ridge axis, they are virtually absent.
Scattered seismic refraction stations from a variety of sources
(Laughton et al., 1971) illustrate that, except under the micro-
continents and the ridge axes, normal oceanic crust is found. The
only seismic data available on a mid-ocean ridge is in the complex
Copyright American Geophysical Union