Recent and Glacial Age Organic Carbon and Biogenic Silica Accumulation in Marine Sediments

249 Pages·2016·8.5 MB·English

by  Douglas S. Cwienk

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Open Access Master's Theses
1986
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Douglas S. Cwienk
University of Rhode Island
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Cwienk, Douglas S., "Recent and Glacial Age Organic Carbon and Biogenic Silica Accumulation in Marine
Sediments" (1986). Open Access Master's Theses. Paper 809.
https://digitalcommons.uri.edu/theses/809
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RECENT AND GLACIAL AGE ORGANIC CARBON AND BIOGENIC
SILICA ACCUMULATION IN MARINE SEDIMENTS
BY
DOUGLAS S. CWIENK
A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
IN
OCEANOGRAPHY (GEOLOGICAL)
UNIVERSITY OF RHODE ISLAND
1986
MASTER OF SCIENCE THESIS
OF
DOUGLAS S. CWIENK
APPROVED:
Thesis Committee
Major Professor
DEAN OF ': GRADUATE SCHOOL
ii
ABSTRACT
Sedimentation rate data for the late Pleistocene and
Holocene was compiled and mapped along with bulk sediment
accumulation rate data estimated from the surface calcium
carbonate concentration. This data was combined with
surface organic carbon and opal (biogenic silica)
concentration data in order to calculate the recent rate of
accumulation of these biogenically derived sedimentary
components. The maps of organic carbon and opal
accumulation rates showed similar trends, being highest in
known regions of upwelling and high productivity. Annual
organic carbon burial was estimated by multiplying the
accumulation rates by the areas between the contours and
14
found to be 0.21xl0 gC/yr for the deep-sea (pelagic and
14
hemipelagic) and 0.04xl0 gC/yr for the shelves exclusive
of deltaic sediments. Burial of organic carbon in deltaic
sediments is very large, however the necessary data is not
available to calculate the burial of organic carbon in all
the worlds major river deltas. For this reason an estimate
14
of 1.04xl0 gC/yr from Berner (1982) is assumed to be
correct for delta deposits, yielding a global organic carbon
14
burial rate of 1.29xlo gC/yr. Organic carbon burial in
14
the most recent Mediterranean sapropel is 0.016xl0 and
herefore had little or no affect on t he global carbon
cycle. Glacial versus interglacial organic carbon
accumulation is compared at 10 sites, showing glacial rates
higher in areas of present upwelling. Organic carbon
iii
accumulation rates and organic carbon accumulation r ates
divided by productivity are plotted versus sedimentation.
2 2
While correlations were fairly good (r =0.81 and r =0.66,
respectively), sedimentation rate data alone is insufficient
for estimating organic carbon accumulation.
Al l available quartz and opal concentrations from deep
sea surface sediments were int ercalibrated, plotted ,and
contoured on a cal cium carbonate- f ree basis. The maps show
highest concentrations of opal al ong the west coast of
Africa, along equatorial divergences in all oceans, and at
the Polar Front in the southern Indian Ocean. These are all
areas where upwelling is strong and there i s high biological
pr oductivit y. Quartz in pelagic sediments deposited far
from land is generally eolian in origin. Its distribution
r eflects dominant wind systems in the Pacific, but in much
of the Atlantic and Indian oceans the distribut ion pattern
is strongly modified by turbidite deposition and bottom
current processes.
iv
ACKNOWLEDGEMENTS
Support for this work came from National Science
Foundation grants ATM 81-16301, OCE 82-00388, and OCE 85-
11896 to M. Leinen and also through the award of the URI
Industrial Associates Fellowship in 1985 from Exxon. I
thank the many technicians and students who generated the
data used in this compilation, most of whom I do not know,
but including Patricia Price, formerly of Oregon State
University, and Tammy King Walsh, University of Rhode
Island. I also thank Ray Cranston of the Atlantic
Geoscience Centre, Bedford Inst itute of Oceanography and
J.H.f. Jansen of the Netherlands Institute for Sea Research
for providing me with unpublished data.
I would like to thank Richard Burroughs for once again
being an outside committee member for a defending graduate
student at GSO, and for his insight into the problem from
out side the immediate area of my work. I would like to
thank Mike Arthur for hi s suggestions and many long
discussions of my work. I would especially like to thank my
major professor Margaret Leinen for her help in defining the
direction my work was to take, pointing me in the right
direction to find what was needed, for showing me how to
write scientific works, and for consistently providing
funding for me, so that I could complete my work. I would
also like to thank Ken Hinga for his help and his insight
into the workings of GSO.
On a more personal note I woul d like to thank my friends
v
at GSO, the girls in the lab who listened to me complain
when things went wrong, the other students who drank,
laughed and enjoyed life beyond work with me, especially
Frank Hall and the intramural football team, White Noise,
who helped me blow off steam both on the field and in the
bar. Above all I would like to t hank my parents for their
constant love and support regardless of what I chose to do
with my life and my wife Eileen, who supported, comforted,
and loved me through the many ups and downs that my work and
my moods created.
vi
PREFACE
This thesis is presented in the form of one manuscript,
in accordance with the guidelines of the University of Rhode
Island Graduate School of Oceanography. The manuscript is
to be submitted to the journal, Biogeochemical Cycles.
Appendix I consists of an article previously published under
the authorship of Margaret Leinen, Douglas Cwienk, G. Ross
Heath, Pierre Biscaye, V. Kolla, Jorn Thiede, and J. Paul
Dauphin. Much of the plotting and contour ing was done by me
as was the writing of the initial draft of the text, however
the text was heavily revised and the unpublished data used,
had been obtained prior to my beginning work on that
project. Appendix I, while not an integral part of this
thesis, provided data and experience in plotting and
handling large data sets, used in the preparation of this
thesis. Appendix 2 and 3 contain all of the raw data used
to generate both t he maps for my thesis and the maps of
Leinen, et al, 1986. Appendix 4 contains the calculated
values used to generate the sedimentation rate, bulk
sediment, organic carbon and opal accumulation rate maps.
vii
TABLE OF CONTENTS
Abstract ii
Acknowledgement iv
Preface vi
Table of Contents vii
List of Tables
lX
List of Figures x
Introduction 1
Methods
Organic Carbon 7
Biogenic Silica 10
Sedimentation Rates 11
Accumulation Rates 13
Discussion
Sedimentation Rate Map 16
Bulk Sediment Accumulation Rate 18
Organic Carbon Accumulation 19
Opal Accumulation Rates 20
Global Organic Carbon Deposition 21
Organic Carbon Burial in Sapropels 26
Glacial vs Interglacial Organic Carbon Accumulation 27
Estimating Organic Carbon Accumulation 28
Conclusions 29
Literature Cited 31
Tables 43
Figures 46
Appendi ces 78
viii
Bibliography 221