Ecological and environmental consequences of oceanic anoxic events and the Cretaceous-Paleogene mass extinction event [Elektronische Ressource] : a molecular-isotopic approach / vorgelegt von Julio C. Sepúlveda Arellano

Julios

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Ecological and environmental consequences of Oceanic Anoxic Events and the Cretaceous-Paleogene mass extinction event: a molecular-isotopic approachDissertation zur Erlangung des Doktorgrades der Naturwissenschaften - Dr. rer. Nat. – Am Fachbereich Geowissenschaften der Universität Bremen vorgelegt von Julio C. Sepúlveda Arellano Bremen September 2008 Thesis committee 1. Supervisor: Prof. Kai-Uwe Hinrichs, University of Bremen, Germany 2. Co-Supervisor: Prof. Roger E. Summons, Massachusetts Institute of Technology, USA 3. Member: Prof. Jörn Peckmann, University of Bremen, Germany 4. Member: Prof. Wolfgang Bach, University of Bremany Thesis defense thMonday, 17 November 2008 Faculty of Geosciences, University of BremenMira niñita, te voy a llevar a ver la luna brillando en el mar… Para Annette y Amaya TABLE OF CONTENTSAbstract Thesis abstract……………………………………………………………. I Kurzfassung……………………………………………………………...III Acknowledgements.……………………………………………………………………...VList of Figures………………………………………………………………………….VIIList of Tables…………………………………………………………………………....IXList of Abbreviations…………………………………………………………………....XChapter I: Introduction………………………………………………………………..1 General introduction………………………………………………………2 1. Biological and geological processes influencing the global…………..2 carbon and nutrient cycles2. Oceanic anoxia during the Cretaceous………………………………...4 3. Cretaceous-Paleogene mass extinction event ……………………….10 4.

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2008
• Nombre de lectures: 83
• Langue: English
• Poids de l'ouvrage: 8 Mo

Extrait

Ecological and environmental consequences of Oceanic Anoxic

s-Paleogene mass extinction event: a Events and the Cretaceou

molecular-isotopic approach

Dissertation

zur Erlangung des Doktorgrades

der Naturwissenschaften

- Dr. rer. Nat. –

Fachbereich Geowissenschaften Am

en ität Bremder Univers

vorgelegt von

Julio C. Sepúlveda Arellano

en Brem

ber 2008 Septem

ittee mThesis com

1. Supervisor: Prof. Kai-Uwe Hinrichs, University of Bre

any en, Germm

of. Roger E. Summons, Mar2. Co-Supervisor: Pte of Technology, USA ssachusetts Institu

any en, Germann, University of Brember: Prof. Jörn Peckm3. Mem

4. Member: Prof. Wolfgang Bach, University of Bremen, Germany

se Thesis defen

Monday, 17

th

November 2008

fces, University oFaculty of Geoscienen Brem

r… ar la luna brillando en el mMira niñita, te voy a llevar a ve

aya Para Annette y Am

Abstract

TABLE OF CONTENTS

Thesis abstract……………………………………………………………. I

Kurzfassung……………………………………………………………...III

……………………………………………………………………...Vledgements.Acknow

………………………………………………………………………….VIIresList of Figu

…………………………………………………………………………....IXList of Tables

…………………………………………………………………....XList of Abbreviations

Introduction………………………………………………………………..1 Chapter I:

General

Chapter II:

1.

2.

3.

4.

5.

6.

7.

8.

introduction………………………………………………………2

sses influencing the global…………..2 Biological and geological proce

carbon and nutrient cycles

s………………………………...4 e Cretaceouxia during thOceanic ano

ss extinction event …as-Paleogene mCretaceou…………………….10

arker concept…………………………………………………...18 Biom

tions based on the use of……………22ental reconstrucPaleoenvironm

arkers and compound specific isotope ratios lipid biom

Research foci and objectives……………….………………………...26

Contribution to publications…………………………………………27

References……………………………………………………………30

ental and ecological………….41 environmMolecular-isotopic evidence of

changes across the Cenom-Turonian boundary in theanian

of central Jordan Levant Platform

Chapter III:Chapter IV:Chapter V:

s in the Late………………………85 ciOceanographic and climatic dynam

DP Site 1259): s Equatorial Atlantic (OCretaceou

pound-specific stable isotope approachA com

ents ganic-rich sedimation of orinto the form

Rapid Resurgence of Marine Productivity after the …………………...115

ction Event s-Paleogene Mass ExtinCretaceou

nuscript………………………………………………….116 aPrinted m1.

entary online inforSupplem2.ation…………………………………129 m

rks and Perspectives…………………………………141 amConcluding Re

1.

2.

3.

4.

Conclusions…………………………………………………………142

Perspectives…………………………………………………………146

Presentations and other activities……………..…………………….149

Erklärung……………………………………………………………151

THESIS ABSTRACT

Abstract Thesis

in aim of this thesis was to study the biotic and abiotic consequences ofaThe mextreme environmental conditions during Cretaceous Oceanic Anoxic Events (OAE), and
the recovery of prievent through the use of lipid biommary production at the Cretaceous-Paleogene (K-Pg) markers, compound-specific stable isotopes, and bulk ass extinction
geochemistry. This multiproxy approach contributes new evidence for understanding the
intricate environmental and biological interactions occurring during these important
rth’s history, which were responsible for rapid biological turnover that aevents in Eical cycles. eochempacted bioggreatly im Two OAEs covering the Late Cretaceous were studied - the Coniacian-Turonian vant illion years ago, Ma) in an intra-shelf basin of the LeBoundary OAE2 (~ 93.5 m in Central Jordan, and the Coniacian OAE3 (~ 88-89 Ma) at the western Platformequatorial Atlantic off the coast of Surinam (ODP Site 1259, Demerara Rise). OAE2 at
Jordan was characterized by sea-level changes that resulted in water column stratification
ocline, hypersalinity, and oxygen depletion, whereas evidence of with a fluctuating chemsteranes and hopanoids, including 2-mphotic zone euxinia (PZE) was only found after the termethyl hopanes (2-MeH), and 13ination of this event. Abundant C enriched aryl
isoprenoids suggest that the observed enviecological successions of planktonic assemblages domronmental changes were accominated by algae, inclupanied by ding
dinoflagellates, cyanobacteria and green-sulfur bacteria. The synchronous occurrence of 15portance of N values around 0‰ provides evidence for the im2-MeH and n at this stratified/anoxic ary productio-fixation fueling primcyanobacteria and N2continental platform. OAE3 at Demerara Rise was characterized by apparently cyclic,
concomitant variations of stable isotopic composition of carbon and hydrogen (13C and
D, respectively) of marine- and terrestrial-derived n-alkanes. This pattern suggested a
s. Intervals of enhanced marine rine and terrestrial systematight coupling between mproductivity were evidenced by positive 13C excursions of the algal marker n-C17, likely
related to increased growth rates and primary productivity. Parallel 13C enrichments in
C29 and C31 n-alkanes of higher land plant waxes suggest simultaneous changes of

I

Thesis Abstract

resulting in increased ospheric COs. Lowered concentrations of atmterrestrial ecosystem2

importance of C4 plants was one possible scenario explaining the observed molecular-

isotopic patterns. These intervals were also accompanied by D enrichments in n-C17

suggestive of changes in Dwater, likely due to variations in the evaporation/precipitation

balance and continental runoff. Overall, these results revealed a complex interplay of the

climatic and oceanographic regime and a potential coupling of marine and terrestrial

environmental changes.

g (~ 65.5 Ma) was studied in an ss extinction event at the K-PaIn addition, the m

, ned “Fish Clay” layer at Stevns Klint the renowexceptionally expanded section of

ark. At this location, decreased photosynthesis resulting fromDenm the low solar

transmission after the meteorite impact may have lasted less than 50 years. A highly

arkers and increased heterotrophic bacterial activity inished contribution of algal biomdim

was characteristic of the 2-mm-thick organic-rich layer deposited immediately after the

ction. This result e onset of recovery in algal produboundary. This period preceded th

odels suggesting a rapid resurgence of carbon fixation and strongly supported m

pact event, and provided a more r imjoaecological reorganization after this m

prehensive view of the biotic recovery compared to more traditional microfossil com

studies.

II

KURZFASSUNG

Kurzfassung

die biotischen und abiotischen Reaktionen Diese Dissertation untersucht einerseits auf extreme Um(OAE) und andererseits die Erholungphase der Primweltbedingungen während der kreidezeitlichärproduzenten imen „Oceanic Anoxic Events“ Anschluss an das
g) Grenze. Zu diesem Zweck wurden Aussterbeereignis der Kreide-Paläogen (K-Pponenten-spezifische stabile Isotope und arker, komische Biomorganisch-geochemgeochemische Gesamtparameter analysiert. Diese Multiproxy-Studie beleuchtet die
plexe Wechselbeziehung zwischen Umwelt und Biologie, während dieser wichtigen komn biologischen „Turnover“ e, die für einen schnelleEreignisse der Erdgeschicht ische Kreisläufeverantwortlich waren und weitreichende Auswirkungen auf biogeochemhatten. - der Oberkreide wurden untersucht – das OAE2 der ConiaciumZwei OAEs Intraschelf-Becken der Levant-Ma) im Grenze (~ 93.5 Millionen Jahre, TuroniumPlattform in Zentraljordanien, und das OAE3 des Coniacium (~ 88-89 Ma) im westlichen
äquatorialen Atlantik nahe der Küste Surinams (ODP Site 1259, Demerara Rise). Zu den
Jordanien gehörten Meeresspiegelschwankungen, nalen des OAE2 iprägnanten Merkmeinhergehend mit einer Stratifizierung der Wassersäule, variierender Position der
Chemokline, Hypersalinität und SOAE2 Hinweise für eine euxinische, phoauerstoff Mangel; während nach Beendigung des tische Zone (PZE) vorlagen. Erhöhte
Konzentrationen an Steranen und Hopanoiden, einschließlich 2-Methyl Hopanen (2-13C angereicherten Aryl-Isoprenoiden, weisen darauf hin, dass die MeH) und ökologischen Sukzession, der von Algen weltveränderungen von einer beobachteten Uminierten Plankton-kterien, Grün-Schwefel Bakterien) dom(inkl. Dinoflagellaten, CyanobaVergesellschaftungen begleitet wurden. Des Weiteren lässt das synchrone Auftreten von 2-MeH und 15N-Werten um 0‰ auf die Bedeutung von Cyanobakterien und N2-
ärproduktion unter den bestehenden Fixierung als die treibende Kraft der Primn Bedingungen schließen. stratifizierten/anoxischeDie enge Kopplung zwischen marinem und terrestrischem System war
charakteristisch für das OAE3 am Demerara Rise und ging einher mit einer zyklischen
Variation der stabilen Kohlenstoff- und Wasserstoff-Isotopenzusammensetzung (13C

III

Kurzfassung

und D) in marinen sowie terrestrischen n-Alkanen. Episoden mit gesteigerter mariner
Produktivität waren gekennzeichnet durch positive 13C-Anomalien des Algenbiomarkers

C17 n-Alkan, welche voraussichtlich durch einen Anstieg in der Wachstumsrate sowie der
Primärproduktion hervorgerufen wurden. Die parallele 13C Anreicherung