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Impact of Middle Cretaceous Climatic Change on Sub- Equatorial Pacific Settings (Northern and Central Andes, Peru): a Comparison with the Tethyan Realm

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Impact of Middle Cretaceous Climatic Change on Sub- Equatorial Pacific Settings (Northern and Central Andes, Peru): a Comparison with the Tethyan Realm Impact of Middle Cretaceous climatic change on sub- equatorial Pacific settings (Northern and Central Andes, Peru): A comparison with the Tethyan Realm Dissertation zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften an der Fakultät für Geowissenschaften der Ruhr-Universität Bochum vorgelegt von Juan-Pablo Navarro-Ramirez geboren am 12.03.1985 in Sullana, Peru Bochum, November 2015 Die vorliegende Arbeit wurde von der Fakultät für Geowissenschaften der Ruhr-Universität Bochum als Dissertation zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) anerkannt. Erster Gutachter: Prof. Dr. Adrian Immenhauser Zweiter Gutachter: Prof. Dr. Jörg Mutterlose fachfremder Gutachter: Prof. Dr. Stephane Wohnlich Tag der Disputation: 01.02.2016 Erklärung „Ich erkläre hiermit an Eides statt, dass ich die vorliegende Arbeit selbständig angefertigt sowie die benutzten Quellen und Hilfsmittel vollständig angegeben habe. Ich habe alle Fakten, Textstellen und Abbildungen, die anderen Werken dem Wortlaut oder dem Sinn nach entnommen sind, durch entsprechende Zitate gekennzeichnet. Die vorliegende Dissertation wurde in dieser oder ähnlicher Form bei keiner anderen Fakultät oder Hochschule eingereicht.“ Bochum, November 2015 Juan Pablo Navarro Ramirez Publication list of the Dissertation 1. Title: Record of Albian to early Cenomanian environmental perturbation in the eastern sub-equatorial Pacific Authors: Navarro-Ramirez J.P.1, Bodin S.1, Heimhofer U.2, Immenhauser A.1 Published in Palaeogeography, Palaeoclimatology, Palaeoecology in January 2015; Volume 423; Pages 122–137 (chapter 3 of this thesis) DOI: //dx.doi.org/10.1016/j.palaeo.2015.01.025 2. Title: Ongoing Cenomanian – Turonian heterozoan carbonate production in the neritic settings of Peru Authors: Navarro-Ramirez J.P.1,, Bodin S.1, Immenhauser A.1 Published in Sedimentary Geology in October 2015 (chapter 4 of this thesis) Article in Press DOI: 10.1016/j.sedgeo.2015.10.011 3. Title: Response of western South American epeiric-neritic heterozoan ecosystem to OAE 1d and 2 Authors: Navarro-Ramirez J.P.1,, Bodin S.1, Immenhauser A.1 In preparation (chapter 5 of this thesis) 1 Ruhr-Universität Bochum, Institut für Geologie, Mineralogie und Geophysik, D-44870 Bochum, Germany 2 Leibniz Universität Hannover, Institut für Geologie, D-30167 Hannover, Germany The main applicant for the research grant was Prof. Dr. S.Bodin and the co-applicant was Prof. Dr. A. Immenhauser. The research was financed by the Deutsche Forschungsgemeinschaft (DFG, project no. BO-365/2-1) and by the Deutscher Akademischer Austauschdienst (DAAD) through a scholarship to me (PKZ: 91540654). Analytical work in the isotope laboratories at Bochum University was supported by A. Niedermayr. The Geological survey of Peru (INGEMMET) supported with important logistical support. Author contributions and peer review process First article: J.P.N.R., S.B., and A.I. had initial discussions and were involved in the study design; J.P.N.R. wrote the first draft of the manuscript, implemented co-author comments, made the figures, and prepared the samples for stable isotope and total organic carbon analyses; U.H. was involved in the stable isotope analyses on total organic carbon at Leibniz University Hannover; J.P.N.R., S.B., and A.I. were involved in fieldwork data and sample (bulk rock) acquisition; All authors discussed the results and contributed to revisions of the manuscript. The article was first submitted in July 2014, evaluated by the editor F. Surlyk and by two anonymous reviewers. Ending of January 2015 the paper was accepted. Second article: J.P.N.R., S.B., and A.I. had initial discussions and were involved in the study design; J.P.N.R. wrote the first draft of the manuscript, implemented co-author comments, made the figures, and prepared the samples for stable isotope and total organic carbon analyses; J.P.N.R., S.B., and A.I. were involved in fieldwork data and sample (bulk rock) acquisition; All authors discussed the results and contributed to revisions of the manuscript. The article was first submitted in July 2015, evaluated by the editor Prof. Jones and by the reviewers T. Adatte and B. Sageman. On 23 October 2015 the paper was accepted. Third article: J.P.N.R., S.B., and A.I. had initial discussions and were involved in the study design; J.P.N.R. wrote the first draft of the manuscript, implemented co-author comments, made the figures, and prepared the samples for stable isotope and total organic carbon analyses; J.P.N.R., S.B., and A.I. were involved in fieldwork data and sample (bulk rock) acquisition; All authors discussed the results and contributed to revisions of the manuscript. The article is in preparation and intended to be sent to Sedimentology. Bochum, November 2015 Juan Pablo Navarro Ramirez Abstract The Albian–Turonian interval (ca 113–90 Ma; mid-Cretaceous) is characterized by series of global environmental perturbations referred to as “oceanic anoxic events” (OAEs). OAEs are represented by an expanded and intensified oxygen minimum zone in the world oceans and coincide well with periods of disturbed carbon cycle. OAEs are often related to enhanced accumulation of black shale in deeper and basinal settings, anomalously high burial rates of marine organic carbon, sea-level fluctuations and changes in trophic levels. A linkage between massive volcanism and OAEs has been suggested. To date, much of the present knowledge of oceanic anoxia in the mid-Cretaceous world is biased towards data derived from hemipelagic and pelagic sections in Europe (Tethys), North America (Western Interior Seaway) and data from various ocean drilling projects. Less attention has been paid to the impact of mid-Cretaceous oceanic anoxic events to shallow water carbonate systems, and the sub-equatorial eastern Pacific domain is particularly underrepresented. In this thesis I argue that the Cretaceous epeiric depositional environments in western South America (here Peru) arguably bear crucial information to understand OAEs causes and consequences. In order to close this gap, a field-based project has been performed in Peru. This study is based on a multidisciplinary approach making used of a broad, multi-proxy approach (C, and Sr isotopes, sedimentology, sequence stratigraphy etc.). Geochemical and sedimentological analyses were obtained from 1600 section metres of Albian–Turonian sedimentary rocks, logged in a bed-by-bed approach in six sections in the northern and central part of the Andes Mountain in Peru. The results are compared and discussed to coeval findings from the proto- Atlantic and Tethyan realms in order to understand causal linkages among global geological patterns during the mid-Cretaceous greenhouse world. The Albian–Turonian interval in Peru (western platform) is characterized by the following ecological and environmental patterns: (i) an late Aptian–early Albian major change from siliciclastic-dominated to carbonate sedimentation coinciding with the impact of the Kilian Level; (ii) an early Albian incipient platform drowning linked to the impact of the Paquier Level; (iii) an early middle Albian major demise of neritic carbonate production that coincides with the Leenhardt Level, followed by middle Albian condensed sedimentation that 13 is associated with prominent negative values in δ Ccarb prior to the onset of OAE1c; (iv) renewed carbonate ramp production during the late Albian associated to the impact of OAE1d; (v) early to late Cenomanian heterozoan ramp recording the pre-OAE2 δ13C excursions, specifically the Mid-Cenomanian Event; (vi) a late Cenomanian interval typified by outer-ramp heterozoan type sedimentation prior to the δ13C-trough of the OAE2 interval. i (vii) a late Cenomanian to early Turonian δ13C plateau phase characterized by benthonic inner ramp sedimentation during a phase of sea-level highstand; (viii) a recovery of δ13C values at the end of OAE2 associated to increased influx of argillaceous facies and reduced carbonate production; (ix) and finally an early to middle Turonian fluctuating δ13C curve, linked to a maximum flooding phase in the Mammites nodosoides Zone and enhanced carbonate production during the Collignoniceras woollgar Zone. Results compiled in this thesis are relevant as they come from very expanded neritic sections in the sub-equatorial eastern Pacific domain of the South America Platform. In summary, the present thesis underlines the importance of transient environmental perturbations as a possible mechanism to affect neritic carbonate systems during the Albian– Turonian. Changes in depositional style and carbon isotope signatures are possibly affected by the very specific regional palaeogeographic setting of these sections, i.e., the vast but topographically compartmentalized carbonate ramp of the western platform. Regional features also include high rates of basement subsidence and related relative sea-level change, and transient intervals of increased continental run-off under humid climate conditions from the exposed continental shield to the east (present-day Brazil). Despite these regionally important features, however, the sections measured in Peru record clear evidence of global environmental patterns during the mid-Cretaceous. The very expanded nature of these sections allows for a uncommonly detailed temporal resolution of chemostratigraphic features. ii Kurzfassung Das Albium-Turonium Intervall (ca. 113-90; mittlere Kreide) ist charakterisiert durch eine Reihe von globalen Umweltereignissen, bekannt als „oceanic anoxic
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