Arjen Grothe

Institute of Environmental Biology, Faculty of Science, Utrecht University

Short CV

Born 16th of October 1986 in Veenendaal, The Netherlands.
2011: Start of PhD project
2009-2011: MSc in Earth Sciences – Physical Geography at University Utrecht, Netherlands

Master Thesis: Organic walled dinoflagellate cysts from the Tarim Basin, western China: Implications for the timing of the early Paratethys Sea retreat

Supervision: Prof. Dr. H. Brinkhuis, Dr. G. Dupont-Nivet, R.E. Bosboom MSc. and A.J.P. Houben MSc.

2005-2008: BSc in Earth Sciences at University Utrecht, Netherlands

Bachelor thesis: Paleotopography of the Dover area prior to its opening: a Digital Geological Model

Supervision: Dr. K.M. Cohen; Dr. D.J. Karssenberg

1999-2005: VWO at Rembrandt College, Veenendaal, Netherlands

Track: ‘N&G’ (Nature & Health); with Economics I and Geography

PhD-Project

PRACTICE

"Paratethys Retreat And Causes: Timing and Implications for Climate and Environment”

Promotor: Prof. Dr. Henk Brinkhuis

Co-Promotor:

Dr. Wout Krijgsman
Dr. Gert-Jan Reichart
Dr. Francesca Sangiorgi

Introduction:

During the Cretaceous, Paleogene and Neogene, large parts of “Eurasia” were covered by an epicontinental sea. This sea had probably its largest extent in Eocene, with extensions reaching into western China. Due to the continental collision, in combination glacio-eustatic sea level drops from the Oligocene onwards, this epicontinental sea shrunk and retreated slowly with the Black Sea, the Caspian Sea and the Aral Lake as present-day relicts. Moreover, the northward plate motion of the Africa-Arabia-India complex with respect to Eurasia led to the formation of the Alpine-Himalayan orographic barrier, which separated the Mediterranean realm from the more northerly-situated Paratethys domain. This barrier caused the ‘open oceanic ‘ conditions of Paratethys Sea to evolve into more restricted marine conditions. Ultimately, the Paratethys domain was characterized by brackish and lacustrine conditions. Associated with this transition, open marine fauna was progressively replaced by endemic, fresh to brackish water biota. Besides that, the Paratethys retreat directly altered the moisture sources in the region, which consequently influenced the atmospheric circulation and so contributed to Eurasian climate changes. Due to the inland setting, climate changes will be strongly amplified.

Sediments of the Paratethys Sea in different basins from Austria to western China provide thus a unique record of Cenozoic climate change and tectonism. However, the information that is required to link environmental change to the Paratethys Sea retreat is still lacking. This PhD-project aims to reconstruct climatic and oceanographic implications of the Paratethys Sea retreat.

The main focus of this project will be on the Miocene-Pliocene epoch, during which oceanic connections of the Paratethys to the Atlantic Ocean (via the Mediterranean) and/or Indian Ocean, and subsequently paleocirculation between and within the various sub-basins of the Paratethys domain, deteriorated. This resulted for example, in the accumulation of hundreds of meters of salt in the western Paratethys during the Badenian (Lower Miocene, approx. 13.5 Ma). Timing and nature of water exchange between Paratethys and Mediterranean is an important and yet poorly understood mechanism, especially due to the lack of quantitative proxy information on environmental changes in the Paratethys realm. Understanding the changing connections between these large inland basins and its climatic implications is of crucial importance for quantitative paleo-oceanographic models that simulate evaporate formation.

A precise and accurate chronology for the sedimentary successions is a crucial prerequisite to establish basin-wide correlations and distinguish between synchronous and diachronous events. The combination of paleomagnetic and biostratigraphical data, in particular dinoflagellate cysts (highly resistant organic walled remains of dinoflagellates), should provide a reliable and accurate timeframe for the Paratethys basins. Moreover, geochemical proxies, such as δD (salinity) and TEX₈₆ (sea surface temperature), and palynological data allow for detailed reconstructions of the environmental response to tectonism and global climate change.

This project will be performed in close cooperation with:

Iuliana Vasiliev

Christiaan van Baak

Roderic Bosboom






Heavily weathered marine deposits of the early Paratethys

Fieldwork in Western China