Eocene Southern Atlantic Ocean dinoflagellate cysts: regional correlation and paleoenvironments using statistical methodology

DANERS, G.; GUERSTEIN, RAQUEL; AMENABAR, CECILIA R.; CASADÌO, S.; ALPERIN, M.I.; DOLDAN, A.

Praga

Congreso; XV International Palynological Congress, XI International Organization of Palaeobotany Conference; 2020

International Federation of Palynological Societies (IFPS) and the International Organisation of Palaeobotany (IOP)

The Eocene was a time of regional tectonic events and climatological changes related to the opening of the Drake Passage that separates Antarctica from South America. Know the rifting time of the passage can help us to understand the change of surface circulation patterns and its consequences. In this sense, dinoflagellate cysts (dinocysts) are useful tools for biostratigraphy and palaeoceanographic reconstructions. In this work, qualitative and quantitative dinocyst data of La Meseta Formation (LM), Antarctic Peninsula were used, for the first time, to correlate with middle to late Eocene southern South America units, including the Upper Member of Río Turbio (UMRT), Man Aike (MA) and Leticia (Le) formations in Argentina, and to elucidate similar paleoenvironments using compositional statistics methods. The previously established biozonation scheme for the UMRT allowed the correlation of the studied units suggesting the equivalence of LM, Le and MA with the RTF2 zone of UMRT which is equivalent to zones SPDZ11 and SPDZ12 (late Lutetian to early Bartonian) of the South-West Pacific Ocean. A principal component analysis was applied using 6 variables defined on dinocyst species with similar paleoecological requirements. This allowed to separate two groups: Group A (MA, UMRT, Le and LM) which represents Antarctic endemic dinocyst species, dominant from the middle Lutetian to the early Priabonian; and Group B (upper part of the UMRT) that includes late Priabonian assemblages. In addition, the Group A was subdivided into subgroup A1, with samples representing deeper marine environments (Le, MA and lowest samples of LM), while the subgroup A3 (top of the UMRT), indicates coastal environments. In an intermediate position, the subgroup A2 (base of the UMRT and most of the samples of LM) suggests coastal environments with nutrient-rich waters linked to river discharges coincident with the deltaic system defined for LM by sedimentological evidence.Nota: https://www.prague2020.cz/news.phpNEWSLadies and gentlemen, dear colleagues,for the last several weeks, the organizing committee of the XV IPC/XI IOPC Prague 2020 has been closely following all aspects surrounding the coronavirus COVID-19 pandemic. We all were shocked by its impact on people, families and everyday life - it is affecting all of us. The borders of many countries have been closed, people are working from their homes, etc. Human lives and safety must have priority over all. We all hope that the situation will be getting better.Personal meetings with colleagues are vital for many of us. Personal communication among scientists is always useful and fruitful. Since the organizers cannot guarantee the safety of potential participants of the Conference this September in Prague, and after discussions between the organizing committee, representatives of the IFPS and the IOP, we decided to postpone our conference to 2021. The newly planned date for the conference is May 1st through May 7th, 2021. All necessary information concerning new terms, deadlines, payments etc. will be announced on this web site during May 2020. Thank you for your support! We are trying as best as we can to prepare the Conference for you, and hope to meet you all in Prague next year.Stay with us!Organizing Committee