We present preliminary diatom results from a gravity core KI13-C1 collected in the Central Basin located at the mouth of the Joides Basin (wester Ross Sea, Antarctica). This area represents the main shelf of the Ross Sea carved by a major ice stream that drained the East Antarctic Ice Shelf (EAIS), during the last glacial expansion. This study is part of the STREAM Project (Late Quaternary evolution of the ocean-ice sheet interactions: the record from the Ross Sea continental margin-Antarctica), finaced by the Italian Ministry of Foreign Affairs and International Cooperation between Italy and Rep. of Korea (2019-2021 years). The chronological framework obtained combining 14C radiocarbon dating on organic matter matrix, paleomagnetic measurement and diatom biostratigraphy indicates that the investigated sedimentary sequence covers the last geomagnetic reversal, i.e., the Matuyama-Brunhes transition. Based on the distributional pattern of diatom and foraminiferal assemblages we recognized and characterized different environments as well as we reconstructed the oceanographic dynamics in this area. Additionally, we observed the near synchronism between the magnetic signal and the LAOD of Actinocyclus ingens (0.65 Ma) bioevent. The study underlines the importance of the diatoms as indicators of environmental changes and chronological tool in the Antartctic region.
RECENT AND PAST ENVIRONMENTAL CHANGES IN THE CENTRAL BASIN (ROSS SEA - ANTARCTICA)
Federico Giglio;
2020
Abstract
We present preliminary diatom results from a gravity core KI13-C1 collected in the Central Basin located at the mouth of the Joides Basin (wester Ross Sea, Antarctica). This area represents the main shelf of the Ross Sea carved by a major ice stream that drained the East Antarctic Ice Shelf (EAIS), during the last glacial expansion. This study is part of the STREAM Project (Late Quaternary evolution of the ocean-ice sheet interactions: the record from the Ross Sea continental margin-Antarctica), finaced by the Italian Ministry of Foreign Affairs and International Cooperation between Italy and Rep. of Korea (2019-2021 years). The chronological framework obtained combining 14C radiocarbon dating on organic matter matrix, paleomagnetic measurement and diatom biostratigraphy indicates that the investigated sedimentary sequence covers the last geomagnetic reversal, i.e., the Matuyama-Brunhes transition. Based on the distributional pattern of diatom and foraminiferal assemblages we recognized and characterized different environments as well as we reconstructed the oceanographic dynamics in this area. Additionally, we observed the near synchronism between the magnetic signal and the LAOD of Actinocyclus ingens (0.65 Ma) bioevent. The study underlines the importance of the diatoms as indicators of environmental changes and chronological tool in the Antartctic region.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
