Magnetostratigraphic Chronology of a Cenozoic Sequence From DSDP Site 274, Ross Sea, Antarctica

Author(s)

Jovane, Luigi ^[1] ; Florindo, Fabio ^{[1, 2, 3]} ; Wilson, Gary ^{[4, 5]} ; Leone, Stephanie de Almeida Pecchiai Saldanha ^[1] ; Bin Hassan, Muhammad ^[1] ; Rodelli, Daniel ^[1] ; Cortese, Giuseppe ^[4]

Affiliation

^[1] Univ Sao Paulo, Inst Oceanog, Sao Paulo - Brazil

^[2] Ist Nazl Geofis & Vulcanol, Rome - Italy

^[3] Inst Climate Change Solut, Pesaro E Urbino - Italy

^[4] GNS Sci, Lower Hutt - New Zealand

^[5] Univ Otago, Dept Geol & Marine Sci, Dunedin - New Zealand

• Document type: Journal article
• Source: Frontiers in Earth Science; v. 8, DEC 14 2020.
• Web of Science Citations: 0

Abstract

New paleomagnetic results from the late Eocene-Middle Miocene samples from Deep Sea Drilling Project Site 274, cored during Leg 28 on the continental rise off Victoria Land, Ross Sea, provide a chronostratigraphic framework for an existing paleoclimate archive during a key period of Antarctic climate and ice sheet evolution. Based on this new age model, the cored late Eocene-Middle Miocene sequence covers an interval of almost 20 Myr (from similar to 35 to similar to 15 Ma). Biostratigraphic constraints allow a number of possible correlations with the Geomagnetic Polarity Time Scale. Regardless of correlation, average interval sediment accumulation rates above 260 mbsf are similar to 6 cm/kyr with the record punctuated by a number of unconformities. Below 260 mbsf (across the Eocene/Oligocene boundary) interval, sedimentation accumulation rates are closer to similar to 1 cm/kyr. A major unconformity identified at similar to 180 mbsf represents at least 9 Myr accounting for the late Oligocene and Early Miocene and represent non-deposition and/or erosion due to intensification of Antarctic Circumpolar Current activity. Significant fluctuations in grain size and magnetic properties observed above the unconformity at 180 mbsf, in the Early Miocene portion of this sedimentary record, reflect cyclical behavior in glacial advance and retreat from the continent. Similar glacial cyclicity has already been identified in other Miocene sequences recovered in drill cores from the Antarctic margin. (AU)

• FAPESP's process: 16/24946-9 - Sea-level changes and Global Monsoon System: clues from marine cores in Brazil
• Grantee: Luigi Jovane
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants