Apatite Fission Track Signatures of the Ross Sea Ice Flows During the Last Glacial Maximum

Abstract

Abstract The catchment for the Ross Sea ice includes both the East and the West Antarctic ice sheets, but the mass balance is a direct response to climate change. Our work is aimed to reconstruct the ice flows after the Last Glacial Maximum and is based on apatite fission track data from samples collected from 18 piston cores across the Ross Sea embayment. Fission track ages have been divided into meaningful populations and then compared with bedrock ages from West and East Antarctica. Furthermore, fission track lengths have been measured on each population and then compared through forward modeling with thermal histories derived from literature. The widespread presence of apatites with cooling ages of about 30–40 Ma reveals a main exhumation phase of the Transantarctic Mountains during the Oligocene associated to the last phases of the West Antarctic Rift System. Furthermore, the presence of key marker apatites (e.g., younger than 21 Ma or older than 230 Ma) allows to identify the Central High as a major ice flow divide.

Keywords

• detrital thermochronology
• Ross Sea
• Late Glacial Maximum