Evidence of a full West Antarctic Ice Sheet back to the early Oligocene: Insight from double dating of detrital apatites in Ross Sea sediments

The West Antarctic Ice Sheet is the most unstable component of the Antarctic cryosphere. Its fluctuations are well documented since the Pliocene, but its behaviour over the last 35 Ma is more controversial, particularly during periods of past high global pCO2 values similar to those predicted in fut...

Full description

Bibliographic Details
Published in:Terra Nova
Main Authors: Olivetti, Valerio, Balestrieri, Maria Laura, Thomson, Stuart N., Talarico, Franco M., Rossetti, Federico, ZATTIN, MASSIMILIANO
Other Authors: Zattin, Massimiliano
Format: Article in Journal/Newspaper
Language:English
Published: Blackwell Publishing Ltd 2015
Subjects:
double dating
detrital apatites
Ross Sea sediments
Antarctic
Cape Roberts
Ross Sea
The Antarctic
West Antarctic Ice Sheet
Antarc*
Ice Sheet
Online Access:http://hdl.handle.net/11577/3188325
https://doi.org/10.1111/ter.12153
Description
Summary:The West Antarctic Ice Sheet is the most unstable component of the Antarctic cryosphere. Its fluctuations are well documented since the Pliocene, but its behaviour over the last 35 Ma is more controversial, particularly during periods of past high global pCO2 values similar to those predicted in future global climate scenarios. Here, we present new U–Pb dating of detrital apatite grains (previously dated by the fission-track method) from Cape Roberts Project Oligocene to Pliocene marine sediments in the Ross Sea. Two past ice-flow patterns were identified: one formed by outlet glaciers sourcing short-travelled apatites and one, northerly directed, bringing far-travelled apatite grains. The latter provides the first robust physical evidence for the presence and repeated expansion of an Oligocene West Antarctic Ice Sheet.

Similar Items