thumbnail

A view of Antarctic ice-sheet evolution from sea-level and deep-sea Isotope Changes During the Late Cretaceous-Cenozoic

Open-File Report 2007-1047-KP-06

By:
, , , , , , and
DOI: 10.3133/ofr20071047KP06

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

The imperfect direct record of Antarctic glaciation has led to the delayed recognition of the initiation of a continentsized ice sheet. Early studies interpreted initiation in the middle Miocene (ca 15 Ma). Most current studies place the first ice sheet in the earliest Oligocene (33.55 Ma), but there is physical evidence for glaciation in the Eocene. Though there are inherent limitations in sea-level and deep-sea isotope records, both place constraints on the size and extent of Late Cretaceous to Cenozoic Antarctic ice sheets. Sealevel records argue that small- to medium-size (typically 10-12 × 106 km3 ) ephemeral ice sheets occurred during the greenhouse world of the Late Cretaceous to middle Eocene. Deep-sea δ 18O records show increases associated with many of these greenhouse sea-level falls, consistent with their attribution to ice-sheet growth. Global cooling began in the middle Eocene and culminated with the major earliest Oligocene (33.55 Ma) growth of a large (25 × 106 km3 ) Antarctic ice sheet that caused a 55-70 m eustatic fall and a 1‰ δ 18O increase. This large ice sheet became a driver of climate change, not just a response to it, causing increased latitudinal thermal gradients and a spinning up of the oceans that, in turn, caused a dramatic reorganization of ocean circulation and chemistry.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
A view of Antarctic ice-sheet evolution from sea-level and deep-sea Isotope Changes During the Late Cretaceous-Cenozoic
Series title:
Open-File Report
Series number:
2007-1047-KP-06
DOI:
10.3133/ofr20071047KP06
Year Published:
2007
Language:
English
Publisher:
National Academies Press
Publisher location:
Washington, DC
Description:
16 p.
First page:
55
Last page:
70
Other Geospatial:
Antarctica