The University of Southampton
University of Southampton Institutional Repository

Environmental magnetic record of Antarctic palaeoclimate from Eocene/Oligocene glaciomarine sediments, Victoria Land Basin

Sagnotti, Leonardo, Florindo, Fabio, Verosub, Kenneth L., Wilson, Gary S. and Roberts, Andrew P. (1998) Environmental magnetic record of Antarctic palaeoclimate from Eocene/Oligocene glaciomarine sediments, Victoria Land Basin Geophysical Journal International, 134, (3), pp. 652-662.

Record type: Article

Abstract

The onset of continent-wide glaciation in Antarctica is still poorly understood, despite
being one of the most important palaeoclimatic events in the Cenozoic. The Eocene/
Oligocene boundary interval has recently been recognized as a critical time for Antarctic
climatic evolution, and it may mark the preglacial–glacial transition. Magnetic susceptibility,
intensity of natural and artificial remanences, hysteresis parameters and magnetic
anisotropy of the lower half ( late Eocene/early Oligocene) of the CIROS-1 core (from
McMurdo Sound, Antarctica) reveal alternating intervals of high and low magnetic
mineral concentrations that do not correspond to lithostratigraphic units in the core.
Pseudo-single-domain magnetite is the main magnetic mineral throughout the sequence,
and sharp changes in magnetite concentration match changes in clay mineralogy
beneath and at the Eocene/Oligocene boundary. The detrital magnetite originated from
weathering of the Ferrar Group (which comprises basic extrusive and intrusive igneous
rocks). Weathering processes and input of magnetite to the Victoria Land Basin were
intense during periods when the Antarctic climate was warmer than today, but during
intervals when the climate was relatively cool, chemical weathering of the Ferrar Group
was suppressed and input of detrital magnetite to the Victoria Land Basin decreased.
Our results also indicate that a cold and dry climate was not established in Antarctica
until the Eocene/Oligocene boundary, with major ice sheet growth occurring at the
early/late Oligocene boundary. Some earlier cold intervals are identified, which indicate
that climate had begun to deteriorate by the middle/late Eocene boundary.

Full text not available from this repository.

More information

Published date: 1998
Keywords: Cenozoic, palaeoclimate, palaeomagnetism, rock magnetism, sediments

Identifiers

Local EPrints ID: 66111
URI: http://eprints.soton.ac.uk/id/eprint/66111
ISSN: 0956-540X
PURE UUID: 120ffbb9-98f9-4aef-92ac-13c9c18ff2ee

Catalogue record

Date deposited: 30 Apr 2009
Last modified: 19 Jul 2017 00:27

Export record

Contributors

Author: Leonardo Sagnotti
Author: Fabio Florindo
Author: Kenneth L. Verosub
Author: Gary S. Wilson
Author: Andrew P. Roberts

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×