Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica
Hole 690B, drilled on Maud Rise near Antarctica, provides one of the most important Palaeocene/Eocene boundary interval sections. Magnetostratigraphy plays a key role in dating Palaeocene/Eocene boundary events, but there are two problems with the published scheme in Hole 690B. The first concerns ma...
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ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/D81C26BV 2023-05-15T13:50:01+02:00 Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica Ali, Jason R. Kent, Dennis V. Hailwood, Ernie A. 2000 https://doi.org/10.7916/D81C26BV English eng https://doi.org/10.7916/D81C26BV Geology Articles 2000 ftcolumbiauniv https://doi.org/10.7916/D81C26BV 2019-04-04T08:07:15Z Hole 690B, drilled on Maud Rise near Antarctica, provides one of the most important Palaeocene/Eocene boundary interval sections. Magnetostratigraphy plays a key role in dating Palaeocene/Eocene boundary events, but there are two problems with the published scheme in Hole 690B. The first concerns major mismatches of several magnetozones and biozones in the succession. The second is an unexplained pervasive declination cluster, which should not be present in these azimuthally unoriented piston cores. To resolve these issues, a palaeomagnetic reinvestigation was carried out on 98 specimens from 12 cores through the upper Palaeocene-middle Eocene section in Hole 690B. The bulk of the samples carry an approximately uniformly directed magnetically hard component resulting in a declination cluster effectively identical to that of the earlier study. The spurious magnetization can be explained either as an 'inward-radial magnetization' or as a 'core-split overprint'. By estimating the extent of the overprint within each sample, it has been possible to construct a filtered magnetostratigraphy for the section. The result is that many of the magnetozone-biozone mismatches are eliminated, and the record of the 2.5 Myr Chron C24r, which brackets the various events associated with the Palaeocene/Eocene boundary, is considerably cleaner. It is not possible to define the upper and lower boundaries of this magnetochron, so we recommend that the dating of the events within this section be based on the biostratigraphy only. Article in Journal/Newspaper Antarc* Antarctica Columbia University: Academic Commons Maud Rise ENVELOPE(3.000,3.000,-66.000,-66.000) |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Geology |
spellingShingle |
Geology Ali, Jason R. Kent, Dennis V. Hailwood, Ernie A. Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
topic_facet |
Geology |
description |
Hole 690B, drilled on Maud Rise near Antarctica, provides one of the most important Palaeocene/Eocene boundary interval sections. Magnetostratigraphy plays a key role in dating Palaeocene/Eocene boundary events, but there are two problems with the published scheme in Hole 690B. The first concerns major mismatches of several magnetozones and biozones in the succession. The second is an unexplained pervasive declination cluster, which should not be present in these azimuthally unoriented piston cores. To resolve these issues, a palaeomagnetic reinvestigation was carried out on 98 specimens from 12 cores through the upper Palaeocene-middle Eocene section in Hole 690B. The bulk of the samples carry an approximately uniformly directed magnetically hard component resulting in a declination cluster effectively identical to that of the earlier study. The spurious magnetization can be explained either as an 'inward-radial magnetization' or as a 'core-split overprint'. By estimating the extent of the overprint within each sample, it has been possible to construct a filtered magnetostratigraphy for the section. The result is that many of the magnetozone-biozone mismatches are eliminated, and the record of the 2.5 Myr Chron C24r, which brackets the various events associated with the Palaeocene/Eocene boundary, is considerably cleaner. It is not possible to define the upper and lower boundaries of this magnetochron, so we recommend that the dating of the events within this section be based on the biostratigraphy only. |
format |
Article in Journal/Newspaper |
author |
Ali, Jason R. Kent, Dennis V. Hailwood, Ernie A. |
author_facet |
Ali, Jason R. Kent, Dennis V. Hailwood, Ernie A. |
author_sort |
Ali, Jason R. |
title |
Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
title_short |
Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
title_full |
Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
title_fullStr |
Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
title_full_unstemmed |
Magnetostratigraphic reinvestigation of the Palaeocene/Eocene boundary interval in Hole 690B, Maud Rise, Antarctica |
title_sort |
magnetostratigraphic reinvestigation of the palaeocene/eocene boundary interval in hole 690b, maud rise, antarctica |
publishDate |
2000 |
url |
https://doi.org/10.7916/D81C26BV |
long_lat |
ENVELOPE(3.000,3.000,-66.000,-66.000) |
geographic |
Maud Rise |
geographic_facet |
Maud Rise |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
https://doi.org/10.7916/D81C26BV |
op_doi |
https://doi.org/10.7916/D81C26BV |
_version_ |
1766252749790380032 |