Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica
An expanded Oligocene-Miocene boundary interval recovered in the Cape Roberts Project CRP-2A core from beneath the Ross Sea, Antarctica, has yielded a high-resolution integrated chrono stratigraphy that has, in turn, enabled a new, more direct, calibration of magnetic polarity and biostratigraphic e...
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Online Access: | https://eprints.soton.ac.uk/45395/ https://eprints.soton.ac.uk/45395/1/54._Wilson_et_al._Geology_PUB_VERSION.pdf |
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ftsouthampton:oai:eprints.soton.ac.uk:45395 2023-07-30T03:59:20+02:00 Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica Wilson, G.S. Roberts, A.P. Harwood, D.M. Fielding, C.R. Watkins, D.K. Naish, T.R. Florindo, F. Sagnotti, L. Scherer, R.P. Villa, G. Lavelle, M. McIntosh, W.C. Bohaty, S.M. Verosub, K.L. 2002 text https://eprints.soton.ac.uk/45395/ https://eprints.soton.ac.uk/45395/1/54._Wilson_et_al._Geology_PUB_VERSION.pdf en eng https://eprints.soton.ac.uk/45395/1/54._Wilson_et_al._Geology_PUB_VERSION.pdf Wilson, G.S., Roberts, A.P., Harwood, D.M., Fielding, C.R., Watkins, D.K., Naish, T.R., Florindo, F., Sagnotti, L., Scherer, R.P., Villa, G., Lavelle, M., McIntosh, W.C., Bohaty, S.M. and Verosub, K.L. (2002) Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica. Geology, 30 (11), 1043-1046. (doi:10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2 <http://dx.doi.org/10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2>). Article PeerReviewed 2002 ftsouthampton https://doi.org/10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2 2023-07-09T20:51:44Z An expanded Oligocene-Miocene boundary interval recovered in the Cape Roberts Project CRP-2A core from beneath the Ross Sea, Antarctica, has yielded a high-resolution integrated chrono stratigraphy that has, in turn, enabled a new, more direct, calibration of magnetic polarity and biostratigraphic events. The Oligocene-Miocene boundary interval in the CRP-2A core comprises three 60-m-thick, rapidly deposited (>0.5 m/k.y.) sedimentary sequences (sequences 9, 10, and 11). In sequences 10 and 11, single-crystal, laser-fusion 40Ar/39Ar analyses of anorthoclase phenocrysts from two tephra horizons independently calibrate the CRP-2A magnetic-polarity stratigraphy and age model. Sequences 10 and 11 encompass subchron C6Cn.3n, which is dated as 24.3 ± 0.1 to 24.16 ± 0.1 Ma. Sequence 9 is interpreted to encompass subchron C6Cn.2n and the Oligocene-Miocene boundary, which is dated as 24.0 ± 0.1 Ma. These ages are 0.2 m.y. older than those of the geomagnetic polarity time scale calibrated from seafloor-spreading ridges and 0.9–1.3 m.y. older than the newly proposed astronomically calibrated ages. We contend that the discrepancy with the astronomically calibrated ages arises from a mismatch of three 406 k.y. eccentricity cycles or a 1.2 m.y. modulation of obliquity amplitude in the astronomical calibration of the Oligocene–Miocene time scale. Article in Journal/Newspaper Antarc* Antarctica Ross Sea University of Southampton: e-Prints Soton Ross Sea Cape Roberts ENVELOPE(-70.467,-70.467,-68.950,-68.950) |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
An expanded Oligocene-Miocene boundary interval recovered in the Cape Roberts Project CRP-2A core from beneath the Ross Sea, Antarctica, has yielded a high-resolution integrated chrono stratigraphy that has, in turn, enabled a new, more direct, calibration of magnetic polarity and biostratigraphic events. The Oligocene-Miocene boundary interval in the CRP-2A core comprises three 60-m-thick, rapidly deposited (>0.5 m/k.y.) sedimentary sequences (sequences 9, 10, and 11). In sequences 10 and 11, single-crystal, laser-fusion 40Ar/39Ar analyses of anorthoclase phenocrysts from two tephra horizons independently calibrate the CRP-2A magnetic-polarity stratigraphy and age model. Sequences 10 and 11 encompass subchron C6Cn.3n, which is dated as 24.3 ± 0.1 to 24.16 ± 0.1 Ma. Sequence 9 is interpreted to encompass subchron C6Cn.2n and the Oligocene-Miocene boundary, which is dated as 24.0 ± 0.1 Ma. These ages are 0.2 m.y. older than those of the geomagnetic polarity time scale calibrated from seafloor-spreading ridges and 0.9–1.3 m.y. older than the newly proposed astronomically calibrated ages. We contend that the discrepancy with the astronomically calibrated ages arises from a mismatch of three 406 k.y. eccentricity cycles or a 1.2 m.y. modulation of obliquity amplitude in the astronomical calibration of the Oligocene–Miocene time scale. |
format |
Article in Journal/Newspaper |
author |
Wilson, G.S. Roberts, A.P. Harwood, D.M. Fielding, C.R. Watkins, D.K. Naish, T.R. Florindo, F. Sagnotti, L. Scherer, R.P. Villa, G. Lavelle, M. McIntosh, W.C. Bohaty, S.M. Verosub, K.L. |
spellingShingle |
Wilson, G.S. Roberts, A.P. Harwood, D.M. Fielding, C.R. Watkins, D.K. Naish, T.R. Florindo, F. Sagnotti, L. Scherer, R.P. Villa, G. Lavelle, M. McIntosh, W.C. Bohaty, S.M. Verosub, K.L. Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
author_facet |
Wilson, G.S. Roberts, A.P. Harwood, D.M. Fielding, C.R. Watkins, D.K. Naish, T.R. Florindo, F. Sagnotti, L. Scherer, R.P. Villa, G. Lavelle, M. McIntosh, W.C. Bohaty, S.M. Verosub, K.L. |
author_sort |
Wilson, G.S. |
title |
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
title_short |
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
title_full |
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
title_fullStr |
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
title_full_unstemmed |
Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica |
title_sort |
integrated chronostratigraphic calibration of the oligocene-miocene boundary at 24.0 ± 0.1 ma from the crp-2a drill core, ross sea, antarctica |
publishDate |
2002 |
url |
https://eprints.soton.ac.uk/45395/ https://eprints.soton.ac.uk/45395/1/54._Wilson_et_al._Geology_PUB_VERSION.pdf |
long_lat |
ENVELOPE(-70.467,-70.467,-68.950,-68.950) |
geographic |
Ross Sea Cape Roberts |
geographic_facet |
Ross Sea Cape Roberts |
genre |
Antarc* Antarctica Ross Sea |
genre_facet |
Antarc* Antarctica Ross Sea |
op_relation |
https://eprints.soton.ac.uk/45395/1/54._Wilson_et_al._Geology_PUB_VERSION.pdf Wilson, G.S., Roberts, A.P., Harwood, D.M., Fielding, C.R., Watkins, D.K., Naish, T.R., Florindo, F., Sagnotti, L., Scherer, R.P., Villa, G., Lavelle, M., McIntosh, W.C., Bohaty, S.M. and Verosub, K.L. (2002) Integrated chronostratigraphic calibration of the Oligocene-Miocene boundary at 24.0 ± 0.1 Ma from the CRP-2A drill core, Ross Sea, Antarctica. Geology, 30 (11), 1043-1046. (doi:10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2 <http://dx.doi.org/10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2>). |
op_doi |
https://doi.org/10.1130/0091-7613(2002)030<1043:ICCOTO>2.0.CO;2 |
_version_ |
1772810106545635328 |