Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges
Prior studies have proposed and examined the hypothesis that India and Australia are separate rigid plates separated by a wide, near-equatorial, E-W striking, plate boundary. Attempts to place narrow limits on the location of the Africa-Australia-India triple junction have been hindered, however, by...
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fthighwire:oai:open-archive.highwire.org:gji:119/3/893 2023-05-15T13:44:46+02:00 Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges Demets, Charles Gordon, Richard G. Vogt, Peter 1994-12-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/119/3/893 https://doi.org/10.1111/j.1365-246X.1994.tb04025.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/119/3/893 http://dx.doi.org/10.1111/j.1365-246X.1994.tb04025.x Copyright (C) 1994, Oxford University Press Articles TEXT 1994 fthighwire https://doi.org/10.1111/j.1365-246X.1994.tb04025.x 2016-11-16T17:21:51Z Prior studies have proposed and examined the hypothesis that India and Australia are separate rigid plates separated by a wide, near-equatorial, E-W striking, plate boundary. Attempts to place narrow limits on the location of the Africa-Australia-India triple junction have been hindered, however, by the lack of useful magnetic profiles crossing the eastern Carlsberg Ridge and northern Central Indian Ridge. Herein we present near-ridge portions of new profiles from an aeromagnetic survey of the Carlsberg Ridge east of 66°E and of the Central Indian Ridge north of 19°S. These new data are used to estimate 35 new spreading rates averaged from the middle of chron 2A (3.03 Ma) to the present. All other plate motion data along the Central Indian and Carlsberg ridges are also analysed to investigate the present kinematics of the Indian Ocean, especially the motion and boundary between the Indian and Australian plates. Unlike prior efforts, we objectively estimate uncertainties in the strikes of transform faults along the Carlsberg and Central Indian ridges. Indian Ocean plate motion data are unambiguously inconsistent with a model in which India and Australia lie on the same rigid plate, but remain consistent with the existence of distinct and rigid Indian and Australian plates. The plate motion data also remain consistent with closure of the Africa-Arabia-India plate motion circuit. The data are consistent with closure of the Africa-Antarctic-Australia plate motion circuit and place an upper bound of 7 mm yr−1 on the summed deformation around the Rodriguez triple junction if we have accurately estimated the errors in the data. From data along the Carlsberg and Central Indian Ridges, 95 per cent confidence limits on the location of the Africa-Australia-India triple junction are 6.2°S to ∼9°S if the boundary between India and Australia is discrete (i.e. very narrow) where it intersects the Central Indian Ridge. When closure is enforced about the Owen and Rodriguez triple junctions, these limits decrease to 8°S-9°S, ... Text Antarc* Antarctic HighWire Press (Stanford University) Antarctic Indian Rodriguez ENVELOPE(-56.720,-56.720,-63.529,-63.529) Geophysical Journal International 119 3 893 930 |
institution |
Open Polar |
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HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
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English |
topic |
Articles |
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Articles Demets, Charles Gordon, Richard G. Vogt, Peter Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
topic_facet |
Articles |
description |
Prior studies have proposed and examined the hypothesis that India and Australia are separate rigid plates separated by a wide, near-equatorial, E-W striking, plate boundary. Attempts to place narrow limits on the location of the Africa-Australia-India triple junction have been hindered, however, by the lack of useful magnetic profiles crossing the eastern Carlsberg Ridge and northern Central Indian Ridge. Herein we present near-ridge portions of new profiles from an aeromagnetic survey of the Carlsberg Ridge east of 66°E and of the Central Indian Ridge north of 19°S. These new data are used to estimate 35 new spreading rates averaged from the middle of chron 2A (3.03 Ma) to the present. All other plate motion data along the Central Indian and Carlsberg ridges are also analysed to investigate the present kinematics of the Indian Ocean, especially the motion and boundary between the Indian and Australian plates. Unlike prior efforts, we objectively estimate uncertainties in the strikes of transform faults along the Carlsberg and Central Indian ridges. Indian Ocean plate motion data are unambiguously inconsistent with a model in which India and Australia lie on the same rigid plate, but remain consistent with the existence of distinct and rigid Indian and Australian plates. The plate motion data also remain consistent with closure of the Africa-Arabia-India plate motion circuit. The data are consistent with closure of the Africa-Antarctic-Australia plate motion circuit and place an upper bound of 7 mm yr−1 on the summed deformation around the Rodriguez triple junction if we have accurately estimated the errors in the data. From data along the Carlsberg and Central Indian Ridges, 95 per cent confidence limits on the location of the Africa-Australia-India triple junction are 6.2°S to ∼9°S if the boundary between India and Australia is discrete (i.e. very narrow) where it intersects the Central Indian Ridge. When closure is enforced about the Owen and Rodriguez triple junctions, these limits decrease to 8°S-9°S, ... |
format |
Text |
author |
Demets, Charles Gordon, Richard G. Vogt, Peter |
author_facet |
Demets, Charles Gordon, Richard G. Vogt, Peter |
author_sort |
Demets, Charles |
title |
Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
title_short |
Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
title_full |
Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
title_fullStr |
Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
title_full_unstemmed |
Location of the Africa-Australia-India Triple Junction and Motion Between the Australian and Indian Plates: Results From an Aeromagnetic Investigation of the Central Indian and Carlsberg Ridges |
title_sort |
location of the africa-australia-india triple junction and motion between the australian and indian plates: results from an aeromagnetic investigation of the central indian and carlsberg ridges |
publisher |
Oxford University Press |
publishDate |
1994 |
url |
http://gji.oxfordjournals.org/cgi/content/short/119/3/893 https://doi.org/10.1111/j.1365-246X.1994.tb04025.x |
long_lat |
ENVELOPE(-56.720,-56.720,-63.529,-63.529) |
geographic |
Antarctic Indian Rodriguez |
geographic_facet |
Antarctic Indian Rodriguez |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/119/3/893 http://dx.doi.org/10.1111/j.1365-246X.1994.tb04025.x |
op_rights |
Copyright (C) 1994, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.1994.tb04025.x |
container_title |
Geophysical Journal International |
container_volume |
119 |
container_issue |
3 |
container_start_page |
893 |
op_container_end_page |
930 |
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1766206100193935360 |