The Evolution of the Indian Ocean since the Late Cretaceous
All available ship and aeroplane tracks across the Indian Ocean were searched for identifiable magnetic anomalies and transform faults, and hence the age and direction of motion at the time of formation of about two-thirds of the floor of the ocean established. The magnetic lineations show that Indi...
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1971
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fthighwire:oai:open-archive.highwire.org:gji:24/5/437 2023-05-15T13:56:55+02:00 The Evolution of the Indian Ocean since the Late Cretaceous McKenzie, Dan Sclater, John G. 1971-12-01 00:00:00.0 text/html http://gji.oxfordjournals.org/cgi/content/short/24/5/437 https://doi.org/10.1111/j.1365-246X.1971.tb02190.x en eng Oxford University Press http://gji.oxfordjournals.org/cgi/content/short/24/5/437 http://dx.doi.org/10.1111/j.1365-246X.1971.tb02190.x Copyright (C) 1971, Oxford University Press Articles TEXT 1971 fthighwire https://doi.org/10.1111/j.1365-246X.1971.tb02190.x 2012-11-23T22:14:16Z All available ship and aeroplane tracks across the Indian Ocean were searched for identifiable magnetic anomalies and transform faults, and hence the age and direction of motion at the time of formation of about two-thirds of the floor of the ocean established. The magnetic lineations show that India moved away from Antarctica at about 18 cm/y for 20 My in the Early Tertiary. This rapid motion ceased in the Eocene and was followed by a period in which little or no spreading took place west of the Ninety East Ridge. Australia separated from Antarctica during this period. The present spreading episode began about 36 My ago. This detailed study has permitted instantaneous poles of rotation to be obtained, and has established that Africa is now moving northward at 2cm/y relative to Antarctica in the South West Indian Ocean. The evolution of the triple junction between the South East, South West and Central Indian Ridges is clearly reflected in the topography and magnetic lineations. The depth of parts of the ocean formed since the Late Cretaceous increases with age in the manner expected from the temperature structure of a cooling plate, and supports the evolution determined from the magnetic lineations in a most remarkable way. Heat flow observations are more scattered but also consistent with the same thermal model. The proposed evolution agrees with the distribution of known continental fragments and with the Late Cretaceous palaeomagnetic poles from surrounding continents and one obtained from the shape of the magnetic lineations south of India. It is, however, not yet clear how to reconstruct Gondwanaland from the Late Cretaceous reconstructions. Text Antarc* Antarctica HighWire Press (Stanford University) East Ridge ENVELOPE(-136.671,-136.671,63.833,63.833) Indian Geophysical Journal International 24 5 437 528 |
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HighWire Press (Stanford University) |
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fthighwire |
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English |
topic |
Articles |
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Articles McKenzie, Dan Sclater, John G. The Evolution of the Indian Ocean since the Late Cretaceous |
topic_facet |
Articles |
description |
All available ship and aeroplane tracks across the Indian Ocean were searched for identifiable magnetic anomalies and transform faults, and hence the age and direction of motion at the time of formation of about two-thirds of the floor of the ocean established. The magnetic lineations show that India moved away from Antarctica at about 18 cm/y for 20 My in the Early Tertiary. This rapid motion ceased in the Eocene and was followed by a period in which little or no spreading took place west of the Ninety East Ridge. Australia separated from Antarctica during this period. The present spreading episode began about 36 My ago. This detailed study has permitted instantaneous poles of rotation to be obtained, and has established that Africa is now moving northward at 2cm/y relative to Antarctica in the South West Indian Ocean. The evolution of the triple junction between the South East, South West and Central Indian Ridges is clearly reflected in the topography and magnetic lineations. The depth of parts of the ocean formed since the Late Cretaceous increases with age in the manner expected from the temperature structure of a cooling plate, and supports the evolution determined from the magnetic lineations in a most remarkable way. Heat flow observations are more scattered but also consistent with the same thermal model. The proposed evolution agrees with the distribution of known continental fragments and with the Late Cretaceous palaeomagnetic poles from surrounding continents and one obtained from the shape of the magnetic lineations south of India. It is, however, not yet clear how to reconstruct Gondwanaland from the Late Cretaceous reconstructions. |
format |
Text |
author |
McKenzie, Dan Sclater, John G. |
author_facet |
McKenzie, Dan Sclater, John G. |
author_sort |
McKenzie, Dan |
title |
The Evolution of the Indian Ocean since the Late Cretaceous |
title_short |
The Evolution of the Indian Ocean since the Late Cretaceous |
title_full |
The Evolution of the Indian Ocean since the Late Cretaceous |
title_fullStr |
The Evolution of the Indian Ocean since the Late Cretaceous |
title_full_unstemmed |
The Evolution of the Indian Ocean since the Late Cretaceous |
title_sort |
evolution of the indian ocean since the late cretaceous |
publisher |
Oxford University Press |
publishDate |
1971 |
url |
http://gji.oxfordjournals.org/cgi/content/short/24/5/437 https://doi.org/10.1111/j.1365-246X.1971.tb02190.x |
long_lat |
ENVELOPE(-136.671,-136.671,63.833,63.833) |
geographic |
East Ridge Indian |
geographic_facet |
East Ridge Indian |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
http://gji.oxfordjournals.org/cgi/content/short/24/5/437 http://dx.doi.org/10.1111/j.1365-246X.1971.tb02190.x |
op_rights |
Copyright (C) 1971, Oxford University Press |
op_doi |
https://doi.org/10.1111/j.1365-246X.1971.tb02190.x |
container_title |
Geophysical Journal International |
container_volume |
24 |
container_issue |
5 |
container_start_page |
437 |
op_container_end_page |
528 |
_version_ |
1766264522849386496 |