The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time
Present crustal evolution models fail to account for the generation of the large volume of continental crust in the required time intervals. All Archaean plate tectonic models, whether invoking faster spreading rates, similar to today's spreading rates, or longer ridge lengths, essentially prop...
Main Author: | |
---|---|
Format: | Other/Unknown Material |
Language: | unknown |
Published: |
1988
|
Subjects: | |
Online Access: | http://ntrs.nasa.gov/search.jsp?R=19880020870 |
id |
ftnasantrs:oai:casi.ntrs.nasa.gov:19880020870 |
---|---|
record_format |
openpolar |
spelling |
ftnasantrs:oai:casi.ntrs.nasa.gov:19880020870 2023-05-15T16:00:25+02:00 The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time Wilks, M. E. Unclassified, Unlimited, Publicly available JAN 1, 1988 http://ntrs.nasa.gov/search.jsp?R=19880020870 unknown http://ntrs.nasa.gov/search.jsp?R=19880020870 Accession ID: 88N30254 No Copyright Other Sources 46 Lunar and Planetary Inst., Workshop on the Growth of Continental Crust; p 168 1988 ftnasantrs 2012-02-15T17:28:16Z Present crustal evolution models fail to account for the generation of the large volume of continental crust in the required time intervals. All Archaean plate tectonic models, whether invoking faster spreading rates, similar to today's spreading rates, or longer ridge lengths, essentially propose that continental crust has grown by island arc accretion due to the subduction of oceanic crust. The petrological differences that characterize the Archaean from later terrains result from the subduction of hotter oceanic crust into a hotter mantle. If the oceanic crust was appreciably thicker in the Archaean, as geothermal models would indicate, this thicker crust is surely going to have an effect on tectonic processes. A more valid approach is to compare the possible styles of convergence of thick oceanic crust with modern convergence zones. The best modern analog occurs where thick continental crust is colliding with thick continental crust. Oceanic crustal collision on the scale of the present-day Himalayan continental collision zone may have been a frequent occurrence in the Archaean, resulting in extensive partial melting of the hydrous underthrust oceanic crust to produce voluminous tonalite melts, leaving a depleted stabilized basic residuum. Present-day island arc accretion may not have been the dominant mechanism for the growth of the early Archaean crust. Other/Unknown Material Day Island NASA Technical Reports Server (NTRS) |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
46 |
spellingShingle |
46 Wilks, M. E. The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
topic_facet |
46 |
description |
Present crustal evolution models fail to account for the generation of the large volume of continental crust in the required time intervals. All Archaean plate tectonic models, whether invoking faster spreading rates, similar to today's spreading rates, or longer ridge lengths, essentially propose that continental crust has grown by island arc accretion due to the subduction of oceanic crust. The petrological differences that characterize the Archaean from later terrains result from the subduction of hotter oceanic crust into a hotter mantle. If the oceanic crust was appreciably thicker in the Archaean, as geothermal models would indicate, this thicker crust is surely going to have an effect on tectonic processes. A more valid approach is to compare the possible styles of convergence of thick oceanic crust with modern convergence zones. The best modern analog occurs where thick continental crust is colliding with thick continental crust. Oceanic crustal collision on the scale of the present-day Himalayan continental collision zone may have been a frequent occurrence in the Archaean, resulting in extensive partial melting of the hydrous underthrust oceanic crust to produce voluminous tonalite melts, leaving a depleted stabilized basic residuum. Present-day island arc accretion may not have been the dominant mechanism for the growth of the early Archaean crust. |
format |
Other/Unknown Material |
author |
Wilks, M. E. |
author_facet |
Wilks, M. E. |
author_sort |
Wilks, M. E. |
title |
The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
title_short |
The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
title_full |
The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
title_fullStr |
The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
title_full_unstemmed |
The effect of thicker oceanic crust in the Archaean on the growth of continental crust through time |
title_sort |
effect of thicker oceanic crust in the archaean on the growth of continental crust through time |
publishDate |
1988 |
url |
http://ntrs.nasa.gov/search.jsp?R=19880020870 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
Day Island |
genre_facet |
Day Island |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19880020870 Accession ID: 88N30254 |
op_rights |
No Copyright |
_version_ |
1766396400136880128 |