Skip to Main Content
Book Chapter

The c. 1000–900 Ma and c. 550–500 Ma tectonothermal events in the Prince Charles Mountains–Prydz Bay region, East Antarctica, and their relations to supercontinent evolution

By
Xiaochun Liu
Xiaochun Liu
Search for other works by this author on:
Yue Zhao
Yue Zhao
Search for other works by this author on:
Jianmin Hu
Jianmin Hu
Search for other works by this author on:
Published:
January 01, 2013

Abstract

The Prince Charles Mountains (PCM)–Prydz Bay region in East Antarctica experienced the late Mesoproterozoic/early Neoproterozoic (c. 1000–900 Ma) and late Neoproterozoic/Cambrian (c. 550–500 Ma) tectonothermal events. The late Mesoproterozoic/early Neoproterozoic tectonothermal event dominates the Rayner Complex and spreads over the main part of the Prydz Belt. This event includes two episodes (or stages) of metamorphism accompanying the intrusion of syn- to post-orogenic granitoids at c. 1000–960 Ma and c. 940–900 Ma. The c. 1000–960 Ma metamorphism in the northern PCM and Mawson Coast records medium- to low-pressure granulite facies conditions accompanied by a near-isobaric cooling path, whereas the c. 940–900 Ma metamorphism in Kemp Land reaches relatively higher PT conditions followed by a near-isothermal decompression or decompressive cooling path. The late Mesoproterozoic/early Neoproterozoic orogeny (i.e. the Rayner orogeny) involved a long-lived (c. 1380–1020 Ma) magmatic accretion along continental/oceanic arcs and a protracted or two-stage collision of the Indian craton with a portion of East Antarctica, forming the Indian–Antarctic continental block independent of the Rodinia supercontinent. The late Neoproterozoic/Cambrian tectonothermal event pervasively overprinted on both Archaean–Proterozoic basements and cover sequences in the Prydz Belt. Except for high-pressure granulite boulders from the Grove Mountains, the metamorphism of most rocks records medium-pressure granulite facies conditions with a clockwise P–T path. In contrast, this event is lower grade (greenschist–amphibolite facies) and localized in the PCM. Regionally, the late Neoproterozoic/Cambrian tectonothermal event seems to have developed on the southeastern margin of the Indo-Antarctic continental block, suggesting that the major suture should be located southeastwards of the presently exposed Prydz Belt. The precise dating for different rock types reveals that the late Neoproterozoic/Cambrian orogeny (i.e. the Prydz orogeny) commenced at c. 570 Ma and lasted until c. 490 Ma, which is roughly contemporaneous with the late collisional stage of the Brasiliano/Pan-African orogenic systems in Gondwanaland. Therefore, the final assembly of the Gondwana supercontinent may have been completed by the collision of a number of cratonic blocks during the same time period.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Antarctica and Supercontinent Evolution

S. L. Harley
S. L. Harley
University of Edinburgh, UK
Search for other works by this author on:
I. C. W. Fitzsimons
I. C. W. Fitzsimons
Curtin University of Technology, Australia
Search for other works by this author on:
Y. Zhao
Y. Zhao
CAGS, China
Search for other works by this author on:
Geological Society of London
Volume
383
ISBN electronic:
9781862396470
Publication date:
January 01, 2013

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal