New Zealand Journal of Geology and Geophysics abstracts
Postemplacement deformation of plutons and their metasedimentary
host, Mt Dromedary area, southern Victoria Land, Antarctica
C. R. WALCOTT
D. CRAW
Geology Department
University of Otago
P.O. Box 56
Dunedin, New Zealand
Abstract The Mt Dromedary massif, in the Precambrian-Paleozoic
Wilson Terrane of the Transantarctic Mountains, consists of about 10
plutons intruded into a metasedimentary sequence dominated by marble.
The plutons and the meta-sediments have been deformed after pluton
intrusion. The foliation in the metasediments has been recrystallised
and realigned during postplutonic deformation, and now parallels pluton
margins. Postplutonic folds are rare and concentrated in zones at the
ends or margins of some plutons. A postplutonic lineation is generally
steeply plunging and lies parallel to folds where present. A 6 km long,
southeast trending, high strain zone with shallow-plunging stretching
lineation formed in a narrow (< 1 km) belt of metasediment between
the Dromedary Metagabbro and a granite pluton. The margins of both
plutons were affected by this high strain zone up to 1 km beyond pluton
margins. The high strain zone dies out laterally into a lower strain,
complexly folded zone. The structure of the Dromedary area can be
interpreted in terms of rigid bodies (plutons) that have remained
largely internally undeformed while strain was concentrated in
relatively incompetent metasediments between plutons.
Keywords Antarctica; granite; metasediment; deformation;
metagabbro; pluton
Received 28 January 1993; published 3 December 1993
New Zealand Journal of Geology & Geophysics, 1991, Vol. 36:
487—496
0028Ð8306/06/3604—0487 ©The Royal Society of New Zealand 1991
PDF file of entire paper: medium quality
(1762K); (scanned from paper original: notes about this process).
Digitisation of this article from the printed journal was kindly
facilitated by the Geological Society of New Zealand
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