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Early Precambrian mantle derived rocks in the southern Prince Charles Mountains, East Antarctica: age and isotopic constraints
Open-File Report
2007-1047-SRP-039
By: E.V. Mikhalsky, F. Henjes-Kunst, and N.W. Roland
Mafic and ultramafic rocks occurring as lenses, boudins, and tectonic slabs within metamorphic units in the
southern Mawson Escarpment display mantle characteristics of either a highly enriched, or highly depleted nature.
Fractionation of these mantle rocks from their sources may be as old as Eoarchaean (ca 3850 Ma) while their tectonic
emplacement probably occurred prior to 2550 Ma (U-Pb SHRIMP data). These results provide for the first time
evidence for Archaean suturing within East Antarctica. Similar upper mantle sources are likely present in the northern
Mawson Escarpment. A younger age limit of these rocks is 2200 Ma, as indicated by presumably metamorphic zircon
ages while their magmatic age may be constrained by single zircon dates at 2450-2250 Ma. The area of the northern
Mawson Escarpment is most likely of ensimatic origin and includes mafic rocks which were derived from distinct
mantle source(s) during Palaeoproterozoic time.
Suggested Citation
Mikhalsky, E., Henjes-Kunst, F., and Roland, N., 2007, Early Precambrian mantle derived rocks in the southern Prince Charles Mountains, East Antarctica: age and isotopic constraints: U.S. Geological Survey Open-File Report 2007-1047-SRP-039, 4 p., https://doi.org/10.3133/ofr20071047SRP039.
ISSN: 2331-1258 (online)
Study Area
Publication type
Report
Publication Subtype
USGS Numbered Series
Title
Early Precambrian mantle derived rocks in the southern Prince Charles Mountains, East Antarctica: age and isotopic constraints
Series title
Open-File Report
Series number
2007-1047-SRP-039
DOI
10.3133/ofr20071047SRP039
Year Published
2007
Language
English
Publisher
U.S. Geological Survey
Publisher location
Reston, VA
Description
4 p.
Larger Work Type
Report
Larger Work Subtype
USGS Numbered Series
Larger Work Title
Antarctica: A Keystone in a Changing World--Online Proceedings for the Tenth International Symposium on Antarctic Earth Sciences. Santa Barbara, California, U.S.A.--August 26 to September 1, 2007