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In-situ U-Pb geochronology and Hf isotope analyses of the Rayner Complex, east Antarctica
journal contribution
posted on 2023-05-17, 10:28 authored by Jacqueline HalpinJacqueline Halpin, Gerakiteys, CL, Clarke, GL, Belousova, EA, Griffin, WLIn-situ zircon U–Pb and Hf isotopic analysis via laser ablation microprobe-inductively coupled plasma mass spectrometer (LAM-ICPMS) of samples from Kemp and MacRobertson Lands, east Antarctica suggests that the Kemp Land terrane evolved separately from the rest of the Rayner Complex prior to the ca. 940 Ma Rayner Structural Episode. Several Archaean metamorphic events in rocks from western Kemp Land can be correlated with events previously reported for the adjacent Napier Complex. Recently reported ca. 1,600 Ma isotopic disturbance in rocks from the Oygarden Group may be correlated with a charnockitic intrusion in the Stillwell Hills before ca. 1,550 Ma. Despite being separated by some 200 km, THf DM ages indicate felsic orthogneiss from Rippon Point, the Oygarden Group, Havstein Island and the Stillwell Hills share a ca. 3,660–3,560 Ma source that is indistinguishable from that previously reported for parts of the Napier Complex. More recent additions to this crust include Proterozoic charnockite in the Stillwell Hills and the vicinity of Mawson Station. These plutons have distinct 176Hf/177Hf ratios and formed via the melting of crust generated at ca. 2,150–2,550 Ma and ca. 1,790– 1,870 Ma respectively.
History
Publication title
Contributions to Mineralogy and PetrologyVolume
148Issue
6Pagination
689-706ISSN
0010-7999Department/School
School of Natural SciencesPublisher
Springer-VerlagPlace of publication
175 Fifth Ave, New York, USA, Ny, 10010Rights statement
Copyright 2004 Springer-VerlagRepository Status
- Restricted