In-situ U-Pb geochronology and Hf isotope analyses of the Rayner Complex, east Antarctica

• Published in: Contributions to Mineralogy and Petrology
• Main Authors: Halpin, JA, Gerakiteys, CL, Clarke, GL, Belousova, EA, Griffin, WL
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer-Verlag 2005
• Subjects: Earth Sciences; Geology; Geochronology; East Antarctica; Havstein; Havstein Island; Kemp Land; Mawson Station; Napier; Rayner; Rippon Point; Stillwell Hills; Antarc*; Antarctica
• Online Access: https://doi.org/10.1007/s00410-004-0627-6; http://ecite.utas.edu.au/75906

In-situ zircon UPb and Hf isotopic analysisvia laser ablation microprobe-inductively coupled plasmamass spectrometer (LAM-ICPMS) of samples fromKemp and MacRobertson Lands, east Antarctica suggeststhat the Kemp Land terrane evolved separatelyfrom the rest of the Rayner Complex prior to the ca.940 Ma Rayner Structural Episode. Several Archaeanmetamorphic events in rocks from western Kemp Landcan be correlated with events previously reported for theadjacent Napier Complex. Recently reported ca.1,600 Ma isotopic disturbance in rocks from the OygardenGroup may be correlated with a charnockiticintrusion in the Stillwell Hills before ca. 1,550 Ma.Despite being separated by some 200 km, T Hf DM agesindicate felsic orthogneiss from Rippon Point, theOygarden Group, Havstein Island and the Stillwell Hillsshare a ca. 3,6603,560 Ma source that is indistinguishablefrom that previously reported for parts of theNapier Complex. More recent additions to this crustinclude Proterozoic charnockite in the Stillwell Hills andthe vicinity of Mawson Station. These plutons havedistinct 176 Hf/ 177 Hf ratios and formed via the melting ofcrust generated at ca. 2,1502,550 Ma and ca. 1,7901,870 Ma respectively.