Title Contrasting metamorphic P-T path between Schirmacher Hills and Mühlig- Hofmannfjella, central Dronning Maud Land, East Antarctica
Author Baba, S.; Owada, M.; Shiraishi, K.
Author Affil Baba, S., University of the Ryukyus, Department of Natural Environment, Nishihara, Japan. Other: National Institute of Polar Research, Japan; Kyushu University, Japan; Chiba University, Japan; National Institute of Polar Research, Japan; Graduate School of Advanced Studies, Japan
Source Geodynamic evolution of East Antarctica; a key to the east-west Gondwana connection, edited by M. Satish-Kumar, Y. Motoyoshi, Y. Osanai, Y. Hiroi and K. Shiraishi. Geological Society Special Publications, Vol.308, p.401-417, . Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719. ISBN: 978-1-86239-268-7
Publication Date 2008
Notes In English. 40 refs. Ant. Acc. No: 85831
Index Terms Antarctica--East Antarctica; Antarctica--Schirmacher Hills; amphibole group; Antarctica; chain silicates; chemical composition; clinoamphibole; clinopyroxene; correlation; East Antarctica; fayalite; feldspar group; framework silicates; garnet group; geochemistry; geologic barometry; geologic thermometry; gneisses; high-grade metamorphism; hornblende; International Polar Year 2007-08; IPY 2007-08 Research Publications; major elements; metamorphic rocks; metamorphism; mineral assemblages; mineral composition; Muhlig-Hofmann Range; nesosilicates; olivine group; orthopyroxene; orthosilicates; P-T conditions; plagioclase; pyroxene group; Queen Maud Land; Schirmacher Hills; silicates
Abstract Retrograde metamorphic P-T paths of garnet-pyroxene-bearing mafic gneisses from three regions in central Dronning Maud Land (CDML) were examined. No difference in P-T conditions estimated from rocks of the three regions was recognized, and they are within the range of c. 6-8 kbar, 750-830°C. However, localities in the Muhlig-Hofmann Range (Filchnerfjella and Jutulsessen) preserve rocks with mineral textures that indicate near-isothermal decompressional histories. In the Schirmacher Hills, an isolated exposure on the Princess Astrid Coast, metamorphic texture observed in mafic gneiss is indicative of an isobaric cooling history. Combining their P-T paths and age determinations suggests that the Schirmacher Hills was a separate terrane, together with present-day SE Africa, whereas the Grenvillian-age east-west-trending CDML inland nunatak regions are characterized by an isothermal decompressional metamorphic history related to the final amalgamation of Gondwana.
URL http://hdl.handle.net/10.1144/SP308.20
Publication Type journal article
Record ID 290776