Title Geochemistry of post-kinematic mafic dykes from central to eastern Dronning Maud Land, East Antarctica; evidence for a Pan- African suture in Dronning Maud Land
Author Owada, M.; Baba, S.; Osanai, Y.; Kagami, H.
Author Affil Owada, M., Yamaguchi University, Department of Earth Sciences, Yamaguchi, Japan. Other: National Institute of Polar Research, Japan; Kyushu University, Japan; Chiba University, Japan; University of the Ryukyus, Japan; Kyushu University, Japan; Niigata University, 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.235-252, . Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719. ISBN: 978-1-86239-268-7
Publication Date 2008
Notes In English. 55 refs. Ant. Acc. No: 85823
Index Terms Antarctica--East Antarctica; Antarctica--Sor-Rondane Mountains; absolute age; Antarctica; Ar/Ar; dates; diabase; dikes; East Antarctica; geochemistry; igneous rocks; International Polar Year 2007-08; intrusions; IPY 2007-08 Research Publications; K/Ar; lamproite; lamprophyres; lower Paleozoic; mafic composition; magmatism; major elements; paleogeography; Paleozoic; Pan-African Orogeny; plutonic rocks; Precambrian; Proterozoic; Queen Maud Land; Rb/Sr; Sm/Nd; Sor-Rondane Mountains; trace elements; upper Precambrian
Abstract The region comprising central to eastern Dronning Maud Land (2W to 40E), East Antarctica, is underlain by Mesoproterozoic to Cambrian metamorphic rocks and post-kinematic intrusive rocks with varied compositions. The post-kinematic mafic dykes linked to the Pan-African orogen include various types of lithologies: lamprophyre and lamproite in Muhlig- Hofmannfjella in central Dronning Maud Land and lamprophyre and high-K dolerite in the Sor Rondane Mountains in eastern Dronning Maud Land. Most of the mafic dykes have been weakly affected by low-grade metamorphism, but clearly preserve their igneous textures. The mafic dykes show a high abundance of Rb, Ba, Sr and light rare earth elements with negative anomalies of Nb, Ta and Ti in a multi-element primitive mantle-normalized diagram. The geochemical characteristics of the mafic dykes suggest that they were derived from a metasomatized mantle source leaving phlogopite, rutile and/or titanite as residual phases. Considering Sr and Nd isotopic systematics of the mafic dykes and the host metamorphic rocks and coeval felsic intrusive rocks, a large crustal boundary potentially related to a suture zone of West and East Gondwana should pass between Muhlig- Hofmannfjella and the Sor Rondane Mountains.
URL http://hdl.handle.net/10.1144/SP308.12
Publication Type journal article
Record ID 290784