Title Macroscopic geological structures of the Napier and Rayner complexes, East Antarctica
Author Toyoshima, T.; Osanai, Y.; Nogi, Y.
Author Affil Toyoshima, T., Niigata University, Graduate School of Science and Technology, Niigata, Japan. Other: National Institute of Polar Research, Japan; Kyushu University, Japan; Chiba University, Japan; National Institute of Polar Research, 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.139-146, . Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719. ISBN: 978-1-86239-268-7
Publication Date 2008
Notes In English. 24 refs. Ant. Acc. No: 85817
Index Terms Antarctica--East Antarctica; Antarctica; Archean; basement; block structures; cratons; crust; East Antarctica; faults; foliation; geophysical methods; geophysical surveys; International Polar Year 2007-08; IPY 2007-08 Research Publications; magnetic anomalies; magnetic methods; magnetic survey maps; maps; metamorphic rocks; metamorphism; mobile belts; Napier Complex; orientation; Precambrian; Rayner Complex; structural analysis; structural maps; surveys; systems; tectonic elements
Abstract This paper presents a form-line map of the Napier and Rayner Complexes, East Antarctica, constructed from attitude data for foliations shown on published geological maps, and discusses the macroscopic geological structures. The form-line map shows that the two complexes consist of several, structurally distinct, units or blocks bounded by east-west-, NE-SW- and NW- SE-striking faults. The major boundary between the two complexes, as indicated on the published geological maps, is a structural discontinuity shown as a large fault on the form-line map. On the form-line map, east-west- and NE-SW-trending folds are abundant and NW-SE-trending ones occur locally in both complexes. North-south- trending folds are also abundant in the Napier Complex. Dome-and-basin fold patterns on a regional scale occur in some regions. The regional strikes, macroscopic structures, and the major boundary between the two complexes are considered to have resulted from the same later deformation episode. The form-line map and distribution map of key mineral assemblages show that the Napier Complex is not uniform and includes at least two types of metamorphic units or fragments of the Archaean crust that were formed through distinct P-T-t evolutionary processes and divided by several faults.
URL http://hdl.handle.net/10.1144/SP308.6
Publication Type journal article
Record ID 290790