DSpace
 

Researchspace >
General science, engineering & technology >
General science, engineering & technology >
General science, engineering & technology >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10204/4190

Title: Shear wave velocity structure of the lower crust in southern Africa: evidence for compositional heterogeneity within Archaean and Proterozoic terrains
Authors: Kgaswane, EM
Nyblade, AA
Julia, J
Dirks, PHGM
Durrheim, RJ
Pasyanos, ME
Keywords: Archaean
Proterozoic terrains
Earth crust
Issue Date: Dec-2009
Publisher: American Geophysical Union
Citation: Kgaswane, EM, Nyblade, AA, Julia, J et al. 2009. Shear wave velocity structure of the lower crust in southern Africa: evidence for compositional heterogeneity within Archaean and Proterozoic terrains. Journal of Geophysical Research, Vol. 114, pp B12304 (1-19)
Abstract: The nature of the lower crust across the southern African shield has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations located in Botswana, South Africa and Zimbabwe. For large parts of both Archaean and Proterozoic terrains, the velocity models obtained from the inversions show shear wave velocities =4.0 km/s below ~20–30 km depth, indicating a predominantly mafic lower crust. However, for much of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain in South Africa, as well as for the western part of the Tokwe terrain in Zimbabwe, shear wave velocities of =3.9 km/s are found below ~20–30 km depth, indicating an intermediate-to-felsic lower crust. The areas of intermediate-to-felsic lower crust in South Africa coincide with regions where Ventersdorp rocks have been preserved, suggesting that the more evolved composition of the lower crust may have resulted from crustal reworking and extension during the Ventersdorp tectonomagmatic event at c. 2.7 Ga.
Description: Copyright: 2009 American Geophysical Union
URI: http://hdl.handle.net/10204/4190
ISSN: 0148-0227
Appears in Collections:Mining and geoscience
General science, engineering & technology

Files in This Item:

File Description SizeFormat
Kgaswane_2009.pdf1.59 MBAdobe PDFView/Open
View Statistics

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback