Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Tinker, J. H. Articles by Royden, L. H. Search for Related Content GeoRef GeoRef Citation

Old, strong continental lithosphere with weak Archaean margin at ~1.8 Ga, Kaapvaal Craton, South Africa

CIGCES, Geological Sciences, University of Cape Town, Rondebosch 7701, South Africa

Leigh H. Royden

EAPS, Massachusetts Institute of Technology, Cambridge, MA 02139-4307

Correspondence: Correspondence should be addressed to J.T. (e-mail: Justine{at}cigces.uct.ac.za) or M.dW. (e-mail: Maarten{at}cigces.uct.ac.za)

Low elastic strength of ancient lithosphere based on flexural analyses has been interpreted to reflect elevated regional geothermal gradients in response to higher global heat production in the past. Here we present a flexural analysis of Archean/Palaeoproterozoic sediment cover along the western margin of the Archaean Kaapvaal craton based on seismic stratigraphy. Our results show that between ~1.93 and ~1.75 Ga, the Archaean margin of the craton had an effective elastic thickness of 7.5 to 10km compared to its present day value of 60 to 70km. Because the Kaapvaal craton had already stabilized by ~2.7 Ga and was underlain by 150 to 300km thick strong mantle lithosphere, it is unlikely that the relatively thin elastic thickness along this old margin reflects a change in secular cooling of the Earth. Instead, we interpret the low elastic strength to be a transient marginal tectonic effect similar to that recorded along modern continental margins.

This article has been cited by other articles:

				M. de Wit and J. Tinker Crustal structures across the central Kaapvaal craton from deep-seismic reflection data South African Journal of Geology, June 1, 2004; 107(1-2): 185 - 206. [Abstract] [Full Text] [PDF]