Description

Given the established nature of geoscientific knowledge of the Kaapvaal craton compared to the Slave craton, and given the exciting new interdisciplinary results coming from the Kaapvaal Project and from Slave craton studies, scientists working on both cratons were brought together in a workshop to compare and contrast the nature of these two cratons. Of the 54 papers presented at the workshop, 24 are included in this volume.

There are clearly major similarities and differences between these two Archean cratons. The crust of both was predominantly formed in the Mesoarchean. Both contain crustal sections consisting of terranes of different ages welded together by Archean accretionary events. Both crustal sections are underlain by lithospheric mantle sections consisting of peridotites that experienced extensive partial melt extraction between 2.9 Ga and 3.2 Ga, but this is where the similarities between the cratons end. One of the most striking differences between the Slave and Kaapvaal cartons is the apparent seismic homogeneity of the Kaapvaal craton's SCLM whereas the Slave craton is seismically layered. The seismic layering in the centre of the craton correlates laterally and with depth with electrical layering and geochemical layering.

Taken together, these differences suggest that SCLM formation was different for the two cratons, implying that the search for a single causative formation process is bound to fail.

Reprinted from the journal Lithos Volume 71, numbers 2-4.

Table of Contents

1. The late Archean record: a puzzle in ca. 35 pieces (W. Bleeker). 2. Cratonic mantle roots, remnants of a more chondritic Archean mantle? (D. Francis). 3. The timing of kimberlite magmatism in North America: implications for global kimberlite genesis and diamond exploration (L.M. Heaman, B.A. Kjarsgaard, R. A. Creaser). 4. Thermal and chemical variations in subcrustal cratonic lithosphere: evidence from crustal isostasy (W.D. Mooney, J.E. Vidale). 5. A classification scheme for mantle-derived garnets in kimberlite: a tool for investigating the mantle and exploring for diamonds (D.J. Schulze). 6. The evolution of lithospheric mantle beneath the Kalahari Craton and its margins (W.L. Griffin et al.). 7. Regional patterns in the paragenesis and age of inclusions in diamond, diamond composition, and the lithospheric seismic structure of Southern Africa (S.B. Shirey et al.). 8. Samples of Proterozoic iron-enriched mantle from the Premier kimberlite (K.O. Hoal). 9. Mesozoic thermal evolution of the southern African mantle lithosphere (D.R. Bell, M.D. Schmitz, P.E. Janney). 10. The origin of garnet and clinopyroxene in "depleted" Kaapvaal peridotites (N.S.C. Simon et al.). 11. Re-Os systematics of diamond-bearing eclogites from the Newlands kimberlite (A.H. Menzies et al.). 12. Trace element geochemistry of coesite-bearing eclogites from the Roberts Victor kimberlite, Kaapvaal craton (D.E. Jacob, B. Schmickler, D.J. Schulze). 13. Mantle structure and composition to 800-km depth beneath southern Africa and surrounding oceans from broadband body waves (R.E. Simon et al.). 14. South African seismicity, April 1997 to April 1999, and regional variations in the crust and uppermost mantle of the Kaapvaal craton (C. Wright et al.). 15. Pn

Details

No. of pages:
504
Language:
English
Copyright:
© 2004
Published:
Imprint:
Elsevier Science
Print ISBN:
9780444516145
Electronic ISBN:
9780080930657

About the authors

A. Jones

Affiliations and Expertise

Geological Survey of Canada, Ottawa, Ontario, Canada

R.W. Carlson

Affiliations and Expertise

Carnegie Institution of Washington, Department of Terrestrial Magnetism, Washington, DC, USA