A SHRIMP U-Pb study of zircons from the layered sequence of the Great Dyke, Zimbabwe, and a granitoid anatectic dyke

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Scientific paper

This paper reports the first SHRIMP zircon U-Pb study of rocks from the Great Dyke layered intrusion of Zimbabwe. Zircons were extracted from a pegmatoidal websterite within the layered succession and also a granitoid dyke intrusive into the ultramafic sequence, which is interpreted as an anatectic melt derived from the wall rocks. The anatectic dyke yielded a single population of zircons. The analyses for the websterite and the dyke yielded statistically indistinguishable 207Pb/206Pb crystallisation ages of 2579+/-3 and 2574+/-7 Ma, respectively. These ages are approximately 120 million years older than the previously accepted Rb-Sr age of the Great Dyke and agree with other recently determined conventional U-Pb, Pb-Pb and Sm-Nd isochron ages. As the anatectic dyke did not contain xenocrystic zircons, derivation from the older country rock granitoids, which in this area yield an 207Pb/206Pb age of 2647+/-9 Ma, must have taken place by complete melting of the country rocks. Confirmation of this older age has important implications for the Archaean crustal history of Zimbabwe. The Chilimanzi granitoid suite, ca. 2600 Ma in age, constitutes nearly 50% of the currently exposed surface area of the craton and is the last tectono-thermal event before complete stabilisation of the craton which must have occurred at least by the time the Great Dyke was emplaced, that is, over a period of some 20-25 million years.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

A SHRIMP U-Pb study of zircons from the layered sequence of the Great Dyke, Zimbabwe, and a granitoid anatectic dyke does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A SHRIMP U-Pb study of zircons from the layered sequence of the Great Dyke, Zimbabwe, and a granitoid anatectic dyke, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A SHRIMP U-Pb study of zircons from the layered sequence of the Great Dyke, Zimbabwe, and a granitoid anatectic dyke will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1718595

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.