Single zircon dating constraining the maximum age of the Barberton greenstone belt, southern Africa

Abstract:

One of the central issues in early Precambrian crustal evolution is the age and genetic relationship between greenstone belt supracrustal assemblages and nearby high-grade gneiss terranes. The crucial question, in most cases, is which of the two is older. Zircon ages, using the new single grain evaporation technique, from a metaquartzite and a felsic volcanic flow of the Onverwacht Group in the Barberton greenstone belt (BGB), South Africa and Swaziland, constrain the age of this basal part of the greenstone sequence between 3451±15 and 3438±6 Ma and are thus demonstrably older than the greenstones; also, they cannot be derived from them by partial melting as has been proposed previously. -from Authors

Año de publicación:

1988

Keywords:

Fuente:

scopus