Archaean and proterozoic metamorphic rocks on Southern Eyre Peninsula, South Australia

Abstract
A slightly disturbed Rb‐Sr isochron age of 2643 ± 130 m.y. has been obtained from granulite‐facies metamorphics at Cape Carnot, Southern Eyre Peninsula. Pro‐terozoic granitic gneiss 1855 ± 10 m.y.) is present at Kirton Point, Port Lincoln (X 87Rb = 1.39 x 10‐11y‐1 and NBS 70A = 522 ppm Rb, 65.3 ppm Sr). Part of the Gawler Block therefore yields an Archaean age comparable with many from the Yilgarn Block. The outcrop of known Archaean rocks in southern Australia has been extended eastward by about 1000 km. A summary of the petrological and structural features of the rock types dated is also presented.