RbSr radiometric age of late Precambrian fossil-bearing and associated rocks from Sinai

摘要: Abstract Six samples of metamorphic rocks from three essentially coeval stratigraphic units, two which contain Precambrian microfossils, have been analyzed by the Rb-Sr whole-rock radiometric method. Least-squares regression data yields an isochron date 934 ± 80m.y. with initial 87 Sr/ 86 Sr= 0.7007 0.0011. This may reflect approximate age formation these or, alternately, a time major metamorphism. Regardless, is significant in that it (a) agreement 900-m.y. for containing similar types fossils Bitter Springs, Australia, and (b) coupled structural evidence, supports equivalence 1000-m.y. old (“Kibaran cycle”) Saudi Arabia.