Dating
No dating has been possible at the type section of the Ediacaran Period in South Australia. Therefore the age range of 635 to 542 million years before the present is based on correlations to other countries where dating has been possible. The base age of approximately 635 million years ago is based on U-Pb (uranium-lead) isochron dating from Namibia and China. Applying this age to the base of the Ediacaran assumes that individual cap carbonates are synchronous around the world and that the correct cap carbonate layers have been correlated between Australian and Namibia. This is controversial because an age of about 580 million years has been obtained in association with glacial rocks in Tasmania which some scientists tentatively correlate with those just beneath the Ediacaran rocks of the Flinders Ranges. The age of the top is the same as the widely recognised age for the base of the Cambrian Period 542± 0.3 Mya (million years ago).
Read more about this topic: Ediacaran
Famous quotes containing the word dating:
“We go on dating from Cold Fridays and Great Snows; but a little colder Friday, or greater snow would put a period to man’s existence on the globe.”
—Henry David Thoreau (1817–1862)