Peter J. Smith
Department of Earth Sciences
Open University
Milton Keynes, U.K.

" A search in Zimbabwe has revealed detrital zircon grains up to 3,800 million years old. Although older than any dated Zimbabwean rocks, they are, disappointingly, much younger than the precrustal zircons of Western Australia (4,200 million years old).

M.H. Dodson, W. Compston, I.S. Williams, J.F. Wilson, "A search for ancient detrital zircons in Zimbabwean sediments," Journal of the Geological Society, 145 (6), 977-83, November 1988.

" One of the Moon's ferroan anorthosites, believed to be a remnant of the oldest lunar crust, has been accurately dated at 4,440 million years. Those and other isotopic data suggest that the Moon could be as young as 4,510-4,440 million years, which would be consistent with its having been formed from the Earth by collision ejection.

R.W. Carlson, G.W. Lugmair, "The age of ferroan anorthosite 60025: Oldest crust on...

Interested in reading more?

Become a Member of

Receive full access to digital editions of The Scientist, as well as TS Digest, feature stories, more than 35 years of archives, and much more!
Already a member?