1.
2.
Science
; 158(3798): 261-2, 1967 Oct 13.
Article
in English
| MEDLINE
| ID: mdl-17839507
ABSTRACT
Exceptionally high contents of chromium and nickel in shales from the early Precambrian Fig Tree series of South Africa ( 3.1 x 10(9) years old) suggest that the ancient crustal rocks from which these sediments were derived were ultramafic in composition.
