Archean Stromatolites as Microbial Archives

摘要: Stromatolites are morphologically circumscribed accretionary growth structures with a primary lamination that is, or may be, biologically influenced (biogenic). They found in Archean sedimentary carbonate rocks, almost always associated extensive volcanic sequences. Thirty-two occurrences have been reported from n small regional clusters representing the world’s principal preserved cratons: North America 16, Africa 7, Australia 5, Asia 3, and Europe s; none presently known rocks of South Antarctica; less than two dozen viewed as definitely stromatolitic. The earliest stromatolite records date back to nearly 3.5 Ga, their worldwide distribution abundance increase time progresses.