Clues of early life: Dixon Island-Cleaverville Drilling Project (DXCL-DP) in the Pilbara Craton of Western Australia

Abstract

"Dixon Island-Cleaverville Drilling Project (DXCL-DP)" was successfully completed in summer 2007. Three holes were cored, the CL1 and CL2 cover the Snapper Beach Formation, while the DX drillcore covers the Dixon Island Formation, both of which belong to the Cleaverville Group. The CL1 and CL2 drillcores consist mainly of organic-rich massive black shales with little cross-laminated fine sandstone, and the DX drillcore contains very finely laminated black shales with lamination and veins of pyrite and weathered pillow basalt. These sulfide-containing black shales are not found anywhere in surface outcrops. It is the first discovery of these geological units. A systematic combination of geological, sedimentological, geochemical, and geobiological approaches to the drillcore samples will be applied to obtain critical information on the characteristics of the samples and to understand the influence of submarine hydrothermal activity on the biological and chemical fingerprints. From these we intend to reconstruct the environmental conditions at thetime of deposition.