SPP 1006 - Subproject: The Archean to Paleoproterozoic transition as recovered in the FAR DEEP cores: LA-ICP-MS U-Pb geochronology of detrital zircons and accompanying provenance analysis of siliciclastic sedimentary rocks

Basic data for this project

Description

During the transition from the Archean to the Proterozoic (c. 2500-2000 Ma), major changes in the modus operandi of the Earth system ocurred. Plate tectonic reorganisations like supercontinent breakup coincided with major global environmental changes. These include the first global glaciation, the first pronounced rise in atmospheric oxygen (Great Oxidation Event), the largest and longest duration positive excursion of carbon isotopic composition of sedimentary carbonates (Lomagundi-Jatuli Event), and the deposition of sediments anomalously rich in organic carbon leading to the formation of the shungite "coals" (Shunga Event). Presently, rocks registering these events are being drilled in northern Russia in the FAR DEEP project as part of the ICDP program. In view of the considerable significance of all these events for Earth evolution it is notable that the geochronological constraints on these events are rather poor.- In order to improve the geochronological constraints on these events, the proposed project will perform U-Pb dating of detrital zircons using LA-ICP-MS on siliciclastic sedimentary rocks bracketing the major Early Proterozoic events. In addition, determination of the weathering proxy CIA, provenance indicative elements and minerals will provide information on climate and plate tectonic provenance controls on deposition.