Séminaire / Seminar (Site Buffon) - Exploring the connection between the Great Oxidation Event and Earth's biggest C-isotope excursion - Malcolm Hodgskiss

Lundi 18 novembre 2024 à 11 h.

IMPMC, salle des élèves, 2^e étage, bâtiment 52 (« 20 allée des crapauds »), 61 rue Buffon, Paris 5^e

Malcolm S. W. HODGSKISS - Trinity College/University of Cambridge

Abstract

Understanding changes in the oxygenation of Earth’s surface environment and the carbon cycle remains an outstanding challenge in Precambrian geology and geochemistry. This is especially true for the Great Oxidation Event (GOE) ca. 2.3 Ga and the Lomagundi-Jatuli Excursion (LJE) ca 2.3 – 2.1 Ga, which may represent Earth’s largest and longest carbon isotope excursion. Both of these events remain poorly understood but are often interlinked, highlighting the need for more targeted study. Here, I present findings on changes in the size of Earth’s biosphere, ocean redox chemistry, and carbon cycle during this pivotal time in Earth history to understand the connection between the GOE and LJE. More broadly, these results underline the challenges posed by an incomplete geological record and the importance of paleoenvironmental information for contextualizing geochemical data. A brief synopsis of my ERC Starting Grant Proposal and future CNRS candidature will be presented, as well as potential host institution links with IMPMC.