5:15 PM - 7:15 PM
[SMP27-P01] Proterozoic oceans: A glimpse into past life and world class Zn-Pb sediment hosted deposits
★Invited Papers
Keywords:Proterozoic, Pyrite, mineralisation, evolution
The conventional perception of the Paleo-Mesoproterozoic era as the "Boring Billion" has often overshadowed critical milestones in biological evolution. Despite evidence suggesting significant events such as eukaryogenesis, this period is characterized as one of geostability that supposedly hindered macroscopic evolution. However, recent geological discoveries challenge this consensus, revealing a dynamic era with profound impacts on the evolution of complex life. The period is also characterised by global occurrences of world class-sediment hosted Zn-Pb deposits. Therefore, the Proterozoic oceans warrant closer investigation to provide insights into the geochemical conditions that may have been favourable for both biological breakthroughs and economic mineralisation. This presentation will discuss the application of the pyrite geochemical proxy alongside latest research with a view to reinterpret geological trends and evolutionary history during the "Boring Billion". In particular, the talk will focus on the trace element (such as Ni, Co, Mo, Zn, Pb, As, Se etc ) content of pyrite (in-situ) in marine black shales acquired using LA-ICP-MS and their temporal trends. These trends will help assess availability and scarcity of bioessential trace elements and their profound impact on biological processes. Pyrite textures and trace element distribution around Zn-Pb mineralisation will also be discussed including its potential to inform exploration strategies. This research underscores the interplay of abiotic factors, including plate tectonics, atmosphere-ocean redox structures, and marine nutrient cycles, in shaping the course of biological evolution and formation of marine mineral deposits.