Web: https://goldschmidt.info/2020/index
Includes the following sessions:
09b: Large Igneous Provinces, perturbations in biogeochemical cycles and mass extinctions through Earth history
Convenors: Richard Ernst (richard.ernst@ernstgeosciences.com), Ying Cui (cuiy@montclair.edu), Yogaraj Banerjee (ybanerjee15@gmail.com), Prosenjit Ghosh (pghosh@iisc.ac.in)
There is an increasing recognition of the role of Large Igneous Provinces (LIPs) in major environmental perturbations and mass extinction events in Earth history. LIPs can affect the atmosphere and ocean through a wide array of processes including, but not limited to, carbon cycle perturbations, global warming, global cooling, acid rain, ash clouds, and enhanced hydrothermal and terrestrial nutrient fluxes. Some of these factors, in return, can lead to mass extinctions through eg. ocean anoxia and acidification and mercury poisoning. However, our current understanding of the connections between LIPs, environmental change, and mass extinctions is incomplete in many ways. The goal of this session is to bring together researchers approaching this problem from multiple perspectives. We welcome contributions that show: (1) geological, geochemical evidences of LIPs throughout geological time; (2) geochronological constraints on LIPs, (3) the interactions between the effects (direct and indirect) of LIPs and climatic change, (4) reconstructing changes in global weathering regime across the LIPs, (5) spatiotemporal constraints on marine chemical conditions (e.g., redox conditions, and ocean acidification) from inorganic and organic proxies and linked to LIPs; (6) investigations of causal links between LIPs, environmental conditions, and the diversity and ecological structure of marine ecosystems during mass extinctions and subsequent recoveries. (7) we also invite contributions unraveling biogeochemical processes during extinction events related to LIPs using proxies including (but not limited to) trace elements, conventional and non-conventional stable isotopes, radioisotopes, clumped isotopes, biomarkers and modeling studies.
03d: Examining mantle sources and magmatic processes through the geochemistry of intraplate and hotspot magmas
Convenors: Angus Fitzpayne (angus.fitzpayne@erdw.ethz.ch), Laura Miller (laura.miller@anu.edu.au), Edward Marshall (edmarshall4@utexas.edu), Michael Bizimis (mbizimis@geol.sc.edu)
Intraplate volcanism in continental and oceanic regions provides constraints on the composition and evolution of the mantle through time. The wide variety of geochemical and isotopic signatures in intraplate magmas is a window into the diverse world of mantle heterogeneity and chemical transport within the Earth. Additionally, the specific nature of production and evolution of intraplate melts is still uncertain particularly in cratonic environments. This session will focus on the latest developments in the study of hotspot and intraplate magmas and their mantle sources, with applications to metasomatism, crustal recycling, mantle heterogeneity, melt generation, and other topics on the behavior and evolution of Earth’s interior. We welcome contributions that examine the petrology, mineralogy, redox state, trace element and isotope geochemistry of basalts, kimberlites, lamprophyres, and other melts that teach us about the mantle sources and magmatic evolution of hotspot and intraplate magmas.