Pardee Keynote Symposia
P7. Pulse of the Earth: Geochronology and Paleomagnetism of Large Igneous Provinces — The Key to Reconstructing Precambrian Supercontinents
Cosponsored by Precambrian [At Large]; International Geological Correlations Program Project 509, Paleoproterozoic Supercontinents and Global Evolution
Figure created by Wouter Bleeker,
Geological Survey of Canada.
click for larger image
David A.D. Evans and Joseph G. Meert
Sun., 28 Oct., 1:30 p.m.-5:30 p.m.
Wegener's Pangea took shape nearly 100 years ago, and efforts to reconstruct Rodinia, Pangea's Neoproterozoic predecessor, began in earnest only within the last two decades. New advances in the techniques of geochronology and paleomagnetism provide an unprecedented opportunity to acquire precise and accurate data that can constrain Precambrian plate kinematics. U-Pb geochronology of igneous accessory minerals in mafic rocks, the primary components of large igneous provinces (LIPs), has become more feasible due to innovations in mineral separation and laboratory analysis. These mafic rocks are a preferred target of paleomagnetic studies due to their suitable mineralogy and, commonly, exceptional preservation within the interiors of stable cratons. As more LIPs become dated precisely, there is impetus for detailed paleomagnetic study including rigorous field stability tests to demonstrate primary magnetizations. LIPs can form in several tectonic environments, but commonly they are associated with rifting and thus supercontinental breakup. A global effort that focuses on precise geochronology and paleomagnetism of Precambrian LIPs will generate the data necessary to reconstruct pre-Pangean supercontinents, including not only Rodinia but also its Paleoproterozoic precursors. This in turn will finally enable the broader geoscience community to assess supercontinent cyclicity, long-term patterns of mantle convection and nature of the Earth's magnetic field, the influence of global paleogeography on paleoclimate and even biological evolution. The proposed session is sponsored by the UNESCO-IGCP Project 509, "Paleoproterozoic Supercontinents and Global Evolution" and invites a range of presentations relating supercontinents, LIPs, technological advances in geochronology and paleomagnetism, and secular change in the Earth system.
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