Geophysical Detection of Relict Metasomatism from an Archean (~3.5 Ga) Subduction Zone
作者： C.-W. Chen , S. Rondenay , Rob. L. Evans , D. B. Snyder
关键词: Subduction 、 Lithosphere 、 Geology 、 Archean 、 Geochemistry 、 Mantle (geology) 、 Craton 、 Paleoarchean 、 Plate tectonics 、 Metasomatism
摘要: When plate tectonics started on Earth has been uncertain, and its role in the assembly of early continents is not well understood. By synthesizing coincident seismic electrical profiles, we show that subduction processes formed Archean Slave craton Canada. The spatial overlap between a discontinuity conductive anomaly at approximately 100 kilometers depth, conjunction with occurrence mantle xenoliths rich secondary minerals representative metasomatic front, supports cratonic by accretion lithospheric fragments. Although evidence rarely preserved, these results suggest was operating as Paleoarchean times, 3.5 billion years ago (Ga).
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