DID SUBDUCTION PLATE TECTONICS START WITH A BANG?

Is it coincidence that two of the largest outpourings of lava in Earth’s history, the Deccan Traps and Siberian Traps, occurred simultaneously with the Cretaceous-Tertiary (KT) and Permian-Triassic (PT) extinctions respectively? Either the outpourings of lava caused the extinctions or what caused the extinctions caused the lava outpourings. It is proposed that the primary cause of both extinctions is a bolide impact and that the traps are the antipodal outpourings caused by the impacts. Is it coincidence that the Hawaiian Hotspot lies in the middle of the Pacific Basin? The formation of the hotspot must be related to the formation of the basin. It is proposed that a very large bolide impact created both the Hawaiian Hotspot and the Pacific Basin. These propositions infer several corollaries. The Earth first formed a global continental crust. This global crust lasted until a bolide impact destroyed 2/3 of it to form the Pacific Basin and Hawaiian Hotspot. The impact also caused the PT extinction and the eruption of the Siberian Traps. Subduction plate tectonics did not operate on Earth until the basin crust became negatively buoyant and began to subduct. The KT impact was a smaller version of the PT impact. It broke up crust off the west coast of North America and formed the Yellowstone Hotspot. It also caused the KT extinction and the eruption of the Deccan Traps.

These conclusions represent extensive analysis of existing research and develops a radically new model of the evolution of geodynamic processes on Earth. Cited evidence for early global continental crust includes zircon ages, craton keel structure, and hotter mantle affects on subduction. Cited evidence for restricted mobility of cratons includes lack of structures associated with subduction processes, paleomagnetic readings from major cratons, and configuring Pangea as a round landmass. Initiation of Yellowstone hotspot and Deccan Traps by bollide impact is based on timing of tectonic activity in the Northwest, near 180 degree offset from hotspot to traps, and thermal structure of hotspot. Evidence impact formation of Pacific Basin includes Jurassic Quiet Zone and Ontong-Java plateau structure.