Such a progression helps to reconcile the existing controversies on the interpretation of SCR geochemistry and the involvement of the putative Yellowstone plume. Columbia River Basalt: the Yellowstone hot spot arrives in a flood of fire. The model predicts a petrogenetic sequence for the flood basalt with sources of melt starting from the base of the slab, at first remelting oceanic lithosphere and then evolving upwards, ending with remelting of oceanic crust. This tear would be consistent with the occurrence of major volcanic dikes during the SCR-Northern Nevada Rift flood basalt event both in space and time. mw parser output div.hatnote padding left 1.6em margin bottom 0.5em. volcanic fields - transition + mountain-bounded on plateaus 3 8 eastern SRP. navigation Jump search Natural park located the western United States.mw parser output. The plume head contains recycled stringers of recycled oceanic crust that melts before the Peridotite, yielding a silica-rich basaltic magma equivalent to the main Grande Ronde basalts and leaves a garnet-clinopyroxene residue. Driven by a gradient of dynamic pressure, the tear ruptured quickly north and south and within about two million years covering a distance of around 900 kilometres along all of eastern Oregon and northern Nevada. Open triangle for Steens Mountain Basalt, one of the Oregon. Melting within a heterogeneous plume head (initial stages of the Yellowstone hot spot). Extent of 1714-Ma flood basalts, dikes, and. Here we show that the best-fitting geodynamic model depicts an episode of slab tearing about 17 million years ago under eastern Oregon, where an associated sub-slab asthenospheric upwelling thermally erodes the Farallon slab, leading to formation of a slab gap at shallow depth. Map of western United States showing the track of the Yellowstone hotspot. Recent tomographic inversions based on the USArray data reveal unprecedented detail of upper-mantle structures of the western USA and tightly constrain geodynamic models simulating Farallon subduction, which has been proposed to influence the Yellowstone volcanism. The origin of the Steens-Columbia River (SCR) flood basalts, which is presumed to be the onset of Yellowstone volcanism, has remained controversial, with the proposed conceptual models involving either a mantle plume or back-arc processes.
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