Siberian Traps
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The Siberian Traps (Russian: Сибирские траппы) form a large igneous province in Siberia. The massive eruptive event spans the Permian-Triassic boundary and was essentially co-incident with the Permian-Triassic extinction event in what was one of the largest known volcanic events of the last 500 million years of Earth's geological history.
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[edit] Geographical extent
Vast volumes of basaltic lava paved over a large expanse of primeval Siberia in a flood basalt event. Today the area covered is about 2 million km² and estimates of the original coverage are as high as 7 million km². The original volume of lava is estimated to range from 1 to 4 million km³.
The area covered lies between 50 and 75 degrees north latitude and 60 to 120 degrees east longitude. The volcanism continued for a million years and spanned the P-Tr Boundary. There is no firm evidence that this event caused (or helped cause) the Permian extinction, but the timing of the two events is provocative.
[edit] Reason for formation
The source of the Siberian Traps basalt is considered to be a mantle plume which impacted the base of the crust and erupted through the Siberian Craton. Helium isotope geochemistry from the basalts indicates a plume origin. The scientific debate continues, however.
[edit] Siberian Traps and nickel
The Siberian Traps are considered to have erupted via a vent at Norilsk in Siberia, and the giant Norilsk-Talnakh nickel-copper-palladium deposit formed within the magma conduits which formed the eruptive centre.
[edit] External links
- The Siberian Traps
- The Siberian Traps, by Richard Cowen
- Mantle Plumes geology. Map and detailed geologic evidence for non-plume origin.
