Siberian trap
The Siberian Trapp ( Russian Сибирские траппы ) is an extensive flood basalt ( Trapp ) in Siberia . The volcanic eruptions responsible for this form one of the largest globally known volcanic events in the history of the earth and took place around 250 million years ago on the Permian-Triassic border . The eruptions and their consequences are causally related to the mass extinction at the end of the Permian . Due to its size and its relatively rapid geological formation, the Siberian Trapp is an outstanding example of a magmatic large province .
Extent and duration of outbreaks
As a result of the eruption, large amounts of basaltic lava covered an extensive area of primeval Siberia. The area still occupied by the basalts today is about 2 million square kilometers, lies between 50 ° and 75 ° north and 60 ° to 120 ° east and includes the western and northern Siberian lowlands as well as the central Siberian mountainous region and part of the central Yakut lowland including the Western slope of the East Siberian Mountains . The Putorana Mountains provide particularly good exposure conditions today . Estimates of the area originally covered by the volcanic deposits amount to up to 7 million square kilometers. The maximum thickness of the Trapp is in the area of Norilsk and the rivers Maimecha River and Kotui more than 3,000 m, estimates indicate a total combined power of the Trapp of up to 6,500 m. The resulting amount of basaltic lava that has flowed out is around one million to four million cubic kilometers.
The volcanic event lasted about a million years. Numerous volcanic vents near Norilsk are considered to be the center of the eruption . Some of the eruptions have produced up to 2000 km³ of lava or more. The occurrence of large amounts of volcanic tuffs and pyroclastic deposits indicates that explosive eruptions also occurred before or during the eruption of the flood basalts, which spread the material as volcanic ash over large areas. This is supported by the occurrence of silicon- rich magmatites such as rhyolite .
Causes and consequences
The source of the Siberian trap is considered to be a plume that rose from the mantle under the Siberian craton . This interpretation is supported by isotope geochemical studies of helium . However, the scientific debate on this is still ongoing. Another theory suggests that the impact of a large asteroid was the cause of the Trapp volcanism.
There is no firm evidence that the volcanic event caused the great mass extinction at the end of the Permian ; however, the approximate coincidence of the two events is seen as an indication of a causal connection. A current model describes that enormous releases of methane, hydrogen sulfide, but also hydrogen chloride and carbon dioxide may have occurred before the main phase of volcanism and could have caused mass extinction. Presumably, not only the toxicity of the gases, but also the resulting temperature increase of up to ten degrees was responsible. It is estimated that it took at least 30 million years for life to recover.
Natural resources of the Siberian Trapps
Nickel , copper and palladium were deposited in large quantities in the ascent of the magma . The metal-bearing rocks form extensive deposits that are mined today by the Russian mine operator MMC Norilsk Nickel in the Komsomolski mine near Norilsk.
Individual evidence
- ↑ a b http://www.mantleplumes.org/Siberia.html Gerald K. Czamanske and Valeri A. Fedorenko: The Demise of the Siberian Plume , Jan. 2004.
- ↑ Adrian P. Jones; David G. Price; Paul S. DeCarli: Richard Clegg: Impact Decompression Melting: A Possible Trigger for Impact Induced Volcanism and Mantle Hotspots? , in: Koeberl and Martinez-Ruiz, pp. 91-120 (PDF, 460 kB).
- ↑ Volcanic gases to blame for the greatest mass extinction.
- ↑ Stephan V. Sobolev, Alexander V. Sobolev, Dmitry V. Kuzmin, Nadezhda A. Krivolutskaya, Alexey G. Petrunin, Nicholas T. Arndt, Viktor A. Radko & Yuri R. Vasiliev: Linking mantle plumes, large igneous provinces and environmental catastrophes . (http) In: nature . 477, February 2011, pp. 312-316. doi : 10.1038 / nature10385 . Retrieved March 30, 2013.
- ↑ S. Sahney, MJ Benton: Recovery from the most profound mass extinction of all time . (PDF) In: Proceedings of the Royal Society: Biological . 275, No. 1636, 2008, pp. 759-65. doi : 10.1098 / rspb.2007.1370 . PMID 18198148 . PMC 2596898 (free full text).
