Sills and gas generation in the Siberian Traps.

Autor: Svensen HH; Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway hensven@geo.uio.no., Frolov S; Faculty of Geology, Lomonosov Moscow State University, Moscow, Russia., Akhmanov GG; Faculty of Geology, Lomonosov Moscow State University, Moscow, Russia., Polozov AG; Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway.; Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences (IGEM RAS), Moscow, Russia., Jerram DA; Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway.; DougalEARTH Ltd., Solihull, UK., Shiganova OV; Siberian Scientific Research Institute of Geology, Geophysics and Mineral Resources, Novosibirsk, Russia., Melnikov NV; Siberian Scientific Research Institute of Geology, Geophysics and Mineral Resources, Novosibirsk, Russia., Iyer K; GeoModelling Solutions GmbH, Zurich, Switzerland.; GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Germany., Planke S; Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway.; Volcanic Basin Petroleum Research (VBPR), Oslo Innovation Center, Oslo, Norway.
Jazyk: angličtina
Zdroj: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences [Philos Trans A Math Phys Eng Sci] 2018 Oct 13; Vol. 376 (2130).
DOI: 10.1098/rsta.2017.0080
Abstrakt: On its way to the surface, the Siberian Traps magma created a complex sub-volcanic plumbing system. This resulted in a large-scale sill emplacement within the Tunguska Basin and subsequent release of sediment-derived volatiles during contact metamorphism. The distribution of sills and the released sediment-stored gas volume is, however, poorly constrained. In this paper, results from a study of nearly 300 deep boreholes intersecting sills are presented. The results show that sills with thicknesses above 100 m are abundant throughout the upper part of the sedimentary succession. A high proportion of the sills was emplaced within the Cambrian evaporites with average thicknesses in the 115-130 m range and a maximum thickness of 428 m. Thermal modelling of the cooling of the sills shows that the contact metamorphic aureoles are capable of generating 52-80 tonnes of CO 2  m -2 with contributions from both marine and terrestrial carbon. When up-scaling these borehole results, an area of 12-19 000 km 2 is required to generate 1000 Gt CO 2 This represents only 0.7-1.2% of the total area in the Tunguska Basin affected by sills, emphasizing the importance of metamorphic gas generation in the Siberian Traps. These results strengthen the hypothesis of a sub-volcanic trigger and driver for the environmental perturbations during the End-Permian crisis.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
(© 2018 The Author(s).)
Databáze: MEDLINE
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