FOSSIL TRAVERTINES AND QUASI-TRAVERTINE IN THE MINUSA BASIN (West Siberia): STRUCTURE, COMPOSITION, AND COMPARATIVE ANALYSIS
G.S. Fedoseev1,2, A.A. Vorontsov3,4, A.A. Orekhov5
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
3Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Favorskogo 1a, Irkutsk, 664033, Russia
4Irkutsk State University, ul. Karla Marksa 1, Irkutsk, 663033, Russia
5Far East Geological Institute, Far East Branch of the Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022, Russia
Keywords: Палеотравертин, малоглубинные силлы, долерит, базальт, квазитравертин, спарит, пренит, керит, Минусинский прогиб, Fossil travertine, shallow sill, dolerite, basalt, quasi-travertine, sparite, prehnite, Minusa basin
Abstract
We study a carbonate body looking like a classical fossil travertine which was discovered in the Chebak-Balakhta basin within the Minusa Trough Basin (Khakassia, Russia) and called quasi-travertine . It is a thin layer sandwiched between a basalt-dolerite sill and calcareous siltstone. Comprehensive studies of the quasi-travertine and its comparison with Devonian fossil travertines located a few kilometers away in terms of structure and composition have made the basis for its formation model. According to this model, the quasi-travertine has had a two-stage history: deposition and subsequent hydrothermal metasomatism. Laminated limestone coexisting with calcareous siltstone of the Early Devonian Shunet Formation formed during the first stage and then experienced hydrothermal metasomatism with precipitation of secondary calcite, prehnite, and pyrobitumen (kerite).
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