Zastosowanie metody K-Ar do oznaczenia wieku deformacji skał metaosadowych formacji Yargait terranu Zavkhan (Khasagt, Mongolia) : wstępne wyniki badań

The SW margin of the Zavkhan terrane is significant for research on Paleozoic amalgamation of the Central Asian Orogenic Belt (CAOB). The study area is located in the western part of the Khasagt Mountains, western Mongolia. We present a new preliminary K-Ar dating of metasedimentary rocks from the Yargait Formation which were deformed during collision of the Zavkhan terrane with the Lake Zone terrane. Our results include two dating that are similar to earlier data by other authors (Stípskáetal., 2010; Bold et al., 2016b). The first dating equal to 544.1 ±13.7 Ma can be interpreted as the age ofmetamorphism and the subduction of the SW margin ofthe Zavkhan terrane under the Lake Zone terrane during the late Ediacaran-early Cambrian. The second dating of 441.1 ±11.7 Ma indicates the Late Ordovician - Silurian regional extension event.