S3: Mineralogy, Petrology and Economic Geology of Northeast Asia (Special Session)

[S3P-04] Pressure–temperature-time conditions of metamorphism of pelitic gneisses in the Gobi-Altai Mountains from southwestern Mongolia.

*Kundyz Syeryekkhaan¹, Y. Osanai¹, N. Nakano¹, T. Adachi¹, S. Jargalan², M. Owada³, M. Satish-Kumar⁴, Ch. Boldbaatar⁵ (1. Kyushu Univ., 2. Mongolian Univ. Sci. Tech., 3. Yamaguchi Univ., 4. Niigata Univ., 5. Ochir Undraa LLC)

Keywords:aluminosilicates, P–T conditions, monazite dating, Gobi-Altai Mountains, Mongolia

Amphibolite-facies pelitic gneisses from the Erdene area, Gobi-Altai Mountains exhibit several types of P-T conditions based on modes of occurrence of aluminosilicates and chemical-zoning of garnet. U–Th–Pb monazite dating from all samples yielded similar ages of c. 270 Ma. Similar age with various P–T conditions are previously reported from Gobi-Altay Mountains, these complex distributions of P-T conditions are probably formed during a continent-continent collision.