Wykorzystanie mikrosondy jonowej SHRIMP IIe/MC do weryfikacji wieku skał krystalicznych w górach Chasagt (zachodnia Mongolia)

Over 60 years ago, the first age determination of granitoids was performed by the potassium-argon method, initiating a long-standing tradition of geochronological investigations at the PGI, as well as field exploration by the Polish Geological Expeditions in Mongolia. However, the early results require verification due to advances in equipment and methodology. One of the first projects carried out after the installation and commissioning of the SHRIMP ion microprobe at the PGI was the study of age of the several igneous rocks sampled in western Mongolia by a new Polish expedition. The fieldwork was carried out in the area of the Khasagt Mountains. The U-Pb SHRIMP analysis of the zircons revealed an emplacement age of the reddish granite and mafic granodioritic bodies in the range of816-775 Ma, accompanied by second generation of igneous rocks intruded at 783-768 Ma. These new data document a widespread late Tonian magmatic activity in this area. Moreover, a much younger Middle Permian magmatic episode between 276 and 268 Ma has been recognized. All these results represent progress in the correlation of the Mongolian terranes and allow for a partial correction of the chronostratigraphic position of the units, updating the geological map of Mongolia.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).