Heavy clastic minerals as an indicator of geodynamic settings of accumulation and provenance of cretaceous sediments of the West Sakhalin terrane

• Main Author: Малиновский А.И.
• Format: Article
• Language: Russian
• Published: Institute of Volcanology and Seismology FEB RAS 2021-03-01
• Series: Вестник Камчатской региональной ассоциации "Учебно-научный центр". Серия: Науки о Земле
• Subjects: west sakhalin terrane; cretaceous; sandstones; heavy minerals; power sources; geodynamic settings
• Online Access: http://www.kscnet.ru/journal/kraesc/article/view/652

The article discusses the results of studying heavy clastic minerals from the Cretaceous sandy rocks of the West Sakhalin Terrane, and also presents their paleogeodynamic interpretation. It is shown that in terms of mineralogical and petrographic parameters, the terrane sandstones correspond to typical graywackes and are petrogenic rocks formed mainly by destruction of igneous rocks of the source areas. The sediments were found to contain both sialic, granite-metamorphic association minerals, and femic, formed by products of the destruction of basic and ultrabasic volcanic rocks. The interpretation of the entire set of data on the content, distribution and microchemical composition of heavy minerals was carried out by comparing them with minerals from older rocks and modern sediments accumulated in known geodynamic settings. The results obtained indicate that during the Cretaceous, sedimentation occurred along the continent-ocean boundary in a basin associated with large-scale left-lateral transform movements of the Izanagi Plate relative to the  Eurasian continent. The source area that supplied clastic material to that basin combined a sialic landmass composed of granite-metamorphic and sedimentary rocks, a mature deeply dissected ensialic island arc, and fragments of accretion prisms, in the structure of which involved ophiolites.