Age and composition of igneous rocks from the cenozoic sedimentary cover of the sakhalin shelf

For the first time, data on the K-Ar isotopic age and petrological-geochemical composition were obtained for igneous rocks using the core samples recovered from the previously drilled holes on the Sakhalin shelf. Based on these data, the igneous rocks were compared to the rocks of the Anivsky, Orlovsky, Lamanonsky, and Chekhovsky volcanic complexes. Isotopic dating on rocks from the Lesogorsky complex of hypabyssal small intrusions exposed on the west coast of Sakhalin Island allowed tighter constrains to be placed on the timing of its formation (8.9–16.2 Ma).