Rheological Gravity Model of the Crust in the Sinegorsk Ore Region (Southwest of Primorsky Krai)

Abstract

The spatial correlation of the South Sinegorsk basin with the Paleozoic magma chamber at the depth of 5–7 km is revealed as a result of interpreting the statistical gravitation model representing the rheological properties of the crust in the Sinegorsk ore region to the depth of 30 km. The intrusion center of the volcanic formation is approached at the midst of the basin to the depths of 1–2 km, where a local volcanotectonic elevation is formed with uranium mineralization associated with the eastern flank of the latter. The western flank of this volcanic center occupying the area of the Monastyrishche volcanic depression, overlapped mainly by Cenozoic cover, is assumed to be highly promising. The distribution of density contrasts in the middle and lower layers of the crust indicates the absence of any actual relationships between the uppercrust igneous structures and the deep-seated upper-mantle formations. It is concluded that the top layer of the crust to the depth of 10 km was separated during the Late Paleozoic–Mesozoic time from the mantle “root” of the South Sinegorsk structure and displaced southwestwards synchronously to overthrust and strike–slip dislocations in the west of Sikhote Alin. The occurrence of this root is proposed because of the presence of Paleozoic andesibasalts, basite–hyperbasites, peridotites, and basalts over the entire area considered.