Paleozoic and Early Mesozoic terrigenous deposits of the South-West Primorye: material composition and origin. A.I. MALINOVSKY

Abstract

Paleozoic and Early Mesozoic terrigenous deposits of the South-West Primorye: material composition and origin. A.I. MALINOVSKY (Far East Geological Institute, FEB RAS, Vladivostok).

Results of material composition study of Paleozoic–Early Mesozoic terrigenous deposits of Laoeling-Grodekovo
terrane (South-West Primorye) are collected. The purpose of the study was to reconstruct paleogeodynamic setting of deposits of studied formations, as well as to determine the types and rock compositions of their power sources. It was established that the deposits differ significantly in their material composition and, accordingly, were formed in different paleogeodynamic settings. Deposits of the Kordonka formation accumulated in the basin associated with the oceanic island arc, while the source area was the arc itself, composed of basic and intermediate volcanic rocks, as well as igneous and sedimentary formations that were part of its foundation. The accumulation of the Reshetnikovka formation took place in basin located on the passive continental margin. The sources of the matter were the cratons and marginal parts of rifts participating in the structure of this margin, composed of granitoids, metamorphic, and sedimentary rocks.  The accumulation of the Tal’mi formation took place on the active continental margin in the basins of riftogenic origin. The sources of the clastic material were the marginal parts of these rifts, composed of acidic and intermediate igneous Laoeling-Grodekovo terrane as an accreationary prism formed by Silurian, Permian and Triassic deposits, which were formed in various paleogeodynamic settings.