Геодинамика и тектонофизика (Jun 2019)
RELATIONSHIP BETWEEN SUBDUCTION‐RELATED AND PLUME MAGMATISM AT THE ACTIVE BOUNDARIES OF LITHOSPHERIC PLATES IN THE INTERACTION ZONE OF THE SIBERIAN CONTINENT AND PALEOASIAN OCEAN IN THE NEOPROTEROZOIC AND PALEOZOIC
Abstract
This paper is focused on the relationship between plate‐ and plume‐tectonic processes during the formation of Neoproterozoic and Vendian‐Paleozoic island‐arc systems and active continental margins in the interaction zone of the Siberian continent and Paleoasian Ocean (PAO). In this study, we use our own materials collected in the long‐term research of the Central Asian Orogenic Belt (CAOB) and the published models showing convection in the asthenosphere and mantle, subduction‐related and plume magmatism at the Cenozoic active margins of the Western Pacific and California types. It is clearly shown that subduction‐related magmatism of the Paleoasian Ocean active margins should not be considered separately from plume magmatism. These interrelated processes played a major role in the CAOB formation. Based on the reconstructed Neoproterozoic, Vendian – Early and Middle Paleozoic paleogeodynamic features, 25 island‐arc systems of PAO are characterized. These island arcs are related to the occurrence of more than 30 plume magmatism areas. At the active margin of the Siberian continent, there are numerous fields of intraplate magmatism in riftogeneous structures. Such fields of various scales not related to subduction zones, especially at the final Late Paleozoic stage. All the major stages of the CAOB development, including the Cambrian‐ Ordovician collision stage, are clearly correlated with plume magmatism. Considering a revealed combination of the island arcs and the plume magmatism areas, there are grounds to suggest that the development of the entire Neoproterozoic‐ Paleozoic region of Central Asia was related to the activity of mantle plumes.
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