Model of the deep structure of the earth’s crust and upper mantle in the area of the Karymshinskiy gold- ore cluster according geophysical data (south Kamchatka)

• Published in: Georesursy
• Main Authors: Alexandr G. Nurmukhamedov, Mikhail D. Sidorov, Yury F. Moroz
• Format: Article in Journal/Newspaper
• Language: English; Russian
• Published: Georesursy Ltd. 2020
• Subjects: crust; upper mantle; transition layer; deep model; heat flow; ecwm; mtz; south kamchatka; Geology; QE1-996.5; Apacha; Mutnaya; Kamchatka
• Online Access: https://doi.org/10.18599/grs.2020.1.63-72; https://doaj.org/article/a0e453bc027147f98c7c699d775ca096

In the South of Kamchatka, modern geodynamic processes are actively taking place. A deep geological and geophysical model of the structure of the earth’s crust and upper mantle along the regional profile of the Apacha Village -Mutnaya Bay in the zone of Tolmachevsky active magmatic center (TAMC) is presented. The profile passes near the South-Western border of the Karymshinskaya volcano-tectonic structure (VTS) and crosses the Ahomtenskaya VTS. The model created on the basis of integrated interpretation of materials of the earthquake converted-wave method (ECWM), gravity and magnetotelluric sounding (MTS). The thickness of the earth’s crust along the profile varies from 30-33 km at the edges reaching 44-46 km, in its Central part. The dominant feature of the model is a high-density formation – a block of the earth’s crust, saturated with intrusions of the main and ultrabasic composition. The formation of the block is associated with a permeable zone between the crust and the upper mantle. In the block correlation of seismic boundaries is disturbed and in a density model the area with massive heterogeneity is allocated. A significant increase in depth to the M-Boundary in the center of the model is explained by the presence of a “bloated” transition layer between bark and mantle in this place. The thickness of the layer is about 10 km, and the density of the mantle reaches 3,4 g/cm3. It is supposed that it is a site of eklogization of breeds in a zone of paleosubduction of oceanic lithosphere under a continental. The area is favorable for the accumulation of meteor waters, which are in contact with high-temperature environment and postmagmatic solutions of intrusions, which leads to the formation of hydrothermal systems. The genetic connection of Karymshinsky gold- ore cluster with the intrusive array of medium-sour composition, allocated in the zone of the Tolmachevsky active Magmatic Center is shown.