Geophysical Journal | 2010 volume 32 6

Once more on the nature of the Crimean gravitational anomaly

© Entin V.A., Gintov O.B., Guskov S.I.

Materials of gravimetric survey of the scale 1:50 000 of the Crimean peninsula are generalized here. A map of Bouguer's anomalies at the density of the intermediate layer of 2,3 g/cm3 and a map of residual anomalies received after their averaging in a sliding square window of 24x24 km was built. Contours and structure of the Crimean gravity maximum with 110 mGal intensity have been specified. Quantitative interpretation of two profiles crossing the Steppe and Mountain Crimea as well as the Black sea shelf has been executed. It is shown that the origin of the Crimean anomaly is related to the forming of crust-mantle mixture on the border of the crust and mantle and subsequent extrusion of the ultra basic and basic rock into middle and upper part of the crust as a mantle diapir. The penetration of protrusions of mantle diapir into the rocks of granitic layer and Paleozoic caused the raising of Mesozoic structural floor and formation of anticlinoria built by the rocks of the Tavric series. It is assumed that the raising of the Crimean mountains has been connected with this process. The origin of the Black-sea trough because of rifting-spreading, the formation of the West-East-Black-sea micro plates, their reversed movement towards the North and an indentered pressure on the Crimean peninsula under the influence of the Arabian plate were the cause of the formation of the crust-mantle mixture and mantle diapir on the border of the Scythian and Black-sea plates.

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