East-European microplate as an indentor and its orogenic margin

• Дата: 2019
• Автор: Gonchar, V. V.
• Формат: Стаття
• Мова: rus
• Опубліковано: Subbotin Institute of Geophysics of the NAS of Ukraine 2019
• Теми: East-Black Sea region; Caucasus; Crimea; up-to-date orogenesis; numerical modeling; indentor; vertical and horizontal tectonic displacements
• Онлайн доступ: https://journals.uran.ua/geofizicheskiy/article/view/158867
• Назва журналу: Geofizicheskiy Zhurnal

A problem of modern orogenesis in the northern margin of the East-Black Sea micro-plate has been considered based on numerical modeling. It has been shown that only the upper part (up to 40 km) of its sub-oceanic lithosphere can possess indentor properties. It has been found for planned model that the presence of reinforced area corresponding to sub-oceanic crust of the East-Black Sea depression results in redistribution of deformation field and production of northwestern elongated maximum comparable with the Central and Northwestern Caucasus; the movement of the Arabian plate does not create sufficient conditions for orogenesis along northwestern border of the microplate (the Crimean sector), the required reinforcement of deformations and redistribution of paths of normal tensions is obtained if we use an independent local indentor coinciding with the outlines of Alushta-Batumi zone of magnetic anomalies. Models of orogenesis in vertical sections of lithosphere for the Central Caucasus, Crimea and the Azov sector have been worked out. The character of distribution of deformation fields has been established, zones of plastic and elastoviscous behaviour, three-dimensional compression and expansion (dilatancy) have been separated. The obtained scales of indentor displacement are: 22 km for Caucasus, 14 km — for Crimea, 8 km — for Azov. The plotted curves of vertical motions have nonlinear accelerating character that is connected with elastoviscous transitions in the lithosphere. Comparison of values obtained in the model with published independent data demonstrated if not a coincidence but their good accordance.