Electrical conductivity of the crust and mantle of the East European platform in the western part of Ukraine from 2D inversion

• Дата: 2019
• Автори: Logvinov, I. M., Tarasov, V. N.
• Формат: Стаття
• Мова: rus
• Опубліковано: Subbotin Institute of Geophysics of the NAS of Ukraine 2019
• Теми: conductivity; Earth’s crust and upper mantle; East European Platform; mineral resources
• Онлайн доступ: https://journals.uran.ua/geofizicheskiy/article/view/158863
• Назва журналу: Geofizicheskiy Zhurnal

2D inversion of the magnetotelluric and magnetovariational data along 40 profiles made it possible to create overview model of electric resistivity for the territory between eastern longitudes 28° and 36° and by the northern latitudes 47.8° and 52°. Analysis of sections of resistances in the depth interval from 5 to 105 km indicate the absence of objects of low resistance (less than 100 Ohm × m — OLR), the dimensions of which would allow them to be called a layer. The geometrical parameters of the OLR indicate their locality. Along the border of the East European platform are geoelectric objects of low and high (more than 4000 Ohm × m — HO) resistances, at low depths of 20 km low-resistance objects prevail. Comparison of anomalous geoelectrical objects (OLR and HO) with fault tectonics, metallogeny, oil and gas content and modern activation shows that most of the OLR are confined to fault nodes, in which nodes and areas are often concentrated of minerals having an electronic type of conductivity (graphite, polymetallic ore and noble metals). The areas promising for oil and gas content, identified on the maps of various authors, are partially consistent with the Yavoriv, Lokachi, Ternopil and Chernivtsi zones of modern activation, and in this case are accompanied by conducting objects. It is interesting to note the consistency of geological and geophysical conclusions about the prospects of the North-West oil and gas province with the presence of the OLR. Depth and power of conducting objects allows to assume the presence of a gene-tic connection of various minerals not only with sedimentary metamorphosed rocks, but also with the presence of deep fluids. It seems that the results obtained can contribute to the development of ideas about the deep structure of the studied territory and its connection with both existing deposits of various minerals and during the spillage of new ones.