The Bug mining area of the Ukrainian shield. Structural-petrophysical map of the crystalline basement and some problems of the Early Precambrian geology

• Datum: 2020
• Hauptverfasser: Gintov, О .B., Entin, V. A., Mychak, S. V., Farfuliak, L. V.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: S. Subbotin Institute of Geophysics of the NAS of Ukraine 2020
• Schlagworte: Ukrainian shield; Middle Bug; tectonics; ore area; folding; granulite facies
• Online Zugang: https://journals.uran.ua/geofizicheskiy/article/view/204699
• Назва журналу: Geofizicheskiy Zhurnal

Structural and petrophysical map of a scale 1:100 000 of the Bug mining area (BMA), one of the most promising areas of ore minerals in the eastern part of the Ukrainian shield has been built. The area is located in the Middle Bug (sheets of topographic map M-35-XXXVI-eastern half and M-36-XXXI). Materials of geological survey of a scale 1:50 000, deep geological mapping of a scale 1:200 000, exploration, as well as: geophysical surveys of a scale 1:10 000—1:50 000, seismic and geoelectric deep sounding; special tectonic works on outcrops; published results of determining the isotopic age of Precambrian rocks have been put into the basis of the constructions.Authors tried to enclose only indisputable data such as material composition, structural and textural features, petrophysical characteristics of rocks, the contours and dimensions of bodies by geophysical data and drilling, tectonophysical parameters of discontinuous structures directly in the map content.Unclear and discussion debatable points on the map are not shown and discussed in the text. These problems include the tectonic position of BMA (the Bug Mining Area), which, according to the authors, belonged to the Bug megablock in the Archean and in the Proterozoic  it was divided by the  fault Talnov zone  and as a result of the process of shifting-pulling apart  its eastern part joined the Ingul megablock. The deep crust-mantle nature established in the territory of BMA of the large Golovanevsk and Bandurivka gravitation anomalies have been shown.The authors rejected the division of Early Precambrian rocks of granulite facies into suites as because the principle of a sequence of strata and correlation of sections in the area is not observed. The problem of the scope of the Dniester and Bug series from which rocks of Proterozoic kinzigite formations were excluded is being discussed here. Particular attention has been paid to the mechanisms of formation of subvertical layered banded structure of thickness of Early Precambrian granulite complexes of the area. It is shown that this structurally textured rock fabric formed in the early Proterozoic as a result of horizontal forces and horizontal movements of the substance and the folding has mainly near-fault shift character with subvertical hinges of folds, which is clearly seen in the horizontal sections and by the results of drilling.