卷 66, 编号 4 (2024)

Extremely little attention is paid to the issues of detecting and interpreting of central type structures (CTS) when conducting remote structural-geological and structural-geomorphological studies. At the same time, in the 70–80s of the 20th century, the important role of CTSs in the localization of deposits and ore fields was proven. The position of these structures must necessarily be taken into account when solving problems of searching for and predicting mineral resources in the context of metallogenic analysis and reconstruction of the geological history of development of the studied areas. The almost absence of results of mass detecting and interpreting of CTSs can be explained by the still poorly developed methodology for identifying and analyzing this type of structure. In the present study for the territory of southeastern Transbaikalia, based on modern geoinformation technologies, the use of remote sensing data (radar topographic survey) of high resolution, the creation of a digital elevation model and the application of an integrated structural-spatial analysis, an author’s approach to detection and interpretation of the CTSs is presented, including in connection with the localization of ore objects of various geological-industrial (geological-genetic) types within the framework of the concept of the formation of mineral systems. A statistical analysis of the CTSs identified in the area was carried out, which made it possible to establish a smooth increase in the number of structures with a decrease in their diameter. It is shown that the spatial maxima of ore mineralization extent within the territory are concentrated on the periphery of large CTSs and in their immediate vicinity. Most of the known large ore objects are confined to the internal areas of structures less than 10 km in diameter. Based on the approach of constructing model sections, it was possible to reconstruct the deep position of magma chambers associated with the identified CTSs, and, thereby, to determine the probable sources of metal-bearing fluids. A close spatial relationship between the identified magma chambers and deep faults has been established. To determine the most favorable sites for the deposition of ore mineralization, based on structural-spatial criteria, which include not only structural elements of the CTSs, but also segments of known fault structures, weight of evidence models of the territory have been created. The accuracy of the complex model is 89%. Thus, in accordance with the concept of mineral systems, the sources, migration pathways and sites of the most probable deposition of ore mineralization have been reconstructed.

Based on the study of typomorphic features of gold from alluvial deposits of the Kyvvozh region of Middle Timan, including industrial placers, the most probable genetic types of primary sources were determined. The size of gold particles varies widely, reaching the size of small nuggets; along with rounded ones, there are weakly rounded and unrounded particles. Many of them have undergone repeated deformations in the form of envelope-shaped bends, dents and tears. Most gold coins have high-fineness rims. Gold always contains Ag, sometimes Cu, Pd and Cu. Gold particles with a block structure with high-silver vein zones are often found. In intergrowths with gold and in the form of inclusions are noted in it pyrite, galena, and occasionally minerals of the cobaltine-gersdorfite series, ankerite, galenobismutite, native bismuth, aurostibite, and also sudovikovite (PtSe₂), which was first identified in the region. Three types of gold have been identified: 1 – homogeneous silver-containing, 2 – block with highly silvery vein-like zones, 3 – rare silver-containing with impurities of Cu, Pd. The morphology, composition and structure of placer gold indicate its entry into placers from various sources, including nearby sources. Of greatest interest are the zones of development in Riphean rocks of hydrothermal veinlet-disseminated sulfide mineralization, oriented in the northwest direction, partially exposed during the development of placers. Gold with Cu and Pd impurities is most likely associated with derivatives of mafic magmatism. The Volsko-Vymskoe, as well as the Tsilemskoe and Chetlasskoe uplifts of Middle Timan can be considered promising in terms of primary gold content and deserve further study and prospecting.