Detection and Interpretation of Central Type Structures within the Territory of Southeastern Transbaikalia for Prediction of Ore-Forming Systems

Abstract

Extremely little attention is paid to the issues of detecting and interpreting of central type structures (CTSs) when conducting remote structural-geological and structural-geomorphological studies. At the same time, in the 1970–1980s, it was proven that CTSs play an important role in the localization of deposits and ore fields. 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 complete absence of results of mass detection 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.