Content and technological scheme of geotectonic research in geological mapping of the basement of the Ukrainian shield

Abstract

One of the important results of the state geological mapping is the understanding of tectonics and the history of the geological development of the surveyed areas. According to their purpose, they should be the main synthesizing result of the work performed and, at the same time, the scientific basis for further predictive metallogenic studies. Meanwhile, in modern literature there are still no clear definitions of the content and methodology of regional geotectonic studies, including during the state geological mapping. This is reflected in the completeness of the collection, use and generalization of the necessary data, especially when studying the Early Precambrian crystalline basement of the shields of ancient platforms, including the Ukrainian Shield. This article provides a detailed definition of regional geotectonic studies and their components – geotectonic analysis and synthesis. In the development of these definitions, a methodology is proposed – a technological scheme for geotectonic analysis in geological mapping, consisting of a number of sequential operations. They are aimed at revealing the structural and material features of the study area, due to tectonic movements and related processes. The results of geotectonic analysis form the basis of geotectonic synthesis, the purpose of which is to create a geoevolutionary model for the development of the studied area. The issue of geotectonic periodization of the Early Precambrian, on which this model should be based, is specially considered. Modern data on the composition and structural position of the main stratigenic metamorphic complexes of the shields make it possible to distinguish two major stages of the Early Precambrian evolution of the Earth's crust: eogean – the stage of indistinct (pre-geoblock) geotectonic differentiation, and protogean – the stage of distinct geoblock geotectonic differentiation. The proposed method was tested in compiling overview tectonic maps of the basement of the Ukrainian Shield. It is the first experience of an unbiased regional geotectonic study of the Lower Precambrian and can be used in state geological mapping as a supplement to existing instructions.

Keywords

• geological mapping
• ukrainian shield
• shields basement
• lower precambrian
• geotectonic studies
• geotectonic analysis
• geotectonic synthesis
• early precambrian geotectonic periodization
• eogean
• protogean