Classification and application effect of structural deformation lithofacies in the orefield

The orefield is equivalent to the grade V metallogenic belt of geological exploration object. It is necessary to study the geological phenomenon of "structure and construction association" and establish the corresponding concept and field observation method. It is different from the theoretical viewpoints of "sedimentary tectonic lithofacies", "magmatic lithofacies", "metamorphic lithofacies", "geotectonic facies", "tectonic lithofacies" and "tectonic facies". On the basis of long-term orefield structure and deep peripheral ore prospecting practice, the geological concept of "tectonic deformation lithofacies" is proposed in this paper. Tectonic deformation lithofacies is regarded as "a part of lithofacies showing structural deformation", which indicates the part of lithofacies (sedimentary, magmatic and metamorphic geological processes) affected by structure. It is a geological entity containing structural deformation and formation characteristics or structural formation features. Tectonic deformation lithofacies is a geological body closely associated with rock deformation and phase transformation. It can not only reflect the geological environment of diagenesis but also contain the physical and chemical conditions of diagenesis. It is a kind of structural rock unit suitable for observation and analysis of "structure combined construction". According to the types of geological processes, four types of tectonic deformation lithofacies are recognized:sedimentary structural deformation lithofacies, magmatic tectonic deformation lithofacies, metamorphic structural deformation lithofacies and composite structural deformation lithofacies. According to the geological subfacies, 27 types of tectonic deformation lithofacies at the orefield scale are distinguished. The establishment of observation and analysis methods of structural deformation lithofacies in the orefield not only promotes the geological investigation and study of structural combination construction but also lays a foundation for the development of orefield structure to orefield geology. With different precision from 1:1000~1:50000, tectonic deformation lithofacies can be used to investigate geological prospecting problems in the range of tens to hundreds of km², directly serving the deep peripheral prospecting of known deposits. The best way to delineate the target area is to depict the distribution characteristics of mineralized lithofacies zones from the surface and large-scale mapping in the middle section. On the basis of "prospecting on the basis of ore", this paper discusses the prediction direction of medium distance ore prospecting, that is, the metallogenic belt of tectonic deformation lithofacies interface.