Exploration on the ore-forming regularities of tin deposits in Qitianling area,southern Hunan

Qitianling area which located at the middle part of the Yanling-Chenzhou-Lanshan NE-trend-ing tectonomagmatic belt of basement is an important part of polymetallic metallogenic belt in the middle of Nanling region.It is in the area that Furong ore field with prospect of prospecting in super-large tin deposit has been found lately,and the111-333resources of tin have been identified about one million and thirteen thousand tons ;the types of the tin deposits can be divided into four types,the pneumato-hypothermal type,the hypo-mesothermal type,the volcanogenic hydrothermal type and the alluvial type,and seven subtypes,all of which formed nearly a complete metallogenic series.Where,the tin deposit of any type is the product of several times of tectonizations and magmatisms ,its main epoch of mineraliza-tions are at an late stage of early and an early stage of late Yanshanian period;and there are distributive regularities of place on distributing the tin ore among belt,group and being equal distance,for the special geologic structural background,and showed an excellent prospect of prospecting.