Poly-metallic Mineralized Characteristic And Information Extraction With GIS In Taipusi Caldera, Inner Mogolia

The caldera in Inner Mongolia is located in the boundary of the north margin of the Chinese Platform and the Tian Mountain-Xing’an Geosyncline. There are fractures in EW、NW、NNE、NE positions in the research area. Mesozoic tectonic and magmatic activity form a series of volcano-tectonic units of different levels, and Taipusi caldera which is controlled by NE an NW fractures, is a typical agency. This caldera is nearly annular in the remote sensing image and geophysical anomaly map. Distribution of the mountain and water appear annular form, and fractures in annular and radical form develop obviously; The poly-metallic chemical anomalies (Ag, Au, Pu, Zn, Bi, As, W, Mo) is concentrated in the caldera research area in the chemical anomaly map; seven mineralization points is identified in the base of the field survey and sample spectroscopy, Besides, there are a large number of altered fractured belts. So the relation between the caldera and poly-metallic mineralized characteristic from stratum、tectonic、volcanic evolution、mineralization and so on, is an important basis provide for the poly-metallic mineralized.The main ore-controlling factors in Taipusiqi caldera are: (1) Regional tectonic. EW and NE fractures are the master leading tectonic, and control the magmatic activity. Then the NW fracture is the important ore fracture, and it forms altered fractured belts. (2) Volcanic organ. A series of annular and radial fractures and broken rock in the formation of caldera evolution are in favor of the migration and enrichment of the ore fluid. The intrusion of the granite-porphyry and the extrusion of the froth control the enrichment of the Ag、Pb、Zn、Mo elements, and they are main ore-controlling factors and mineralization period. The mineralization points focus on the contact zone of the granite-porphyry and the froth.(3) Alteration type. In the process of hydrothermal mineralization, Fe-Mn mineralization, silicification, chlorite mineralization,and potassium mineralization altered in the surrounding rock, are the important sign of looking for poly-metallic mine.Ore-forming prediction is put forward after the research of the poly-metallic ore-forming characteristic, and GIS ore-forming prediction is based on the MapGis platform to establish database. Use MapGis to analyze and extract the graphic and attribute information of the stratums, fracturse, alterations and chemical anomalies. Then mark the ore-forming prediction in the research. And the predicitions line up the EW,NE and NNE direction.