Geological Characteristics And Structure Analysis Of Shibandun Iron Deposit In Subei County Of Gansu Province

Shibandun iron deposit is a large-scale magnetite (hematite) deposit, which was found in Subei County, Gansu Province recent years, the mining area is located in the middle of the qilian block (II10),which is a sedimentary metamorphic iron ore bed type. It experienced a long and complex geological structure process after generation, so it is difficult to exploration deployment.Therefore this areticle focus from the perspective of structural geometry, kinematics to identify characteristics of tectonic stress field in different periods and determin the structure and distribution of ore body and its activities in the region.An in-depth discussion on the structure and spatial and temporal relationship between ore bodies guides provide reliable geological prospecting in the region basis.1.Through almost3years of mining geological exploration work, according to the geological characteristics, ore body characteristics, such as ore quality, we summarize the metallogenic regularity, prospecting and ore genesis of the deposit and initially determined that the deposit is of sedimentary metamorphic iron bed.2.We think that mining area and regional constructed are basic correspondence with analysising Mining area and regional tectonic geometry. The main structural framework is for East-West imbricate thrusting fault, mining area is for the overall performance of axial E-W complex anticline;the second is for North West, and North Sissy to inverse rushed fracture; the tension fracture of North West, and North East should be for area within last a period development of fracture, which damaged and displaced the part of early structure.3.East-West structural mining area north and south side of the knoll gabbro rock, red springs north of diorite had staggered. The LA-ICP-MS zircon U-Pb age display. Noel gabbro rock zircon U-Pb age of471.6±3.7Ma,469.3±2.8Ma. red springs north of diorite zircon U-Pb age of470.9±3.7Ma. whitch are in the early Ordovician of the magma activity.So we inferred zone tectonic frame after the magma activity.4.Through a large number of observation of conjugate shear joints, using mathematical statistics method of staging facilities, preferring the tectonic stress, we think that the tectonic stress field is divided into three phases:the first period is SN to the extrusion stress, which was the major stress field in the regional, forming a regional tectonic framework; the second period is NE-SW to the extrusion stress;the third period is to NNW. Because of this three stage tectonic stress superposition effect, ore bodies in the area occurs fault, fold and other complex deformation metamorphism.