Research On The Characteristics Of Structure And Alteration And The Prediction Of Prospecting Targets For Uranium In Wanheyong Basin,Chi Feng

Wanheyong basin is located in the Hongshanzi – Wufendi points to sub-metallogenic belt of the China Guyuan – Hongshanzi uranium metallogenic belt, tectonic history has experienced the dual role of the paleo Asian tectonic domain and the Pacific tectonic domain, the metallogenic geological condition is superior, with great prospecting potential.This treatise is based on the extensive collecting of former data, making full use of the remote sensing technology, extracting of basin structure, alteration information, and on this basis to carry out the targeted field verification, the measured of structure section, statistic of joints, collection of sample and thin section identification under microscope etc. Identified the features of structural trellis and alteration of the temporal and spatial distribution on basic, finally has carried on the system analysis from the point of view of uranium source, ore bearing stratum, structure, alteration, rock mass, ore-forming conditions of Wanheyong basin of uranium, meanwhile, combined with the existing data, predicted the favorable area for prospecting.Research shows that, the basin structural framework is based on the ruptures of NE, NNE and NW, NWW trending, SN and EW trending fractures are not very developed, the NE trending ruptures are mainly of Ⅱ-2, Ⅱ-3, Ⅱ-4, NNE trending ruptures are mainly of Ⅰ-2, Ⅰ-3, Ⅰ-5, Ⅰ-7, NW、NWW trending, to the representative ruptures were IV-1, V-1 and V-2.The properties of fracture is based on the tensional, where NE trending fault properties of structure is tensional at early, late into the pressure, fault structure of NNE and NW, NWW trending take on tensional more.Tectonic activity has several times and the phenomenon of fracture cutting between faults is more obvious, according to the relationship of pull-apart’s in faults, the sequence of each fracture formation is NE�'NW、SN�'NNE�'NWW�'NE.Volcano tectonic was significantly affected by the linear fracture control, spreaded along the NE-NEE fault zone and often located in the composite part of NE and NW faults.Basin hydrothermal alteration is mostly for acidic hydroxyl alteration in the surface, the distribution with the block and linear features characteristic, hydroxyl alteration which is close related to the mineralization distributed in the internal distribution of the xinmin group which has ring structure, also at the intersection part or clamping area of multiple faults and round with main faults, which has the spreading characteristics of NE and NW.Mineralized alteration has the characteristics of superposition of multi period, can be divided into three phrases, five stages, early as kaolinite – hydromica – fluorite – pyritization stage, metallogenic period including hydromica – microcrystal quartz – hematitization、colloidal fluorite – pyritization、jordisite – colloidal pyrite Mineralization stage, the late containing chlorite – carbonation – oxidation stage.According to the condition of basin source of uranium, formation, structure, alteration, rock-mass, mineralization of uranium, considered that the metallogenic condition of Wanheyong basin is superior, has favorable mineralization, and delineated five prospecting target areas according to the advantages and disadvantages of the delineation of uranium mineralization.