The Sedimentary Characteristics And The Analysis Of The Uranium Ore-formation Condition In Changliushui Area Of Tuha Basin

The Turpan-Hami Basin is located in the middle of the Tianshan Mountains and is sandwiched between the Junggar Basin and the Tarim Basin from the topography.The southern margin of the Turpan-Hami basin has both the tectono-sedimentary environment of interlayer oxidation zone sandstone-type uranium deposit and epigenetic ore-forming conditions.In recent years,the nuclear industrial production unit has carried on the key exploration of the long flowing water region on the southern edge of the eastern Turpan-Hami Basin.Based on the sandstone type uranium mineralization theory,this paper analyzes the petrology and sedimentary facies of the Changliushui area in the south edge of eastern areas of the Turpan-Hami basin through field geological surveys,indoor microscope identification,and borehole data analysis.Combined with borehole data and oxidation zone distribution,the following understandings are obtained:Through field geological surveys and drilling core cataloging,samples were collected and microscopically identified.It is considered that the target sandstones in the study area are dominated by feldspar lithic sandstones and lithic sandstones.From the Dickinson map,we can see that the source of the study area mainly exists in the cut-off island arcs and over arcs.It is believed that the source of the study area comes from the basin south.At the same time,it was found that both the compositional maturity and the structural maturity of the sample were low,reflecting the characteristics of rapid deposition near the source.Based on the data analysis of sandstone porosity,permeability and grain size data analysis combined with microscopy observations,it is considered that the porosity connectivity of the study area is very good,and the sediment of the target layer is roughly in the initial consolidation stage.The overall permeability is more than 0.3 m / d,which is beneficial to the development of runoff and inter-layer oxidation of confined groundwater during its development,which is beneficial to mineralization.Based on the data of element geochemistry analysis in the study area and the comparison of the southern margin of the Yili Basin,it is concluded that the metallogenic environment is basically the same,which is a primary grey geochemical zone with high reduction capacity.It is an ideal geochemical type for the formation of sandstone-type uranium deposits.Through the analysis of sedimentary facies in the study area,the sedimentary microfacies diagram of single well and continuous well profile,the contour map of sand body thickness,the isoline map of sand to ground ratio and the sedimentary facies plane map are plotted.It is considered that the main sedimentary environment of the Xishanyao formation of the Middle and Lower Jurassic in Changshui area is braided river environment.By analyzing the tectonic background conditions,oxidation zone development conditions,hydrodynamic conditions,anomalies and mineralization characteristics of the study area,and combining the results of previous research areas,it is considered that the study area has good uranium metallogenic conditions.