The Formation Of Sequence Of Kuzigongsu Formation ?J₃k? Of Sareke Containing Copper Basin In Wuqia County, Xinjiang And The Study Of Complex Alluvial Fan Sedimentary Facies

The Kuzigongsu formation?J₃k?of Sareke basin is the type of sedimentary facies of complex alluvial fans,on the basis of stratigraphic classification from Proterozoic until Cenozoic,lead zinc copper deposit which is Layer controlled type?J₃k?is determined to a rapid deposition of alluvial fan sedimentary facies in the late Jurassic.The oldest strata which is exposed is metamorphic rock that belongs to Akesu formation of Changchengian System in Sareke basin,in turn,stratums above are Salitashen formation?J₁s?,Kangsu formation?J₁k?,Yangye formation?J₂y?,Taerga formation?J₂t?,Kuzigongsu formation?J₃k?and Kezilesu formation?K1kz?.The research and analysis on the alluvial fan sedimentary facies of Kuzigongsu formation?J₃k?contribute to carry out basic geological survey for copper polymetallic minerals in Sareke basin in order to find out roughly copper prospecting prospect.Guided by the high resolution sequence stratigraphy theory,the sedimentary facies of complex alluvial fans are divided according to the stadaed of the middle-term cycle and the short-term cycle by taking advantage of abundant data of 24 drillings and 13 outcrop analogues.Gathering interfaces of short-term cycles of all profiles and drillings,rock sequence characteristics and flooding surface features,all all profiles and drillings can be divided into several short-term cycles and two middle-term cycles?MSC1?MSC2?.At the same time,according to the vertical variation characteristics of the lithology,sedimen tary facies of alluvial fans are divided into three subfacies including root fan,middle fan and fan edge.The root fan can be divided into 3 microfacies including the main channel,genya debris flow and sheet flow;the middle fan is divided into two microfacies including braided river channel and river flat;the fan edge presents as the microfacy of flood plain at the most time,as the intermittent river sometimes;in addition,there is sediment between two alluvial fans.Considering the different paleocurrent characteristics of different regions located in the basin,I selected appropriate profiles and drillings to build four isochronous stratigraphic frameworks by analyses of individual drilling sedimentary facies,section sedimentary facies and plane sedimentary facies using the high resolution sequence stratigraphy theory,all these are used to analyze the plane distribution characteristics of complex alluvial fans within 2 middle-term cycles.I can draw two planar graphs of sedimentary subfacies within the 2 middle-term cycles using the knowledge of dominant sedimentary facies.Combined with petrological characteristics of the conglomerate and the sandstone,the paper can achieve supplement and perfect about the research of sedimentary facies.During the period of MSC2,there are large-scale copper ore bodies in the northern and southern parts of the basin;During the period of MSC1,there are smaller copper ore bodies in the partial region of the northern and southern parts of the basin.