The Application Of High Resolution Remote Sensing Interpretation Method In Narat Metallogenic Belt Of West Tianshan

West Tianshan Narat mineralization belt is one of the most important metallogenic belt in Xinjiang,currently in the zone have been found several large and medium sized gold deposits.Such as Katebaasu,Niyazitiekexie and Alesituo,etc.The study area is located in the Western Tianshan Mountain,Mount Jarque,Mount Narat and Hora area,landform is in mid-high mountain area.The terrain here is higher in the north and lower in the south,the terrain is strongly cut,the water system is very developed.The tectonic position is located in the joint band of Tarim micro plate and the Yili micro plate,through the comprehensive analysis of sedimentary formation,magmatic formation,metamorphic formation and tectonic facies,the geotectonic evolution history of the Western Tianshan area can be divided into five important stages of development: Precambrian “intermediate massif” stage,Early Paleozoic terrigenous clastic sedimentary stage,the early and middle Late Paleozoic marine facies volcano-sedimentary stage,later period of Late Paleozoic continental volcano-sedimentary stage and Mesozoic Cenozoic stable sedimentary stage.The formation of Geological events as sedimentary cap that represented by Paleozoic with large-scale granitoids intrude into,regional fault tectonics had changed many times,etc.Favorable geological conditions of mineralization.The study area exposed strata of the Changchengian System,Silurian System,Devonian System,Carbonic,Permian,etc.The Devonian System,Carbonic and Permian strata in this area is the main.According to plate theory,divided part of the Bo Rocco Nur Early Paleozoic island arc-back arc area and Awulale-Yishen kelek Late Paleozoic arc basin of Tarim plate and Yili micro plate.The tectonic line is mainly from the NWW to the SEE.Developed several folds such as Yili interdeep,Gongnaisi bend fold,Kashi River intermountain depression,Awulale anticlinorium,the Zeketai – Kansu fault uplift,etc.Controlling the distribution of regional mineral resources on the whole,and the formation of mineralized concentration area in the axis or other weak parts through the fracture magmatic system,such as Yili interdeep is favorable area for the formation of porphyry type,volcano sedimentary iron,copper and molybdenum minerals;Gongnaisi bend fold is favorable area for the formation of Fe-Cu deposits that related to Carboniferous volcanic rock and Fe-Mn deposits that related to Terrigenous clastic rock.The development of fault of Nileke fault,Kunes River fault and Kashi River fracture,etc.These faults are not only the boundary of tectonic units but also limits the distribution of regional metallogenic belt.For example,the Nileke fault controls the gold and polymetallic metallogenic belt in the North,Gongnaisi fracture control the northern Awulale Mountain Copper iron ore district and Fe-Mn mineralized belt as the backbone of the Awulale mountain main ridge fault.In this paper,literature research,qualitative research,quantitative research and other research methods,focuses on the theme of "the West Tianshan Mountains Naratmineralization belt of remote sensing interpretation",on the basis of studying the domestic and foreign literatures about remote sensing interpretation technology,guided by the relevant national standards and industry standards,in depth interpretation the main geological information of strata,intrusive rocks and structures in study area,and combined with the previous 1:20 0000 geological map and field verification results,revise the geological map.Finally,the alteration information was extracted,determine the area remote sensing anomaly.The specific research process is as follows: First of all,the basic geological data,research reports,relevant maps,and a variety of metadata of interpretation required(Including1:50000 interpretation of the use of GF-1,OLI data and 1:10000 interpretation of the use of worldview-2 data).Then,the image data of the study area are pre processed,including pre-processing,geometric processing,radiation treatment and other steps.After that,set up the stratigraphic interpretation marks,the structural interpretation marks,etc.The geological interpretation of the whole region image according to the interpretation mark.Then,based on the OLI data,the extraction of alteration information in the study area was carried out.Finally,arrange the field verification route to conduct field verification in the field.Using the ETM+ image data in the 1,4,5,and 7 channels to extract the hydroxyl anomaly,and 17 anomalies were extracted,divided into three levels according to the abnormal intensity.The use of 1,3,4,and 5 channels for iron extraction anomaly extraction,the region extracted 21 anomalies.After the hydroxyl information is combined with the iron staining information,and based on the structural characteristics of the region,the alteration information is optimized,a total of 7 zones were selected,the No.3 area in accordance with the original 1:20 0000 magnetite.