Optimize And Evaluate Of Hetian Jade Target Area By High Precision Remote Sensing

There are many kinds of jade in the world,but the Chinese Hetian jade has its own school and is loved by people in China and even the world.Hetian jade as a kind of nephrite,mostly is produced in Kunlun Mountains." Jinsha River is rich in gold sand,jade is mostly produced in the Kunlun Mountains " as a famous saying from ?Thousand Words? is a vivid portrayal of Hetian jade origin.The Altyn Tagh is wedged towards the Kunlun Mountains,which is also the important origin of Hetian jade.There are many Hetian jade ore deposits that have been or are being mined.One of the more famous jade ores is Tatelekesu jade mine,which is famous in the world because of its extra large jade.The jade production near the Tashsayi jade mine is very vigorous.The vast area in between two jade mines has great prospecting potential.However,due to the complex topography and harsh climate of the West Altyn Tagh,the traditional prospecting methods are difficult to develop.With the development of remote sensing technology,especially the development of high precision remote sensing technology,it is possible to find the Hetian jade mines in such dangerous areas.The Hetian jade deposit is closely related to hydrothermal solution according to the collected scientific data.Specifically,marble becomes jade under the action of torsional stress fault due to the intrusion of intermediate-acid intrusive body.At present,the remote sensing techniques are relatively mature in searching for similar deposits such as porphyry copper deposits and altered hydrothermal gold deposits.Considering the geological reflection of these deposits in remote sensing,the following characteristics can be seen:(1)These ore deposits are mostly related to hydrotherm,and there are some geological phenomena which are more or less favorable for prospecting,such as structure,mineralization alteration and characteristic rock mass;(2)These mineral prospecting geological elements can be disintegrated and extracted one by one or class by class by remote sensing techniques.Considering the geological characteristics of Hetian jade deposits in the West Altyn Tagh,the geological elements can be disintegrated into marble,granitic intrusive body,torsional compressive fault,mineralization alteration and so on,which can be summed up as "' trinity '+ stress + alteration + others" remote sensing prospecting model to guide the prospecting.In order to effectively extract geological elements of prospecting,ASTER data with moderate spectral resolution and worldview-2 data with high spatial resolution have been collected in this paper.In terms of structure,ASTER data is used to interpret regional structure by spatial filtering,and the advantage of high spatial resolution of worldview-2data is used to interpret small structure and fault mechanical properties.In terms of lithology,marble and granite intrusions closely related to form Hetian jade were mainly extracted on the basis of making full use of 1:50,000 geological map interpreted by remote sensing.The distribution of marble and granite can be determined roughly by ASTER TIR.The specific lithology of granite can be determined by ASTER VNIR-SWIR.According to the spatial distribution location of marble,granite,fault and the known spatial distribution characteristics of Hetian jade mines,the favorable ore-prospecting areas were determined.Worldview-2 data was used to interpret small scale marble and granite intrusion,distinguish schist and gneiss according to the texture features,and finally complete 1:10000 remote sensing interpretation.Under the guidance of remote sensing prospecting theory,twelve remote sensing target areas of Hetian jade were delineated according to the 1:10000 remote sensing interpretation results and the spatial distribution location of the discovered Hetian jade mines.When evaluating the target areas of Hetian jade remote sensing,the ore prospecting elements of Hetian jade target areas are understood in detail to comprehensively judge the possibility of finding Hetian jade in each target area and finally four A-grade target areas,four B-grade target areas and four C-grade target areas were determined.This paper used remote sensing technology to delineate and evaluate the target areas of Hetian jade remote sensing,which has important guiding significance for the exploration of Hetian jade deposit in this area.