Metallogenetic Alteration Pick-up From Remote Sensing Images And Multi-data Fusion To Au-Cu Forming Prediction At Xietongmen Area Of Tibet

Tibet, located in southeast of Qinghai-Tibet plateau, is part of the famous tethys realm. It holds very abundant mineral resources due to its multi-period strong crustal movement, complicated geological structure, frequent magmatic acticity, and predominant metallogenic condition. The geologic study in the past 20 years proved this belt is part of the important area of mineral exploration. Mining in Sitsang not only accelerates its economy development but also provides strategic ensure for the requirement about mineral resources. With constructing of the Qingzang railroad, the exploitation will meet a very golden opportunity.At the same time, limited by the plateau conditions, the geologic work now is very poor and imbalance. Then, how to develop the metallogenetic prediction and how to draw the prospecting targets quickly, economically and accurately is becoming very important.With the development of the computer, remote sensing(RS) and geographical information system(GIS), the manual interpretation, the metallogenetic alteration pick-up and the multi-data fusion gained a new breakthrough. Based on the understanding of previous geological data, in this paper, firstly was processed the data pretreatment about RS image of geometry correction,color image and image enhancement. And then, performed the manual interpretation and the linear structures pick-up with the aid of RS enhancement. Based on the statistical analysis about linear structures, the pattern of geological structure in study area was generalized. Next, the metallogenetic alteration was distilled. Finally, the fusion image of the geological,the geochemical and the aeromagnetic anomaly was analogized, and 3 metallogenetic prediction were circled. In this study we mainly achieved the following results:1,The linear structures statistical analysis improved the reliability and veracity of geological structure interpretation. The results of intensity and frequency of linear structure quantificationally and half-quantificationally showed the spatial distributing characters about geological structure in study area.2, Based on the image brightness value of known lithologys and alterations, the metallogenetic alteration was distilled. And the metallogenetic alteration can be regarded as the ore prospecting symbol.