摘要：
Chromite deposits developed in the Yarlung Zangbo river ophiolite belt have high economic value,especially the ones closely related with harzburgite and dunite.Therefore,the exploration of peridotite related with chromite mineralization is of great significance.Remote sensing,as a new type data,has been applied to lithological delineation and geological mapping.This article selects Luobusa of Tibet as the study object and aims to evaluate the ability and feasibility of remote sensing data on the identification and delineation of Mantle peridotite-the host rock of chromite by analyzing the multi-spectral Landsat 7 ETM satellite data of this area with a series of spectral enhancement methods,including decorrelation stretch (DS),band ratio(BR),false color composite(FCC),principal component analysis(PCA),etc.,by comparing and verifying with various methods,the obtained result shows that the enhanced ETM image is feasible on the delineation of mantle peridotites under the special environment of Tibet,which further proves that remote sensing image enhancement method has prospect on exploring potential chromite deposit and can obtain a certain geological effects.%雅鲁藏布江蛇绿岩带中发育的铬铁矿矿床,具有极高的经济价值,其形成与蛇绿岩成分中的地幔橄榄岩关系密切.因此勘查与铬铁矿相关的橄榄岩变得十分有意义.遥感作为一种新型数据已被应用于岩性圈定及地质填图.文章以西藏山南地区罗布莎为例,旨在通过分析该地区多光谱Landsat7 ETM遥感数据,使用一系列光谱增强方法,包括去相关拉伸,波段比值,假彩色合成,主成分分析等,评估遥感数据对铬铁矿寄主岩石地幔橄榄岩识别与圈定的能力和可行性.经过多种方法对比验证,结果显示经过光谱增强的遥感影像对西藏特殊环境下的地幔橄榄岩范围的圈定是可行的,证明利用遥感影像增强方法探测潜在铬铁矿床是有前景的,能取得一定的地质效果.
