基于ASTER的哈密土墩地区构造及蚀变信息提取与找矿预测

土墩铜镍矿位于东天山黄山—镜儿泉铜镍成矿带,矿床形成主要受岩浆作用和构造作用控制。为了进一步探测该地区的矿产情况,采用ASTER热红外波段比值组合模拟的反演算法,对发射率数据进行Si O2含量的定量反演,在反演图上识别出了研究区内明显的石英断裂带。结合ASTER数据可见光—近红外光谱波段中提取出的构造信息,得出研究区完整的构造解译图。采用主成分分析和阈值分割法对研究区进行了铁染、羟基蚀变信息提取。最后根据区内线性构造、遥感蚀变信息、岩石分布特征、化探异常、已知矿床点分布资料综合分析,圈定出6个成矿有利区,为研究区今后的找矿勘查提供依据。

EXTRACTION OF LINEAR STRUCTURE AND ALTERATION INFORMATION USING ASTER DATA AND PROSPECTING PROGNOSIS FOR TUDUN, HAMI

Copper-nickel deposit of Tudun which is located on the Huangshan-Jingerquan copper-nickel mineralization belt in East Tianshan area is controlled by magmatism and tectonic action. To further prospect the minerals of this region, using thermal infrared data of Aster, the authors quantitatively retrieve SiO₂ content in the rocks from emissivity data by inversion algorithm simulated from different band ratio combination. According to the inversion map view, we extract many large silicified fault zones. Combining with the information of the faults, based on visible - near infrared bands, we obtain the fracture distribution of the study area. Principal component analysis and threshold segmentation were used to enhance the spectrum and space information and extract the iron-stained and hydroxyl alteration information. Through comprehensively analyzing the linear structure, remote sensing alteration information, rock mass distribution characteristics, regional geochemical information and known deposits, six metallogenic prospective areas are delineated.