基于OLI和ASTER数据的蚀变信息提取分析与对比 ——以青海都兰通突尔铅锌多金属矿区为例

研究区位于我国西北部干旱地区,植被稀少,为利用多光谱遥感数据进行蚀变信息提取提供了便利条件,对寻找内生矿床尤其是热液矿床有着重要作用。本文基于OLI数据和ASTER数据,利用主成分分析法(PCA)对都兰县通突尔铅锌多金属矿区进行了羟基蚀变信息提取并取得了良好的效果,已知矿点与提取的羟基蚀变异常吻合程度较高。由于ASTER数据对可见光-短波红外部分的谱段进行了细分,故基于ASTER数据提取出了两类羟基蚀变信息,含铝羟基蚀变(高岭土、绢云母、伊利石等)和含镁羟基蚀变(绿帘石、绿泥石)。通过两类数据蚀变信息的相互补充,为快速寻找矿产勘查靶区提供了有力依据。

Analysis and comparison of extracting alteration information from OLI and ASTER data: An example of the Tongtuer Pb-Zn polymetallic deposit in Dulan, Qinghai Province

The study area is located in the arid region of northwestern China, where vegetation is little, favorable for extracting alteration information from multi-spectral remote sensing data, which is significant for finding endogenous deposits especially hydrothermal deposits. Based on the OLI and the ASTER data, this work used the principal component analysis (PCA) method to extract hydroxy alteration information of the Tongtuer Pb-Zn polymetallic deposit in the Dulan area. The known ore spots are highly consistent with the extracted hydroxy alterations. In addition, there are more spectral bands in the visible-near-infrared(VNIR) part of ASTER data than OLI data. So two types of hydroxy alteration information are extracted from the ASTER data, including Al-OH alterations (kaolinite, sericite and illite) and Mg-OH alterations (epidote, chlorite). Mutual supplement of the two types of data alteration information provide a evidence for the rapid search for mineral exploration targets in this area.