Gold‐copper deposits in Wushitala, Southern Tianshan, Northwest China: Application of ASTER data for mineral exploration

Abstract

The Southern Tianshan area is one of the most important gold belts identified by many world‐class, super large and large gold deposits such as Muruntau (Uzbekistan), Kumtor (Kyrgyzstan), and Jilau (Tajikistan). Some medium‐ to small‐scale gold deposits, such as Sawayaerdun and Bulong, have been discovered and reported in recent years at the China part of the belt. The study area, named the Wushitala area, is located in the eastern part of Southern Tianshan, and it has a strong potential for gold and other metallic mineral deposits. This study utilizes various image processing techniques, including false colour composite, band ratios, and matched filtering, to process Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and map the distribution of hydrothermal minerals (e.g., muscovite, kaolinite, chlorite, epidote, goethite, and malachite) related to the known deposits in the Wushitala area. The identified alteration zones are coincident with the known gold and copper deposits and field samples from the study area. The distribution of the alteration zones also indicates that the acid intrusions and regional structures play an important role in focusing the mineralizing fluids. The results show that ASTER data accompanied with image processing methods and reference spectra (e.g., JPL, lab, or field measured) could be an effective technique for mapping hydrothermal alteration zones in areas with no dominant vegetation cover. Due to the extensively distributed acid intrusions and structures along the Southern Tianshan Belt, the mineral prospecting methodology is suggested for application in similar geological settings in the belt.

Integration of Landsat 8, gravity, and field data for exploration of gold mineralization in Gamba District, Northern Cameroon

“…The study area field checking was dominated by a high intensity of hydrothermal alteration, which affected many rocks that embedded mineral types such as chlorite, epidote, muscovite, or sericite, and opaque minerals. The altered mineralized rocks display secondary minerals, which are common indicators of mineralization, such as gold and copper (Gabr, Ghulam, & Kusky, 2010; Han & Nelson, 2014; Liu, Li, Zhou, Han, & Xu, 2018; Ruiz‐Armenta & Prol‐Ledesma, 1998). Zoheir and Emam (2012) found that the alteration area, comprising pyrite, quartz, carbonate, chlorite, sericite, and goethite, hosts several open pits and trenches within quartz veins and boudins in Egypt.…”

Mapping hydrothermal minerals using remotely sensed reflectance spectroscopy data from Landsat

“…The principal component analysis (PCA)-based Crosta technique and band ratio techniques like the Kaufmann and Sabins ratios proved to be more significant and efficient for hydrothermal mineral exploration. Several researchers have also concluded that advanced image processing techniques like those applied and tested in the current study are quite efficient in terms of mineral mapping through remote sensing data (Manuel et al, 2017;Liu et al, 2018). The maps produced in this study are not only appropriate for any spatial queries and analysis, but also for environmental modelling such as assessing the impacts of mining activities on environmental features such Mapping hydrothermal minerals using remotely sensed reflectance spectroscopy data as the forest, farmland, and urban areas.…”

“…The band combination of shortwave infrared 2 with spectral band 2.11-2.29 μm and near infrared with spectral band 0.85-0.88 μm in Figure 11 shows the areas which have the potential to host clay minerals in shades of red to yellow. Liu et al (2018) applied various image-processing techniques, including false-colour composite, band ratios, and matched filtering, to process ASTER satellite data and map the distribution of hydrothermal minerals associated with gold deposits, and concluded that the SWIR and NIR bands are the most effective for this purpose.…”

Tianshan Orogen along the Silk Road (Volume 3): Orogen links, geochemistry, geochronology, mineral deposits, and environments

“…In the paper by Liu, Li, Zhou, Han, and Xu ( ) , the authors used various image processing techniques to map hydrothermal minerals related to known deposits in the Wushitala region of Southern Tianshan. A correlation was established between identified alteration zones and known gold–copper deposits in the study area.…”