How Infrared Spectroscopy Can Help Map Mineralization Zones

Recently, a team of scientists from Hebei GEO University investigated Tibet’s Jiaoxi Deposit for tungsten. In their study, the research team demonstrated the utility of infrared (IR) spectroscopy in mapping mineralization zones. The findings of this study were published in the journal Ore Geology Reviews (1).

99.95% fine tungsten isolated on white background. | Image Credit: © Bjorn Wylezich - stock.adobe.com

The Jiaoxi quartz-vein type wolframite deposit is situated in the western part of the Bangong-Nujiang metallogenic belt (1). Located in the western part of the Lhasa terrane, the belt is already renowned for its porphyry, epithermal, and skarn copper-gold (Cu-Au) mineralization, and the identification of tungsten enrichment marks a significant milestone for resource exploration in the region (1,2).

What did the researchers test in their study?

In their study, the team integrated short-wavelength infrared (SWIR) and Fourier transform infrared (FT-IR) spectroscopy with mineral geochemistry to chart hydrothermal alteration types and their spatial distribution (1). By using SWIR and FT-IR spectroscopy, they were able to uncover new insights into the Jiaoxi deposit as well as provide a technological framework for identifying mineralization signatures in similar geological settings (1).

A key finding of this study is how IR spectroscopy can delineate surface-level hydrothermal alteration centers. This observation is important because it means geologists have a new practical method to pinpoint potential high-grade tungsten zones (1). The findings underscore three major indicators of mineralization potential. First, the presence of muscovite, phengite, and augite mineral assemblages in drill cores emerged as strong markers of tungsten-bearing zones (1). Second, shifts in the wavelength of Al-OH absorption bands in white mica, particularly values greater than 2201 nanometers, correlated with higher mineralization potential (1). Third, elevated Illite Crystallinity (IC) values exceeding 1 were shown to serve as effective vectors for identifying ore-rich zones (1). Together, these parameters provide geologists with a reliable toolkit for narrowing exploration targets.

Another key finding in the study was that the tungsten mineralization in the Jiaoxi deposit is closely tied to muscovite-phengite-augite alteration. This mineral association reflects the interplay between ore-forming fluids and host rocks, offering new theoretical insights into the processes driving hydrothermal tungsten enrichment (1). Importantly, veins hosting mineralization were shown to coincide spatially with regions characterized by high Al-OH absorption wavelengths and elevated IC values, reinforcing the diagnostic power of spectroscopic techniques (1).

According to Zhang, the results hold both scientific and practical implications. The results enrich the mineralization theory of magmatic-hydrothermal tungsten systems, helping geologists better understand how chemical and physical changes in ore-forming fluids are recorded in alteration minerals. They also provide an applied exploration strategy that can be extended beyond Jiaoxi to adjacent areas of the Bangong-Nujiang belt and other regions with similar geological environments (1,2).

What are the important implications of this study?

The findings in this study emerge at a time when tungsten has grown in demand. Tungsten is a critical metal that is essential for applications ranging from high-strength steel alloys to electronics and renewable energy technologies (1). As demand for strategic minerals intensifies, advances in exploration methodologies will play a key role in securing supply chains. Infrared spectroscopy, as demonstrated in this study, provides an efficient and cost-effective means of prospecting rare-metal deposits, particularly in remote and geologically complex terrains (1).

By analyzing the spectral variations of alteration minerals, the team has not only expanded theoretical models of tungsten mineralization but also equipped exploration geologists with practical tools for field application (1). The Jiaoxi study underscores how modern analytical technologies are advancing traditional mineral exploration, pushing the boundaries of how ore deposits are identified, evaluated, and developed (1).

References

1. Liu, X.; Wang, M.; Zhang, J.; et al. Short-wave Infrared Spectroscopy Studies on Hydrothermal Minerals for Exploration of the Jiaoxi W Deposit, Tibet, China. Ore Geo. Rev. 2025, 176, 106397. DOI: 10.1016/j.oregeorev.2024.106397
2. Wang, Y.; He, C.; Tang, J.; et al. Metal Source and Hydrothermal Evolution of the Jiaoxi Quartz Vein-type Tungsten Deposit (Tibet): Insights from Textural and Compositional Variations of Wolframite and Scheelite. Am. Min. 2023, 108 (7), 1258–1274. DOI: 10.2138/am-2022-8440