Xuelian Huang1, Shuai Wang1, Xiaocheng Zhou2,3
(1 State Key Laboratory of Deep Geothermal Resources, School of Sustainable Energy, China University of Geosciences, Wuhan 430078, China; 2 Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China; 3 School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China)
Abstract: Natural hydrogen (H2) is attracting increasing attention as a potential clean energy resource and as a reactive component of geothermal gases. However, its sources, migration pathways, and release mechanisms in continental collision zones remain poorly constrained. This study examines hydrothermal gases from the southeastern margin of the Tibetan Plateau (SETP), a tectonically active part of the India–Eurasia collision zone that includes the Tengchong volcanic field (TCV), the Changning–Menglian suture zone (CMS), and the Red River fault zone (RRF). Here, we report gas compositions and isotopic data, including CO2, N2, Ar, H2, He, CH4, 3He/4He, δ13C–CO2, and δ13C–CH4, from these three tectonic domains. H2 concentrations vary strongly across the region, with the highest values in the CMS (1.0–190,000 ppm), compared with lower concentrations in the TCV (0.6–5,902 ppm) and RRF (1.0–1,746 ppm). These contrasts indicate different H2 sources and controlling processes. In the CMS, high H2 concentrations are linked to serpentinization of remnant oceanic lithosphere. In the TCV, magmatic degassing is the dominant control, whereas in the RRF, H2 is mainly associated with fault-related processes and radiolysis. Our results show that tectonic activity, including seismicity, faulting, and long-term lithospheric deformation, plays a central role in H2 generation and release. Faults provide migration pathways for deep and crustal volatiles, while secondary processes during fluid ascent, such as calcite precipitation and CO2 dissolution, modify gas compositions and promote relative H2 enrichment. These results demonstrate the strong tectonic control on H2 generation and migration in continental collision zones and provide a basis for natural hydrogen exploration in the Tibetan Plateau and other tectonically active regions.
Keywords: Hydrogen emission, Helium, Hydrothermal system, Tectonics, Southeastern Tibetan Plateau
Author Profile (first author): Xuelian Huang, Female, Postdoctoral researcher, focusing on geothermal geochemistry and geothermal-associated energy. E-mail: hxl18@cug.edu.cn
