Khan Muhammad Aslam1,2, Liu Chenglin1,2,*, Yang Guangkun1,2, Wang Haidong1,2
1 National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing), Beijing, 102249, China.
2 College of Geosciences, China University of Petroleum (Beijing), Beijing, 102249, China.
* Corresponding author: liucl@cup.edu.cn.
Abstract: The origin of helium in the Indus Basin, Pakistan, remains poorly constrained despite increasing interest in the basin’s helium potential. This study integrates noble gas geochemistry from natural gas reservoirs with geological and geochemical investigations of the Nagar Parkar Igneous Complex to evaluate the primary sources of radiogenic helium generation in the basin. Natural gas samples from the Middle and Lower Indus Basins display low ³He/⁴He ratios ranging from 1.3 × 10⁻⁸ to 7.8 × 10⁻⁸, indicating a dominantly crustal origin with negligible mantle contribution. Elevated ⁴He/²⁰Ne ratios further support the accumulation of radiogenic helium derived from crustal materials. The absence of strong correlations between helium and hydrocarbons suggests that helium was generated independently from hydrocarbon-forming processes. To identify the potential crustal source, granitoids of the Nagar Parkar Igneous Complex, situated along the northwestern margin of the Malani Igneous Suite on the Indian Shield, were evaluated for their helium generation capacity. The complex consists of highly evolved Neoproterozoic A-type granites and associated felsic and mafic dykes enriched in uranium and thorium bearing accessory minerals such as zircon, monazite, and apatite. Average uranium and thorium concentrations of 3.4 ppm and 15.5 ppm indicate substantial radiogenic helium generation through long-term alpha decay. Geochemical characteristics, including high silica and alkali contents together with enrichment in incompatible trace elements, further confirm the fertility of these granitoids as helium source rocks. The results suggest that Precambrian basement rocks of the Nagar Parkar Igneous Complex, together with radiogenic contributions from sedimentary sequences of the Indus Basin, constitute the principal sources of helium in the Indus Basin.
Keywords: Helium; noble gas geochemistry; uranium-thorium; Indus Basin; Nagar Parkar Igneous Complex
Author Profile (first author):
Khan Muhammad Aslam, Male, Research Scholar, PhD, mainly engaged in research on helium source. Email: aslamkhangeoscience@outlook.com
