Measurement of Carbon Dioxide and Sulfur Dioxide in Soil Gases as a Guide to Mineral Exploration under Exotic Overburden

Abstract

Mineral exploration under exotic overburden has been a great challenge in exploration geochemistry. Gas geochemical measurement is a potential method for mineral exploration due to the characteristics of strong penetrability and vertical migration. The previous rapid gas analyzer cannot determine low concentrations of soil gases because of inadequate sensitivity, therefore, it is necessary to develop a more sensitive analytical technique. In this paper, the pilot studies on CO₂ and SO₂ geochemical measurements were performed at the Zhuxi W-(Cu) deposit, Jiapigou gold ore-concentrated area, and Tukuzbay gold deposit. This study employed rapid gas analyzer based on Infrared Absorption Spectroscopy and Electrochemical Analysis, which can detect low concentrations of CO₂ and SO₂ and greatly improve the reliability of test data. The results show that CO₂ and SO₂ show clear anomalies over deeply concealed ore bodies and faults, demonstrating that CO₂ and SO₂ anomalies can reveal indicative information about concealed mineralization and faults. Moreover, CO₂ and SO₂ anomalies can identify mineralization information exceeding 1,000 m in depth, suggesting that this method has large detection depth. Therefore, CO₂ and SO₂ geochemical measurement method is a feasible tool to discern deeply concealed mineralization and faults, and can provide a new idea in prospecting for concealed ore deposits in covered areas.

Keywords

gas measurement / concealed deposit / carbon dioxide / sulfur dioxide / rapid gas analyzer

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2025 Geological Society of China