含硫气体地球化学测量在找矿勘查中具有悠久的历史。但是由于含硫气体的高活动性和反应性、测试结果低重现性、分析测试高成本等缺点,含硫气体未能大规模应用于隐伏矿勘查。矿产勘查由近地表易发现矿转向隐伏矿以及便携式经济、高效和实时气体测量设备的成功研发,为气体地球化学勘查方法体系的完善升级和推广应用提供了一个新的契机。本文重点梳理了富硫化物隐伏矿气体地球化学测量研究进展、面临的挑战和未来发展方向。动力学平衡模拟、矿物(矿石)风化实验和矿区实例研究表明,富硫化物隐伏矿上方土壤中气体地球化学异常受多种因素影响,如矿体矿物组成、盖层特征、微生物作用、地球化学景观类型和含硫气体物理化学特征等。在土壤覆盖区可采用便携式多组分气体测量仪实现现场实时测量,若隐伏矿直接被运积层覆盖,则含硫气体异常与隐伏矿倾向于具有垂向对应关系。在基岩出露区则可采用岩石热解吸的方式测量含硫气体。隐伏矿与含硫气体异常的空间关系取决于断层和裂隙等渗透性通道的发育情况。案例研究统计表明,含硫气体地球化学测量不仅适用于半干旱-干旱地区,在半湿润-湿润地区也具有一定潜力。未来研究主要聚焦含硫气体在表生环境中的形成演化过程(查明主控因素)、不同地球化学景观区(尤其是半湿润-湿润气候区)含硫气体地球化学测量有效性以及便携式土壤气体测量设备小型化和智能化升级改造3个方面。

Sulfur gas geochemical detection has long been applied in mineral exploration. However, this method has not been widely used due to the high activity and reactivity of sulfur gases, low reproducibility of test results, and high cost. Today, as mineral exploration shifts from near-surface, easy-to-discover ore deposits to deep concealed ones, and with the successful development of portable, economical, efficient, real-time gas detection systems, a new opportunity arises to improve and promote this method. This paper reviews research progress, challenges, and future development directions regarding to concealed sulfide-rich deposits. Equilibrium thermodynamic models, simulation experiments on weathering and oxidation of sulfide minerals, and field studies suggest that gas geochemical anomalies of concealed sulfide-rich ore deposits are influenced by their mineral compositions, cover characteristics, geochemical landscapes, and physicochemical characteristics of sulfur gases. In regolith-covered terrains, portable multi-component gas analyzers can be used to obtain on-site, real-time measurements of soil gases including sulfur gases; more importantly, sulfur gas anomalies in soils tend to appear directly above the blind deposits if the blind deposits are covered by regolith directly. In bedrock outcrops, sulfur gases can be measured by rock thermal desorption; and the spatial relationship between the blind deposits and sulfur gas anomalies is primarily influenced by the development of permeable channels such as faults and fractures. Case studies indicate the sulfur gas geochemical detection is effective for mineral exploration in semi-arid and arid terrains and has great potential for mineral exploration in semi-humid and humid terrains. Future research directions should focus on three aspects: the formation and evolutionary process of sulfur gases in surface environment to ascertain the dominant controlling factors; the effectiveness of geochemical detection of sulphur-containing gases under different geochemical landscapes, especially in semi-humid and humid terrains; and the miniaturization and intelligent upgrading of portable soil gas detection equipment.