Radioactive and Spectral Characteristics of the Qiongjiagang Pegmatite-Type Lithium Deposit in the Himalayas and Their Significance of Ore Prospecting

Lithium resources play a crucial role in the new energy industry, and their efficient exploration is directly related to the safety and stability of the new energy industrial chain. Pegmatite-type lithium deposits have become one of the main sources of lithium resources due to their high resource grade and easy exploitability. The Qiongjiagang mining area is the first pegmatite-type lithium deposit with industrial value in the Himalayan metallogenic belt. Previous researchers have conducted extensive studies on its geochemistry and physical prospecting; however, the current research on the radioactive characteristics and spectral characteristics of the pegmatite-type lithium deposits in this mining area remains unclear, which limits the effective application of remote sensing technology in the mining area. This study investigates the radioactive characteristics and spectral characteristics of pegmatite-type lithium deposits in the Qiongjiagang mining area of the Himalayas, explores remote sensing identification methods applicable to this mining area, and establishes a dual-index identification method based on radioactive characteristics and spectral characteristics to achieve rapid and accurate identification of spodumene-bearing pegmatites. In this study, an environmental X and γ radiation detector, an X-ray fluorescence spectrometer, and a hyperspectral ground object spectrometer were used to conduct field radioactive measurements, radioactive element content measurements, indoor spectral test analysis, and mineral composition detection of various rocks in the Qiongjiagang mining area. Studies have shown that the radioactive characteristics of various rocks in the Qiongjiagang mining area follow the order: pegmatite ＞ granite ＞ surrounding rock (marble) ＞ other rocks, with pegmatite exhibiting obvious thorium (Th) anomalies. In terms of spectral characteristics, the wavebands of 1900 nm, 2200 nm, and 2480-2490 nm possess diagnostic features for ore prospecting, which can effectively distinguish spodumene-bearing pegmatites, non-ore-bearing pegmatites, and surrounding rocks. In addition, the reflectance of various rocks generally follows the sequence: ore-bearing pegmatite ＞ non-ore-bearing pegmatite ＞ granite ＞ surrounding rock (marble). This study has obtained the range of radioactive characteristics of various rocks in the Qiongjiagang mining area and the prospecting indicator wavebands for ore-bearing pegmatites, revealed the radioactive and spectral characteristics of pegmatite-type lithium deposits in the Qiongjiagang mining area, and proposed an identification method based on dual indicators, thereby achieving the goal of convenient and efficient ore prospecting.