CHARACTERISTICS OF TRACE ELEMENTS IN SPHALERITE AND ITS IM-PLICATION FOR WUSIHE LEAD-ZINC DEPOSIT,SICHUAN PROVINCE
The Wusihe lead-zinc deposit in Sichuan Province stands out among the large deposits in the Si-chuan-Yunnan-Guizhou area due to its significant germanium(Ge)content.While extensive research has been conducted on this deposit,there are lingering controversies regarding its genetic type and the distri-bution of Ge elements within the deposit.To address this,twelve sphalerite samples representing two sta-ges were collected from various parts of the ore body in the Wusihe Deposit.Microscope observation and LA-ICP-MS analysis were utilized to examine the composition and structural characteristics of trace ele-ments in the ore samples.The results reveal that sphalerite from different stages of the deposit exhibits relatively high levels of cadmium(Cd),gallium(Ga),and Ge elements,while being deficient in selenium(Se)and indium(In).The average Ge content in stage Ⅰ sphalerite is 186 ×10-6,whereas it is 56.4× 10-6 in stage Ⅱ sphalerite.Notably,both stages exhibit Ge contents exceeding 5.00×10-6,with stage Ⅰsphalerite demonstrating higher Ge content compared to stage Ⅱ.Additionally,the Zn/Fe ratio of stageⅠ sphalerite ranges from 32.9 to 276,while stage Ⅱ sphalerite shows a ratio between 126 and 3 183,indi-cating higher temperatures for stage Ⅰ sphalerite than stage Ⅱ.In the Wusihe deposit,Ge enrichment is notably associated with sphalerite formed at higher temperatures.The research findings suggest that the Wusihe deposit diverges significantly from SEDEX,skarn,and magmatic hydrothermal deposits in terms of trace element characteristics,tectonic environment,ore morphology,ore fabric,mineral association,and surrounding rock alteration.Instead,it closely aligns with MVT(Mississippi Valley Type)lead-zinc deposits,such as the Huize lead-zinc deposits in the Sichuan-Yunnan-Guizhou area.Consequently,the Wusihe lead-zinc deposit is categorized as an MVT lead-zinc deposit.
Wusihe depositsphaleritecharacteristics of trace elementsMVT lead-zinc depositLA-ICPMS