Discovery of quartz vein-type tungsten ore body in Chaishan deposit of Shizhuyuan ore field,South Hunan and its indication for deep prospecting
The Shizhuyuan ore field in Hunan is well-known for its rich concentration of skarn-type tungsten-tin polymetallic deposits.Recent pit exploration at the Chaishan deposit has unveiled a group of newly discovered quartz vein-type tungsten ore body.The ore body intersects the early skarn,indicating a distinctly late mineraliza-tion phase.The discovery not only presents a novel clue for deep exploration in the Shizhuyuan ore field,but also offers an ideal location for investigating the genetic relationship between skarn-type tungsten ore and quartz vein-type tungsten ore in this region.This study investigates the mineral geochemistry and fluid inclusions of wolfram-ite,scheelite,and quartz in the Chaishan quartz vein-type tungsten deposit.The results show that the Chaishan wolframite displays a left-inclin distribution pattern of REE with a noticeable negative Eu anomaly,similar to the geochemical characteristics observed in the wolframite of the Yaogangxian deposit.Scheelite found within quartz veins exhibits a flat REE distribution pattern with a negative Eu anomaly,which is similar to that of skarn-type scheelite in the surrounding area.However,there is no discernible fractionation effect,and the Mo content re-mains significantly low.The Y/Ho ratio of scheelite(ranging from 6.21 to 22.35)within the same ore body signi-ficantly surpasses that of wolframite(ranging from 4.61 to 5.95),a phenomenon likely attributable to the late-stage crystallization of fluorite.The temperature and salinity of fluid inclusions within scheelite and quartz nota-bly differ from those observed in skarn-type tungsten deposits,exhibiting traits indicative of medium to high tem-peratures and medium to low salinity levels in the ore-forming fluids.Considering the findings from mineralogi-cal studies,fluid inclusions analysis,and the ore body's occurrence features,it is inferred that the Chaishan quartz vein-type tungsten deposit and the skarn-type tungsten deposit are distinct magmatic hydrothermal formations originating from disparate sources and geological stages.The ore-forming fluid associated with the quartz vein-type tungsten deposit is postulated to originate from the later stages of granitic magmatism subsequent to the em-placement of the Qianlishan biotite granite in the Shizhuyuan ore field.It is conjectured there is a late-stage mag-matic mineralization in the deeper regions of the southern section of the mining area,potentially interconnected with the quartz vein-type tungsten mineralization.It is anticipated that there exists untapped"second prospecting space"within the deeper sections of the Chaishan skarn-type ore body within the Shizhuyuan ore field.
国家科技期刊平台
NSTL
万方数据
