摘要
AN id=EnChDivSummary name="EnDivSummary">The Baiganhu W-Sn orefield,in the western part of the Qimantage mountains,eastern Kunlun orogenic belt,is the most recently discovered,large,W-Sn discovery in Xinjiang Uygur Autonomous Region,NW China.The orefield comprises four W-Sn ore deposits:Kekekaerde,Baiganhu,Bashierxi and Awaer.Of them,the Kekekaerde W-Sn deposit is largest and has highest exploration intensity.In this study,based on detailed field geological investigation,the ore-controlling structures and age determination on W-Sn ores have been carried out.The results show us that intensive and multi-stage structural activites had took place.They are,from early to late,right-lateral shear structure at pre-metallogenic stage,NE-striking predominately tenso-shear structure at metallogenic stage and nearly SN-striking normal fault at post-metallogenic stage.The 40Ar-39Ar incremental heating method was used to date,the results yield a 40Ar-39Ar plateau age of(411.7±2.6) Ma and an isochron age of(411.8±4.7) Ma with MSWD being 0.21 for muscovite separated from strongly greisenized W-Sn mineralization granite,a 40Ar-39Ar plateau age of(412.8±2.4) Ma and an isochron age of(414.6±3.9) Ma with MSWD being 0.22 for muscovite separated from quartz-wolframite vein with muscovite vertically growing along both walls of quartz vein,respectively.It is shown that the Kekekaerde W-Sn deposit was formed at late Silurian,corresponding to post-collisional stage during Caledonian tectonic cycle in eastern Kunlun area.
