甘肃北山西涧泉硅灰石矿床地质特征及找矿标志

Geological Characteristics and Prospecting Criteria of Xijianquan Wollastonite Deposit in Beishan in Gansu Province

西涧泉硅灰石矿床地处塔里木陆块区(Ⅲ)—敦煌陆块(Ⅲ-2)—敦煌基底杂岩隆起(Ⅲ-2-2),属古亚洲成矿域(Ⅰ-1)—塔里木成矿省(Ⅱ-4)—磁海—公婆泉Fe-Cu-Au-Pb-Zn-Mn-W-Sn-Rb-V-U-P成矿带(III-14)—柳园—平头山加里东期华力西期印支期金铜镍铅锌钨(铁锰)钒磷、铀、钾长石成矿带(Ⅳ-14③),矿体产于晚二叠世花岗岩体与太古宇—古元古界敦煌岩群C岩组的接触带,矿区内共发现矽卡岩化带2条,圈定硅灰石矿体2条,其中Wo1号矿体长610m,平均厚度5.37m,平均品位55.95%,Wo2号矿体长900m,厚度1.79~14.32m,品位44.79%~70.28%,平均品位61.37%,赋矿岩性为石英透辉硅灰岩,顶底板围岩为大理岩,矿石具粒状变晶结构,块状构造,矿石自然类型为硅灰石—方解石—石英型矿石,矿石工业品级为陶瓷工业用硅灰石矿。根据矿区地质特征及矿石特征,该矿床类型为矽卡岩型硅灰石矿床。

Xijianquan wollastonite deposit is located in uplift of Tarim landmass(III)-Dunhuang Landmass(III-2)-Dunhuang basement complex(III-2-2).It belongs to the Ancient Asian metallogenic domain(I-1),Tarim Metallogenic Province(II-4),Cihai-Gongpoquan Fe-Cu-Au-Pb-Zn-Mn-W-Sn-Rb-V-U-P metallogenic belt(II-14),Liuyuan-Pingtoushan Caledonian Indosinian au-Cu-Ni-Pb-Zn-Tungsten(Fe-Mn)vanadium,phosphorus,uranium,potassium feldspar metallogenic belt(IV-14③),The ore body is located in the contact zone between the Late Permian granite mass and the C rock group of the Archaeoeo-Paleoproterozoic Dunhuang group.There are 2 skarn zones found in the mining area and 2 wollite ore bodies delineated.Among them,Wo1 ore body is 610m long with an average thickness of 5.37m and an average grade of 55.95%,and Wo2 ore body is 900m long with a thickness of 1.79~14.32m.With a grade of 44.79%~70.28%and an average grade of 61.37%,the ore-bearing lithology is quartz diopside limestone,the top and bottom wall rocks are marble,the ore has granuloblastic structure and massive structure,the natural type of the ore is wollastonite,calcite and quartz type,and the industrial grade of the ore is wollastonite for ceramic industry.According to the geological and ore characteristics of the mining area,the deposit type is skarn wollastonite deposit..