新疆西准噶尔苏云河钼矿含矿岩体重力异常特征及其地质意义

Gravity Anomalies of Ore-Bearing Rock Masses in the Suyunhe Molybdenum Deposit of West Junggar,Xinjiang and Their Geological Significance

近年来,新疆西准噶尔巴尔鲁克地区发现的苏云河钼矿、加曼铁列克得铜矿、石屋铜金矿等斑岩型矿床,为研究巴尔喀什斑岩型成矿带是否延伸至我国新疆西准噶尔一带提供了新的研究方向。其中苏云河钼矿是该区最大的斑岩型矿床,赋矿岩体为二长花岗斑岩,目前对于该含矿斑岩体的空间形态及规模认识不足。本文以西准噶尔巴尔鲁克山一带区域重力为研究对象,针对苏云河钼矿含矿岩体开展重力三维反演,从构造环境、含矿岩体、成矿年龄等方面对比分析苏云河钼矿与哈萨克斯坦阿克斗卡铜矿的相似性。结果表明,苏云河含矿斑岩体深部最长约9.4 km,最宽约3 km,垂向延伸超过2.2 km,直观展示了苏云河含矿岩体的规模及空间形态,巨型岩体的存在表明深部仍有广阔的找矿空间。此外,巴尔鲁克山一带的重力场反映了西准噶尔洋残余盆地的特征,证实该区在晚石炭世处于俯冲拉伸相关的岛弧环境,为哈萨克斯坦巴尔喀什成矿带向东延伸到我国新疆西准噶尔一带提供了地球物理证据。

The recently discovered Suyunhe molybdenum deposit,Jiamantieliekede copper deposit,Shiwu copper-gold deposit and other porphyry deposits in the Baerluke area of west Junggar provide new research direction with respect to whether the Baerkashi porphyry metallogenic belt extends to west Junggar of China.The Suyunhe molybdenum deposit is the largest porphyry deposit in this area,and the orebodies are hosted in monzonite porphyry.At present,the spatial shape and scale of the ore-bearing porphyry have not been well understood.Focusing on the regional gravity in the Baerluke area of west Junggar,this work conducted three-dimensional gravity inversion of the ore-bearing rock mass in the Suyunhe molybdenum deposit,and analyzed the similarities with the Akedouka copper deposit in Kazakhstan from the aspects of tectonic environment,ore-bearing rock mass and metallogenic age.Results show that the Suyunhe ore-bearing porphyry is about 9.4 km at depth,and is about 3 km wide,with vertical extension of more than 2.2 km.This directly displays the scale and spatial morphology of the Suyunhe ore-bearing porphyry.The existence of the giant rock mass indicates a large prospecting potential in the deep.In addition,the gravity field in the Baerluke area reflects the residual basin characteristics of the west Junggar Ocean.It is confirmed that this area was under an island arc environment related to subduction and stretching during the Late Carboniferous.The result provides geophysical evidence for the eastward extension of the Baerkashi metallogenic belt in Kazakhstan to west Junggar in Xinjiang,China.