北秦岭松树沟铬铁矿床三维地质建模及其找矿意义  

3DGeologic Modeling of Songshugou Chromite Deposit in North Qinling and Its Prospecting Significance

作　　者：仇东东[1] 焦建刚[1] 姜建超 徐翠玲[1] 李宪甫[3] 李飞[3] 

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]陕西省国土资源资产利用研究中心,陕西西安710075 [3]中国人民武警黄金第五支队,陕西西安710100

出　　处：《地球科学与环境学报》2014年第1期210-217,共8页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41072058);陕西省科学技术研究计划项目(2012kjxx-38);陕西省国土资源厅科技攻关项目(陕国土资勘函[2013]67号)

摘　　要：北秦岭松树沟超镁铁质岩体位于商丹缝合带北侧、北秦岭构造带南部边缘,是陕西省出露面积最大的超镁铁质岩体,岩体中赋存了小型铬铁矿床,深部是否具有成矿潜力备受关注。松树沟超镁铁质岩体中岩相呈对称分布,结合钻孔与物探资料,推测岩体呈透镜状产出;岩石地球化学数据显示岩体中部橄榄岩相具有变质橄榄岩或阿尔卑斯橄榄岩特征,边部橄榄岩相具有超镁铁质堆晶岩特征;松树沟与西藏罗布莎纯橄榄岩体中铬铁矿的矿物地球化学特征类似,由此提出松树沟超镁铁质岩体具有形成"豆荚状"和层状铬铁矿体的潜力。基于前期勘探获得的343个钻孔资料,通过3DMine软件建立了矿床的三维地质模型,剖析了矿体分布规律、钻孔控制程度、富矿与贫矿赋存部位等。根据贫矿的富集部位、流动构造、岩浆分异程度、化探异常,预测了2个具有深部找矿潜力的地段,并提出了找矿标志与找矿方法,为本区勘查找矿提供思路。Songshugou ultramafic intrusion,which is located in the northern side of Shangdan suture zone and the southern edge of North Qinling orogenic belt,has the largest outcrop in Shaanxi Province;the ultramafic intrusion hosts small chromite deposit,and the metallogenetic potential at the lower part of intrusion is largely concerned.Combined with drilling holes and geophysical exploration, distribution of petrofacies is symmetrical in Songshugou ultramafic intrusion,the shape of intrusion is supposedly lentoid;based on petrogeochemistry data,the peridotite pertrofacies in the middle have the characteristics of metamorphic peridotite or Alpine peridotite,the peridotite petrofacies in the edge have the characteristics of ultramafic cumulate;the mineralogy and geochemistry characteristics of chromite in Songshugou are similar to that of Luobusha dunite in Tibet,so that Songshugou ultramafic intrusion has the potential to develop “podiform”and layered chromites.According to the 343 drilling loggings of early exploration,a 3D geologic modeling of Songshugou chromite deposit was built by 3DMine software,and the distribution regularity of ore bodies,controlling degree of drilling holes and locations of rich and poor ores in the intrusion were discussed by 3D geologic modeling.According to the enrichment of poor ore,flow structure,magmatic differentiation and geochemical anomaly,two metallogenic areas with higher potential of deep prospecting were put forward,and prospecting marks and methods were summarized in order to provide a new thought for the exploration and prospecting in Songshugou area of North Qinling in future.

关 键 词：铬铁矿 三维地质建模 3DMine软件 矿床成因 找矿标志 成矿预测 北秦岭 

分 类 号：P618.33[天文地球—矿床学] P618.31[天文地球—地质学]