陕西勉略宁地区旧房梁金矿床元素地球化学特征及成矿意义

发布时间：2018-03-13 22:30

本文选题：旧房梁　切入点：微量元素　出处：《地质科技情报》2017年02期 　论文类型：期刊论文

【摘要】：选取一个含金采样剖面,对旧房梁金矿床的成矿流体性质和成矿物质来源进行了探讨。研究结果表明,旧房梁金矿床产于陕西勉略宁三角地区中新元古界碧口群,矿体的分布和产状受地层岩性和韧性剪切带的强烈控制,矿床成因类型为绿岩型金矿床。对矿石及其顶底板围岩的主微量元素和稀土元素地球化学特征及其成矿作用的研究表明:与Au含量正相关性较好的元素有Ag、Hg、Bi、Mo;在成矿过程中,矿石和围岩的Al_2O_3、TFe_2O_3及高场强元素含量较稳定;大离子亲石元素含量在矿石及矿体底板围岩中相对亏损,在矿体顶板围岩中富集;亲硫元素含量表现较为复杂,Pb含量在矿体顶板围岩及氧化矿石中富集,Mo、Hg含量在矿石中普遍升高;同时伴随岩石质量的亏损;稀土元素配分模式显示矿石及近矿围岩相对于远矿围岩具有正Ce异常和负Eu异常的特征。上述特征均表明成矿流体具有高温还原性的特点。结合矿床流体包裹体和硫同位素等特征,认为该矿床的成矿物质来源可能与碧口群地层有关,其成矿过程可能与澄江期在区内广泛形成的NNE向韧性剪切变形有关,构造矿化蚀变对围岩物质组分具一定继承性和差异性。
[Abstract]:A gold bearing sampling section is selected to study the ore-forming fluid properties and the source of ore-forming materials of the old Fangliang gold deposit. The results show that the Jiufang Liangliang gold deposit occurred in the Bikou Group of the Neoproterozoic in the Mianliuning Triangle area, Shaanxi Province. The distribution and occurrence of orebodies are strongly controlled by stratigraphic lithology and ductile shear zones. The origin of the deposit is greenstone type gold deposit. The geochemical characteristics and mineralization of main trace elements and rare earth elements in ore and its surrounding rock of roof and bottom plate are studied. The contents of Al _ 2O _ 3T _ Fe _ 2O _ 3 and high field strength elements in ore and surrounding rock are relatively stable, and the content of large ion lithophile elements is relatively depleted in the rock mass of ore and orebody floor, and is enriched in the surrounding rock of orebody roof. The content of sulfur-lipophilic elements shows that the content of Pb is more complex and the content of Mo-HG is generally increased in the roof surrounding rock and oxidized ore with the loss of rock quality. The REE distribution model shows that the ore and the surrounding rock near the ore have the characteristics of positive ce anomaly and negative EU anomaly compared with those of the distant ore surrounding rock. The above characteristics indicate that the ore-forming fluid has the characteristics of high temperature reduction. Combined with the fluid inclusions of the ore deposit, the ore-forming fluid inclusions have the characteristics of high temperature reduction. And sulfur isotopes, It is considered that the ore-forming source of the deposit may be related to the formation of Bikou Group, and the metallogenic process may be related to the NNE ductile shear deformation formed widely in the area in Chengjiang period. The structural mineralization alteration has certain inheritance and difference to the material composition of surrounding rock.
【作者单位】：国家海洋局第二海洋研究所国家海洋局海底科学重点实验室;中国地质大学(武汉)地质过程与矿产资源国家重点实验室;中国地质大学(武汉)资源学院;
【基金】：陕西省地质矿产勘查开发局地质勘查及科研专项基金项目(陕地财发[2009]34号)
【分类号】：P618.51

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