鄂东南矿集区铜山口侵入体地球化学特征及其成因研究  

Study on Geochemical Characteristics and Genesis of Tongshankou Intrusion,Southeastern Hubei Province

作　　者：刘坤[1] 王敏芳[1] 李喆明 魏克涛 王帅[1] 郭晓南[1] 王伟[1] 江兵 杨晓声 

机构地区：[1]中国地质大学(武汉)资源学院,湖北武汉430074 [2]湖北省地质局第一地质大队,湖北黄石435000 [3]大冶有色铜山口公司,湖北黄石435000

出　　处：《资源环境与工程》2016年第1期25-33,共9页Resources Environment & Engineering

基　　金：国家自然科学基金面上基金项目(编号:41272097);中国地质大学(武汉)教学实验室开放基金项目(SKJ2015010)资助

摘　　要：铜山口铜（钼）矿床位于长江中下游成矿带鄂东南矿集区,成矿作用与铜山口花岗闪长斑岩体密切相关。对花岗闪长斑岩体进行了详细的地球化学研究,研究显示,岩石富集大离子亲石元素,亏损高场强元素,为准铝质、高钾钙碱性系列,具有埃达克质岩的地球化学特征：高Si O2和Al2O3,高Sr,低Y、Yb,具有较高的Sr/Y比值和（La/Yb）N比值。富集LREE,具有微弱的Eu负异常。与典型的埃达克岩相比,铜山口侵入体具有较低的Mg#以及Mg O、Cr、Ni含量,具有较高的K2O含量。研究认为,铜山口花岗闪长斑岩形成温度较高（985~1 000℃）,压力〉1.2 GPa,深度〉40 km,是富集地幔部分熔融的产物,在成岩过程中可能经历了地壳混染以及铁镁质物质分离结晶作用（AFC）,约5%下地壳物质参与岩浆形成。The Tongshankou die-lower reaches of Yangtze associated with Tongshankou Cu （Mo） deposit,located in southeastern Hubei district of metallogenic belt along the mid- River, eastern China,is a typical skarn-porphyry composite deposit. Mineralization is closely granodiorite and Lower Triassic marine carbonates. In this paper,the authors report major, trace and rare earth elements of the ore-relate Tongshankou granodiorite. The trace elements are characterized by enrich- ment of LILE, depletion of HFSE. The study shows that the rocks are metaluminous and high-K calc-alkaline, and have geochemical characteristics of adakitic affinity：with high SiO2, A1203and Sr contents,low Y and Yb contents, high Sr/Y and （La/Yb）N ratios. The REE characteristics are LREE enriched, and lack any significant negative Eu anomaly. Com- pared with typical adakites, Tongshankou intrusive rocks had lower Mg^#, MgO, Cr,Ni content and higher K20 content. These data suggested that Tongshankou granodiorite was formed at higher temperature （985 -1 000℃ ）and pressure （ 〉 1.2 GPa） ,which were mainly derived from partial melting of an enriched mantle source that possibly experienced signifi- cant contamination of lower crust materials and fractional crystallization of marie minerals in the course of the diagenesis （AFC）, nearly 5 percent lower ernst materials oarticioated in the forming of magma.

关 键 词：铜山口侵入体 花岗闪长斑岩 地球化学 

分 类 号：P59[天文地球—地球化学] P588.121[天文地球—地质学]