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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 copper (molybdenum) deposit is located in the southeastern ore-hosting area in the middle and lower reaches of the Yangtze River, and its metallogenesis is closely related to the Tongshankou granodiorite porphyry. A detailed geochemical study of granodiorite porphyry bodies has been carried out. The study shows that the rocks are enriched in large ion lithophile elements and depleted in high field strength elements, which are quasi-aluminum and high-K calc-alkaline series, The geochemical characteristics of the metamorphic rocks are high Si O2 and Al2O3, high Sr, low Y and Yb and high Sr / Y ratio and (La / Yb) N ratio. Enriched LREE, with weak Eu negative anomaly. Compared with typical adakites, Tongshankou intrusions have lower contents of Mg #, MgO, Cr, Ni and higher K2O content. The study suggests that the formation temperature of the Tongshankou granodiorite porphyry is high (985-1000 ℃), the pressure is> 1.2 GPa and the depth is> 40 km, which is the product of partial enrichment of the mantle. During the diagenesis, the crust may have experienced the crust Contamination and the separation and crystallization of ferromagnes (AFC). About 5% of the lower crustal materials participate in magmatic formation.