中文摘要：

江浪穹窿位于扬子陆块西缘,核部地层为里伍岩群变质岩系,针对里伍岩群的成岩物质来源及构造背景研究所进行的岩石地球化学分析显示：（1）岩石具有高的SiO2（其质量分数为80.32%-71.76%）与Al2O3（其质量分数为12.85%-8.40%）;（2）稀土元素配分型式显示为右倾型（（La/Yb）N=12.9-7.65）,具有明显的Eu负异常（Eu/Eu＊=0.73-0.49）;（3）富集大离子亲石元素（如Rb,Ba和U等）,亏损高场强元素（如Nb,Ta,P和Ti）。原岩恢复结果表明,里伍岩群变质岩原岩均为沉积岩。综合分析认为里伍岩群变质岩的原岩物源区主要为大陆上地壳,很可能形成于Gondwana超大陆聚合之后的弧后盆地环境。弧后盆地岩浆活动带来丰富的成矿物质并形成里伍式富铜矿床初始的矿源层,同时接受陆源碎屑物质沉积形成碎屑岩系。

英文摘要：

The core strata of Jianglang dome in the western margin of Yangtze block are composed of metamorphic rocks of the Liwu Group. Geochemical studies on the Liwu Group metamorphic rocks are carried out to determine the source of rock-forming materials and tectonic setting. It shows that the metamorphic rock samples exhibit high SiO2 [w（SiO2）= 80.32% -71.76%] and Al2O3[-w（Al2O3）=12.85%-8.40%] contents with right-declined REE pattern [（La/Yb）N =12.9-7.65] and negative Eu anomalies （Eu/Eu＊ =0. 73-0.49）. these rocks enrich in large ion lithophile elements （e. g. ,Rb,Ba and U） and depletion in high field strength elements （e. g. , Nb,Ta,P and Ti）. It reveals that the protolith of the samples are all sedimentary in origin and the protolith provenance of metamorphic rocks is mainly the continental upper crust. The study also indicates that the rocks are most likely formed in a back-arc basin tectonic setting after the con- vergence of Gondwana supercontinent. Magmatic activity of back-arc basin brings about abundant ore-forming materials, forms the initial source bed of Liwu-type Cu-rich deposits, and simultaneously receives the terrigenous deposition which formed the clastic rock series.