中文摘要：

金山复式岩体位于福建南部华安县和南靖县交界地区,为一燕山晚期的花岗质复式大岩基,由早白垩世早期的华安洋竹径单元（锆石U-Pb年龄为140.3±1.2Ma）和早白垩世晚期的南靖龙山单元（锆石U-Pb年龄为105.1±0.8Ma）组成。复式岩体东部的洋竹径单元主体岩性为中粒钾长花岗岩,在中心部位发育部分黑云母花岗岩,地球化学特征上,该单元岩石总体为弱过铝质（A/NKC值变化于1.00～1.05）,富硅,碱含量中等（K2O＋Na2O介于8.30%～8.84%）,碱铝指数（AKI值）变化于0.80～0.90,富钾（K2O含量变化于4.59%～5.58%,K2O/Na2O值介于1.18～1.95）,富轻稀土和大离子亲石元素（如Rh、Th等）,贫Ba、Sr、Ti、P,Rb/Sr值高,具中到强的铕负异常。复式岩体西部的龙山单元主体岩性为黑云母二长花岗岩,与洋竹径单元相比,其硅、碱含量及Rb/Sr值均相对偏低,轻重稀土比值更高,而铕负异常相对不明显。复式岩体各单元岩石的Ga/Al值以及Zr、Nb、Ce、Y等高场强元素含量较之典型的A型花岗岩均偏低,综合地质地球化学资料指示该复式岩体应属高钾钙碱性I型花岗岩。洋竹径单元黑云母花岗岩和钾长花岗岩具有一致的Nd同位素组成,εNd（t）值分别为-1.13和-1.16～-1.94,表明它们具有相同的岩浆源区,二者应为同源岩浆经分异演化的产物。龙山单元的成岩年龄明显晚于洋竹径单元,二者有约35Ma的成岩时差,且该单元的岩石学和元素地球化学特征与洋竹径单元存在较明显的差别,相关的元素演变趋势表明两单元岩石不可能为同一原始岩浆分异演化所形成,而应是不同岩浆事件的产物。综合分析表明,金山复式岩体极可能是在弧后伸展背景下,由于持续的幔源岩浆底侵作用导致早期底侵物质（初生地壳）与古老基底地壳混合的地壳原岩叠次熔融复合的产物。

英文摘要：

The Jinshan composite pluton, a large Late Yanshanian granitic batholith, is located in the borderland between Hua＇an and Nanjing Counties, southern Fujian Province. It can be divided into two units, the Yangzhujing （YZJ） unit in Hua＇an and the Longshan （LS） unit in Nanjing. Zircon LA-ICP-MS U-Pb dating yields an age of 140. 3±1. 2 Ma for YZJ unit and an age of 105. 1±0. 8 Ma for LS unit. Lithologically, the YZJ unit in the east part of the composite pluton consists mainly of medium-grained moyites and small biotite granites in its central part. Geochemically, the granites of the YZJ unit have high SiO2 （= 73. 72% - 76. 06%） and moderate Al2O3 （= 12. 70% - 13. 52%） contents. They are weakly peraluminous with A/NKC values ranging from 1.00 to 1.05, and have moderate alkaline contents （K2O＋ Na2O=8.30% 8.84%, AKI=0.80-0.90） but high potassium abundances （K2O=4.59-5.58%,K2O/ Na2O=1. 18-1.95）. The rocks are also rich in LREE and LILE （e. g. , Rh, Th） and poor in Ba, St, Ti, P, and show high Rb/Sr ratios （1.55-12.24）. Chondrite-normalized REE distribution patterns of them display moderate to strong negative europium anomalies （δEu=0.11-0.52）. The LS unit in the west part of the composite pluton is homogeneous and comprises predominantly of biotite adamellites. Compared with the YZJ unit, the LS biotite adamellites show lower contents of SiO2 and K2O＋Na2O, lower Rb/Sr ratios, but higher LREE/HREE ratios, and display weak negative europium anomalies. In comparison with the representative A-type granites, all the granites of the Jinshan composite pluton have lower Ga/Al ratios and HFSE （e. g. , Zr, Nb, Ce, Y） concentrations. Integrated geological and geochemical data suggest that the rocks are genetically of high-K calc-alkaline I-type granites. The biotite granites and moyites in the YZJ unit display consistent Nd isotopic compositions, with εNd（t） values of -1. 13 and -1.16- -1. 94 respectively, indicating that they were originated from a common source via fraction