中国东南部处于扬子地块、印度板块和太平洋板块的中间地区,位于亚洲东部大陆边缘的最南段,是中生代以来欧亚板块与太平洋板块相互作用非常活跃的区域.本文通过对产在活动大陆边缘的福州复式岩体的花岗岩类中的锆石进行LA-ICP-MS U-Pb定年,得到早期的涧田花岗闪长岩、中期的丹阳二长花岗岩一福州钾长花岗岩和晚期的魁歧晶洞碱性花岗岩年龄分别为110Ma、100～107 Ma、95 Ma,属于燕山晚期,相当于早白垩世中晚期.说明产在活动大陆边缘的福州复式岩体,从早期的钙碱性Ⅰ型花岗岩,到晚期的碱性A型花岗岩,其侵位时间相应从早白垩世中-晚期到晚白垩世早期.表明福州复式岩体岩浆作用的时间持续了15Ma.%Southeast China, located at the interior part of Yangtze block, Indian plate and Pacific plate and the southmost of the continental margin of Eastern Asian, has been most active region due to interaction between Eurasian plate and Pacific plate since the Mesozoic. LA-ICP-MS U-Pb dating of zircons from the granitoids of the Fuzhou compound complex in the active continental margin yields an age of HOMa for the early Jiantian granodiorite, an age of 100~107 Ma for the mid-stage Dangyang monozonitic granite, and an age of 95 Ma for the late-stage Kuiji alkaline granite. All these data suggest they formed in a Yanshanian epoch, equivalent to mid- ot late Late Cretaceous. These data indicate that the Fuzhou compound complex evolved from early calci-alkaline I-type granite to late alkaline A-type granite, and correspondingly, emplacement lasted from mid- and late Early Cretaceous to early Late Cretaceous. Our research shows that magmatism of the Fuzhou compound complex had been active for at least 15 Ma.
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