碱性A型花岗岩与铝质A型花岗岩成因联系：以福建沿海魁岐岩体为例

华南东南沿海分布有大量晚白垩世早期A型花岗岩，包括碱性A型花岗岩和铝质A型花岗岩，是我国东部晚中生代A型花岗岩带的重要组成部分。前人对这些A型花岗岩的成因做过很多研究，但碱性A型花岗岩和铝质A型花岗岩的成因联系还存有争议。我们的研究发现福建沿海魁岐岩体同时发育碱性A型花岗岩和铝质A型花岗岩，是研究碱性A型花岗岩和铝质A型花岗岩成因联系的理想岩体。本项目选择魁岐岩体为例，拟在野外地质填图和室内岩相学观察的基础上，对碱性A型花岗岩和铝质A型花岗岩进行系统的含U副矿物(锆石、榍石、独居石和磷灰石)U-Pb年代学、原位微区微量元素和Sr-Nd-Hf-O同位素的研究，结合全岩主微量元素和同位素数据，查明碱性A型花岗岩和铝质A型花岗岩的形成时代、岩浆源区和成岩过程，建立碱性A型花岗岩和铝质A型花岗岩的成因联系，反演碱性A型花岗岩和铝质A型花岗岩形成的地球动力学机制。

The early Late Cretaceous A-type granites, including alkaline A-type granites and aluminous A-type granites, are widespread in the coastal area of southeast China, forming an important A-type granitoids belt in east China. Those A-type granites have been studied for a long time, but the genetic relationship between the alkaline A-type granites and aluminous A-type granites are still problematic. The Kuiqi batholith in the coastal area of southeast China is a well-known A-type granite. Our recent work has identified both alkaline A-type granites and aluminous A-type granites in this batholith. Thus, the Kuiqi batholith is an ideal case to study the genetic relationship between the alkaline A-type granites and aluminous A-type granites. In this study, we plan to make detailed mapping and petrographic observation for the Kuiqi batholiths. In addition, in-situ U-Pb ages, in-situ trace elements and Sr-Nd-Hf-O isotopes, and whole-rock major and trace elements and isotopic data will be obtained for the alkaline A-type granites and aluminous A-type granites, respevtively. These works aim to constrain the ages and petrogenesis of the A-type granites; and, on this basis, to understand the genetic relationship between alkaline A-type granites and aluminous A-type granites and to further explore rock-forming tectonic background.