徐淮地区高镁闪长岩中的角闪石和斜长石的地球化学特征及其对高镁闪长岩形成机制的制约

Mesozoic high-Mg diorites are widely distributed in the North-China Craton. Despite of the extensively mineralogical, petrologic and geochemical study of high-Mg diorites, the mechanism and geodynamic setting for their formation is highly controversial.To explore the petrogenesis of the hornblende and determine the crystallization sequence of main rock-forming minerals of high-Mg diorite at Xuhuai area, this study mainly focuses on the petrography, the mineralogy of hornblende and in-situ geochemical analysis of the hornblende and plagiocalse. The purpose of this study is to explore the initial magma composition for high-Mg diorite and the source and the depth of the initial magma and study the origin of the water in the high-Mg diorite and the pressure and temperature for the magma intrusion. The ultimate purpose of this study is to explore the mechanism for the generation of high-Mg diorite and its geodynamical significance.

中生代高镁闪长岩在华北克拉通中广泛分布，尽管前人对华北克拉通高镁闪长岩进行了大量的岩石学，地球化学和年代学研究，然而对高镁闪长岩的形成机制和地球动力学背景仍存在很大争议。本项目研究旨在，重点开展徐淮地区高镁闪长岩中的角闪石和斜长石的岩相学，矿物学和原位地球化学的研究，探讨角闪石的成因机制，确定高镁闪长岩中的主要矿物的结晶顺序。在此基础上，进一步探讨高镁闪长岩的初始岩浆的成分和源区性质及来源深度，高镁闪长岩中水的来源，岩浆的结晶时的温度和压力条件，并探讨高镁闪长岩的形成机制及其地球动力学意义。