东南沿海中生代安山岩的地质意义

在中国东部大陆边缘中生代火山岩带中 ,东南沿海火山岩岩性岩相出露最全 ,火山地质调查研究程度较高。以往的研究主要集中于大面积酸性火山岩和与之共生的玄武岩 ,而对安山岩注意不够。作为过渡性岩类 ,安山岩的成因研究对于探讨中生代火山岩带物质来源、岩浆分异演化、大地构造背景等具有不可替代的作用。近年来在东南沿海新生代玄武岩中陆续发现了一些基性麻粒岩包体 ,为研究底侵作用与壳幔作用过程提供了珍贵的实物材料。结合基性麻粒岩包体的研究 ,进行系统的安山岩成因研究 ,对于研究中生代火山岩带成因、进而探讨东部大陆边缘形成演化动力学过程 ,具有重要意义

Geological significance of Mesozoic andesites in the coastal area of Southeast China

Among the Mesozoic volcanic belt in the continental margin eastern China, the coastal area of Southeast China has been given comprehensive geological surveys and studies, and outcrops rather complete volcanic lithologies and petrofacies are well exposed. Former studies mainly focus on large-scale acid volcanic rocks and their paragenetic basalts, and andesites have been paid less attention. In fact, the genetic studies of andesites play inestimable roles for pursuing derivatives, magmatic evolutions and tectonic settings of Mesozoic volcanic belt. Recently in the Cenozoic basalts of the coastal area of Southeast China, some mafic granulite xenoliths have been discovered in succession. They provide precious objects for studying underplating and crust-mantle interaction. Combined with studying mafic granulite xenoliths, systematic petrogenetic studies of andesites will have profound geological significance for probing into origin of Mesozoic volcanic belt, and further geodynamic processes of continental margin of eastern China.