摘要
对马里亚纳海槽玄武岩斜长石和橄榄石斑晶中的熔融包裹体进行了镜下观察和均一化测温实验。镜下观察表明,斑晶中结晶质熔融包裹体和玻璃质熔融包裹体均较发育,具有不同的相态特征和演化程度,反映了岩浆被捕获处不同的地质条件。捕获在橄榄石和斜长石斑晶中的包裹体均一化测温结果分别为1035～1100℃和1050～1145℃,比利用玄武岩全岩化学成分计算的矿物结晶温度结果低100℃左右,反映了斑晶矿物结晶的多期性。根据本次实验结果,结合马里亚纳海槽的构造背景和地质资料,对研究区玄武岩浆的运移过程进行了探讨。
The microscopic observation and homogenization temperature determination experiment of melt inclusions in plagioclase and olivine in basalt phenocrysts from the Mariana Trough were made. It is shown from the microscopic observation results that the crystallized and glassy melt inclusions are well developed in basalt phenocrysts, and their characters of phase state and evolutionary degrees reflect their respective geologic conditions in which the magmas were trapped. The homogenization temperatures of melt inclusions hosted in olivine and plagioclase are 1035 to 1100 ℃ and 1050 to 1145 ℃, respectively, and the two temperatures are all about 100° lower than those calculated with the chemical components of bulk rock, which reflects the multiphase character of phenocryst mineral crystallization. Based on this experimental results and other techtonic and geologic setting information of the Mariana Trough, the transport process of basaltic magmas in the study area is discussed.
出处
《海洋科学进展》
CAS
CSCD
北大核心
2004年第3期292-298,共7页
Advances in Marine Science
基金
国家自然科学基金资助项目--北极楚科奇海沉积物中古环境地球化学代用指标研究(49873015)
国家自然科学基金资助项目--西太平洋弧后盆地海底热水活动的地球化学特征(40176017)
南京大学地球科学系内生金属矿床成矿作用实验室开放基金资助项目
关键词
马里亚纳海槽
熔融包裹体
均一温度
Mariana Trough
melt inclusion
homogenization temperature
