摘要
对东太平洋表层沉积物的扫描电镜观察表明 ,样品中除陆源碎屑和生物壳体外 ,存在着一组特征性的石英 钠长石 重晶石自生矿物组合。它们均呈完好自形晶 ,显然未经历过明显的搬运 ,都是原地形成的自生矿物。X射线衍射分析进一步确认了这组矿物的存在。迄今为止自生钠长石主要见于埋深较大的储层砂岩 ,其结晶温度不低于70℃ ,是一种典型的热水成因矿物。而同样完整晶形的重晶石曾在加利福尼亚湾Guaymas盆地被发现 ,并被确认属热水成因。作者据此认为 ,存在于东太平洋表层沉积物中的自生石英 钠长石 重晶石属于热水矿物组合。这意味着在远离洋中脊的大洋盆地亦有一定规模的热水活动 ,它对深海成矿作用和全球环境。
XRD analyzing on the surface sediments from the East Pacific found that there is an identical assemblage of quartz, albite and barite in most samples. Under SE an euhedral crystal structure appears in the most samples, which shows that they have been without considerable transpartatin and can be regarded as authigenic minerals in situ.Up to now, authigenic albite is mainly found in reservoir sandstone in great depth, with a crystalline temperature above 70 ℃. Barite with similar idiomorph has been reported in the Guaymas Basin, California, and been confirmed with hydrothermal origin. For these reasons, the authors believe that the authigenic quartz albite barite found in the surface sediment from East Pacific is a typical thermal water assemblage. This means that in the ocean basin far away from the mid ocean ridge there is thermal water activities with certain scale, which may have some impacts on the global environment, especially the long cycle climate changes.
出处
《海洋科学》
CAS
CSCD
北大核心
2001年第12期27-30,共4页
Marine Sciences
基金
中国大洋协会DY95 06 03课题
国家973计划资助项目2000078500号
