摘要
在滇东南中三叠统拉丁阶法郎组锰矿床的矿石中一般都可以观察到鲕、豆状结构,同心环带构造。对采自这一地区的斗南、岩子脚、老乌等典型矿床的锰矿石样品进行了系统的薄片显微镜和扫描电镜观察,同时应用阴极发光技术对有代表性的样品进行了分析。根据对鲕、豆状结构矿石显微结构特征的研究发现,这些矿石中的鲕、豆状结构是蓝绿藻类微生物凝聚形成的显微叠层构造,具有核形石特有的核心和包壳,其明暗纹层相间的显微结构特征可以与现代深海大洋铁锰结核类比,初步研究结果表明,该区锰的富集可能与微生物活动密切相关。
The manganese deposit of Ladinian Falang Formation of the Middle Triassic lies in southeast Yunnan. Concentric rings structure are obviously observed in oolitic and pisolitic manganese ores. The thin sections from manganese ore samples are systematically observated from typical deposits in Dounan, Yanzijiao and Laowu. The microstructures of oolitic and pisolitic ores are described on the observation of microscope. The cathodeluminescence and SEM（scanning electron microscope） are firstly used to distinguish micro-texture changes in mm-μm scale laminar. It is suggested that these concentric laminar structures in manganese deposits are origin of blue-green algae micro-organism and similar to common oncolitic structures. They have nucleus and encrustation fabric that can be compared with present Fe-Mn nodule in modern deep ocean environment. The preliminary study results show that Mn enrichment in this region is probably relative to micro-organism activity.
出处
《地质科技情报》
CAS
CSCD
北大核心
2009年第5期78-83,共6页
Geological Science and Technology Information
基金
"十一五"国家科技支撑计划项目(2006BAB01A12-5)
关键词
锰质核形石
阴极发光
微生物成因
中三叠统法郎组
滇东南地区
manganese oncolite
cathodeluminescence
microbiogenic
Falang Formation of Middle Triassic
Southeast Yunnan
