| 广西宁明组植物化石中黄铁矿及其沉积意义 |
| |
| 引用本文： | 马福军,吴媛欣,刘松,孙柏年,闫德飞,张凤太,王秋军.广西宁明组植物化石中黄铁矿及其沉积意义[J].沉积学报,2018,36(1):33-41. |
| |
| 作者姓名： | 马福军 吴媛欣 刘松 孙柏年 闫德飞 张凤太 王秋军 |
| |
| 作者单位： | 1.贵州师范学院地理与旅游学院&贵州省地理国情监测重点实验室, 贵阳 550018; |
| |
| 基金项目： | 国家自然科学基金项目，贵州省科技厅科技计划项目，贵州大学引进人才科研项目，贵州师范学院科研基金项目，National Natural Science Foundation of China |
| |
| 摘 要： | 对化石中的黄铁矿进行研究，有助于明确生物的化石化过程以及期间的沉积微环境。利用光学显微镜和扫描电镜，对广西宁明组植物化石中保存的黄铁矿进行了分析，发现离散型单晶和成群的莓状体共同保存。单晶绝大多数为无规则至球状体，晶棱不明显，表面可见凹点；少数为八面体，晶棱明显，表面光滑；单晶直径为0.79~1.58 μm；莓状体为圆球状，粒径为7.23~14.95 μm，S/Fe原子个数比的均值为1.54。莓状体的粒径大小和变化幅度均处于低值段，其S/Fe原子个数比值小于2，结果均说明当时植物体上、下表皮间为一种贫氧的水体环境，并在短时间内形成了莓状体。植物化石上、下表皮间由于未保存组织结构，而被大量的、近似层状分布的黄铁矿单晶和莓状体充填，结果支持了化石内莓状体形成与有机质降解之间存在着必然联系。
|
| 关 键 词： | 黄铁矿 植物化石 渐新世 沉积微环境 宁明组 |
| 收稿时间： | 2017-01-03 |
Pyrites in the Plant Fossils from the Ningming Formation,Guangxi, and Their Depositional Significance |
| |
| MA FuJun,WU YuanXin,LIU Song,SUN BaiNian,YAN DeiFei,ZHANG FengTai,WANG QiuJun.Pyrites in the Plant Fossils from the Ningming Formation,Guangxi, and Their Depositional Significance[J].Acta Sedimentologica Sinica,2018,36(1):33-41. |
| |
| Authors: | MA FuJun WU YuanXin LIU Song SUN BaiNian YAN DeiFei ZHANG FengTai WANG QiuJun |
| |
| Institution: | 1.School of Geography and Tourism & Guizhou Provincial Key Laboratory of Geographic State Monitoring, Guizhou Education University, Guiyang 550018, China;2.Geopark Administration of Qiandongnan Miao and Dong Autonomous Prefecture, Kaili, Guizhou, 556000, China;3.School of Earth Sciences, Lanzhou University, Lanzhou 730000, China;4.Guizhou Research Centre for Palaeontology & College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China |
| |
| Abstract: | The study of pyrites preserved in fossils can provide useful information on the process of organic fossilization and the depositional microcondition of these fossils. Using the light and scanning electron microscopes, we observed pyritization tissues preserved in plant fossils from the Ningming Formation, Guangxi. Pyrite textures are preserved in two forms,which are dissolved crystals and framboidal clusters. Most of crystals are of irregular to spherulitic shapes with pits on the surface and indistinct edge, whereas few are of octahedron shapes with smooth surface and distinct edge. The size of crystals ranges from 0.79-1.58 μm. Pyrite framboids are densely packed. They are spheroidal in shape and 7.23-14.95 μm in diameter. The individual crystal units of pyrite framboids have an S/Fe ratio of 0.16-2.06, with the mean value of 1.54. The ratio of S/Fe is less than the standard value 2 and thus shows a relative sulfur deficiency. The sizes of these pyrite framboids are small and vary within a narrow range. Their mean diameters fall generally within the dysoxic field. The size distribution and S/Fe ratio of pyrite framboids indicate that the intervals between the abaxial and adaxial cuticles of plant detritus had a dysoxic water microcondition during the formation of pyrites. And in this microcondition, framboids were formed rapidly in a very restrictive time span. Numerous pyrite crystals and framboids infilling the intervals between the cuticles of plant detritus also support the conclusion that the formation of pyrite framboids is in association with the decay of organic matter. |
| |
| Keywords: | |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《沉积学报》浏览原始摘要信息 |
| 点击此处可从《沉积学报》下载免费的PDF全文 |
|
