| 内蒙古西乌珠穆沁旗阿木山组海绿石的特征及其沉积环境 |
| |
| 引用本文： | 王俊涛,张永生,宋天锐.内蒙古西乌珠穆沁旗阿木山组海绿石的特征及其沉积环境[J].岩石矿物学杂志,2011,30(2):259-266. |
| |
| 作者姓名： | 王俊涛 张永生 宋天锐 |
| |
| 作者单位： | 1. 中国地质科学院矿产资源研究所,北京,100037
2. 中国地质科学院地质研究所,北京,100037 |
| |
| 基金项目： | 中国地质调查局资源评价资助项目 |
| |
| 摘 要： | 在内蒙古西乌珠穆沁旗晚石炭世—早二叠世阿木山组第三段泥晶灰岩中发现有海绿石。对海绿石的微观特征分析表明,阿木山组海绿石呈团粒状结构,同时呈胶体产出于方解石周边,显示了原生海绿石的基本特点。电子探针的组分分析表明,阿木山组中的海绿石为高成熟度的海绿石。通过对不同地区和不同环境下海绿石的组分特征分析,建立了一种海绿石沉积的理想模式,同时揭示了阿木山组第三段海绿石化作用是在含氧量不够充分的弱还原状态下的正常浅海中进行的。本区阿木山组的下碎屑岩段和上灰岩段是在海水两进两退环境下的沉积,阿木山组灰岩中发现的海绿石则有可能代表了一个海进的开始。本区海绿石的发现及研究,对于进一步研究该区层序地层特征、地层格架及区域地层对比具有重要意义。
|
| 关 键 词： | 海绿石 西乌珠穆沁旗 阿木山组 沉积环境 |
Characteristics and sedimentary environment of authigenic glauconite from limestone of the Amushan Formation in Xi Ujimqin Banner, Inner Mongolia |
| |
| WANG Jun_tao,ZHANG Yong_sheng and SONG Tian_rui.Characteristics and sedimentary environment of authigenic glauconite from limestone of the Amushan Formation in Xi Ujimqin Banner, Inner Mongolia[J].Acta Petrologica Et Mineralogica,2011,30(2):259-266. |
| |
| Authors: | WANG Jun_tao ZHANG Yong_sheng and SONG Tian_rui |
| |
| Institution: | 1.Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;2.Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China) |
| |
| Abstract: | Glauconite is closely linked to some particular sedimentary environments and conditions. Authigenic glauconite grains were discovered in micritic limestones of 3rd Member of the Late Carboniferous-Early Permian Amushan Formation in Xi Ujimqin Banner, Inner Mongolia. Through analyzing the sedimentary environment of Amushan Formation, the authors have found that the glauconite grains commonly occur as colloids around calcite cement and assume granular structure, which are indicative of typical authigenic feature, suggesting that the glauconite grains were less influenced by later diagenesis. There are framboidal pyrites around glauconite grains, implying that the sedimentary environment of glauconite grains in Amushan Formation was probably weakly reductive. The spectral curve of glauconite in limestone of Amushan Formation demonstrates typical glauconite composition characteristics. The EPMA data indicate that they are highly mature in nature. Through a comparative study of EPMA data of glauconite samples collected from different areas and different environments (such as Cambrian glauconitic limestone in Texas of the USA, glauconitic sandstone of the Late Proterozoic Qingbaikou System in Western Hills of Beijing, authigenic glauconite grains form Cretaceous sandstone in Jixi basin of Heilongjiang, and authigenic glauconite grains from micritic limestones in Late Carboniferous-Early Permian Amushan Formation of west Ujimqin, Inner Mongolia), an ideal glauconite sedimentary environment model has been established in this paper, which shows that the authigenic glauconite grains in Amushan Formation might have benefited from the semi-closed reductive microenvironment produced by the biological clastic rock at the top of the open clastic platform and the glauconitization probably occurred in the normal shallow water of slight reduction with low-oxygen levels in the air. The sedimentary environment of the low clastic rock and upper limestone of Amushan Formation in this area was characterized by two transgressions and two regressions. The formation of glauconite in Amushan Formation may represent the beginning of the transgression. The discovery and study of glauconite in this area have an important significance in such research fields as regional correlation, tectonic evolutionary framework and regional tectonic environmental analysis. |
| |
| Keywords: | glauconite Xi Ujimqin Banner Amushan Formation sedimentary environment |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《岩石矿物学杂志》浏览原始摘要信息 |
| 点击此处可从《岩石矿物学杂志》下载免费的PDF全文 |
|
