| 摘要: |
| 在上扬子台地早三叠世嘉陵江组的白云岩中,产有一种呈"针状"、"板柱状"、"麦粒状"或"树枝状"等形态的不同于常见沉积白云石的特形白云石。本文借鉴国外近年来在特形方解石方面的研究成果,提出特形白云石是由类似形态的特形方解石经白云石化作用假像交代而成,因而它同特形方解石一样,可以指示沉积及成岩环境,具有大气渗流、介质溶液过饱和及微生物强烈参与等特点。 |
| 关键词: 特形白云石|假像交代|上扬子台地|三叠系|指相意义 |
| DOI： |
| 附件 |
| 投稿时间：1995-04-25 |
| 基金项目: |
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| CHARACTERISTIC DOLOMITE IN THE TRIASSIC CARBONATE ROCKS ON THE UPPER YANGTZE PLATFORM AND ITS SIGNIFICANCE |
| Zhu Jingquan |
| (Institute of Geology, Chinese Academy of Sciences) |
| Abstract: |
| A new type of dolomite,which is called characteristic dolomite in this paper owing to its abnormal morphologies of "neelde", "tabular-prismatic", "wheat" or "dendritis" forms, occurs on a wide range of scales in the fourth member of the Trassic Jialinjiang Formation on the Upper Yangtze Platform. Unlike the normal sedimentary dolomite,the dolomite may be formed by pseudomorphous replacement of fibrous and dendritic calcite as a result of the similarity both in morphologies and intergrowth patterns. The occurrence of the characteristic dolomite indicates that sedimentary and/or diagenetic environments are characterized by meteoric vadose,medium fluids supersaturated with respect to calcite,and plentiful micro-organisms,which created some conditions suitable for the growth of characteristic calcite and dolomite. |
| Key words: characteristic dolomite|pseudomorphic replacement|Upper Yangtze platform|Triassic|facies significance |
