| 从氧、碳同位素组成看蓟县元古宙碳酸盐岩特征 |
| |
| 引用本文： | 赵震.从氧、碳同位素组成看蓟县元古宙碳酸盐岩特征[J].沉积学报,1995,13(3):46-53. |
| |
| 作者姓名： | 赵震 |
| |
| 作者单位： | 中国地质科学院天津地质矿产研究所 天津 300170 |
| |
| 摘 要： | 蓟县元古宙碳酸盐岩出露广袤，厚度巨大，产状稳定，化石丰富，沉积形象众多。其内赋含的氧、碳同位素组成及其数值变化对成岩机制及沉积环境仍然蕴含着较清楚的内函关系。依据其数值演化，探讨了蓟县碳酸盐岩的成岩作用、古盐度，进而结合其沉积环境特征，阐释了碳酸盐岩，更主要是白云岩为原生沉积所成。
|
| 关 键 词： | 氧、碳同位素 碳酸盐岩 元古宙 蓟县 |
| 收稿时间： | 1994-06-16 |
Characteristics of Proterozoic Carbonate Rocks in Jixian by Means of the Oxygen and Carbon Isotope Composition |
| |
| Institution: | Tianjin Institue of Geology and Mineral Resources, Tianjin 300170 |
| |
| Abstract: | The Middle-Upper Proterozoic Eon in Jixian County, Tianjin, is a sedimentary series measured for 3000m in thickness. The middle- ower part of which is mainly composed of primary sedimentary dolostone, while the upper Part mostly of limestone. Seventeen dolostone and calcite samples were selected to determine the oxygen and carbon isotope in order to analyse the diagenesis and paleosalinity, then to discuss the genesis of the dolomite accumulated there 1) DiagenesisWhen plentiful rains fare present on land-surface, a vadose zone, where the 18O.12C Contents would be plantiful would appear. Yangzhuang Formation shows larger negative values of δ18O and δ13C. From these analytic data, it can be seen that the carbonate rocks of Yangzhuang Formation and Tuaneshanzi Formation have a δ13C Value of -3.53‰, and the other δ13C value of carbonate rocks of stratigraphic formations varies in the range from+1‰, to-1‰, The δ18O value has the similar changes. It is interesting in Wumishan FOrmation that the oxygen and carbon isotopes of carbonate rocks in sedimentary micro factes reflect that fresh water perticipated in the course of diagenesis, and from this point of view it can be seen that greater part of carbonate rocks of the Upper-Middle Proterozoic in Jixian is of primarily sedimentary origin.2) Paleosalinity The value of δ18O in seawater is increasing with the increase of salinity, and the δ18O value may be applied as an indicator for peleosalinity. The increase of its value may reflect the augment o f Paleosalinity. The carbonate rocks of Wumishan Formation may reflect such a change that indirectly shows the primary depositional properties of dolostone in situ, this may provide the quantitative signs for sedimentary factes. |
| |
| Keywords: | |
| 本文献已被 CNKI 维普 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 |
|
