-
摘要: 以地球化学指标为主，结合地层古生物和原生沉积构造等各方面的证据，进一步分析了鄂尔多斯盆地东部山西组的沉积环境。泥岩样品的地球化学特征表明，由于受潮汐和海侵作用的影响，整个山西期盆地东部的沉积水体以混合水为主，其中硼元素反映了基准面长期旋回的变化特征，而Sr/Ba则是超长期的变化指标；从沉积构造和海相化石分布特征可知，在山西早期中等强度的潮汐作用直接影响了研究区的东南部，对三角洲沉积进行改造，到了山西中晚期三角洲进积作用增强，潮汐作用范围逐渐退至研究区东南缘；此外，地层的分布特点和沉积相也说明在整个山西期盆地东部地层和晋西地层联片沉积且属于同一三角洲沉积体系，东部的水下隆起还不足以阻隔水体形成湖盆，所以鄂尔多斯盆地东部山西组是发育在浅海陆棚基础上的三角洲沉积。Abstract: The depositional environment was deeply analyzed in this paper by geochemical proxies, stratum and fossil distribution, and original sedimentary tectonics. The geochemical proxies in mudstone implied that tide and transgression reacted with the fresh water and mixed each other, concretely speaking, Element B implied the characteristics of longterm cycle of basic level, and Sr/Ba is a good proxy of super longterm cycle in the period of Shanxi in Eastern Ordos Basin. The sedimentary tectonics and fossil distribution indicated that the middlelevel tide has directly influenced the delta in southeastern part of the area in the early period of Shanxi, gradually the delta progradation become strong and tide evacuated to the southeastern fringe of the basin in the middle and late period. What's more, the stratum distribution and lithofacies also illuminated that the stratum in Eastern Ordos Basin and West Shanxi province belongs to the same deltasedimentary system, and the underwater dome in the east part of the area is not efficient to obstruct the flow to form the lake. Consequently, the delta in Shanxi Formation deposited in the shallowsea continental shelf.
-
Key words:
- Ordos Basin /
- Shanxi Formation /
- delta /
- shallowsea continental shelf
-
点击查看大图
计量
- 文章访问数: 1932
- HTML全文浏览量: 44
- PDF下载量: 858
- 被引次数: 0
下载:
