水体环境对咸化湖盆沉积物分布的定量控制:以渤南洼陷沙四上亚段为例

发布时间：2018-07-29 14:57

【摘要】：咸化湖盆普遍存在着碎屑岩、碳酸盐岩、硫酸盐岩及氯化物共生的沉积现象,但多类型沉积物有序分布的机制尚不明确。渤南洼陷沙四上亚段沉积期为咸化湖盆,通过对古盐度和古水深量化,表征其多类型沉积物的分布规律,建立咸化湖盆水体分异控制模式。研究结果表明:水体盐度和深度耦合共同控制化学岩的分布,其中碳酸盐岩和硫酸盐岩分布以盐度和水深构成的斜线为界,碳酸盐岩在此线上方分布,而硫酸盐岩则主要发育在其下方,随着卤水浓度的增大在深部水体中还有氯化物沉积;水体深度对不同成因类型的碳酸盐岩以及碎屑岩分布产生影响,15 m水深是生物成因碳酸盐岩和化学成因碳酸盐岩的分界线,在其上还发育砂岩滩坝,30 m水深则是扇三角洲和近岸水下扇的分界面;模式的建立对验证沉积现象及预测沉积体具有参考价值。
[Abstract]:The sedimentary phenomena of clastic rock carbonate rock sulfate rock and chloride are common in the saline lake basin but the mechanism of orderly distribution of many types of sediments is unclear. The sedimentary period of the upper submember of Sha 4 in Bonan depression is saline lake basin. By quantifying paleosalinity and paleodepth, the distribution law of many kinds of sediments is characterized, and the control model of water body differentiation in saline lake basin is established. The results show that the distribution of chemical rocks is controlled by the coupling of salinity and depth. The distribution of carbonate rock and sulfate rock is bounded by the diagonal line composed of salinity and water depth, and the carbonate rock is distributed above this line. The sulfate rock is mainly developed under the brine, with the increase of the concentration of brine, there is chloride deposition in the deep water. The effect of water depth on the distribution of carbonate and clastic rocks of different genetic types is that the water depth of 15 m is the dividing line between biogenic carbonate rock and chemically formed carbonate rock. The 30 m water depth of sandstone beach dam is the interface between fan delta and nearshore underwater fan, and the establishment of model has reference value for verifying sedimentary phenomena and predicting sedimentary body.
【作者单位】：中国石化胜利油田分公司勘探开发研究院;
【基金】：国家重大专项资助项目(2011ZX05006)~~
【分类号】：P618.13;P343

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