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  

Quantitative controls in water environment to distribution of sediments in saline lacustrine basin: a case of Es4~1 in Bonan sag

作　　者：刘雅利[1] 刘鹏[1] 

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《中南大学学报（自然科学版）》2017年第1期239-246,共8页Journal of Central South University:Science and Technology

基　　金：国家重大专项资助项目(2011ZX05006)~~

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。Though clastic rock, carbonate, sulfate and chloride co-exist in saline lacustrine basin, the mechanism that multiple types of sediments are distributed orderly is not clear. Bonan sag is a saline lacustrine basin in the sedimentary period of Es41. Through quantized characterization of the paleosalinity and palaeobathymetric,distribution law of multiple types of sediments was studied. The control pattern about stratified water was established in saline lacustrine basin eventually. The results show that the coupling of paleosalinity and palaeobathymetric jointly controls the distribution of chemical sedimentary rock, and the distribution of carbonate and sulfate is divided by an oblique line coupled by paleosalinity and palaeobathymetric. The distribution area of carbonate is above this line and sulfate is mainly developed below it. With the increase of the palaeobathymetric, the chloride deposites in deep water. Water depth has effect on distribution of different types of carbonate and clastic rock. The water depth of 15 m is the dividing line between biogenic carbonate and chemical carbonate, and sand beach bar is also developed above it. Beside this, the water depth of 30 m is the dividing line between fan delta and near-shore subaqueous fan. The control pattern about stratified water has reference to verifying sedimentary phenomenon and predict sedimentary body.

关 键 词：水体分异 咸化湖盆 沉积分布 定量控制 渤南洼陷 

分 类 号：P618.130.2[天文地球—矿床学]