成都理工大学学报（自然科学版）2012，Vol.39Issue(4)：353-361,9.
下刚果盆地A区块下白垩统Albian阶沉积层序与古地理演化
Sedimentary sequence and paleogeographic evolution of Albian Stage,Lower Cretaceous in Block A of Lower Congo Basin
摘要
Abstract
Lower Congo Basin is located on the passive continental margin of West Africa. This paper studies the sedimentary facies and sequence stratigraphy of Block A, ascertains that Albian is a set of carbonate rocks mixed with terrigenous sand and mud forming in a mixed mechanism of "intermittence-cross" diamictic process. Albian can be divided into five third-order sequences in the area. The whole sedimentary and evolutionary process of the strata has undergone the sedimentary ramp→-peripheral diamictic platform→ fractured diamictic platform→deep-water diamictic continental shelf→deep sea basin (deep-water fan), corresponding to the transformation phase of the Wilson structural cycle from back-arc rift depression to continental drift. SQ2 and SQ3 sequences, the main reservoirs, are Type II sedimentary sequences of peripheral diamictic-fractured platform and each sequence can be further divided into TST and HST systems tracts. The response characteristics of sedimentary sequences and sedimentary filling of mixed siliciclastic-carbonate rock are analyzed. The sedimentary evolution model of the gang control of multiple factors including "slippage, salt arch and conversion" is established. Besides, at the SQ3 sequence stage, the fractured and diamictic platform edge shoal with a broom-like distribution and the development of vertical accretion on the top of the salt arch structure will be the most favorable microfacies in the area. By taking TST and HST systems tracts as the two mapping units, the authors draw a lithofacies paleographic map of each system tracts, discuss the distribution of the favorable reservoir facies, and then make a prediction about Albian in Block A. Finally the authors think that the superimposed platform edge shoal facies in the SQ2-HST, SQ3-TST and SQ3-HST system tracts should be the key areas in the future exploration.关键词
沉积-层序/混积碳酸盐岩/浅滩/沉积演化模式/层序-岩相古地理/Albian阶/下刚果盆地Key words
sedimentary sequence/ mixed siliciclastic-carbonate rock/ shoal/ sedimentary evolution model/ sequence-lithofacies paleogeography/ Albian/ Lower Congo Basin分类
能源科技引用本文复制引用
于水,文华国,郝立华,郝立业,程涛,郑荣才..下刚果盆地A区块下白垩统Albian阶沉积层序与古地理演化[J].成都理工大学学报（自然科学版）,2012,39(4):353-361,9.基金项目
国家科技重大专项(2008ZX05030-003-02) （2008ZX05030-003-02）
国家自然科学基金青年科学基金资助项目(41002033) （41002033）
