柴达木盆地柴西南区岩性圈闭形成及有利勘探区带划分

Formation of lithologic traps and partition of favorable exploration regions in Qaixinan area of Qaidam basin.

柴达木盆地柴西南第三系为一套拗陷湖盆沉积地层,具备形成岩性圈闭的地质条件。该区经过多期次勘探后,目前已进入以岩性圈闭为主要目标的勘探阶段。本文根据柴西南具有相对平缓沉积背景、三大物源控制沉积相带和后期构造运动剧烈的特点,通过建立等时层序地层格架,分析各时期的主要物源和沉积相展布,研究岩性圈闭形成的构造沉积背景,明确岩性圈闭发育的主要目的层段和有利勘探区带。

The Tertiary in Qaixinan of Qaidam basin is a set of depressed lake basin sedimentary strata that have geologic condition forming lithologic traps.Currently,the direction of exploration mainly is lithologic traps after many phases' exploration.In accordance with the properties of relatively flat sedimentary background,sedimentary facies controlled by three source materials and latter severe tectonic movement,the paper analyzed the main source materials and distribution of sedimentary facies in separate periods by creating isochronal sequence-stratigraphic framework,studied structural and sedimentary background forming lithologic traps and defined main litholoigic-traps-developed target strata and favorable exploration blocks.