CAJ | 학술논문

北部湾盆地乌石凹陷流沙港组油页岩具有良好的生油潜力，但由于其发育条件和空间分布不清，造成生烃潜力评价存在困难。为此，在油页岩地化特征评价的基础上，对乌石凹陷和涠西南凹陷流沙港组油页岩发育的古湖泊学特征及主控因素开展了对比分析。研究结果认为，在流沙港组油页岩沉积时期，湖泊藻类爆发性繁盛，为油页岩的形成提供了充足的物质条件；而较强的水体还原环境为有机质提供了良好的保存条件；不同的古湖泊演化历史，导致了乌石凹陷和涠西南凹陷流沙港组油页岩发育特征和空间分布存在差异。乌石凹陷内部较为复杂的构造沉降和沉积古地貌、分割性沉积水体，是流沙港组油页岩发育与分布规律性不强的根本原因。
북부만분지오석요함류사항조유혈암구유량호적생유잠력，단유우기발육조건화공간분포불청，조성생경잠력평개존재곤난。위차，재유혈암지화특정평개적기출상，대오석요함화위서남요함류사항조유혈암발육적고호박학특정급주공인소개전료대비분석。연구결과인위，재류사항조유혈암침적시기，호박조류폭발성번성，위유혈암적형성제공료충족적물질조건；이교강적수체환원배경위유궤질제공료량호적보존조건；불동적고호박연화역사，도치료오석요함화위서남요함류사항조유혈암발육특정화공간분포존재차이。오석요함내부교위복잡적구조침강화침적고지모、분할성침적수체，시류사항조유혈암발육여분포규률성불강적근본원인。
Oil shale in the Liushagang Formation of Wushi sag has great potential for oil generation.However,it remains difficult toevaluate the oil shale’s potential for hydrocarbon generation due to a lack of knowledge regarding its developmental condition andspatial distribution.Based on geochemical characteristic analysis,a comparative study is carried out on the paleolimnological charac-teristics and major controlling factors for the development of oil shale in Liushagang Formation between Wushi sag and Weixinansag.Results show that in the depositional period of oil shale of the Liushagang Formation,planktonic algae thrived explosively andprovided adequate material condition for oil shale formation,whereas the strong reducing environment was favorable for conservingorganic matter.Different paleolimnological evolution resulted in various characteristics of oil shale development and distribution inthe Liushagang Formation of Wushi sag and Weixinan sag.Then it is concluded that complex tectonic subsidence,depositional pal-eotopography and disjunctive water body in Wushi sag were fundamental causes for the complex characteristics of oil shale develop-ment and distribution in the Liushagang Formation.