辽河盆地东部凹陷中段深层沙河街组沉积相  

SEDIMENTARY FACIES OF THE SHAHEJIE FORMATION IN DEEP ZONE OF MIDDLE AREA OF EAST DEPRESSION IN LIAOHE BASIN

作　　者：回雪峰[1] 管守锐[1] 张凤莲[2] 谢庆宾[1] 

机构地区：[1]石油大学,北京102249 [2]辽河油田分公司研究院,辽宁盘锦124010

出　　处：《古地理学报》2003年第3期291-303,共13页Journal of Palaeogeography：Chinese Edition

摘　　要：辽河盆地东部凹陷中段深部地层中的古近系沙河街组由沙一段、沙三段构成 ,缺失沙二段和沙四段。由于沙一段沉积学研究已相当深入 ,而沙三段还未进行过系统沉积学研究 ,因此本文中重点研究了沙三段。沙三段可以划分为上、中、下三个部分。通过碎屑岩稳定重矿物指数、碎屑岩岩石磁组构中剩余磁化率、岩性等分析发现其主要物源区为中央凸起。孢粉组合、岩性等分析表明其沉积时的古气候为温暖潮湿气候。古生物组合分析证实其沉积时水体南深北浅 ,水质南咸北淡。研究区内存在冲积扇、曲流河、扇三角洲、湖泊等相类型。沙三段下部沉积时期 ,推测盆地开始进入裂陷期 ,发育冲积扇 -浅湖 -半深湖沉积体系。沙三段中部沉积时期 ,湖盆扩张达到最大 ,成为湖盆发育的欠补偿时期 ,发育了扇三角洲 -湖泊沉积体系。沙三段上部沉积时期 ,水体变浅 ,逐渐从水下完全过渡到陆上 ,碳质泥岩及煤层发育 ,形成冲积扇 -河流沉积体系。在此基础上通过分析油源条件、砂岩储集体发育情况 ,指出西侧欧 35井区到欧 39井区及铁 5井区到铁 2井区具有较为优越的成藏条件 ,为本区的有利勘探地区。The Shahejie Formation of the Paleogene in the deep zone of the middle area of the East Depression in Liaohe Basin is made up of its Member 1 and Member 3 and lacks its Member 2 and Member 4. In this paper, the Member 3 is discussed, because its Member 1 has been studied well and the Member 3 has not been studied yet. The Member 3 of Shahejie Formation can be divided into 3 parts,i.e.upper(S1 3), middle(S2 3) and lower(S3 3). Its main material supply area can be found in the central uplift by analyzing ZTR index, detrital remanent magnetization and lithology. The sporopollen assemblage and lithology show that the Member 3 of the Shahejie Formation was deposited in humid climate. The analyzing result of paleontology has proved that water in the south was deeper and more saline than that in the north while Shahejie Formation was deposited. Under this depositional setting, alluvial fan, river, fandelta and lake facies are developed. It is inferred that the basin began to depress while S 3 3 was deposited. Alluvial fan-shallow-deep lake depositional system was formed at that time. While S 2 3 was deposited, the lake reached its maximum area. That epoch was the under-compensation stage of the lake. Fandelta-lake depositional system was developed. While S 1 3 was deposited, the depth of the lake became smaller and smaller. Finally, the study area turned to be land. Carbonaceous mudstone and coal layer were developed. Alluvial-river depositional system was developed. With this understanding, it is pointed out that the area from Well Ou 35 to Well Ou 39 and the area from Well Tie 5 to Well Tie 2 are the main exploration targets by analyzing the source of oil and reservoir.

关 键 词：辽河盆地 深层 沙河街组 沉积相 东部凹陷 石油地质 

分 类 号：P618.130.1[天文地球—矿床学]