摘要
湖相盆地层序发育的主要控制因素为构造升降、湖平面变化和沉积物供应速率的变化。叠合盆地区域构造体制的转换是划分一级层序的基础 ,构造幕的产物构成了二级层序 ,三级以上层序主要反映岩相古地理与沉积风格的变化。湖相盆地的体系域在不同条件下等时性存在着明显的差异。在一个沉积物源控制的“沉积场”或多个物源控制的多个“沉积场”的可容空间与沉积速率变化的比值都小于 1或都大于 1时 ,所定义的体系域是等时的。但在不同的“沉积场”之间的可容空间与沉积速率的变化存在明显的非均一性时 ,在同一等时单元内 ,可以有不同体系域共生。湖相盆地中隐蔽油气藏的勘探目标主要为断陷型盆地坡折 (带 )下方的低位砂。
Main controlling factors of sequence development in lacustrine basins are tectonic uplift and subsidence,lake-level changes,and changes of sediment supply rates.Transformation of regional tectonic regimes in stacked basins is the basis for defining the first-order sequence.Sedimentary products of tectonic episodes consist of the second-order sequence,the third-and higher-order sequences chiefly reflect changes of paleogeography and depositional styles.Isochroneity of system tracts of lacustrine basin under various conditions is obviously different.System tracts defined above are isochronic when change ratios between compatible space of one 'sedimentary field' controlled by one extrabasinal sediment supply or multi 'sediment fields'controlled by several extrabasinal sediment supplies and sedimentation :rates are all more than 1 or less than 1.Lowstand sandstone and conglomerate bodies controlled by structural break(zone) in fault-depressed type lacustrine basin and delta-front sandstone bodies underlainl and overlain by two largest flooding acustrine mudstones in depressed-type lacustrine basin are main targets for explorating subtle pools.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2002年第2期115-120,共6页
Oil & Gas Geology
基金
国家教育委员会留学回国人员科研资助费
中国石油天然气总公司留学回国人员科研基金资助项目
关键词
湖相盆地
层序
隐蔽油气藏
体系域
lacustrine basin
sequence
system tract
subtle hydrocarbon pool
