关键词: 断陷湖盆, 盆缘沟谷, 构造坡折带, 古地貌, 砂体展布, 裂陷幕

Abstract: The relationship between palaeogeomorphology and development of sand bodies shows that there developed fault through,faults-transfer zone and incised valley in the depression wedges of the Paleogene of Bohai Bay Basin.Three basic valleys all controlled the positions of sandstone and conglomerate fan.The syndepositional tectonic slope-break zone controlled the distributions of sandstone and conglomerate.The thickness of sandstone and conglomerate is bigger at lower part of tectonic slope-break zone,and the distribution directions of sandstone and conglomerate are same as that of the syndepositional tectonic slope-break zone.The characteristics of syndepositional tectonic slope-break zone and its control to the distribution of sand bodies are different in different rifting episode.The main steep-slope faults and gentle-slope faults with dip-reverse strata were developed in the rift initiation episode.The main steep-slope faults and gentle-slope faults with dip-same strata were developed in the rift climax episode.Many syndepositional faulted slope-break zone resulted from above faults controlled the distribution of sand bodies.In post-rift episode,part syndepositional faulted slope-break zone changed into bent slope-break zone.The two kinds of slope-break zones together controlled the distribution of sand bodies.

Key words: rift-subsidence basin, basin-wedge valley, tectonic slope-break zone, palaeogeomorphology, sand-body distribution, rifting episode