渤海湾西部声纳探测发现全新世埋藏槽谷  

A Holocene buried valley discovered by sonar surveys in the western Bohai Bay, China

作　　者：赵根模[1] 李振海[1] 杨港生[1] 王大宏[1] 

机构地区：[1]天津市地震局,天津300201

出　　处：《地质通报》2005年第6期520-523,共4页Geological Bulletin of China

基　　金：国家计委<中国大城市活断层探测与地震危险性评价>项目;天津市城市活断层工程项目资助研究。

摘　　要：声波探测具有很高的分辨率和信号发射频度,可以获得高品质浅地层剖面,显示出沉积地层的结构与构造细节、斜层理等三角洲沉积标志特征。展示了渤海湾西部浅地层声纳探测原始记录。探测发现,在大沽口以东27km处存在一个以前不为人知的埋藏槽谷,涉及地层的时代为晚更新世末期与全新世中期。宽达几百米到1km,深约30m,走向北北西,形成时代距今约5000～6000a,可能代表了某种重大地质事件,其成因有溺谷充填和构造断陷2种可能。Sonar survey has a very high resolution and signal emission frequency, so it can be used to obtain high-quality shallow profile and the textural and structural details of sedimentary strata and indicators of deltaic deposits such as oblique bedding. The paper presents the primary records of sonar surveys of the shallow strata in the western Bohai Bay. Sonar surveys show that a buried valley which nobody knew before exists 27 km east of Dagukou.. The strata involved are of terminal late Pleistocene and middle Holocene age. The basin, several hundred meters to 1 km wide and ～30m deep, strike NNW and formed about 5000-6000 years ago. It might represent a certain important geological event and has two possible origins: drowned valley filling and tectonic downfaulting.

关 键 词：渤海湾西部 声纳探测 埋藏槽谷 全新世 

分 类 号：P631.5[天文地球—地质矿产勘探] P534.632[天文地球—地质学]