东非鲁伍马盆地窄陆架背景下的深水沉积体系  

Deepwater Depositional System in the Background of Narrow Shelf in the Ruvuma Basin, Eastern Africa

作　　者：刘子玉 吕明 卢景美 吕栋 王颖 郭刚 Liu Ziyu;Lü Ming;Lu Jingmei;Lü Dong;Wang Ying;Guo Gang

机构地区：[1]中海油研究总院 [2]中国海洋石油国际有限公司

出　　处：《海相油气地质》2017年第4期27-34,共8页Marine Origin Petroleum Geology

基　　金：中海油研究总院专业基础建设自立课题"被动大陆边缘背景下深水沉积体系成因研究"项目(编号:2016OT-KTZL-15)资助

摘　　要：通过岩心、钻井、地震等资料以及物源分析,详细研究了东非鲁伍马盆地构造及沉积演化特征,初步提出了研究区窄陆架背景之下的沉积体系模式。研究认为,鲁伍马盆地陆坡较陡峭且峡谷水道非常发育,而深海平原地形趋于平缓,这有利于形成大型海底扇沉积体系。鲁伍马盆地沉积主要受控于鲁伍马河水系,尤其从渐新世开始受区域隆升影响,导致盆地西缘遭受抬升剥蚀,沉积物源供应充足,加之鲁伍马河水系较为发育,并伴随全球性海退,形成了庞大的向海推进的鲁伍马三角洲沉积体系,这也为海底扇的发育提供了丰富的物源,使得研究区发育了鲁伍马三角洲—水道—海底扇复合沉积体系。Based on the analysis of core observation,drilling data,seismic data and sediment provenance,the tectonic and sedimentary evolution of Ruvuma Basin are characterised in detail,and the preliminary sediment model under the condition of typical narrow shelf is proposed.The analysis result shows that the shelf is very narrow,and the upper slope is rather precipitous where the canyon and channel develop well,but lower slope is tending to flat and it is conducive to developing a wide range of submarine fan system.The deposit is mainly controlled by Ruvuma drainage,and the sediments supply is adequate triggered by uplifting and erosion in western part of Ruvuma Basin which undergone the regional uplift since Oligocene.In addition,Ruvuma drainage developed so well which coincided with the global regressive that huge sedimentary system of delta-channel-submarine fan developed with strong provenance supplying to submarine fan.

关 键 词：陆架 深水沉积 海底扇 水道 鲁伍马盆地 东非 

分 类 号：TE121.3[石油与天然气工程—油气勘探]