【摘要】 深水水道沉积构型及其演化一直是沉积学界研究的热点。基于Rio Muni盆地深水区470 km2高分辨率三维地震数据,在精细地震解释的基础上,对研究区发育的深水水道的沉积构型、演化进行探讨。主要取得4点认识:(1)深水水道的弯曲度主要受控于物源供给和海底坡度,研究区发育弯曲水道、顺直水道2类深水水道;(2)起源于陆架边缘的深水水道,物源供给相对充分,弯曲度高,其剖面往往不对称,水道壁发育滑塌或阶地,垂向演化具有侧向迁移特征,发育废弃水道;(3)而起源于中上陆坡的深水水道,其弯曲度低,剖面具有U形特征,水道壁光滑无滑塌或阶地,主要以垂向加积为主。由于物源供给不足,顺直水道逐渐被深海泥质披覆沉积充填;(4)同一条深水水道,由上陆坡向下陆坡,随着海底坡度的降低,其弯曲度呈增大趋势。更多还原

【Abstract】 Study on the sedimentary architecture and evolution of deep-water channel is one of the most interesting fields in sedimentology. Based on high-resolution three-dimensional seismic data sets which cover 470 km2,the sedimentary architecture and evolution of submarine channels are discussed in deep-water Rio Muni basin.Four conclusions can be drawn in this paper:(1) The sinuosity of submarine channels are main dominated by the sediment supply and the seafloor gradient. Two main types of submarine channels: straight channels and sinuous channels have been recognized in the study area.(2) The high sinuosity submarine channel indents the shelf margin and is linked to areas of high coarse-grained sediment supply. Their mophologies often show asymmetrical cross-sections,terraces,slumped edges,lateral migration and abandoned channel.(3) The submarine channels heading on middle or upper continental slopes have a low sinuosity. Straight channels’ morphologies commonly include a U-shaped cross-section,smooth walls lacking slumps or terraces,aggradational evolution.The straight channels with low sediment supply were draped by hemipelagic deposition.(4) The sinuosity of a submarine increases as the shelf gradient decreases.更多还原