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。
Study on the sedimentary architecture and evolution of deep-water channel is one of the most interest-ing 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 sin-uous 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 asym-metrical 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.
出处
《现代地质》
CAS
CSCD
北大核心
2015年第1期80-88,共9页
Geoscience
基金
国家自然科学基金项目(41302147
41372118)
全国大学生创新创业计划项目(201210705013)
西安石油大学2013年大学生科研训练计划项目
