深水弯曲水道几何形态定量分析——以赤道几内亚Rio Muni盆地为例

深水水道作为深水沉积体系中重要的沉积单元之一，一直是深水沉积和地层研究的热点。基于西非几内亚湾Rio Muni盆地陆坡区的高分辨率三维地震资料，利用地震属性及参数定量分析法对第四系陆坡重力流水道的剖面和平面形态进行了研究，旨在探索深水水道内部结构的相互影响和外部因素对水道形态的控制，丰富深水沉积学理论。研究表明：坡度及距水道头部距离影响了深水水道的剖面和平面形态，随着坡度变缓，距水道头部距离越远，水道宽度越小；堤岸于中、下陆坡开始发育，水道堤岸脊的高程差及内、外弯曲带都不同程度地影响了堤岸的长度；水道的弯曲度控制着堤岸脊高程差的变化，同时作用于堤岸长度的变化；样本水道为高弯曲水道，且弯曲度受地形坡度控制。

QUANTITATIVE ANALYSIS OF THE GEOMETRY OF SINUOUS SUBMARINE CHANNELS: A CASE FROM THE RIO MUNI BASIN OF EQUATORIAL GUINEA

As a kind of important sedimentary elements in deep-water depositional systems, submarine channels have long been a focus of research in deep-water sedimentology and stratigraphy. Based on the interpretation of high-resolution 3D seismic data from the slope area of the Rio Muni Basin in the Gulf of Guinea, West Africa, quantitative analysis method for seismic attributes and parameters are used to analyze the Quaternary continental slope gravity flow channels in both profiles and plane views. It is observed that: (1) the slope and length of a channel are the key factors that affecting the profile and plane shape of the deep water channel. As the slope becomes gentler, the channel extends longer, and the water channel develops from "deep and wide" to "deep and narrow". However, the depth of the channel adjacent to the slope break of shelf is greater than the channels on other types of slopes; (2) the sinuous channel usually begins to develop on the middle-lower part of a slope, and the heights of the inner bank and the outer bank of the channel control the length of banks, and the length of the inner bank in the channel is greater than that of the outer bank; (3) as the curvature of the channel increases, the difference in the height of channel banks is getting larger, and the average length of the bank is longer; (4) in the steep slope area, the curvature of the channel is small, and the curvature increases as the slope becomes gentler.