| Combined with high-resolution three-dimensional seismic data and the genetic mechanism of deep-water channels and the morphology of channel cross-sections at the studied Block A in Miocene Congo fan, Lower Congo Basin, it is shown that the deep-water channels can be divided into erosional, erosion-aggradational and aggradational channels, which can be further divided into nine subtypes. This classification indicates the lateral variations of these deep water channels from proximal to distal source at the Block A. From proximal to distal source, the channels display an evolutional process in morphology along with the hydrodynamic condition of these channels gradually decreases, that is, from limit, through unlimit and limit, to frontal splay, which results in the width/depth ratio and the sinuosity of the channels gradually increase. Based on the RMS amplitude diagram of per third-order sequence, considering of both sea level changes and tectonic uplift, it is claimed that the Miocene Congo fan migrates from south to north, and progresses toward the basin. The whole sedimentary sequence represent, from lower to upper and from south to north, that the aggradational channel and the distant fan are replaced by erosion-aggradational channels and erosional channels. |
