High Restriction Seismic Facies and Inner Structural Segmentation Features of the Central Canyon Channel Systems in Xisha Trough Basin

Key words: 
• Xisha trough /
• central canyon channel /
• restriction /
• seismic facies /
• segmentation

Abstract: The central canyon channel of the Xisha trough basin is in large scale, great depth and low sinuosity, showing great restriction and east-west segmentation. By taking advantage of the two-dimensional seismic data, the seismic facies features identification and its segmentation features are investigated in this paper. From the seismic profile in the research area, five seismic facies types are identified. They are:bottom sands and gravel, turbidite deposits, mass transport complex, muddy sediments, and slumps. The internal filling sequence correlates with the restriction level. According to the paleo-geomorphology map, seismic and sedimentary faces maps, the central canyon of the Xisha trough is distributed in the east and west direction. It is low-lying and wider in west, high and narrow in east. Since segmentation shows good consistency and parallelism to the structural fault zone, a turning point is defined to divide the two sections in the Xisha secondary recession. The western section is strongly restricted while the eastern section is weakly restricted. Totally 13 types of segmentation features are summarized from the aspects of distribution, shape, filling etc. of the channel system. And assume that the restriction and segmentation are mainly controlled by tectonic activity, topography and provenance supply.