海底峡谷汇流过程对盐底辟响应的定量分析:以墨西哥湾北部陆坡为例OA

Submarine canyons are critical conduits for turbidity currents transportingterrigenous sediments into deep-water environments.Their head regions,often comprising multiple tributary canyons,frequently experience confluence influenced by geomorphology and hydrodynamic processes.The hydrodynamic conditions within these confluence zones significantly impact the spatiotemporal evolution of deep-water depositional systems.While existing research has explored various morphological and depositional features associated with submarine canyon confluences,the hydrodynamic mechanisms governing confluences under structural controls,such as salt diapirism,remain poorly understood,particularly lacking quantitative analyses integrating morphological and hydrodynamic aspects.This study focuses on the Dorsey-Sounder canyon system in the northern Gulf of Mexico.We integrate 3D seismic data,canyon morphological recognition and quantitative hydrodynamic assessment to systematically reveal the morphological evolution,hydrodynamic response characteristics and depositional evolution patterns during canyon confluence under the control of salt diapirism.The results demonstrate that the present-day main canyon of the Dorsey-Sounder system consists of an east tributary canyon and a post-confluence canyon.The confluence point has migrated approximately 1 km southeastward from a scour,resulting in a distinct trumpet-shaped widening and deepening morphology.Salt diapirs dominantly controlled the confluence process through three-dimensional mechanisms:planar structural diversion confined canyon pathways and defined the confluence zone;enhanced vertical confinement promoted canyon incision and erosion;and differential diapir growth rates governed confluence point migration.This study presents the first systematic elucidation of the three-dimensional hydrodynamic processes and morphological evolution mechanisms governing submarine canyon confluences in salt diapir-affected settings.The findings provide novel practical and theoretical insights for predicting deep-water depositional systems and informing hydrocarbon exploration in analogous basins.