The spatial and temporal variation of stratigraphic components within the San Fernando Channel System, Baja California, Mexico

The San Fernando Channel System is a superbly exposed submarine channel system of late Cretaceous age located on the Pacific coast of Baja California, Mexico. High-resolution mapping and extensive system-wide correlation panels coupled with detailed sedimentology studies and interpretation of high-resolution photomosaics have shown that the system comprises a distinct hierarchy of stratigraphy components. Extensive outcrops have allowed a detailed submarine channel model to be proposed which describes architecture and facies spanning outcrop to seismic scales. Channel complex sets are the largest mappable component within the system and are bounded by basal system-wide erosion surfaces. Each set shows a consistent stratigraphic evolution comprising 3 distinct stages each characterised by distinct channel complexes. Channel complexes in Stage 1 are predominantly coarse-grained, highly amalgamated and confined within an extensive composite erosion surface. Stage 2 is dominated by channel complexes which are finer-grained, less amalgamated and laterally flanked by internal levee deposits. Stage 3 relates to the shutdown and gradual abandonment of the system and is dominated by fine-grained turbidites and well developed condensed intervals. The stratigraphic variation observed within the channel system is linked to sea-level fluctuations. However, throughout the system, local contemporaneous faulting is shown to have a high degree of control on the location of sedimentation and commonly overrides the normal sea-level influenced depositional evolution. Local faulting is also shown to profoundly affect both the local channel-fill type and the stacking patterns of architectural elements and channel complexes. Stacking patterns of individual channel complexes are generally more predictable in Stage 2 than in Stage 1 which is attributed to the variation in relative confinement of the individual channel complexes.EThOS - Electronic Theses Online ServiceGBUnited Kingdo