TIDAL FLAT SEDIMENTATION AT COOLEY LANDING, S. W. SAN FRANCISCO BAY.
STANFORD UNIV CALIF
Pagination or Media Count:
Tidal marsh and mud flat sedimentation is being studied on portions of the southwestern side of San Francisco Bay. Sediments transported and deposited within this low energy environment are distributed in accordance with a principle of scour and settling lag proposed for sediments in the North Sea. The finer sediments are concentrated nearer the higher portions of the tidal flats and marshes where lower ebb flow velocities are unable to transport them farther bayward. Greater quantities of bedload sediment are moved on the flood than on the ebb portions of the tidal cycle both on the tidal flat and through the marsh channel system. A sediment budget is maintained within the tidal marshes, whereby the growth of the tidal channels accompanies the extension of the marsh onto the tidal flat. This development is documented on aerial photographs taken during a six-year period. Higher shear strengths and densities are displayed by the slightly elevated tidal channel levees than are present for the adjacent mud flats because of the longer periods of desiccation the levees experience. X-radiologic studies of near-surface tidal flat mud slabs show sedimentary structures not apparent in photographs, and suggest penecontemporaneous deformation of the muds. Author
- Hydrology, Limnology and Potamology