GRAIN-SIZE DISTRIBUTION PATTERNS SUPPORTING SEDIMENT BYPASSING ON THEFRASER-RIVER DELTA FORESLOPE, BRITISH-COLUMBIA, CANADA

Sediment distribution patterns from sediment cores and grab samples on the Roberts Bank area of the Fraser River delta suggest that much of the coarsest sediment supplied to the mouth of the Fraser River bypass es the tidal flats and upper slope, and is deposited on the lower fore slope. Transport is via a number of subaqueous channels which serve no t only as conduits for sediment bypassing. but also control the locati on and geometry of prodelta depositional lobes. Textural parameters, s edimentary structures and geometry of the deposits suggests that these lobes are formed by turbidity currents.