Ecological Land Classification of Mount Revelstoke and Glacie r ...

Table 10 . Characteristics of Glaciofluvial material A .Textural PropertiesGenetic Dominant Calcareous- Fine CoarseMaterial Unit Source ness Earth FragmentsGlaciofluvial Noncalcareous Noncalcareous 60-100% sand, 35-70 %material A glacial deposits 0-5% clayFluvial landforms are of two types . The first is level floodplain, with simple slopes of 0 to 2%, whichcontains the major streams that formed it . Weak terracing with risers 1 m occur under sedge fen vegetation. Yet nearby localities may still receive substantial amounts o fsediment. Fresh silty material up to 7 cm thick was observed in 1983 on a few Beaver River flood -plain sites dominated by dense, wet shrub thicket vegetation .Mudflow beds, in contrast to stream deposits, tend to be unsorted and more uniformly textured wit hlittle or no internal stratification because each bed was usually produced by a single flow event (Sharpand Nobles 1953, Winder 1965, Ryder 1971, Roed and Wasylyk 1973, Rachocki 1981) . Coarse fragmentsvary in size, shape, and abundance and are usually embedded in a finer grained matrix . Th elargest debris is often deposited near fan and apron apexes (Sharp and Nobles 1953, Rochocki 1981) .Thus, mudflows are strongly influenced by source materials (e .g. till and colluvium) and the deposit soften resemble till (Sharp and Nobles 1953, Harland et al. 1966, Landim and Frakes 1968, Pe an dPiper 1975, Ryder 1981) .Fluvial Material AOnly one fluvial genetic material, Fluvial material A, was recognized in MRNP and GNP and is similarto Fluvial material A in BNP and JNP . Because of its polygenetic composition and wide textura lrange (Table 11, Fig. 5), it is termed coarse-stratified .21