Detailed Soil Survey of the Mount Revelstoke Summit Area.

Soil Map Unit 3(Orthic and Cumulic Regosol)The imperfectly to somewhat poorly drained soils of this mapunit occur in weakly defined snowmelt runoff channels and depressionalareas of late snow cover and seasonal ponding of meltwater (Plate 3) .Plant cover is predominantly Luetkea pectinatain the runoff channels andCarex nigricans or Luetkea pectinata in the depressional areas .These soils have deep(20 to 40 cm), black, organic Oh surfacelayers which contain 30 tois well decomposed and is65 percent organic matter . The organic mattermixed with predominantly silt-sized alluvialmaterials overlying till . Bulk density of the Oh horizons is very low,3in the order of 0 .3 g/cm , and there are few coarse fragments . Thinvolcanic ash layers often occur at approximately the 20 cm depth . The Ohlayers overlie a yellowish brown C horizon,thus the soils are classifiedas Regosols .The C horizons consist of the sandy loam till materials thatcover most of the Summit area .These soils do not display mottling or gleying and are betterdrained than the soils of mapunit 4 and do not have a hummocky surfacelike the soils of map unit 6 .The Regosols of map unit 7are betterdrained thanthe map unit 3 soils and do not have organic layers .Thefollowing isa brief description of an Orthic Regosol typical of map unit3 soils .Horizon Depth (cm) Color Texture % C .F . % O.M .Ohl 0 - 7 black organic 0 64 .9Oh2 7 - 19 black organic 0 32 .0ash 19 - 21 yellowish brown SiL 0Oh3 21 - 31 black organic 0 37 .8C 31+ yellowish brown GSL 25