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Qmf Mudflow deposits (Holocenel: clay and fine- <br />. grained debris that may include larger rock <br />fragments incorporated into the debris during <br />downslope movement of the wet, viscous mass <br />of soil and rock material. The deposits have <br />a youthful physiography characterized by a <br />gently undulating topography with an incised, <br />braided drainage network. With decreasing <br />viscosity during movement the deposits grade <br />to fluvial sediments and with increasing <br />viscosity grade to slow-moving earth-flows. <br />Qdfl Debris-fan deposits (Holocene to late <br />Qdf~ Pleistocene): unsorted, unconsolidated debris of soil, <br />rock, and displaced vegetation deposited where stream <br />gradient decreases. This gradient decrease is most <br />commonly near the confluence of a tributary stream with <br />a larger trunk stream. Usually composed of mud, sheet, <br />and debris-flow material, the deposits result from the <br />rapid movement and deposition of solid material during <br />unusually heavy rain or snowmelt runoff. Qdfl deposits <br />probably formed during the Holocene; Qdf, deposits most <br />likely were deposited during previous glacial stages. <br />Qsc Soil-creep/solifuction deposits (Holocenel: <br />mixtures of sand, silt, and clay with some <br />• larger rock fragments formed by the slow, <br />downslope movement of near-surface materials. <br />These deposits, characterized by a series of <br />small swales and ridges perpendicular to <br />direction of movement, generally are active <br />and indicate areas with unstable slope <br />conditions. <br />Qda Debris-avalanche deposits (Holocenel: <br />unsorted mixtures of soil and rock material <br />formed by their generally sudden and rapid <br />downslope movement and deposition. Usually <br />formed during periods of rainfall, the <br />deposits generally produce a relatively <br />small, elongate rise that may extend out to <br />gently sloping areas below the steep slopes <br />from which the materials originate. <br />Qsfcl Slope-failure-complex (unit) deposits (Holocene to late <br />Qsfc, Pleistocene): unsorted mixtures of soil and rock <br />Qsfc, material formed by various mass-wasting processes <br />including landslides, earthflows, mudflows, soil creep, <br />and debris avalanches. Not all of these processes <br />occur within a specific deposit and the age of movement <br />may vary with a particular area. The general age of <br />the unit is noted by subscripts (1 is the youngest). <br />• <br />esnxxr,~recxcsxxox EXH-12 - 12 - <br />