cUNITCDESCRIPTIOCDETAILC A Alluvial Deposits stratified silt, sand, clay, and gravel; floodplain, delta, and fan deposits; in places overlies and includes glaciofluvial deposits A Alluvial Deposits stratified silt, sand, clay, and gravel; floodplain, delta, and fan deposits; in places overlies and includes glaciofluvial deposits bC Colluvial Blocks Blocks, and rubble with sand and silt; derived from crystalline bedrock, medium grade metamorphic substrate, and cemented sandstone cL Coarse grained (Glacio)Lacustrine sand, silt, and gravel; deposited as deltas, sheet sands, and lag deposits cM Coarse grained (Glacio)Marine sand and gravel; deposited as sheet sands, deltas, and extensive flights of beaches E Eolian Deposits sand and minor silt; dunes, blowouts, and undulating plains; in most places overlies deltaic sediments, coarse lacustrine sediments, or glaciofluvial deposits E Eolian Deposits sand and minor silt; dunes, blowouts, and undulating plains; in most places overlies deltaic sediments, coarse lacustrine sediments, or glaciofluvial deposits fC Colluvial Fines silt, clay, and fine sand; derived from substrate weakly consolidated shale and siltstone substrate fL Fine grained (Glacio)Lacustrine silt, and clay, locally containing stones; deposited as quiet water sediments fM Fine grained (Glacio)Marine dominantly silt and clay, locally containing stones; deposited as quiet water sediments Gp Glaciofluvial Plain sand and gravel; deposited as outwash sheets, valley trains, and terrace deposits Gx Glaciofluvial Complex sand and gravel and locally diamicton; undifferentiated ice contact stratified drift, and outwash; locally includes till and rock I Glaciers ice and minor morainal debris I Glaciers ice and minor morainal debris mL Lacustrine Mud fluid silty clay and clayey silt; deposited as quiet water sediments mM Marine Mud fluid silty clay and clayey silt; deposited as quiet water sediments Mv Lag (Glacio)Marine sand, gravel, and pockets of finer sediment; thin to discontinuous sediment veneer and residual lag developed during marine submergence; includes areas of washed till and rock O Organic Deposits peat, muck and minor inorganic sediments; large bog, fen, and swamp areas where organic fill masks underlying surficial materials; geneally >2 m thick O Organic Deposits peat, muck and minor inorganic sediments; large bog, fen, and swamp areas where organic fill masks underlying surficial materials; geneally >2 m thick R Undivided rock with minor Quaternary deposits R Undivided rock with minor Quaternary deposits Ra Alpine Complexes rock, colluvium, and till; rock and Quaternary deposits complex in an area, characterized by alpine and glacial landforms rC Colluvial Rubble rubble and silt; derived from carbonate and consolidated fine clastic sedimentary rock substrate sC Colluvial Sand Sand and gravel; derived from poorly lithified sandstone and conglomerate substrate sL Lacustrine Sand sand and locally gravel; deposited as sheet sands, lags, and beaches sM Marine Sand sand and locally gravel; deposited as sheet sands, lags, and beaches Tb Till Blanket thick and continuous till Tv Till Veneer thin and discontinuous till; may include extensive areas of rock outcrop V Quaternary Volcanics consolidated lava, breccia and tephra; dominantly basaltic and andesitic in composition; includes flows, volcanic piles, and cinder cones V Quaternary Volcanics consolidated lava, breccia and tephra; dominantly basaltic and andesitic in composition; includes flows, volcanic piles, and cinder cones water water