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
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
mL
Lacustrine Mud
fluid silty clay and clayey silt; deposited as quiet water sediments
mM
Marine Mud
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
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
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
water