Surficial Geology Color Chart of the NYSGS 2-10-97 The following symbols are used to plot the NYSGS Suficial maps, and are designed for use with a Calcomp electrostatic plotter. They have been used with an HP-Inkjet Plotter and Tektronix phaser. The symbol number will have to be modified depending on the plotter being used, as color is VERY HARDWARE SPECIFIC. The Symbolset comes from ArcInfo: Calcomp1.shd. The symbolset can be imported into ArcView. In the future, we will have an ArcView legend available. SURFICIAL SYMBOL alp 739 al 739 co 739 cof 739 alt 739 d 17 mb 473 lb 473 ld 473 md 473 lsc 37 sc 37 ls 742 s 742 og 31 fg 31 ki 123 ali 123 k 123 sf 186 km 186 tm 417 ta 417 udc 377 r 235 h2o 724 cd 761 usd 123 af 41 bi 739 b 739 to 417 c 739 af 739 t 377 du 123 wt 604 cs 300 .787 Alluvium: Recent floodplain deposits; most are sandy with silt, clay, or organic lenses as minor constituents. Low terraces that mimic irregularities of stream gradient are mapped as alluvium. .787 Fluvial Terrace: Stream terraces are mapped as fluvial terrace. Fluvial Terrace is mapped rather than outwash where there is no obvious source for outwash, or where fluvial deposits grade toward, rather than away from, a presumed glacier margin. .787 Colluvium: Unsorted mixture of fine to coarse material. Colluvium is mapped only where deposits are obvious, otherwise it is designated till. Much of the diamict mapped as till may well be till-derived colluvium, particularly on the lower portion of steep valley walls. .976 Paludal Sediment: Organic silt, sand, and organic accumulations deposited in swamps or marshes. .72 Ice-Contact Stratified Drift: Coarse to fine sand and/or gravel. Inferred where constructional topography suggests collapse of subjacent ice, and by characteristic topography above outwash terraces. Numbers 1-4 refer to morpho-sequences described below. .31 Outwash: Coarse to fine gravel with sand; restricted to valley bottoms and stream terraces; numbers 1-4 refer to morpho-sequences described below. .725 Lacustrine Sand: Sand deposited as deltas and beaches in large proglacial lakes; may be gradational with outwash. Numbers 1-4 refer to morpho-sequences described below. .37 Lacustrine Clay: Lake clay; or laminated silt, silt and clay, or silty clay; deposited in proglacial lakes. .61 Glacial Till: Mixture of clay, silt, sand to boulder sized material in varied proportions; unsorted to poorly sorted; deposited beneath glacial ice; till is generally more than 2 meters thick. .417 Glacial Till: As above, but generally 1-2 meters thick; overlies bedrock which may crop out sporadically. .109 Superglacial Till: Similar to till descibed above, but less compact and commonly contains pockets and stringers of stratified drift or matrix deficient till; generally 1-2 meters thick. .2 Bedrock: Exposed or generally within 1 meter of the surface. .724 Water .739 Recent alluvium: Oxidized fine sand to gravel, permeable, generally confined to floodplains within a valley, in larger valleys may be overlain by silt, subject to flooding, thickness 1-10 meters. .37 Undifferentiated marine and lacustrine silt and clay: Elevation within highest marine level, generally laminated to massive silt and clay, may include fossil shells, deposited in brackish to salt water, low permeability, potential land instability, thickness variable (up to 50 meters). .17 Dune sand: Fine to medium sands, well sorted, stratified, generally wind-reworked lake sediment, permeable, well drained, thickness 1-10 meters. .883 Swamp Deposits: Peat, muck, organic silt, and sand deposits in poorly drained areas, thickness is variable (1-5 meters). .235 Bedrock: Exposed or generally within 1 meter of surface, in some areas saprolite is preserved. .742 Undifferentiated marine and lacustrine sand: Well-sorted, stratified, fine to medium sand, generally a near-shore deposit, at or below highest marine level,may include fossil shells, may be a brackish to salt water deposit, permeable, thickness variable (2-20 meters). .377 Till: Till in a sheet showing little or no morainal topography, variable texture (boulders to silt), generally silty clay to silt loam, sedimentary provenance, usually poorly sorted sand-rich diamict, deposition beneath glacier ice, permeablility varies with compaction, thickness variable (1-50 meters). .604 Winnowed till: Gravel left when waves of the lakes or Champlain Sea "winnowed" out the clay, silt and fine sand of the till to leave coarse, poorly rounded gravel.