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About the CD: Legend

File and Data Structure
Data Dictionary
Projections
Legend

Legend includes detail description for each surficial geologic unit.

Unit Label
Surficial geological unit description
QUATERNARY
HOLOCENE - Post Erratics Train Glaciation
m
Made Land: Artificial fill and mine waste.
I
lce: Flowing or stagnant glacial ice. Contains or is covered by variable amounts of rock debris ranging from clay to boulders; thickness of ice ranges is 20 - 40 metres.
O
Organic Sediments: Water-saturated Sphagnum peat and organic silt formed predominantly by the accumulation of vegetal material in bogs, fens, and swamps. Organic deposits are usually underlain by lacustrine silt and clay. Thickness up to 5 m.
Eb
Eolian Blanket: Sand, well sorted, massive. Forms gently undulating plains marked by crescent-shaped dunes. Thickness up to 5 m.
COLLUVlAL SEDIMENTS: Stony diamicton resulting from the mixture of varying amounts of broken bedrock, soil and glacial sediments by non-fluvial gravitational processes such as creep, solifluction, debris flow, snow avalanching, and rockfall. Reworked glacial sediments in colluvium occur within the limits of past glaciations.
Cb
Colluvial Blanket Sediments: Diamicton, stony, massive, 1 to 2 m thick.
Cv
Colluvial Veneer Sediments: Diamicton, stony, massive, < 1 m thick or patchy. Overlies bedrock.
Ca
Colluvial Apron Sediments: Bouldery diamicton and poorly sorted and, stratified sand and gravel. Sediments form a wedge-shaped slope-toe complex of small steep debris flow and avalanche-dominated fans and solifluction deposits derived from bedrock or glacial debris up slope. Thickness ranges from < 1 m at the up slope limit to up to 10 m or more in the thickest part of the apron.
Cc
Rockfall Sediments: Bouldery rockfall deposits. Forms cone shaped landforms at the angle of repose below steep bedrock slopes. Thicknesses range from < 1 m at the margins to 10 m near the midpoint of the cone.
Ch
Landslide Sediments: Diamicton formed of broken rock, soil and glacial deposits. Forms a hummocky or ridged topography with ridges transverse to direction of movement. Thickness variable, may range up to 10 m or more (direction of movement indicated by symbol).
Cx
Undivided Colluvial Sediments: Hummocky apron terrain adjacent to mountainous uplands possibly of mass wasting origin.
ALLUVlAL SEDIMENTS: Gravel to silt size sediments deposited by streams either within channels or as overbank deposits. Deposits are usually stratified and moderately to well sorted, with the exception of some alluvial fan deposits.
Ap
Alluvial Plain Sediments: Gravel and sand, massive to stratified, moderately to well sorted. Locally overlain by or include lacustrine silt and clay and minor peat and organic silt deposited in abandoned channels and along floodplain margins. Forms plains within about 1 m of present stream level which are subject to inundation during floods. Thickness 1 to 5 m.
At
Alluvial Terrace Sediments: Gravel and sand, massive to stratified, moderately to well sorted. Sediments are of floodplain origin now isolated from flooding by stream incision. Thickness ranges from a discontinuous covering on bedrock to several m. Where alluvial terraces are cut into glaciofluvial plains, total thicknesses of gravel and sand may be 5 m or more.
Af
Alluvial Fan Sediments: Gravel and gravelly diamicton, stratified, poorly to moderately sorted. Forms fan-shaped landforms where streams enter larger valleys. ln mountainous terrain, alluvial fans may be subject to inundation of debris flows. Thickness up to 10 m.
Ax
Alluvial Complex Sediments: Flood plains, fans, and terraces that cannot be subdivided at this map scale.
WISCONSlNAN -- Erratics Train Glaciation Sediments Deposited During Advances and Retreats of Glaciers From Rocky Mountains and Continental Interior
GLAClOLACUSTRlNE DEPOSlTS: Well stratified sand, silt and clay deposited in lakes dammed by glacial ice. Where deposition was distant from ice margins, glaciolacustrine sediments underlie plains or gently rolling terrain. Where deposition was near to ice, they may underlie ridged, hummocky, or pitted terrain caused by subsequent ice meltout. May include some post glacial lacustrine sediments.
Lv
Glaciolacustrine Veneer Sediments: Silt, clay and fine sand, well stratified, thinly bedded to laminated or discontinuous. Thickness < 1 m thick to discontinuous.
Lb
Glaciolacustrine Blanket Sediments: Silt, clay and fine sand. Surface morphology conforms to underlying topography.
Ll
Glaciolacustrine Plain Sediments, local relief < 1 m: Silt, clay and fine sand, thinly bedded to laminated. Surface morphology is a plain and underlying topography is generally obscured by these sediments. Thickness 1 to 20 m.
Lp
Rolling Glaciolacustrine Plain Sediments, local relief 1-2 m: Fine sand, silt, and clay, thinly to massively bedded, surface morphology undulating. Underlying topography is generally obscured by these sediments. Thickness 1 to 20 m.
Lh
lce-contact Glaciolacustrine Complex Sediments: Predominantly silt and sand; gravel, diamicton lenses and dropstones may comprise up to 10% or more of this unit. Bedding thin to massive. Bedding is commonly deformed due to syndepositional slumping and ice meltout. Surface morphology is hummocky, pitted and ridged with relief up to 10 m. Often underlain by hummocky moraine sediments. Thickness 5 to 10 m.
GLAClOFLUVlAL SEDlMENTS: Sand, gravel and minor silt and diamicton deposited by streams flowing away from, or in contact with glacial ice. Sorting ranges from good to poor and stratification from thinly bedded to massive. Sediments may display evidence of syndepositional collapse due to meltout of buried or supporting ice. Provenance ranges from entirely montane (Precambrian and Paleozoic limestone, dolostone, argillite and quartzite, and may include mafic and felsic volcanic rocks in the Oldman River basin) in the areas formerly covered by montane glaciers and include sandstone, mudstone, conglomerate and Canadian Shield provenance granitic and metamorphic lithologies within areas formerly covered by glacier ice from the continental interior.
Gp
Glaciofluvial Plain and Fan Sediments: Gravel and sand, massive to thickly bedded, former outwash plains and fans. Thickness 1 to 10 m.
Gt
Terraced Glaciofluvial Sediments: Gravel and sand, massive to thick bedded, former outwash plains and fans incised into a succession of terraces. Thickness 1 to 10 m.
Gd
Glaciofluvial Delta Sediments: Sand, gravel and minor silt and clay, thinly bedded to massive, flat surfaced, delta-form in plan view, deposited as a delta along the margin of a former glacial lake. Thickness ranges from 5 to 10 m.
Gh
Glaciofluvial lce Stagnation Complex Sediments: Sand, gravel, diamicton and minor silt and clay, thinly bedded to massive. Bedding is frequently contorted and folded due to syndepositional ice meltout. Surface morphology includes hummocks, kettle, esker and crevasse-fill ridges 2 to 10 m in relief with minor elements of unit Gp and Gt. Thickness 5 to 10 m.
Gx
Undivided Glaciofluvial and Ground Moraine Sediments: a patchwork of glaciofluvial sediments and ground moraine (till) too variable to resolve at the scale of mapping.
Gv
Glaciofluvial Veneer Sediments: gravel and sand, massive to thickly bedded. Thickness < 1 m thick or patchy. Overlies bedrock.
MORAlNAL SEDIMENTS (Till): Diamicton (pebble to boulder size clasts suspended in a poorly sorted clay to sand size matrix) deposited directly by glacial ice; redeposition, where it has occurred, has been by sediment gravity flow and/or ductile deformation. Tills of two provenances were deposited during the Erratics Train Glaciation: TC contains clasts of Rocky Front and Main ranges Precambrian and Paleozoic limestone, dolostone and quartzite, Foothills and lnterior Plains Mesozoic and lower Tertiary sandstone, mudstone and coal, as well as Canadian Shield provenance granitic and metamorphic rocks; TM contains Rocky Mountain Precambrian and Paleozoic limestone, dolostone, argillite and quartzite (may include Precambrian igneous rocks south of Crowsnest River), and Foothills Mesozoic and lower Tertiary sandstone, shale, and coal (includes lower Cretaceous volcanics in the Crowsnest Pass area). Trace amounts of Canadian Shield provenance clasts are present only where montane ice overran preexisting drift containing Canadian Shield provenance clasts.
TvC
TvM
Till Veneer : < 1 m thick or discontinuous diamicton with patches of exposed bedrock or colluvium. TvM generally contains more and coarser pebble and larger clasts than does TvC and both may contain extensive areas of thin (< 1 m) and patchy colluvium. Overlies bedrock.
TbC
TbM
Till Blanket: 1 to 5 m of diamicton that conforms to the underlying bedrock topography. TbM generally contains more and coarser pebble and larger clasts than does TbC.
ThC
ThM
Hummocky Moraine: Diamicton and interstratified glaciofluvial gravel and sand, massive to thick bedded. Bedding slumped faulted and folded by syndepositional ice meltout. May contain variable amounts of ice-walled lake fine sand and silt. Forms hummocky, kame and kettle topography. Local relief of up to 30 m. Thickness may be tens of m.
TmC
TmM
Rolling Till Plain: More than 5 m of diamicton. Surface morphology undulates with 1-2 m of local relief. Surface morphology of underlying bedrock totally or largely obscured.
EARLY PLElSTOCENE OR PLlOCENE GLAClAL OR NONGLAClAL SEDIMENTS
TbU
Till? Blanket: Stony diamicton cemented to a calcrete. Contains striated clasts. Thickness 2 to 3 m. Rests on a succession of similar sediments of glacial or nonglacial origin.
PALEOZOlC TO EARLY TERTlARY ROCK
R
Sandstone, siltstone, shale, mudstone, conglomerate, coal and minor volcanic rocks of early Tertiary and Mesozoic age and limestone, dolostone and quartzite of Paleozoic and Precambrian age (includes areas of thin colluvial cover, blockfields, sorted stone polygons in alpine areas).
R-A
Areas of rock as above subject to rapid mass wasting processes (rockfall and snow avalanches).
R-G
Late Mesozoic and early Tertiary rock eroded into badland topography.

 

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Natural Resources Canada GSC  Terrain Sciences Division SE Cordillera NATMAP Project Area