Location Map

M1

M

bM1v

M1

M/Op

bM1

M1

GFI

bM2h//Op

bM2

bM2-bM1//Op

M

GFIv//Rr

bM1

M1v

bM2

bM1

Op

bM1

bM1//BF

bM2h//BF

GFIr

Op

GFIh//Op

bM1//BF

bM2

bM1v//Rr

Op

bM2/BF

bM1

bM2h

bM2h/BF

Op

bM1

bM1bM2

M1vOp/bM2

bM1/BF bM1

Op

Op

bM

bM2h

bM2

bM1v//Rr

Op

bM1

bM1

OpOp

bM2h//Op

bM1v

bM2h/BF

Op/M2

Op/M

bM1

M2h

GFI

Op

GFIv|bM1

bM2h

OpOp

GFIv-bMve/BF

bM1//Op

Op

Op

GFIv-bMe//Op

Op

GFIv/Rr

Op

Op

Op

Op

Op

Op

bM1/GFIv

Op

Op

M1v//GFIv

Op

Op

Op

Op

Op

bM1

Op

Op/BF

GFI

Op

Op/bM2h

Op

Op

Op

Op

bM1//BF

Op

Op

bM2h//Rr

GFIv|bM2-Me//BF

Ov-OpGFIr/Op

Op/M1

Op

GFIh/Op

Op//bM2h

Op/bM2h

M/Op

497000

497000

498000

498000

499000

499000

500000

500000

501000

501000

502000

502000

503000

503000

504000

504000

505000

505000

506000

506000

507000

507000

508000

508000

509000

509000

510000

510000

6644

000

6644

000

6645

000

6645

000

6646

000

6646

000

6647

000

6647

000

6648

000

6648

000

6649

000

6649

000

6650

000

6650

000

6651

000

6651

000

105°W

105°W

59°5

7'N

59°5

7'N

This Map

Astrolabe

Premier

Clut

FontaineLake

Lake

Lake

Scott

Elizabeth LakeBlack

LakeGrollier

Lake

Lake

Lakes

Dodge

LakeSovereign

Lake

LakeBompas

Kaskawan

Chipman

Lake

LakeRobins

Hawkins

LakeYoung

CharleboisLake

Lake

Lake

Selwyn Lake

74P-11

74P-05 74P-06

74P-12

74P-1374P-14 74P-15

74P-10

74P-07

74O-16

74O-09

74O-08

74P-0474O-01105°W

105°W

106°W

106°W60°N 60°N

59°30'N 59°30'N

Although the Saskatchewan Ministry of the Economy has exercised all reasonable care in the compilation, interpretation, and production of this item, it is not possible to ensure total accuracy, and all persons who rely on the information contained herein do so at their own risk. The Ministry of the Economy and the Government of Saskatchewan do not accept liability for any errors, omissions, or inaccuracies that may be included in or derived from, this item.

Catalogue Number 2012-4.2-(5.2)

O

GFI

M

M1

M2

R

Symbols

Dodge Domain

Tantato Domain

Train Domain

MudjatikDomain

2010 Map

Esker (flow direction known)

Major meltwater channel/escarpment (teeth on down-slope side)

Striae (ice-flow direction known)

Boulder field

Observation site

Observation site/till sample site

Unit contact

Topographic contour (10 m interval)

River

Transitional Association Locally, two or more terrain units can be juxtaposed by reason of related origin, temporal sequence or ambiguous geomorphic distinction. In the case of the latter, both components may or may not be present. All such situations are identified by a compound designation marked by a hyphen. For example:

GFIh-M2h indicates ice-contact kame and kettle topography that blends with hummocky stagnant-ice moraine.

Morphologic Overprint Where a sequence of geomorphic processes has produced a multi-aspect or compound terrain fabric, the geomorphic modifier suffixes are appended in the inferred order of superposition. For example:

Mvdc indicates that a veneer of till has been moulded into a drumlinoid form and finally channelled by former meltwater streams. GFIphr indicates that a glaciofluvial plain has been discontinuously covered by ice-contact hummocks and ridges.

Geomorphic Modifier e eroded Planar to undulating surface eroded by glacial meltwater, often capped by a

boulder lag deposit and/or thin deposit of glaciofluvial sand and gravel; surface of deposit may exhibit channel scars; commonly occurs in topographically low areas.

h hummocky Assemblage of approximately equi-dimensional hills and hollows; moderate to high relief (commonly greater than 2 m): hummocky stagnant-ice moraine (M2h), knob-and-kettle glaciofluvial terrain (GFIh).

p plain Deposit greater than 2 m thick; commonly masks geomorphic pattern of underlying deposits; flat to gently rolling topography (commonly less than 2 m relief): organic plateaus (Op).

r ridged One or more parallel or sub-parallel, convex, linear morphological features with a length to width ratio greater than 2; low to high relief; can be composed of bedrock, till or stratified sediments: bedrock ridges (Rr), esker ridges (GFIr).

v veneer Thin cover of unconsolidated material too thin to mask minor irregularities of underlying material; less than 2 m thick and may be discontinuous.

UNIT NOTATION EXAMPLE: sandy glaciofluvial plain

Genetic Class

Textural Modifier Textural characteristics may be applied to the terrain classification as a prefix based on field observations or by inference from distinctive genesis and/or morphology. When two modifiers are given, the second letter is the dominant texture, with the first letter indicating the secondary texture, i.e., sz for sandy silt. b = boulder p = pebble g = gravel s = sand z = silt c = clay Complexes Where two or more classes of terrain are interspersed in a mosaic or repeating pattern on a scale too small to warrant meaningful differentiation, the proportion of each component in the combination is given in a two or three position designation set off by slashes denoting arbitrary percentage limits. For example:

Mp/GFv indicates that the area is underlain by approximately 60% morainal plain and up to 40% glaciofluvial veneer. Mv/Ov/Rr indicates that at least 60% of the area is underlain by thin till interspersed with up to 40% thin organic areas and less than 15% scattered rock outcrop. GFp//M indicates more than 60% of the area is underlain by a glaciofluvial plain interspersed with less than 15% moraine.

Stratigraphic Sequence Where materials of different origin or texture are known to be superimposed, or can be reasonably confidently inferred, the sequence is indicated in conventional order using vertical separators. For example:

Mhv Md indicates thin hummocky moraine deposited on drumlinoid moraine.

sGFp Textural Modifier

Geomorphic Modifier

directly by glacial ice either beneath the glacier (lodgement or melt-out till) or at ice margins (supra- and subglacial melt-out till) and locally as gravity flows (flow deposits); meltwater has variably affected till units.

Undivided moraine of undetermined genesis and texture. Unsorted to poorly sorted, moderately to well-compacted till with a silty sandy matrix

containing pebbles, cobbles and boulders; locally the texture of the till may vary from silty to sandy depending on the local source material; massive; may contain sedimentary bedding structures (lenses/layers) associated with subglacial melting of active ice; deposited by lodgement and subglacial melt-out processes.

Unsorted to poorly sorted, loosely to moderately compacted sandy till; massive, locally

includes some sorting; may include stratified glaciofluvial sediments; variable thickness; commonly forms low to high-relief hummocky topography; extensive deposits common adjacent to subglacial meltwater channels; interspersed with ice-contact and cavity-fill deposits; results from the collapse and lateral movement of subglacial, englacial and supraglacial sediment in response to melting of buried stagnant ice at the ice margin.

bM1, bM2: boulder-rich till; surface is boulder strewn; commonly associated with boulder

fields.

PRE-QUATERNARY

Bedrock1: undivided; includes Precambrian granitic, gneissic, metasedimentary and metavolcanic rocks and felsic and mafic dykes; may include patches of till veneer, reworked till and/or glaciofluvial deposits; outcrop surfaces may be striated and grooved or moulded to form roche moutonnée or may be concealed by moss and lichen; small, unmapped outcrops and felsenmeer (frost-heaved and shattered bedrock) occur in most terrain units.

Surficial Geology of the Opescal Lake Area (Parts of NTS 74P14 and 15) at 1:50 000 scale Preliminary Geological Map (2012) by M.A. Hanson

LEGEND

QUATERNARY

HOLOCENE

ORGANIC DEPOSITS: undifferentiated black peat layers, woody to fibrous muck; up to 4 m thick; commonly underlain by till and/or boulders, less commonly silt; permafrost

commonly associated with organic plateaus; occurs as undifferentiated wetlands (bogs and fens) in relatively flat, low-lying, poorly-drained areas and around lakes and rivers; small, unmapped organic deposits occur in most terrain units.

PLEISTOCENE

GLACIOFLUVIAL DEPOSITS: poorly- to very well-sorted sand and gravel, minor silt, minor diamicton; massive to stratified; deposited by glacial meltwater in contact with, or adjacent to, glacial ice; small, unmapped glaciofluvial deposits occur in many terrain units.

Ice-Contact Stratified Deposits: poorly- to very well-sorted angular to well-rounded

sand to cobble gravel, minor silt, minor diamicton; massive to stratified; interbedded with silt units of variable thickness; minor loading structures; 1 to 20 m thick; deposited by glacial meltwater in direct contact with glacial ice, either within and/or beneath glacial ice; forms eskers and associated plains, kames and kettle holes.

BOULDER FIELDS: moderately large (0.5 to 2.5 m diameter), subangular to

subrounded, matrix-free boulders; form continuous, level veneer in low-lying areas, along lake shores, at the base of slopes and adjacent to organic deposits; primarily formed as a glacial meltwater erosion lag but also consist of glacially abraded, short-transported boulders and felsenmeer (frost-heaved blocks of bedrock).

MORAINAL DEPOSITS: unsorted to poorly sorted diamicton (till), minor lenses of sorted

sediments; may contain blocks of pre-existing stratified drift; commonly less than 2 m thick but thicker in depressions; two textural facies are present: a silty sandy till (M1) and a sandy till (M2); glaciofluvial sediment may form discontinuous cover (<1 m); deposited

Scale 1:50 0000 1 2 3 40.5

Kilometres0 0.5 1 1.5 20.25

Miles

Breynat and Dodge Map

The area was mapped by Michelle Hanson in the summer of 2012 with the assistance of Michael Berry, Dunja Gaco and Logan Lesmeister. Jon Berthiaume, Drew Lubiniecki, Clarke Plews and Melissa Scansen also assisted with fieldwork. The author gratefully acknowledges Bernadette Knox for collecting till samples, measuring ice-flow indicators and making surficial geological observations while mapping the bedrock geology. This map was produced based on interpretation of 1:67 000-scale aerial photographs, SPOT5 imagery and Landsat 7 imagery and follow-up ground-truthing. This map was printed from the geologist’s digital file. Geological data were processed using Microsoft Access and ArcView 10 software. Base maps were compiled from CanVec 1:50 000-scale digital cartographic maps produced by Natural Resources Canada. Grid coordinates are NAD83 CSRS98 UTM zone 13. The map was processed overall using ArcView 10 software. The map is issued in a package with the Summary of Investigations 2012 Volume 2, Saskatchewan Geological Survey, and is available separately from www.er.gov.sk.ca/soi. This map accompanies the following publication: Hanson, M.A. and Knox, B. (2012): Snowbird project: Quaternary investigations in the Dodge, Breynat, and Opescal lakes areas, Dodge Domain, Saskatchewan; in Summary of Investigations 2012, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of the Economy, Misc. Rep. 2010-4.2. This map may be referenced as: Hanson, M.A. (2012): Surficial geology of the Opescal Lake area (parts of NTS 74P14 and 15); 1:50 000 scale prelim. map with Summary of Investigations 2012, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of the Economy, Misc. Rep. 2012-4.2.

Rhondda Lake

Opescal Lake

Opescal Lake

Yotin Lake

1References to bedrock maps in the same map area

Knox, B., Biss, S., Wood, C., and Morell, C. (2010): Bedrock geology of the Shagory Lake area, east-central Dodge Domain (Snowbird Project) (parts of NTS 74P10, 11, 14, and 15) Northeast Sheet; 1: 20 000-scale prelim. map with Summary of Investigations 2010, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of Energy and Resources, Misc. Rep. 2010-4.2-(4.2).

Knox, B., Biss, S., Wood, C., and Morell, C. (2010): Bedrock geology of the Shagory Lake area, east-central Dodge Domain (Snowbird Project) (parts of NTS 74P10, 11, 14, and 15) Northwest Sheet; 1:20 000-scale prelim. map with Summary of Investigations 2010, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of Energy and Resources, Misc. Rep. 2010-4.2-(4.1).

Knox, B., Plews, C. R., and Lubiniecki, D. C. (2012): Bedrock geology of the Opescal Lake area, north-eastern Dodge Domain, Snowbird Project (parts of NTS 74P14 and 15); 1:20 000-scale prelim. map with Summary of Investigations 2012, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of the Economy, Misc. Rep. 2012-4.2.

BF