SE SASKATCHEWAN — FORMATION EDGES AND THICKNESS MAPS
26 maps; 20 mapped stratigraphic intervals; 28-page PDF atlas.
Prepared 22 October 2026 from the 2014 regional SPFPS compilation.

CONTENTS
SE_Sask_Formation_Edges_and_Thickness_Atlas.pdf — printable vector atlas, 17 × 11 inches, with bookmarks.
PNG/ — 26 individual maps, 3400 × 2200 pixels, 200 dpi.
GIS/ — 40 geological GeoJSON layers, official province boundary, 25 GNBC settlement points and discussion rectangle.
Sources/ — exact source-layer metadata, original-map verification, acquisition manifests and validation.
Map_Index.json — map numbers, subjects, extents and PNG filenames.
Reproduce/ — complete clipped inputs, source audits and plotting script for regeneration.

MAP INDEX (PDF page number = map number + 2)
01  Bakken–Alida: regional edges
02  Kisbey–Ratcliffe: regional edges
03  Red River / Birdbear / Torquay edges
04  Mesozoic: regional edges
05  Bakken–Alida: corridor edges
06  Mesozoic: corridor edges
07  Red River thickness
08  Birdbear thickness
09  Torquay thickness
10  Bakken thickness
11  Souris Valley thickness
12  Tilston thickness
13  Alida thickness
14  Kisbey thickness
15  Frobisher thickness
16  Frobisher Evaporite thickness
17  Midale thickness
18  Midale Evaporite thickness
19  Ratcliffe thickness
20  Total Mississippian thickness
21  Total Watrous thickness
22  Lower Watrous thickness
23  Gravelbourg thickness
24  Total Jurassic thickness
25  Cantuar thickness
26  Mannville thickness

GEOGRAPHIC AND CARTOGRAPHIC SCOPE
Regional geology extraction: longitude −105.0 to −101.2; latitude 49.0 to 51.0.
Corridor enlargement: longitude −104.05 to −101.5; latitude 49.65 to 50.7.
All geological delivery layers are clipped to the study rectangle and the official Saskatchewan polygon. The display includes a small cartographic margin.
Province outlines are drawn from true source boundary segments. Clipping-box sides are not drawn as provincial borders.
Maps use NAD83(CSRS) / UTM zone 13N, EPSG:2957, with geographic graticules. GeoJSON uses longitude/latitude EPSG:4326 as returned by the ArcGIS server.
The dashed discussion rectangle only identifies the enlargement area. It is not a geological or prospect boundary.

READING THE GEOLOGY
An isopach contour joins equal values of total thickness of the named mapped interval. All ordinary contour values and intervals are in metres, verified against original published map legends.
These are present preserved stratigraphic thickness maps. They are not reconstructions of original sediment accumulation before erosion, structure/depth maps, net-pay maps or resource estimates.
The official source calls its boundary layers Zero Edge. This atlas uses that terminology, but the source attributes do not classify individual segments by erosional, depositional or diagenetic origin.
A closed edge loop identifies a mapped limit loop; it does not prove a structural closure or trapped hydrocarbons. Blank areas between contour lines are not classified absence polygons or data-coverage masks.
Where no dedicated edge crosses the region (Red River, Cantuar and Mannville), the map says so. An empty edge GeoJSON is intentional.
Total Mississippian, total Jurassic, Mannville, total Watrous and their subdivisions overlap stratigraphically with other maps. Do not sum overlapping packages.
Red Jacket, Rocanville, Moosomin, Yeoman and Lake Alma member maps were not available in the inspected digital services. Total Jurassic or Red River maps must not be relabeled as those members.

SOURCE RESOLUTION AND PROCESSING
The Saskatchewan Geological Survey describes modified, equally spaced 2 km grids produced with Surfer 9 kriging. The 2014 compilation combined validated/edited regional correlations and adjacent-jurisdiction wells. A 2 km grid is not a statement of well spacing, positional accuracy or a quantitative uncertainty bound.
The 2026 date is the retrieval/atlas date, not the date of a new subsurface interpretation.
The contour and edge polylines have been projected and clipped without new geological gridding, smoothing or interpolation. The colour scale colours the existing lines; there is no inferred filled thickness surface.
Some zero-edge lines carry small positive ZLEVEL attributes, also present in the isopach source. These are not plotted or labelled as ordinary thickness contours. All original numeric values remain in GIS and are documented in unit_manifest.json.
Cantuar source OBJECTID 1 and 2 carry −0.5 ZLEVEL values. These unresolved/nonphysical records remain in the isopach GeoJSON but are omitted from drawn thickness contours.
For Birdbear, the companion boundary-coded isopach and dedicated edge differ slightly after source generalization; the dedicated official edge controls the map. The source manifest documents the approximately 9 m difference.
Native Shape__Length attributes are retained source values and have not been recomputed after clipping. Do not use them as clipped-line lengths or thicknesses.
The displayed low/high values are contour levels present in the frame, not independently established minimum/maximum thickness everywhere in the map.
No new well-log correlations, core interpretations or reservoir-quality analysis were performed to create these maps.

VERIFIED CONTOUR INTERVALS
Red River: 10 m; ordinary contour levels in this frame 70–160 m.
Birdbear: 5 m; ordinary contour levels in this frame 5–45 m.
Torquay: 5 m; ordinary contour levels in this frame 5–75 m.
Bakken: 5 m; ordinary contour levels in this frame 5–70 m.
Souris Valley: 20 m; ordinary contour levels in this frame 20–160 m.
Tilston: 10 m; ordinary contour levels in this frame 10–120 m.
Alida: 10 m; ordinary contour levels in this frame 10–110 m.
Kisbey: 5 m; ordinary contour levels in this frame 5–35 m.
Frobisher: 10 m; ordinary contour levels in this frame 10–90 m.
Frobisher Evaporite: 2 m; ordinary contour levels in this frame 2–10 m.
Midale: 5 m; ordinary contour levels in this frame 5–35 m.
Midale Evaporite: 2 m; ordinary contour levels in this frame 2–18 m.
Ratcliffe: 5 m; ordinary contour levels in this frame 5–60 m.
Total Mississippian: 25 m; ordinary contour levels in this frame 25–575 m.
Total Watrous: 20 m; ordinary contour levels in this frame 20–160 m.
Lower Watrous: 20 m; ordinary contour levels in this frame 20–140 m.
Gravelbourg: 10 m; ordinary contour levels in this frame 10–80 m.
Total Jurassic: 20 m; ordinary contour levels in this frame 20–380 m.
Cantuar: 20 m; ordinary contour levels in this frame 20–120 m.
Mannville: 25 m; ordinary contour levels in this frame 25–150 m.

SOURCE CITATION AND LINKS
Saskatchewan Mining and Petroleum GeoAtlas, SPFPS isopach and zero-edge layers, retrieved 22 October 2026.
Marsh, A. and Love, M. (2014), Regional Stratigraphic Framework of the Phanerozoic in Saskatchewan; Saskatchewan Phanerozoic Fluids and Petroleum Systems Project; Saskatchewan Geological Survey, Open File 2014-1, set of 156 maps.
https://gis.saskatchewan.ca/egis/rest/services/Economy/Mississippian/FeatureServer
https://gis.saskatchewan.ca/egis/rest/services/Economy/Mesozoic/FeatureServer
https://gis.saskatchewan.ca/egis/rest/services/Economy/Devonian/FeatureServer
https://gis.saskatchewan.ca/egis/rest/services/Economy/Lower_Paleozoic/FeatureServer
Boundary: https://gis.saskatchewan.ca/arcgis/rest/services/OverviewMap/MapServer/0
Settlements: Natural Resources Canada, Canadian Geographical Names Database; individual record URLs retained in town properties.
Contains information licensed under the Government of Saskatchewan Standard Unrestricted Use Data Licence (Version 2.0).
https://gisappl.saskatchewan.ca/Html5Ext/Resources/GOS_Standard_Unrestricted_Use_Data_Licence_v2.0.pdf
Adapted cartography; no Government of Saskatchewan endorsement is implied.

USING THE GIS FILES
Load the GeoJSON layers in QGIS or other GIS software. Set the project projection to EPSG:2957 for consistency with these maps. The raw ZLEVEL field preserves original contour and boundary attributes. Apply the documented ordinary-value filter before treating it as thickness.

REPRODUCTION
Python dependencies: numpy, matplotlib, shapely>=2.1, pyproj, Pillow, pypdf, PyMuPDF.
From the extracted Reproduce directory run: python research_maps/build_formation_atlas.py
Inputs are included; rendering requires no network. Outputs are created in Reproduce/output/formation_maps. Original full-map PDFs are not bundled; their source URLs and checked legend metadata are retained.
