Stratigraphic Maps

Click here for MAP LIST.      Click here for INTERACTIVE MAP INSTRUCTIONS.      Back to TGI II Home

MAP VIEW - Unit Extent

Simplified Time Scale

To view an image of the Okulitch Time Scale click here.

The Stratigraphic Map series from the TGI II project provides seamless 1:1 000 000 maps of the project area, including 45 structure maps and 53 isopach maps, mapping a total of 58 horizons from the Mesozoic and Paleozoic. The maps were drawn from a database containing a selected list of formation tops totalling 9012 wells, which included 2606 wells from Manitoba, 5046 wells from Saskatchewan, 771 wells from North Dakota, and 589 wells from Montana. Computer-generated structure and isopach maps for 56 geological horizons, spanning Manitoba, Saskatchewan, North Dakota and Montana were created. North Dakota and Montana data are hidden on the final suite of maps, but were used during map generation to maintain geological accuracy of the contours at the at the Canada–United States border.

All the maps were computer-generated using ArcInfo® GIS Workstation (version 9.2). Map specifications are as follows: Universal Transverse Mercator projection with a central meridian of 101oW; North American Datum (NAD) 1983. Data points were rasterized as ArcInfo grids which were then contoured, entirely within the ArcInfo Workstation environment. Tension spline spatial interpolation was used to rasterize the structure data and inverse distance weighting used with the isopach data. In areas with sparse well coverage, triangulated irregular networks were used in conjunction with the above techniques. In areas of extremely dense coverage, point values were first averaged in order to avoid bulls-eyes from anomalous data. Extrapolated point values were added outside of the data extents to prevent mathematically anomalous erratic contour behaviour ("edge-effects"). Finally, raster grids were smoothed using a focal mean filter in order to avoid jagged contours.

Data Files

Data files used to create the maps are supplied for each horizon. The data file can be downloaded here, and contains the raster file in ArcInfo grid format, data point shapefiles, contour shapefiles (structure and/or isopach), and the formation edge shapefiles.

The specialized combinations of spatial interpolation and filtering were chosen to portray the regional trends of the data at a small scale. As such, some of the data points may not match the contour values accurately in places, and it would be difficult to replicate the maps using the TGI database without the actual modelling script that was developed specifically for this project. Use of the data files supplied for each horizon is at the user discretion.


The TGI team was dedicated to maintaining accuracy and consistency in the picks and information presented, however due to the size of the project, some errors may have been missed. The TGI team is not liable for these errors. The user of this information accepts all responsibility for any work done on their part that uses all or part of this data.

This data is provided free of charge and may be used and redistributed as long as no fee for the data is charged to third parties. Please ensure that proper referencing of the source is maintained with data sent to third parties.

Maps for free download:


  • Moving the mouse over the geological periods listed under PERIOD will display a list of formations/groups in that Period.
  • Selecting a formation/group will display the corresponding geology on the Map View on the left.
  • Clicking on the Map View will allow you to choose the corresponding isopach or structure map in a printable PDF (1100 kb) format.

 PLEASE NOTE: The TGI stratigraphic column will only function properly with Internet Explorer 5.5 or higher.

  Back to top