Identification Information:
Citation:
Citation Information:
Originator: Alberta Energy Regulator
Originator: Alberta Geological Survey
Originator: Peterson, J.T.
Publication Date: 201704
Title:
Sub-Cretaceous Unconformity Paleotopography, Peace River - Slave Lake Region, Alberta (gridded data, ASCII format)
Geospatial Data Presentation Form: raster digital data
Series Information:
Series Name: Digital Data
Issue Identification: DIG 2017-0008
Publication Information:
Publication Place: Edmonton, Alberta, Canada
Publisher: Alberta Geological Survey
Online Linkage: http://ags.aer.ca/document/DIG/DIG_2017_0008.zip
Description:
Abstract:

The sub-Cretaceous unconformity is a major component of the three-dimensional geological model of Alberta. This dataset is a two-and-a-half dimensional (2.5D) grid surface of the sub-Cretaceous unconformity paleotopography for the Peace River and Slave Lake regions of Alberta. The study area covers NTS map sheets 83N, 83O, 84C, and 84B.

To create this grid, stratigraphic picks of the top of the sub-Cretaceous unconformity were geostatistically analyzed and interpolated to model the unconformity surface elevation. A grid of the dominant regional trend was created and subtracted from the elevation grid, creating a residual grid that is a representation of the sub-Cretaceous unconformity paleotopography. The grid was then clipped by the study area boundary.

Purpose: To provide a 2.5D grid surfaceof the sub-Cretaceous unconformity paleotopography.
Supplemental Information: Language: In English;
Time Period of Content:
Time Period Information:
Range of Dates/Times:
Beginning Date: 20150101
Ending Date: 20160101
Currentness Reference: ground condition
Status:
Progress: Complete
Maintenance and Update Frequency: Unknown
Spatial Domain:
Bounding Coordinates:
West Bounding Coordinate: -118.060101
East Bounding Coordinate: -113.831872
North Bounding Coordinate: 57.036901
South Bounding Coordinate: 54.956539
Keywords:
Theme:
Theme Keyword Thesaurus: none
Theme Keyword: data
Theme Keyword: digital data
Theme Keyword: geology
Theme Keyword: gis data
Theme Keyword: paleotopography
Theme Keyword: sub-cretaceous
Theme Keyword: unconformity
Place:
Place Keyword Thesaurus: none
Place Keyword: 83n
Place Keyword: 83o
Place Keyword: 84b
Place Keyword: 84c
Place Keyword: alberta
Place Keyword: canada
Access Constraints: Public
Use Constraints:
Acknowledgement of the Alberta Energy Regulator/Alberta Geological Survey as the originator/source of this information is required as described in the Open Government License - Alberta.
Point of Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Alberta Geological Survey
Contact Person: AGS Information Manager
Contact Position: AGS Information Manager
Contact Address:
Address Type: mailing and physical
Address: Alberta Energy Regulator
Address: 4th Floor, Twin Atria Building
Address: 4999-98 Avenue NW
City: Edmonton
State or Province: Alberta
Postal Code: T6B 2X3
Country: Canada
Contact Voice Telephone: (780) 638-4491
Contact Facsimile Telephone: (780) 422-1459
Contact Electronic Mail Address: AGS-Info@aer.ca
Hours of Service: 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.
Cross Reference:
Citation Information:
Originator: Alberta Energy Regulator
Originator: Alberta Geological Survey
Originator: Peterson, J.T.
Originator: MacCormack, K.E.
Publication Date: 2015
Title:
Paleotopography of the Sub-Cretaceous Unconformity Surface, Peace River - Slave Lake Region, Alberta (NTS 83N, 83O, 84C and 84B)
Geospatial Data Presentation Form: map
Series Information:
Series Name: Map
Issue Identification: MAP 578
Publication Information:
Publication Place: Edmonton, Alberta, Canada
Publisher: Alberta Geological Survey
Other Citation Details: Scale 1:500000. ISBN: 978-1-4601-0148-3
Online Linkage: http://www.ags.aer.ca
Cross Reference:
Citation Information:
Originator: Alberta Energy Regulator
Originator: Alberta Geological Survey
Originator: Peterson, J.T.
Publication Date: 201704
Title:
Sub-Cretaceous Unconformity Picks, Peace River - Slave Lake Region, Alberta (tabular data, tab-delimited)
Geospatial Data Presentation Form: tabular digital data
Series Information:
Series Name: Digital Data
Issue Identification: DIG 2017-0006
Publication Information:
Publication Place: Edmonton, Alberta, Canada
Publisher: Alberta Geological Survey
Online Linkage: http://www.ags.aer.ca
Cross Reference:
Citation Information:
Originator: Alberta Energy Regulator
Originator: Alberta Geological Survey
Originator: Peterson, J.T.
Publication Date: 201704
Title:
Sub-Cretaceous Unconformity Elevation, Peace River - Slave Lake Region, Alberta (gridded data, ASCII format)
Geospatial Data Presentation Form: raster digital data
Series Information:
Series Name: Digital Data
Issue Identification: DIG 2017-0007
Publication Information:
Publication Place: Edmonton, Alberta, Canada
Publisher: Alberta Geological Survey
Online Linkage: http://www.ags.aer.ca
Cross Reference:
Citation Information:
Originator: Alberta Energy Regulator
Originator: Alberta Geological Survey
Originator: Peterson, J.T.
Publication Date: 201704
Title:
Subcrop Extents of Geological Units at the Sub-Cretaceous Unconformity, Peace River - Slave Lake Region, Alberta (GIS data, polygon features)
Geospatial Data Presentation Form: vector digital data
Series Information:
Series Name: Digital Data
Issue Identification: DIG 2017-0009
Publication Information:
Publication Place: Edmonton, Alberta, Canada
Publisher: Alberta Geological Survey
Online Linkage: http://www.ags.aer.ca
Data Quality Information:
Logical Consistency Report:
The grid was exported as a continuous surface in ArcGIS ASCII grid format. The grid cell spacing is 500 m by 500 m, and any grid cells with a null value have been assigned the value -9999.
Completeness Report:
Both the sub-Cretaceous structural elevation grid and regional trend grids were both 500 m x 500 m grids covering the entire study area. The pick dataset used to create these 2 grid surfaces contained a minimum of 3 wells per township where available. In townships where more than three wells were available, wells were selected based on spatial distribution, log data quality, log availability, and log depth. In areas of increased geologic complexity, more wells were used.
Positional Accuracy:
Horizontal Positional Accuracy:
Horizontal Positional Accuracy Report:
We estimate that the recorded well locations are within a 10 m radius of their actual locations. The cells of this grid are 500 m on each side, so any horizontal positional error will have little impact on the accuracy of the grid, considering this is a provincial scale grid and not intended for local scale studies.
Vertical Positional Accuracy:
Vertical Positional Accuracy Report:

The vertical positional error in the paleotopography grid is a function of the unconformity pick set, including data density, the surface complexity (i.e., topographic variability), and the removal of points from the pick set identified as outliers.

Error in the formation pick elevation has two sources, error in the kelly bushing (KB) elevation, from which the pick elevation is derived, and actual errors in the making of the stratigraphic pick. Combined, these two sources of error are likely to have the largest impact on the grid’s vertical accuracy. The occurrence and magnitude of these errors are difficult to quantify. However, they were mitigated in the creation of this grid by geostatistical evaluation to identify and remove outliers.

Lineage:
Process Step:
Process Description:

Step 1: (Input) 4919 picks of the sub-Cretaceous unconformity were created. 4175 of the picks are located within the study area boundary, and an additional 744 picks are located outside the study area boundary to account for edge effects. These picks were geostatistically analyzed for the presence of outliers, defined as points with an elevation value that differs more than 25 m from the predicted value of the modelled surface. All outliers were reviewed, and adjustments were made where necessary to ensure all 4919 picks represented the sub-Cretaceous unconformity as accurately as possible.

Step 2: (Modelling the elevation surface) The sub-Cretaceous unconformity picks were brought into ESRI’s ArcMap software. These data were used to model a regional trend surface which was removed prior to interpolation of the 2.5D elevation surface. The ordinary kriging algorithm was then used in the ArcMap Geostatistical Analyst extension to interpolate the residual elevation values and create a grid of the structure top of the sub-Cretaceous unconformity.

Step 3: (Creating the elevation grid) The regional trend was added back to the residual elevation values to create the final geostatistical layer and then converted into an ArcGIS ASCII grid file.

Step 4: (Modelling the trend surface) The paleotopographic surface of the sub-Cretaceous unconformity can only be evaluated once the predominant regional trends throughout the study area are subtracted from the structural elevation surface. A second order regional polynomial trend surface was determined to provide the optimal surface to capture the predominant regional trend. The second order trend was modelled in ArcMap using the original data point set in order to capture the regional trends of the study area.

Step 5: (Creating the paleotopography grid) The paleotopography of the sub-Cretaceous unconformity was produced by subtracting the regional trend surface from the structural elevation surface. The grid subtraction process was completed in ArcMap and resulted in an ArcGIS ASCII grid file.

Process Date: 2016
Spatial Data Organization Information:
Direct Spatial Reference Method: ASCII Raster
Raster Object Information:
Raster Object Type: Pixel
Row Count: 339
Column Count: 689
Spatial Reference Information:
Horizontal Coordinate System Definition:
Geographic:
Latitude Resolution: 8.9831528411952133e-009
Longitude Resolution: 8.9831528411952133e-009
Geographic Coordinate Units: Decimal Degrees
Geodetic Model:
Horizontal Datum Name: D North American 1983
Ellipsoid Name: GRS 1980
Semi-Major Axis: 6378137.0
Denominator of Flattening Ratio: 298.257222101
Distribution Information:
Distributor:
Contact Information:
Contact Organization Primary:
Contact Organization: Alberta Geological Survey
Contact Person: AGS Information Manager
Contact Position: AGS Information Manager
Contact Address:
Address Type: mailing and physical
Address: Alberta Energy Regulator
Address: 4th Floor, Twin Atria Building
Address: 4999-98 Avenue NW
City: Edmonton
State or Province: Alberta
Postal Code: T6B 2X3
Country: Canada
Contact Voice Telephone: (780) 638-4491
Contact Facsimile Telephone: (780) 422-1459
Contact Electronic Mail Address: AGS-Info@aer.ca
Hours of Service: 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.
Distribution Liability:
The Alberta Energy Regulator/Alberta Geological Survey (AER/AGS) licenses this information under the Open Government License - Alberta. Any references to proprietary software in our documentation, and/or any use of proprietary data formats in our releases, do not constitute endorsement by the AER/AGS of any manufacturer's product.
Metadata Reference Information:
Metadata Date: 20170406
Metadata Contact:
Contact Information:
Contact Organization Primary:
Contact Organization: Alberta Geological Survey
Contact Person: AGS Information Manager
Contact Position: AGS Information Manager
Contact Address:
Address Type: mailing and physical
Address: Alberta Energy Regulator
Address: 4th Floor, Twin Atria Building
Address: 4999-98 Avenue NW
City: Edmonton
State or Province: Alberta
Postal Code: T6B 2X3
Country: Canada
Contact Voice Telephone: (780) 638-4491
Contact Facsimile Telephone: (780) 422-1459
Contact Electronic Mail Address: AGS-Info@aer.ca
Hours of Service: 8:00 a.m. to 12:00 p.m. and 1:00 p.m. to 4:30 p.m.
Metadata Standard Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998
Metadata Time Convention: local time
Metadata Access Constraints: none
Metadata Use Constraints: none