Type ArcGIS File Geodatabase (GDB), ESRI Shapefiles (SHP) and TIFF (LZW) files
Regional sediment thickness and bedrock topography maps of southwest Nova Scotia were generated to aid in mineral, groundwater, and aggregate exploration, geotechnical investigations, aquifer vulnerability, and surficial geological studies. An understanding of the bedrock topography and distribution and thickness of surficial sediments across this region, including parts of Digby, Yarmouth, Shelburne, and Queens counties, will inform these types of investigations.
The bedrock topography of southern Nova Scotia was generated using raster interpolation tools (Natural Neighbour) in the Spatial Analyst extension of ArcGIS 10.8.1. Depth to bedrock data for 9890 records with adequate location accuracy were derived from five sources: The Nova Scotia Well Logs database (n = 2729; NSE, 2022), the Nova Scotia Test Holes database (n = 39; Nova Scotia Department of Natural Resources and Renewables, 2021), the Nova Scotia Drillholes database (n = 1684; O’Neill and Poole, 2016), and bedrock outcrop points from bedrock mapping (n = 5438, White et al., 2012).
Water well log records were filtered for accuracy of location and stratigraphic information; those records with incomplete log descriptions, incomplete location data, or no depth to bedrock data were excluded from analysis. It is important to note that water well drillers in Nova Scotia have only used GPS equipment to reference well locations since 2004, and so desktop spatial referencing of historical water well logs was conducted using property identification information (e.g., civic/lot number). Only those water well records where location accuracy is within 500 m were included. For drillhole database records, depth to bedrock was calculated using overburden depth and dip measurements; those records with incomplete data on location, depth, or dip were excluded. Outcrop points were filtered to exclude those identified as float and those identified as ‘no plot’ for cartographic thinning purposes. Data points are unevenly distributed throughout the study area which makes the bedrock surface difficult to identify where data are sparse.
The sediment thickness of southwest Nova Scotia was calculated from the difference between the interpolated bedrock topography surface and the 5 m LiDAR surface elevation data using the raster toolset (minus function) in ArcGIS Spatial Analyst. The sediment thickness model shows the variability in thickness of unconsolidated sediments between the bedrock surface and the present-day land surface, up to a maximum of 76 m. This model also provides details on the regional glacial ice flow and sediment depositional and erosional histories and identifies widespread areas of drumlinized terrain, where drumlin ridges exceeding 40 m in thickness and exhibiting multiple flow directions stand out on the land surface, typically characterized by shallow bedrock with a surficial cover less than 5 m. Glaciofluvial and glaciolacustrine deposits commonly occur in topographic lows, which are now occupied by modern rivers and wetlands.
- D.M. Brushett - G.W. Kennedy - C.C. MacMullen
This data is made available under the Nova Scotia Open Government Licence
There is no extent for this item.
| Maximum (zoomed in) | 1:5,000 |
| Minimum (zoomed out) | 1:150,000,000 |
9:00 a.m. to 5:00 p.m. AST Monday-Friday
Data Set ID = d546sw; Data Class = sgeo50; Project ID = SW Nova Sediment Thickness
- D.M. Brushett - G.W. Kennedy - C.C. MacMullen
9:00 a.m. to 5:00 p.m. AST Monday-Friday
This data is made available under the Nova Scotia Open Government Licence
This data is made available under the Nova Scotia Open Government Licence
There may be positional accuracy errors in the digital data that come from the original data collection, plus there are errors added by the process of digitizing the features from the original published source maps or field maps. The transfer of this data from older base maps onto the current base maps may also produce some error. The user should be aware that using this data overlaid on topographic data that was not used during the digital capture of the data may result in apparent errors in the locations of the data that may or may not be real. The user should always try and use background topographic data that is the same as the source topographic data noted in this metadata. The entire risk as to the quality and accuracy of the data is with the user and the user shall use his/her own judgment in making use of the data or drawing conclusions from it.
No conformance or quantitative report
Sediment thickness mapping was conducted to aid in surficial geological and surficial aquifer mapping, and further our understanding of the distribution and thickness of surficial sediments across southwestern Nova Scotia. A surficial thickness map was generated using ESRI ArcGIS kriging analysis functions. Depth to bedrock data from four sources were used: The Nova Scotia water well logs database (669 records; NSE, 2019), Nova Scotia Drillholes database (1698 records; O’Neill and Poole, 2016), and bedrock outcrop points from bedrock mapping (6962 records, White et al., 2012), and the surface elevation data extracted from the lidar digital elevation model. Data were filtered to remove georeferencing errors and incorrect geological descriptions.
Digital dataset and map were created for the sediment thickness mapping/depth to bedrock modelling. Work was done by Angie and Barras and Jeff McKinnon from the GIS group.
DP 546, Data generated by sediment thickness and bedrock topography model of southwest Nova Scotia.
Data from this database was used as control points in generating the bedrock topography of southern Nova Scotia
Data from this database was used as control points in generating the bedrock topography of southern Nova Scotia
Data from this database was used as control points in generating the bedrock topography of southern Nova Scotia
Data from this database was used as control points in generating the bedrock topography of southern Nova Scotia
Digital Elevation Model used in creation of raster datasets
Available: 9:00 a.m. to 5:00 p.m. AST Monday - Friday
ESRI file geodatabase feature class points - control points
ESRI file geodatabase feature class polygons - neatline
ESRI file geodatabase raster - bedrock topography
ESRI file geodatabase raster - sediment thickness
The data set contains a point and a polygon feature class stored in an ESRI file geodatabase, as well as 2 raster feature classes. The shapefile (SHP) downloadable products contains the point and polygon vector feature classes.
doi: 10.4095/293408
doi: 10.1016/S0277-3791(02)00004-5
doi: 10.4138/atlgeol.2010.008
doi: 10.4138/atlgeol.2017.015
9:00 a.m. to 5:00 p.m. AST Monday-Friday