Geological surface coverage (2021)
The geological layers presented on the ORMGP Website have been created at different times and by different parties over the past 20+ years. ORMGP staff are regularly checking these geological layers, making adjustments as new data accumulates. However, these incremental changes are only periodically updated onto the website. The Figure below shows the various sets of geological layers that have been built into a regional layers and that are currently reflected on the ORMGP website.
- Area 1 - Red Colour - In the Northwest part of the ORMGP area, the geological surfaces have been acquired through the Simcoe Tier 2 Numerical Modelling project completed in 2010. In this area, the bedrock surface reflects the interpretation of the Ontario Geological Survey (OGS);
- Area 2 – Green Colour - Through the eastern parts of the study area, the geological layers were finalized in 2010 by ORMGP staff after a multi-year interpretation of the Quaternary geology through this region;
- Area 3 – Black Colour - The geological layers in the central part of the study area were initially constructed through ORMGP work and were refined as part of the York Region Tier 3 modelling study (2011);
- Area 4 – Blue Colour – This small area in the north parts of Peel Region was not covered by the York Region work and therefore the geological layers here were originally constructed through ORMGP work and finalized in 2006;
- Area 5 – Blue Colour – The geological layers that are focused in Durham Region reflect the surfaces from the most-recent Durham modelling work completed in 2021. The surfaces were adjusted from the original 2006 surfaces that are reflected in Area 4 (above).
- Area 6 – Pink Colour – Through the southwest parts, the geological surfaces were obtained through the Halton Region Tier 2 and Tier 3 Source Water Protection studies, completed in 2013 and 2014.
Top/surface layer
The top of the geology layers representing the land surface is base on the 10 m OMNRF DEM (2006).