The document discusses the Ontario Geological Survey's (OGS) work conducting 3D mapping of surficial aquifers in Ontario. The OGS is mapping regional aquifers to address issues like contaminated municipal water, inform legislation around source water protection, and characterize aquifer vulnerability. Mapping involves developing a conceptual geological framework, fieldwork, geophysics, drilling, and building 3D models of sediment packages. Final products include reports, datasets, maps, cross-sections and interactive tools to aid groundwater management, resource development, and scientific studies.

1. 3D Sediment Aquifer Mapping
Ontario, Canada
Abigail Burt
Ontario Geological Survey

2. Today’s Talk
• Introduction
• Why is the OGS doing 3-D mapping?
• Where are we working?
• What are the goals?
• How do we go about 3-D mapping
• What do we produce?

3. Why is the OGS doing 3-D mapping?
• Contaminated municipal water
• Walkerton Inquiry
• Provincial legislation!!!!!

4. Legislation
Source Water Protection Plans
• Watershed characterization
• Water budget
• Aquifer recharge
• Aquifer vulnerability
• Well head protection areas
• Threats to drinking water
Greenbelt Act
Places to Grow Act

5. Where are we working?

6. Build a 3D model of Quaternary deposits that
form regional-scale aquifers and aquitards
• Reconstruct the regional Quaternary history and develop a
conceptual geological framework
• Construct a 3D model of key sediment packages
• Characterize the properties of modelled sediment packages

7. How do we go about 3-D mapping?

8. Build a Conceptual Framework

9. Fieldwork
• Auger and probe holes
• Pits and quarries
• River and lake bluffs

12. Glaciolacustrine
sediments
Till
Peat
Shallow water
glaciolacustrine Glaciolacustrine
Outwash
Peat
Shallow water
Beverly Swamp

13. Lake Erie Dunes
Dune
Glaciolacustrine
Sediments
Dune
Peat
Lagoon
4135 BP

14. Southern Wetlands
Dune Reactivation
Glaciolacustrine
Sediments
Peat
Till
Dune Reactivation
Glaciolacustrine
Sediments
Peat
4440 BP 8235 BP

15. Lake Ontario Bluffs

16. Till
Deformed
deep water
glaciolacustrine
sediments
Shallow water
glaciolacustrine
sediments
Shore
Till
Deformed
deep water
glaciolacustrine
sediments
Deep water
glaciolacustrine
sediments
Shore

17. Ground-based gravity surveys
• Show the least sensitivity
to cultural interference.
• Not affected by
stratigraphy (velocity
contrasts of stratigraphic
units) and depth to water
table.
• Simple and cheap

19. Time-Domain Electromagnetic Survey

20. Drilling!!!

22. Detailed Logs

23. Legacy Data

24. Reduce and translate
Sand
Sandy
Quicksand
Medium sand
Coarse sand
Sand
New Term
Original
Term 1
Original
Term 2
Original
Term 3
Gravel Gravel Packed Water-bearing
Sand Sand Sand Silt
Sand Sand Soft Clean
Clay Clay Sticky Soft
Diamicton Clay Sand Gravel
Diamicton Hardpan NA NA

25. Building a 3-D Model
Plot borehole
traces
Digitize 3-D
points (picks)

26. Building a 3-D Model
Fill spaces
with blocks
Create 3-D
wireframe
surfaces

27. What really goes on….
Tales from the Orangeville Moraine

28. DEM

29. Drift Thickness

30. Surficial Geology

31. Surficial Geology
We are a long way from
Niagara…
• Lots of till (green)
• Lots of sand and gravel
(orange and beige)
• LANDFORMS!!!!

32. What about those tills?
• Tiny windows into older glaciations
• Some tills look different, some don’t
• PSA, Chittick, HM, Pebbles, fabrics
• LANDFORMS

33. Outwash!
• Paleoflows (sediment source)
• Flow velocity
• Ice margins

34. Bars (no, not that kind of bar)
Bar Front
Bar core
Waning Flow

35. The Orangeville Moraine

36. The Orangeville Moraine

37. Coarse

38. And fine

39. Stratigraphy!

40. Drilling!

41. Conceptual Framework

42. Bedrock Surface

43. Older Sediments
• Weathered bedrock and
contact aquifer
• Older tills (aquitards)
• Stratified sediments overlying
the tills (aquifers)
SE
5 cm
5 cm
5 cm
5 cm

44. The magic of sub-till organics!
5 cm
>52 200
54 500 +2 900
• Radiocarbon dating
• Pollen / macrofossils

45. Late Wisconsin Glaciation
• Early lobate flow
• Main glaciation
characterized by
regional flow
NW SE
5 cm
5 cm
5 cm

46. Breakup of Catfish Creek Ice
• Ice thins and begins
to break up
• Glaciolacustrine
sediments and fine-
textured diamicton
deposited
• Rare coarse-textured
glaciofluvial
sediments
NW SE
5 cm
5 cm
5 cm

47. Orangeville Moraine
• Paleoflow directions to the
southwest
• Coarse-textured proximal
sediments
• Fine-textured distal
sediments dominant
NW SE

48. Ice from all directions
• Port Bruce advance of
Ontario, Huron and
Simcoe lobe ice
• Advanced over the flanks
of the Orangeville
moraine
• Drumlins, streamlined
landforms, till fabrics
NW SE
5 cm
5 cm
5 cm

49. Final Advance
• Advance of
Ontario lobe
ice
• Paris moraine
(end moraine)
NW SE

50. What our clients want to know
• Aquifer or aquitard?
• Location / continuity?
• Thickness / volume?
• Surface elevation?
• Pathways?
• Characteristics?
• Reliability?

51. The subsurface revealed!
• Stratigraphy
• Pathways?

52. Interpretation
Thickness
Surface
Elevation

53. Don’t over do it!

54. Are buried valleys important?

55. YES!!!

56. Aquifer or drain?

57. Monitor!

58. Products: guiding principles
• Standardized from one project
area to the next
• Terminology and geologic
conceptualizations need to be
standardized to allow for
merging of models
• Products need to be useable by a
wide range of clients
• Need to release products that
eliminate the need for high-end
computers or software to use
the data.

59. Products
Groundwater
Resource Studies
Datamine exports of volumes and
grids for hydrogeologists and
geoscience specialists
Interactive
drillhole data

60. Maps and Cross-Sections
Prepared cross-sections
Aquifer recharge and
vulnerability maps
Structural contour and
isopach maps

61. Cross-Section Viewer and Google Earth

62. Groundwater Applications
• Source water protection
• Search for new water supplies
• Groundwater flow models
• Tier 2 and 3 water budgets
• Monitoring wells (PGMN)
• Sanitary landfill planning
• Remediation of Ontario’s brownfields
• Nutrient management plans

63. Resource Applications
• Protection of sensitive ecosystems
• Environmental Bill of Rights
• Geotechnical studies
• Bridges and overpasses
• Building foundations
• Resource development
• Search for buried aggregate

64. Scientific Applications
• Stratigraphic studies
• Improved regional framework
• New radiocarbon dates
• Climate Change
• The past is the key to the future
Measured sections, borehole logs
and geophysical profiles are
excellent primary data sources

65. Summary
• Rural and urban Ontarians rely on overburden aquifers for their water supply.
• The OGS is engaged in the effort to find, assess and protect Ontario’s
groundwater resource through regional scale and targeted 3-D surficial aquifer
mapping projects.
• Each 3-D project addresses
• Quaternary history
• Conceptual framework
• 3-D mapping
• Interpretation
• Groundwater resource reports, digital datasets, maps, cross-sections and
Google Earth applications are key products.

66. http://www.geologyontario.mndm.gov.on.ca/