| Title | The Ambient Groundwater Geochemistry Program: northeastern Ontario pilot project |
| Download | Download (whole publication) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Dell, K M |
| Source | Regional-Scale Groundwater Geoscience in Southern Ontario: An Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario Geoscientists Open House; by Russell, H A J ; Ford, D; Holysh, S; Priebe, E H; Geological Survey of Canada, Open File 8528,
2019 p. 10, https://doi.org/10.4095/313579  Open
Access |
| Year | 2019 |
| Alt Series | Ontario Geological Survey, Open File Report 6349 |
| Publisher | Natural Resources Canada |
| Publisher | Government of Ontario |
| Meeting | Regional-Scale Groundwater Geoscience in Southern Ontario: Open House; Guelph; CA; February 27-28, 2019 |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | This publication is contained in Regional-Scale Groundwater
Geoscience in Southern Ontario: An Ontario Geological Survey, Geological Survey of Canada, and Conservation Ontario Geoscientists Open House |
| File format | pdf |
| Province | Ontario |
| NTS | 31M; 40O; 40P; 41A; 41B; 41G; 41H; 41I; 41J; 41K |
| Area | Sudbury; Lake Huron; Manitoulin Island; North Bay |
| Lat/Long WENS | -85.0000 -79.0000 47.0000 43.0000 |
| Subjects | hydrogeology; geochemistry; regional geology; surficial geology/geomorphology; environmental geology; groundwater; groundwater resources; groundwater flow; groundwater geochemistry; aquifers;
groundwater pollution; pollutants; host rocks; bedrock geology; lithology; sediments; clays; overburden thickness; radioactivity; radionuclides; radon; isotopic studies; hydrogen isotopes; oxygen isotopes; potassium; water wells; well samples; water
quality; uranium geochemistry; metals; bacteria; nitrogen; tritium; cobalt geochemistry; arsenic geochemistry; lead geochemistry; copper geochemistry; calcium geochemistry; potassium geochemistry; chlorine geochemistry; bromine geochemistry; lithium
geochemistry; fluorine geochemistry; source areas; brine; Canadian Shield; Southern Province; Huronian Supergroup; Sudbury Basin; Grenville Province; Precambrian |
| Released | 2019 02 08 |
| Abstract | A northern Ontario component of the Ambient Groundwater Geochemistry Program (AGGP) was initiated to determine if the methods employed in this project in southern Ontario could be successful in
delineating the effect of Precambrian host rock lithology on groundwater chemistry. This third season of the AGGP in northern Ontario was completed in 2018 in the North Bay area and follows two others in 2016 in Sudbury and 2017 along the north shore
of Lake Huron and Manitoulin Island. Together, they provide a broad band of samples across north central Ontario at a relatively uniform density. In total, 105 overburden and 337 bedrock wells were sampled and analyzed for metals, anions, bacteria,
nitrogen parameters, tritium, ?2H and ?18O, and radionuclides. With the 2018 project in North Bay, a sufficient sample density and distribution exists to create a detailed characterization of groundwater trends across northeastern Ontario. This
poster illustrates some of the regional trends and groundwater characteristics observed in the northern Ontario AGGP data thus far.
Our preliminary interpretation suggests that groundwater geochemistry is influenced by host lithology,
hydrogeological flow conditions, drift thickness and drift composition. The Precambrian geologic province from which the groundwater originates may be a factor controlling certain regional variations in groundwater chemistry that have been observed.
Samples collected from Southern Province rocks of the Huronian Supergroup and the Sudbury Basin show relatively high Co, As, Pb and Cu concentrations versus the Grenville Province. However, preliminary interpretation of some parameters also reveals
anomalies coincident with surficial geologic features. In the North Bay area, wells completed in bedrock with overlying Pleistocene clay yield groundwater with higher concentrations of TKN and NH4. These may have originated from the overlying clays
because of breakdown of proteinaceous organic matter within the clay. Areas with overlying clay units also have higher gross beta concentrations which may be caused by an enrichment of the naturally occurring 40K isotope in the clays.
Ratios of
Cl-Br show a subset of samples with a measurable influence from deep brine water and another subset where surface contamination is indicated; either from road salt or septic sources. Groundwater samples indicating brine mixing have higher Li, Ca, F-
and Br- concentrations suggesting longer residence times in the aquifer; and this is supported by lower average tritium (half life = 12.3 years) content. Preliminary interpretation of the 2016 and 2017 data indicate that radon in water is controlled
by availability of uranium in the host aquifer. Uranium concentrations, on the other had, are controlled by redox conditions and ion complexing and may not have a strong relationship with uranium concentration in the rocks. Future work will seek to
further characterize the controls on groundwater chemistry, employing tools such as multivariant analysis and sulphur and strontium isotopes to trace the sources of solutes. |
| Summary | (Plain Language Summary, not published)
Volume of abstracts for Ontario Geological Survey and Geological Survey of Canada groundwater geoscience Open house with Conservation Ontario. |
| GEOSCAN ID | 313579 |
|
|