Project Metadata

Since 1980, the Ontario Geological Survey (OGS) has carried out a series of annual, interdisciplinary studies of northern lakes to investigate the relationship between geochemistry and lake acidification.

These studies have contributed to the development of a more effective methodology for geochemical surveying at the regional level, based on the chemical analysis of lake sediments and waters, for the purpose of mineral resource appraisal and for surveys that also have an environmental component.

The following multi-disciplinary studies (geochemical, limnological, palynological) were carried out:

 

Year	District	OGS Publication
1980	Algoma	OFR5342
1981 + 1982	Algoma	OFR5483
1983	Algoma	MP116, p. 148-150
1983	Sudbury	MP116, p. 161-163

 

The studies in 1980-1982 showed that for an acid precipitation study, the determination of pH in lake waters during regional geochemical surveys was not sufficient.  The team developed a "diatom inferred paleo pH indicator method" for providing data on the pH history of lakes particularly in post Ambrosia time.

The purpose of the 1983 research was to study the limnology and geochemistry of lakes with low pH in a new area in order to establish a wide validity for the diatom inferred pH indicator.  Another purpose was to attempt to distinguish between naturally acid lakes and acid lakes in which the pH has been recently affected by atmospheric fallout.

 

In 1984 and 1985, recognizing that diatom inferred pH measurements were time consuming, required specialized expertise and were therefore impractical for routine use in future regional geochemical surveys, the OGS tested the use of remote sensing techniques to identify geochemical and limnological characteristics of acid lakes:

 

Year	District	OGS Publication
1984	Algoma	MP119, p. 147-151
1985	Algoma	Map M80797

 

In 1984 the possible role of long cores in future regional geochemical surveys which include an environmental (acid rain) component was studied.  The results are published in OGS Map M80757.

In 1986, surveys to provide examples of the new methodology were carried out in two areas: one in the Mitchell Lake area, located 70 km north of Sault Ste. Marie, and the other in the Sturgeon River area, 65 km northeast of Sudbury.  The data and a detailed description of the studies are published on OGS Maps M80798 (Mitchell Lake) and M80799 (Sturgeon River).

The Ontario Geological Survey began as the Ontario Bureau of Mines in 1891, with a mandate to aid in promoting Ontario's mining interests. Through key collaborations and advancing geoscience data collection techniques, the organization evolved into a globally renowned survey that is now at the forefront of geological research.

Since its establishment, the Ontario Geological Survey has contributed significantly to fostering investment in Ontario, protecting public health and safety, informing environmental and land-use planning decisions, and helping the province become Canada's top mineral jurisdiction.

 

[from: https://news.ontario.ca/en/release/36088/celebrating-125-years-of-the-ontario-geological-survey ; accessed August 3, 2021]