Geoscience research topics
Learn how the Ontario Geological Survey uses geoscience data to help inform mineral exploration and land-use planning.
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Metallic minerals are minerals which contain one or more metallic elements.
Metallic minerals occur in rare, naturally formed concentrations known as mineral deposits. These deposits can consist of a variety of metallic minerals containing valuable metals that are used in various aspects of our daily lives, such as:
- nickel (pentlandite)
- copper (chalcopyrite)
- zinc (sphalerite)
- lithium (spodumene)
- lead (galena)
- gold (occurs as a native element or as a minor constituent within other minerals)
Metallic minerals must be broken apart and chemically processed to extract the useful metal from the mineral.
Ontario is a leading producer of metals. Metals such as nickel, copper and lithium are important to modern society since they are used for products, such as:
- stainless steel and rechargeable batteries (nickel)
- electrical wire and plumbing (copper)
- rechargeable lithium-ion batteries (lithium)
What we do
To identify and manage metallic minerals, we:
- maintain an inventory of metallic mineral occurrences
- publish annual recommendations for mineral exploration
- study the earth processes that caused mineral deposits to form
How our maps are used
The geological maps we produce:
- illustrate the geology of Ontario
- identify the geological environments where mineral deposits may occur
Geologists can use these maps to assess the likelihood of an area of land to have potential for metallic mineral deposits. Land-use planners also use these maps to help in their decision-making processes.
Areas with high mineral potential help to:
- attract mineral investment
- provide data for land-use planning and resource development
- ensure large areas of land remain accessible for the discovery of future mineral resources
Industrial minerals are non-metallic minerals used in the construction, chemical and manufacturing industries.
Industrial minerals are used in:
- construction materials, such as building stone, insulation, clays and shales for brick manufacture
- chemical applications, such as salt for de-icing and various chemical products
- manufacturing processes, such as limestone and dolostone for iron and steel, paper production, ceramics and electronics
What we do
We identify areas of the province that have industrial mineral potential by:
- outlining areas of bedrock or surficial material, at or near the surface of the earth, that may contain industrial minerals
- assessing the potential quality and quantity of industrial minerals
- producing maps, reports and datasets of the location, quantity, and physical and chemical characteristics of industrial minerals
Aggregate is a construction product made from sand and gravel or by crushing bedrock.
Land containing aggregate, particularly around cities, is sought after for a variety of competing uses.
Aggregate is used to build:
- roads and highways
- buildings, such as homes or hospitals
- infrastructure that protects and serves the public, such as dams and airports
Identifying aggregate resources:
- helps protect aggregates so they can be used before the land is built on
- ensures a continued supply of close-to-market building materials, which lowers the cost of aggregate
Public infrastructure projects use 60% of the aggregate produced in Ontario.
What we do
To identify areas of potential sources of aggregates, we:
- outline areas of sand and gravel, and bedrock at or near the surface of the earth
- assess the potential quality and quantity of the aggregate sources
- create maps and reports, referred to as Aggregate Resource Inventory Papers
- recommend areas with high aggregate potential for protection in municipal land-use plans
Bedrock geology is the solid rock that lies beneath the soil and other surficial materials like sand and gravel.
Bedrock geology influences the surface features and drainage patterns of the earth.
Types of bedrock geology
The bedrock geology of Ontario is divided into two broad types, based on age:
- Precambrian Canadian Shield
- Paleozoic and Mesozoic sedimentary rocks
Precambrian Canadian Shield
The Precambrian Canadian Shield consists of very old, resistant rocks that range in age from 570 million to more than three billion years old.
The rocks of the Canadian Shield consist of crystalline igneous, sedimentary and metamorphic rocks. These rocks have had a complex history of:
- volcanic eruptions
- mountain building
- weathering and erosion
These rocks contain the majority of Ontario’s metallic mineral deposits. They are located in areas known as greenstone belts because they are mostly composed of green or gray volcanic and sedimentary rocks.
Paleozoic and Mesozoic sedimentary rocks
Ontario’s bedrock is also composed of younger Paleozoic and Mesozoic sedimentary rocks. They range in age from 63 to 570 million years old and contain valuable deposits of:
- natural gas
- building stone
These rocks were deposited in large sedimentary basins during long periods of sedimentation. Paleozoic and Mesozoic rocks underlie:
- the Hudson and James Bay lowlands of Northern Ontario
- the St. Lawrence and Great Lakes lowlands of Southern Ontario, including the Niagara Escarpment
How bedrock geology data is used
Bedrock geology maps influence land-use and development by:
- identifying areas of high mineral potential which attract mineral investment
- identifying faults in the bedrock that control the flow of groundwater
- identifying rock types that can be used for building stone and road construction
- suggesting areas of potential high mineral concentrations which may pose a health risk
Bedrock geology maps are also used as:
- a foundation for further geoscience research by universities and colleges
- educational tools for the public at museums and science centres
What we do
We are responsible for describing the types, characteristics, distribution and history of bedrock to provide:
- a framework for mineral development by documenting areas with favourable mineral potential
- geoscience data for effective and informed land-use planning
- a better understanding of the history and evolution of Ontario’s geology and the earth’s crust
Geochemistry is the study of the chemical composition of earth and its rocks and minerals.
Materials that are frequently sampled for geochemical analysis include:
- mineral grains
- lake sediments (mud from the lake bottom)
- overburden (soils)
- groundwater and surface water
How geochemistry is used
Geochemical analysis is used in mineral exploration. The abundance of one or more elements:
- may indicate the presence of nearby mineralization
- provides a target area for follow-up exploration
Geochemistry is also helpful with assessing the state of the environment. Geochemical analyses can determine the naturally or non-naturally occurring levels of elements and substances in the ecosystem.
The geochemical composition of land and water can also affect human and animal health. Knowing about areas where health threats exist helps address or mitigate them.
What we do
To determine the chemical composition of the landscape, we conduct sampling programs across the province that target a variety of materials. We analyze the samples to determine what elements are present and in what abundance.
- survey regional-scale drift, lake sediment and water, also known as surficial geochemistry
- sample bedrock as part of regional and thematic mapping projects, also known as lithogeochemistry
- sample groundwater across the province, also known as aqueous geochemistry
- research rocks and minerals to address questions or issues
- provide analyses and services through our geoscience laboratories
Geophysics is a way of studying the geology and structure of the earth by measuring its physical properties. Geophysics is used to help find rocks and minerals that are hidden below the surface.
How geophysics is used
Much of Ontario is covered by a thick blanket of overburden, which is overlying material like vegetation and soil. This overburden was deposited by glaciers as they retreated at the end of the last Ice Age. Because there is little rock exposed at surface, geologists and mineral prospectors must use geophysics to help them with their work.
Geophysics is used to measure:
- the Earth’s magnetic and gravitational properties
- electrical properties
- naturally occurring radioactivity
- acoustic (seismic) properties
Many of these surveys can be performed from the air, on the ground and even underground in boreholes and mines.
Geophysics can also be used for:
- geological mapping
- mineral exploration
- land-use planning
- engineering studies
- mapping underground water resources
- energy exploration
What we do
To understand and determine geophysics, we:
- acquire new geophysical data in Ontario
- publish the geophysics as maps and digital data
- use geophysics to help with the geological mapping of Ontario
Water held underground in the soil, rock layers or in pores and crevices in rock is known as groundwater.
Groundwater mapping determines:
- the geologic conditions, both in bedrock and the overlying surficial sediments, that control where groundwater is found
- how much groundwater is available for extraction
Testing samples of the water helps us:
- understand whether groundwater can be used as drinking water
- determines any human-induced impacts
How groundwater mapping is used
Groundwater mapping helps determine the future availability of groundwater, which can be used for drinking water.
Knowing the quality and quantity of groundwater allows municipalities and landowners to plan for long-term sustainable groundwater extraction and use.
Mapping also helps us understand the vulnerability of groundwater resources to contamination from surface sources of pollution or waste. This information can be incorporated into planning decisions to:
- guide development
- preserve current and future sources of groundwater
What we do
Our groundwater mapping program is designed to provide geoscience information on the location and character of subsurface water-bearing layers, called groundwater aquifers.
The program has the following components:
- three-dimensional (3D) aquifer mapping studies
- ambient groundwater geochemical survey
- geology map and data compilations using geographic information system (GIS) applications
- working with other agencies to complete thematic geological studies to address a local groundwater concern or need
Land-use planning is the process of designating sections of land for specific uses.
Land-use planning involves:
- gathering land related descriptions or values
- considering those values for present and future government or societal interests
- designating certain activities that can take place on that land
How geological process influence land-use planning
Geological processes define or create:
Geological processes may also give rise to earthquakes, unstable land and other natural hazards.
The distribution of flora and fauna is influenced by geological materials processes. Recreational and development opportunities are also influenced by the nature of the local geology.
Geological materials may:
- contain groundwater
- contain natural minerals that influence health
- may be the source of mineral resources and non-renewable energy resources
It is important for land use planners to consider geological processes, materials and features when making land-use decisions.
What we do
To assist with land use planning, we:
- provide credible, independent and plain-language geological data and knowledge that can be used by municipal and provincial land use planning officials
- explain impacts of land use planning decisions on mineral and non-renewable resource development
- identify areas where natural or man-made geological hazards have the potential to impact community development
Non-renewable energy is energy that comes from a source that cannot be replaced after it is used.
In Ontario, traditional sources of non-renewable energy include:
- natural gas
- nuclear energy
Ontario also has the potential for non-conventional energy resources in the form of:
- compressed air energy storage (storing electrical energy)
How geological mapping can help identify non-renewable energy
Geological mapping of rock units identifies structures, such as faults, properties and characteristics of sedimentary rock to identify non-renewable resources.
Geological research in the subsurface environment allows more efficient and effective exploration for energy sources by identifying the most prospective units for bearing hydrocarbons and storage of future energy resources.
What we do
We produce maps and reports that describe the type and distribution of the quaternary sediments and bedrock (sedimentary, igneous and metamorphic) to:
- assemble and interpret geoscience data to show where non-renewable energy resources may be present
- conduct research on the character of geological materials that host energy resources so we can understand their potential
- conduct research on the nature of bedrock for:
- potential storage of energy resources (such as compressed air and hydrogen)
- dispersal of gases to reduce the carbon footprint of Ontario industries (for example, carbon sequestration)
- be a source of information and expertise to help those:
- exploring, developing and managing energy resources
- looking to store energy or reduce their carbon footprint
Surficial geology, also referred to as quaternary geology, is the unconsolidated geologic materials lying on top of the bedrock.
The Quaternary Period covers the last 2.588 million years of Earth history. In Ontario, almost all surficial sediments are much younger, less than 45,000 years old, because the sediments were deposited either during or after the last glaciation.
Common surficial materials include:
- sand and gravel
- glacial tills
- clay and silts
In Ontario, Quaternary sediments are generally thin, less than 10m. But in some areas of the province, thick successions (more than 100m) were deposited during the advance and retreat of the Laurentide ice sheet.
How we use surficial geology
Knowledge of Ontario’s surficial geology influences:
- industrial growth
- agricultural practices
- how and where we build roads, buildings and communities
- the flow and quality of surface and groundwater
We need to understand surficial geology to be able to develop on the earth’s surface. For example, mapping the surficial sediments identifies resources, such as sand and gravel, which can be used to:
- produce construction aggregates
- host underground water sources (aquifers) that contribute to the drinking water supply of Ontario residents
Environmental management and land stewardship also benefit from surficial mapping, as it outlines the geological controls in ecologically sensitive terrains, lands containing hazards and areas vulnerable to disturbance.
What we do
We collect detailed, high-quality geoscience data, and produce maps and reports that describe the properties and distribution of surficial deposits to:
- assist with resource evaluations such as groundwater assessments and aggregate inventories
- provide a framework for mineral exploration involving the use of overburden (drift) samples
- identify features and characteristics of Ontario’s landscapes that are ecologically importance or affect public health and safety
How we collect data
We examine sediments exposed at surface along roadsides, trails, excavations, as well as natural exposures along riverbanks and lake bluffs.
Where no exposures are available, we use sediment probes or augers, or we might dig a test-pit to enable sampling of the sediments for various analyses, such as:
- grain size
- geotechnical properties
- sediment age
In areas where sediments are thicker, we may undertake geophysical investigations or drilling programs to assist in characterizing the properties and distribution of different sediment units.