Geology is a science which focuses on the study of solid Earth, the rocks of which it is composed and the processes by which it changes. It provides insight into the Earth's past including the evolutionary history of life and past climates.

Geology is commercially important for mineral exploration and for evaluating natural resources. It also helps find solutions to environmental problems and both predict and understand natural hazards.

Ontario has a long and lively geological past that has shaped the way it appears today. The first piece of the crust that is now Ontario made its appearance more than three billion years ago. Since then, the province has been shaped by the movement of the ever-shifting plates that cover the surface of the Earth.

Ontario is a showcase of geological processes caused by these shifting plates, including volcanism, earthquakes and mountain building. Huge sheets of creeping ice, tropical coral reefs and even salt water lagoons are all part of our province's past.

These exciting events are all recorded in the rocks of the province.

The GeologyOntario (includes OGSEarth) web pages have been updated with a new look.
The updated design improves the user experience by simplifying the layout, making the pages more mobile compatible, and aligning with other Ministry web pages.
Please contact Alphons Evers ( if you encounter any issues after the change or have any questions.

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  • The Ontario Geological Survey regularly publishes maps, reports and digital data on Ontario's geology. The Publications Release Notice identifies upcoming publications one week prior to their release. Publications can be downloaded for free from GeologyOntario (links to new releases are provided in each Release Notice). Maps and reports in hard-copy (paper) format and digital data sets available on physical media (CD or DVD) can be purchased from the Publication Sales office.
  • The Errata section is a compilation of errata that have appeared in the Mines and Minerals Division's Publications Release Notices. Items are organized first by publication type (reports, maps, digital data), then by series number, in descending order. Most errors in publications are found and corrected within 3 months of their release date. If you purchased a copy of any of the publications listed below after this time period, you likely have a corrected version.
  • Land Tenure and Geoscience Resources - The Mines and Minerals division collects data about Ontario's geology. Collected data is assembled into reports, maps and geographic information system data files which are made available through a number of applications.
  • Ontario Geological Survey Publication Indexes - View map indexes and report indexes in pdf format which represent more than 125 years of geologic mapping by the Ontario Geological Survey (OGS).
  • Ontario Geological Survey Map Indexes - Geological Maps and Digital Data indexes for Google Earth contains outlines illustrating areas that have published products released by the Ontario Geological Survey.
    Data includes: published product locations with links to download the product from GeologyOntario.
  • The Ontario Geological Survey conducted approximately 18 geoscience mapping projects across Ontario during 2019. This map highlights active projects planned for Northern and Southern Ontario.
  • Enhance your skills and prepare for your future by working as a summer field assistant with the Ontario Geological Survey!
  • ROCK ONtario - a book which explains the development of Ontario's landforms though geological processes such as plate tectonics, volcanoes, earthquakes and glaciation
  • Simplified Geology and Selected Mineral Deposits - maps which illustrate the simplified geological rock units and mineral deposits that cover Ontario and deposits from the Quaternary period

Resident Geologist Program (RGP)

Resident Geologist Program offices provide public access to geoscience databases and local geological resource material. Resident Geologist Program geologists provide geological consultation and advisory services [pdf]. The Resident Geologist Program also produces monthly reports that may include information on mining and exploration activity, property visits, mine visits, First Nations/Métis meetings, and field trips within each Resident Geologist District. Archived month end reports are available on request.

Recommendations for Exploration highlight key areas for potential mineral exploration and development. Reports are generated annually by staff of the Ontario Geological Survey and are compiled from research, field programs and industry exploration activity that occurred during the year.

Every year, geologists of the Ontario Geological Survey Resident Geologist Program create a compilation of program and mineral sector highlights that occurred throughout the year. This annual compilation is titled Report of Activities, and consists of a series of Open File Reports that include reports from the nine Resident Geologist districts.

Get the latest news on mineral sector activity in Ontario. These reports contain monthly and year-to-date listings of mineral sector activity, and new information available at the Ontario Geological Survey’s 8 Resident Geologist District Offices.

To get in touch with a geologist, contact the Resident Geologists Program or one of their local offices.

Resident Geologist Office Map

Geoscience Topics

Aggregate Aggregate

Aggregate is a construction product made from sand and gravel or by crushing bedrock.

Bedrock Geology Bedrock Geology

Bedrock geology is a general term that refers to the solid rock that lies beneath the soil and other surficial materials like sand and gravel.

Geochemistry Geochemistry

Geochemistry is the study of the chemical composition of Earth and its rocks and minerals.

Geophysics Geophysics

Geophysics is a way of studying the geology and structure of the Earth by measuring its physical properties.

GeoTours Northern Ontario

Welcome to GeoTours Northern Ontario! Rugged Canadian Shield landscapes and a rich mining heritage define much of Northern Ontario. GeoTours dig into the geological stories that explain how Northern Ontario’s well known geological features came to be. We visit lakes and waterfalls, cliffs and canyons, mines and museums.

Groundwater Groundwater

Water held underground in the soil or in pores and crevices in rock is known as groundwater.

Industrial Minerals Industrial Minerals

Industrial minerals are non-metallic minerals that provide resources for the construction, chemical and manufacturing industries of the province.

Land-Use Planning Land-Use Planning

Land-use planning is the process of designating parcels of land for specific uses.

Metallic Minerals Metallic Minerals

A mineral is a solid, naturally occurring combination of inorganic substances. Metallic minerals are minerals which contain one or more metallic elements.

Non-Renewable Energy Non-Renewable Energy

Non-renewable energy is energy that comes from a source that cannot be replaced after it has been used.

Surficial Geology Surficial Geology

Surficial geology, also referred to as Quaternary geology, refers to those unconsolidated geologic materials lying on top of the bedrock.