Skip to main content - press Enter key or tab to Skip to Search Form link

Ministry of Mines

Home » Search GeologyOntario » Ontario Mineral Inventory database description

Home » Search GO » OMI description

Ontario Mineral Inventory database descriptionOMI description


This database is current to .

The Ontario Mineral Inventory (OMI) database (previously known as the Mineral Deposit Inventory or MDI database) provides an overview of mineral occurrences in the province of Ontario. It contains information on location, geological environment, exploration history of metallic and industrial mineral occurrences, as well as some building stone and aggregate sites. Occurrences are categorized by their status (e.g., producing mine, developed prospect with reserves or resources, mineral occurrence, etc.). When available, current and historical production and resource data also are included.

OMI data are maintained by staff of the Resident Geologist Program (RGP) and are compiled on an office-by-office basis. In the past, this meant data was viewable only at the office to which the occurrence pertained. The Mineral Inventory (OMI) Database was created to bring together all the data sets and to allow for broader access to all client groups.

OMI data are extracted from various sources, such as publications of the Ontario Geological Survey (OGS) and Geological Survey of Canada (GSC); press releases from the mining industry; National Mineral Inventory (NMI) files of the former Department of Energy, Mines and Resources; Assessment files, Resident Geologist files and information gathered on property visits by Ministry geologists.

The database now contains in excess of 19,000 records and records are continuously being updated, corrected and expanded. The original OMI database, compiled in the 1970s, provided only skeletal information on items such as occurrence name, location, status, commodities, production figures, and geological environment. In 1999, the RGP undertook a major review of the OMI data, and many of the records were deepened to include exploration history, geological information, and resource/reserve and production data. This process is ongoing. Information collected during property visits by RGP staff, as well as information from other sources (e.g., company press releases; National Instrument (NI) 43-101 reports), is now also being documented and included in the records.

OMI data are presented as point locations mapped thematically based on occurrence status, including occurrences, discretionary occurrences, prospects, developed prospects without reserves or resources, developed prospects with reserves or resources, past producing mines with reserves or resources, past producing mines without reserves or resources, and producing mines. Occurrences can be queried either geospatially through a Geographic Information System interface, or alphanumerically directly from the database.

Methods to View/Download Data

The GeologyOntario application provides access to the OMI database through a quick and effective search engine. Searches can be done by using simple keywords or by using focused searches using Boolean operators. Keywords can include the OMI number, occurrence name, status, classification, commodity group, and geographic area (NTS, township). An overview and description of the search types including Boolean can be found in the Help reference.

The OMI database can be downloaded from the GeologyOntario application. It is available as a packaged product provided in 2 formats: 1) a relational database and 2) a geospatial GIS (ESRI® shapefile) format.

The OMI data found on our OGSEarth page can also be viewed using Google Earth Opens in a new window or other applications compatible with Keyhole Markup Language (KML).

Further Information

Further database information and metadata are found within the download package.