Mineral Deposit Inventory Database

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On hold. This database is current to July 2, 2021.

The Mineral Deposit Inventory (MDI) 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 deposits, as well as some building stone and aggregate sites. Deposits are categorized by their status (e.g., producing mine, mineral occurrence, etc.). When available, current and historical production and reserve data also are included.

MDI 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 Deposit Inventory (MDI) Database was created to bring together all the data sets and to allow for broader access to all client groups.

MDI 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 MDI database, compiled in the 1970s, provided only skeletal information on items such as deposit name, location, status, commodities, production figures, and geological environment. In 1999, the RGP undertook a major review of the MDI data, and many of the records were deepened to include exploration history, geological information, and 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.

MDI data are presented as point locations mapped thematically based on deposit status, including occurrences, discretionary occurrences, deposits, past producing mines with reserves, past producing mines without reserves, and producing mines. Deposits 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 MDI 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 mdi number, deposit 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 Me reference.

The MDI 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 MDI 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.

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