MRDS
The Mineral Resources Data System, a USGS database of reports on mines, prospects, and mineral occurrences, most complete for the United States, no longer systematically updated.
Detailed Definition
MRDS, the Mineral Resources Data System, is a USGS database of reports on metallic and nonmetallic mineral sites. USGS describes it as "a collection of reports describing metallic and nonmetallic mineral resources throughout the world," including "deposit name, location, commodity, deposit description, geologic characteristics, production, reserves, resources, and references."
Where it came from
The USGS metadata calls it "mineral resource occurrence data covering the world, most thoroughly within the U.S." It combines the original USGS MRDS with the Mineral Availability System/Mineral Industry Locator System (MAS/MILS) "originated in the U.S. Bureau of Mines, which is now part of USGS." It was "developed over several decades by hundreds of researchers and reporters." The metadata lists 304,328 point records, with a data extraction date of March 15, 2016.
Current status
USGS states that "as of 2011, USGS has ceased systematic updates to MRDS, and is working to create a new database, focused primarily on the conterminous US." For Alaska, "the Alaska Resource Data File remains the most coherent collection of such reports."
What a record holds
Fields include site name and former names, latitude and longitude, state and county, commodities, deposit type, ore and gangue minerals, form of the ore body, type of workings, deposit models, host rocks, years of discovery and production, and references. Each site has a development status: occurrence, prospect, producer, past producer, plant, or unknown. See Mineral Deposit for the status definitions.
Limits USGS states
- Records reflect their source reports and are "current only as of the date of those source reports." MRDS "does not reflect up-to-date changes to the operating status of mines, ownership, land status, production figures and estimates of reserves and resources."
- "Positional information is highly variable." "Approximately 4000 records have no reliable geographic coordinates."
- "The database is generally sparse." Per the metadata, 77.7 percent of records have no ore mineral listed and 96.1 percent have no deposit model.
- USGS grades records by quality, from A (the most information) to D (summary only); records graded E "generally lack bibliographic references."
Access
MRDS is free from USGS Mineral Resources Online Spatial Data at mrdata.usgs.gov/mrds. It can be searched, viewed on a map, loaded as WMS and WFS web services, or downloaded as CSV or shapefile. Locations use WGS84.
Why it matters in mining claim research
MRDS shows where mines, prospects, and occurrences have been reported, which helps explain why ground was staked and what a tract was prospected for. It says nothing reliable about current ownership or land status. Those come from BLM mining claim records, master title plats, and county records. See also Prospectivity, Mineral Deposit, and Area of Interest.
Related Terms
Mineral Resource
A concentration of material of economic interest in such form, grade, and quantity that there are reasonable prospects for economic extraction, classed as inferred, indicated, or measured.
Claim Density
The number of mining claims in a unit of area, such as a section or township, used to see where ground is being held and how that changes over time.
Prospectivity
How likely an area is to contain a mineral deposit of a particular type, judged from its geology and the deposits already known nearby.
Mineral Deposit
A natural concentration of a useful mineral or metal in or on the earth, large and rich enough to be worth developing, or potentially so.
Claims Research
Finding and reading the records of the mining claims on a tract, from BLM and the county, to learn what is claimed, by whom, and whether the filings were made on time.
Exploration
Work that tests ground for a mineral deposit, such as sampling, trenching, and drilling. BLM defines it as disturbance greater than casual use to evaluate mineral values.