One of the responsibilities of the U.S. Geological Survey (USGS) is to collect, analyze, and disseminate minerals information on nonfuel mineral commodities. This data series reflects an ongoing activity by the USGS to monitor and analyze international mineral exploration activities. Understanding mineral exploration activities helps government policy makers, the minerals industry, and the USGS to understand where future mineral resources are being developed or are likely to be developed. These data also provide background information for quantifying possible world mineral supply and integrating economic, societal, and technological mineral exploration trends with other components of materials flow.

The USGS mineral exploration data compilation and dissemination effort originated in 1976 at the request of the U.S. Senate Appropriations Committee to provide articles on the effects of government policies in Canada and the United States on mineral exploration. A grant from the U.S. Bureau of Mines and the USGS provided support for early compilation efforts. Early publication efforts included contributions to Economic Geology (in 1984 and 1992) and Mining Engineering (beginning in 1984). Comprehensive site data by country or mineral commodity were not published by the USGS until 1996. Summaries of 1995 through 2004 mineral exploration site data have been reported annually in the May issue of Mining Engineering.

This report contains exploration data listed by region and country; data are provided in Microsoft Excel and Adobe portable document format (pdf) files Much of the data were compiled from public sources, including but not limited to company press releases and reports, foreign and U.S. Government publications, and industry reports and trade journals. Data were supplemented with information supplied by USGS scientists, contacts in the minerals industry, and other sources. This report includes data on commodities being sought, companies involved, cost of activity, development stage, location of activity, resource quantity and associated commodity grades, site names, sources of information, and types of exploration activity.

Based on these data, a table of the 100 most noteworthy sites was developed for inclusion in each annual Mining Engineering review. Selection criteria were based on the following parameters:

• The high level of exploration activity at the site, determined either by intensity of drilling activity or level of capital investment;
• The size of resource delineated; and/or
• The high potential for near-term development, based on reported tonnage and grade estimates derived from company announcements.

Regional site counts reported in the annual summaries were derived from these data. The change in the number of sites among regions or among countries within a region served as one indicator of the relative intensity of minerals exploration among and within countries or regions over time. Although the number of sites serves as an indicator of the intensity of exploration activity, this does not imply that significant ore will be located or that there will be production in the future.

Site information is reported as published by the source cited. Blank fields indicate that data for that field were not available. Quantified information reported in the “Notes” column are reported in units specified in the source of information but have been converted to metric units in the “Reported resource” and “Activity type” columns. Reported budgets or expenditures are expressed in currencies as reported by the source of information. Costs are assumed to reflect the year of reported activity unless otherwise noted. No attempt was made to validate reported information.

For purposes of brevity, abbreviations have been used in field text. The definitions of all abbreviations and descriptions of category labels are appended to each year’s file.