In April, the Arizona Geological Survey (AZGS) launched a new digital collection of Arizona’s mining history. The website currently hosts the primary collection of “mine files” created by the former Arizona Department of Mines and Mineral Resources (ADMMR). Documents that were once only accessible by visiting ADMMR can now be found at Minedata.azgs.az.gov. They can be searched by mine name, by points on a map or filtered by keyword. Currently, over 4,000 mine files and 3,300 images are available online.
The content of the mine files varies considerably, but common types of documents include assay results, drill log data, geologic studies, mine owners’ reports, mine maps, photographs, mine histories, and engineers’ field reports.
In 1939, the Fourteenth Arizona Legislature created the Department of Mineral Resources to study the economic challenges of the mining industry in Arizona, particularly those affecting the small mine operator. Shortly after establishment of the department, a call for information was sent out to mining companies, small mine owners, and prospectors. The response was overwhelming and the gathering of information continues to this day. Eventually separate collections for mine maps, photographs, and special collections of consultant and company data were established. These donated collections also contain a great deal of information on exploration projects outside Arizona, primarily in the western states.
The ADMMR was consolidated with the AZGS in 2011. As part of the consolidation, the AZGS received ADMMR’s maps, photos and mining collections. That year, AZGS began an inventory of the 30 archival collections, creating collection guides for the more than 10,000 folders, 6,000 maps, and 7,000 photographs. Inventories of the 30 archival collections are available at Repository.azgs.az.gov (eds. note: use the search term “mining inventory” to list the inventories). Once complete, the team prioritized digitization and description of the three most commonly accessed collections: the ADMMR mining collection, the ADMMR map collection and the ADMMR photo collection.
The mine files are a unique source of historic, geological and mineralogical information for researchers with diverse areas of interest. The primary user group is the exploration geologists in search of data to support further exploration opportunities and potentially economically feasible projects. Reports, drill logs and assays from prior companies are low-hanging fruit compared to fieldwork. Several current exploration projects can be linked to research of these collections.
Others often found reading these files include realtors, developers, historians, genealogists and gem collectors. Archaeologists and environmental geologists commonly review the mine files to learn about the origins of building foundations, adits, shafts or other workings left on the landscape. They may learn when a mine was active, what commodities mined, the minerals that occurred, and the extent of surface or underground workings.
In the coming months, the team will be releasing more files, photos and maps as they are digitized. Until then, please contact us with comments, questions and corrections.
