Metallic ore deposits constitute the largest geochemical anomalies within the crust. Their study has been critical to understanding the behavior of elements and isotopes in mineral- and rock-forming processes, as well as to deciphering the geochemical differentiation of the Earth through time. The study of ore deposits therefore influences and draws upon virtually every subdiscipline in the Earth Sciences.
The four-year research review presented here cannot be comprehensive, given the editor's limit of citing less than 100 research papers by U.S. authors or authors from U.S. institutions. Instead, the intent is to provide the reader with synopses of a representative spectrum of papers containing important advances in U.S. research on ore deposits. In cases where difficult citation choices had to be made the more recent papers on a particular subtopic are usually cited, because they lead the reader back to earlier papers within the 4-year review period. Judicious use of the selected citations in conjunction with standard literature searching tools should allow any reader to quickly find most of the relevant literature on each subtopic.
The most recent quadrennial report on ore deposits was made by Burt [1991] for the period from late 1986 to mid-1990, so the present review cites only publications appearing between mid-1990 and mid-1994. Citations are made only to peer-reviewed publications appearing in major journals, periodicals and books. Meetings abstracts, conference and symposia proceedings, field trip guidebooks, open-file reports, and other ``gray'' literature have not been cited.
Of the journals whose articles deal mainly with ore deposits and economic geology the most important is Economic Geology, which at the time of this review had published the fourth issue of 1994. Occasional Monographs on special topics are also issued. The quarterly Newsletter of the Society of Economic Geologists, which appeared beginning in April of 1990, is also a valuable source of current research, exploration, mining, and environmental trends in the area of metallic mineral resources. Both the Society of Economic Geologists and the Mineralogical Society of America periodically publish review volumes that emphasize U.S. research on ore deposits. Other major journals that sometimes contain articles about U.S. research on ore deposits include American Journal of Science, American Mineralogist, Canadian Mineralogist, Chemical Geology, Geochimica et Cosmochimica Acta, Geology, Journal of Geochemical Exploration, and Mineralium Deposita. The U. S. Geological Survey (USGS) frequently publishes bulletins, papers, monographs, circulars, and maps on ore deposits, as do many state and county geological surveys.