Preliminary Metallogenic Map of North America: A listing of deposits by commodity
The 4,215 ore deposits shown on the Preliminary Metallogenic Map of North America and contained in the Metallogenic Map file have been sorted by their principal (first-listed) commodities and grouped into metallic and nonmetallic categories. Deposit listings for 56 individual metals and minerals have been assembled using the data base and are arranged alphabetically by country, political subdivision (for the larger countries), and deposit name. Map numbers, major and minor constituents, geographic coordinates, and a geologic code are given for each deposit; additionally, the relative size and deposit class have been derived from the code and are listed separately. The frequencies of individual commodities and commodity groups by type, geographic distribution, and geologic occurrence are summarized in tables, and the relationships of associated commodities to principal commodities in the data base are emphasized in both tables and brief texts. In all, 49 metals and minerals are listed as principal (first or only) commodities and 7 more are shown as 'major' but not principal commodities. (Commodities listed as 'minor' in the data base were not sorted or tabulated separately.) Metals, divided into six subgroups, predominate over nonmetallic minerals by a ratio of about 7 to 1, although in terms of quantities and value the disparity is not so great. Within the metals group, the ranking according to frequency is as follows: base, precious, iron and alloying, other (antimony, beryllium, and others), nuclear-fuel, and light metals. The most frequently occurring commodity in the Metallogenic Map file is gold. Copper is ranked second, both in number of occurrences and as the principal commodity in deposits. Silver is ranked third in frequency of occurrence; lead and zinc are ranked fourth and fifth, respectively. Iron, ranked sixth in frequency of occurrence as a major commodity, is the third most reported principal commodity in the data base, ahead of silver (ranked fourth), lead (ranked fifth), and zinc (ranked sixth).