Origin of copper ores of the "red beds" type

Austin Flint Rogers
1916 Economic Geology and The Bulletin of the Society of Economic Geologists  
Oscura in New Mexico contained hematite, pyrite, 'bornire, and only a minor amount of chalcocite. The presence of these minerals and their relations throw some light upon the origin of these interesting ores. • Such light should 'be welcome, for the field relations give no decided evidence as to their origin. The specimens in question are representatives of a widely distributed type of copper ore which may for convenience be called the "Red Beds" type. These copper ores are found principally in
more » ... ound principally in the southwestern part of the United States. They have been described from Arizona, Colorado, New Mexico, Oklahoma, and Texas, 'but seem to be especially common in New Mexico, in which state they have been reported from nine counties. They were first described from A'biquiu, near Santa Fe, New Mexico, by Newberry in a report on the Macomb Expedition of I859, published in I876. Similar occurrences of copper ores are of world-wide distribution, for they have been described from Central Asia (Kirghiz Steppes), Turkestan, Bohemia, England, Nova Scotia, and Bolivia. The Mansfeld (Germany) deposits, though perhaps syngenetic rather than epigenetic, are c}osely related. A general account of the American deposits has been given by S. F. Emmons •' and by Lindgren. a The occurrences in • Since this paper was written Fro. •. Wood replacement (•a) and nodule (•b) from Sierra Oscura, New Mexico. Fro. 2. Polished section of nodule from Sierra Oscura, New Mexico. (p) pyrite; (b) bornite; (cc) chalcocite; (m) melaconite; (h e ) hematite of second generation. Fro. 3. Polished section from Sierra Oscura, New Mexico (h) hematite; (p) pyrite; (b) bornite; (cc) chalcocite; (m) melaconite; (q) quartz. Fro. 4. Polished section of wood replacement from Sierra Oscura, New Mexico. (p) pyrite; (b) bornite with chalcocite border; (m) melaconite. PLATE XVI. ECONOMIC GEOLOGY. VOL Xl.
doi:10.2113/gsecongeo.11.4.366 fatcat:6ocuh3q7znhjbbvvocvasyn2ga