Circular 92—Geochemical anomalies in the Philmont Ranch region, New Mexico

By F. L. Misaqi (Missaghi), 1968, 12 pp., 1 table, 6 figs., 1 plate.

Stream sediment samples were tested for arsenic, lead, zinc, molybdenum, and copper. Anomalous metal contents were noted near Baldy Mountain, along North Fork of Cimarroncito Creek, Sawmill Canyon, Clarks Fork, Bear Creek, Agua Fria Creek, Apache Creek, Bonito Creek, and Moras Creek. More detailed geologic study of these areas may lead to discovery of new ore deposits.

Philmount Scout Ranch, situated in northwestern New Mexico, includes the Baldy mining district, the most important metal producer in Colfax County. In this area, intrusions of dacite porphyry penetrated the sedimentary rock and produced both gold-bearing quartz veins and contact metamorphic deposits in the calcareous sedimentary rocks. The ore of the Aztec mine, the most important mine of the district, came from veins in a sandstone of early Tertiary age or from veins that followed the contact between the sandstone and underlying shale.
Ute Creek, a major placer mining section in the Baldy Mountains area, runs adjacent to the western boundary of Philmount Scout Ranch. Mining operations in this part of the district were conducted to within a mile of the Aztec mill. The Baldy mining district has produced essentially gold. Mining activities in this area ceased after WW II. Metal production of the district prior to 1904 is estimated at 4.5 million dollars. From 1904 to 1948, and additional 3 million dollars' worth of metals was produced.

Stream sediment samples, taken at Philmont Scout Ranch and adjacent areas, were tested for arsenic, lead, zinc, molybdenum, and copper. Some locations in the south-central, southwestern, and southern parts of the investigated area were found anomalous in metal content of stream sediments. The economic significance of the anomalies is yet to be established.