The Black Range is a north-south trending range that stretches some 60 miles from its northern terminus near Bear Mountain southward to the Kingston Mining District, where it merges with the Mimbres Mountains. The Mimbres mountain range is more or less an extension of the Black Range and is geologically related. The Black Range is a product of the intense volcanism that occurred in southern New Mexico and western Texas during the Oligocene Epoch. It was an extremely violent event. At least 12 calderas have been identified, each pouring out massive amounts of rhyolitic ash-flow tuff. The huge Emory caldera comprises much of the southern Black Range and is the source for the ash-flow tuffs and flow-banded rhyolites that dominate this part of the range. The Emory caldera has been cut by numerous late-Tertiary normal faults resulting in a number of separate block-faulted wedges.
The Black Range consists mostly of silicic volcanic rocks which enclose and intrude highly-faulted blocks of Paleozoic sedimentary rocks. The Paleozoic sediments are predominantly limestones and dolomites and form the host rock for most of the mineral deposits in the Black Range. Many of these ore deposits are localized by the extensive north-south trending fault system that transects the range. As mentioned previously, the volcanic rocks are distinctly felsic and consist of quartz latite to rhyolite lava flows and ash-flow tuffs.
The silver deposits of the Carbonate Creek area occur as replacement bodies in the surrounding Paleozoic limestones and dolomites. Acanthite, proustite, polybasite, native silver, and some native gold were found in a gangue of very fine-grained quartz. The extensive north-south trending fault system that cuts the range was the major ore control for these deposits. Indeed, the only two workable ore-grade deposits were associated with shattered and brecciated jasperoid beds.
The eastern flank of the Black Range is well-endowed with mineral deposits. The Chloride, Hermosa, and Kingston districts are a testament to the richness of this part of the range. The area certainly offers some potential for future strikes, although it was prospected heavily during its heyday.
Prospectors may want to concentrate on the alluvial deposits along Carbonate Creek and Mineral Creek, including their tributaries. A search for more acanthite "float", whether surficial or buried, may prove to be rewarding. A metal-detector would certainly be useful in the search. Prospectors may also want to search for brecciated jasper bodies and investigate them with metal-detectors. The soils and alluvium covering any suspected bodies of jasper should also be surveyed.