2
(McLemore, 2000). Both sites have waste rock piles and
tailings available for sampling.
The benefits of this project are to ensure prospects for
critical minerals in New Mexico are not lost to urbaniza-
tion, settlement, or other land use. This project would
ensure that there are data and archived samples for future
studies and advance research as these mine features may
not be accessible after reclamation. Future mining of mine
wastes that potentially contain critical minerals will directly
benefit the economy of New Mexico, as well as potentially
fund reclamation.
MAIN OBJECTIVES
The purpose of this project is to:
• “Beta-test” USGS procedures for sampling mine
wastes.
• Determine the acid generating potential of mine
waste in NM
• Characterize and estimate the critical minerals
endowment of mine wastes in two mining districts
in NM (i.e., Copper Flat at Hillsboro and Carlisle-
Center mines in Steeple Rock district).
THE STUDY AREAS
Figure 1 shows the study areas of the mine waste project.
However, my focus areas would be the Carlisle-Center
mines in the Steeple Rock district and Copper Flat mine
in the Hillsboro district, which are in southwestern New
Mexico.
Carlisle-Center (Steeple Rock)
The Carlisle-Center mines in the Steeple Rock district, west
of Silver City, are an example of a low sulfidation, volca-
nic-epithermal system and contain Au-Ag veins among
other deposit types. Known critical minerals in the district
include As, Bi, Te, fluorite, and Zn. Exploration in the dis-
trict began about 1860, but production was not reported
until 1880. An estimated $10 million worth of metals were
produced from the district between 1880 and 1994, which
includes approximately 151,000 ounces Au, 3.4 million
ounces Ag, 1.2 million pounds Cu, 5 million pounds Pb,
and 4 million pounds Zn, mostly from the Carlisle and
Center mines (McLemore, 1993). In the Steeple Rock dis-
trict, there are 6 distinct types of mineral deposits (base-
metal (Ag, ±Au), Au-Ag (±base metals), Cu-Ag, fluorite,
Mn, and high- sulfidation disseminated Au deposits) that
are spatially related to two types of alteration assemblages
(1) acid-
pH (alunite, kaolinite, quartz or acid-sulfate) and (2)
neutral-pH (propylitic to sericitic) (McLemore, 1993,
1996, 2000). The Center mine operated during the 1990s
and further exploration occurred at the Carlisle mine dur-
ing the 1990s. Both mines are flooded and have waste rock
piles on the surface, which have been sampled. Tailings are
also present at the Carlisle mine and have also been sam-
pled for this project.
Copper Flat (Hillsboro)
The Copper Flat mine in the Hillsboro district, east of
Silver City is an example of a porphyry copper deposit,
among other related deposit types. Known critical minerals
in the district include Te, As, Bi, Mg, Mn, and Zn. Copper
Flat has proven and probable reserves of 45.5Mt of ore at
a reported grade of 0.45% Cu, 0.14g/t Au, 2.3 g/t Ag and
0.0015% Mo. The district consists of Cretaceous andesites
surrounded by Paleozoic sedimentary rocks and Quaternary
alluvial fan deposits. A quartz monzonite stock (74.93±0.66
Ma) with a breccia pipe is located in the center of the dis-
trict and a series of latite dikes radiate outwards from the
quartz monzonite. The quartz monzonite porphyry and the
latite dikes are co-genetic. Replacement deposits, which
occur near the porphyry deposit, are also genetically related
to porphyry deposits. The Copper Flat porphyry copper
deposit consists of Cu, Au, Mo, and Ag disseminations
and quartz veins in the breccia pipe. Propagating outward
Figure 1. Location of the Copper Flat at Hillsboro, Black
Hawk in Burro Mountains, and Carlisle-Center mine in
Steeple Rock areas, southwestern NM
(McLemore, 2000). Both sites have waste rock piles and
tailings available for sampling.
The benefits of this project are to ensure prospects for
critical minerals in New Mexico are not lost to urbaniza-
tion, settlement, or other land use. This project would
ensure that there are data and archived samples for future
studies and advance research as these mine features may
not be accessible after reclamation. Future mining of mine
wastes that potentially contain critical minerals will directly
benefit the economy of New Mexico, as well as potentially
fund reclamation.
MAIN OBJECTIVES
The purpose of this project is to:
• “Beta-test” USGS procedures for sampling mine
wastes.
• Determine the acid generating potential of mine
waste in NM
• Characterize and estimate the critical minerals
endowment of mine wastes in two mining districts
in NM (i.e., Copper Flat at Hillsboro and Carlisle-
Center mines in Steeple Rock district).
THE STUDY AREAS
Figure 1 shows the study areas of the mine waste project.
However, my focus areas would be the Carlisle-Center
mines in the Steeple Rock district and Copper Flat mine
in the Hillsboro district, which are in southwestern New
Mexico.
Carlisle-Center (Steeple Rock)
The Carlisle-Center mines in the Steeple Rock district, west
of Silver City, are an example of a low sulfidation, volca-
nic-epithermal system and contain Au-Ag veins among
other deposit types. Known critical minerals in the district
include As, Bi, Te, fluorite, and Zn. Exploration in the dis-
trict began about 1860, but production was not reported
until 1880. An estimated $10 million worth of metals were
produced from the district between 1880 and 1994, which
includes approximately 151,000 ounces Au, 3.4 million
ounces Ag, 1.2 million pounds Cu, 5 million pounds Pb,
and 4 million pounds Zn, mostly from the Carlisle and
Center mines (McLemore, 1993). In the Steeple Rock dis-
trict, there are 6 distinct types of mineral deposits (base-
metal (Ag, ±Au), Au-Ag (±base metals), Cu-Ag, fluorite,
Mn, and high- sulfidation disseminated Au deposits) that
are spatially related to two types of alteration assemblages
(1) acid-
pH (alunite, kaolinite, quartz or acid-sulfate) and (2)
neutral-pH (propylitic to sericitic) (McLemore, 1993,
1996, 2000). The Center mine operated during the 1990s
and further exploration occurred at the Carlisle mine dur-
ing the 1990s. Both mines are flooded and have waste rock
piles on the surface, which have been sampled. Tailings are
also present at the Carlisle mine and have also been sam-
pled for this project.
Copper Flat (Hillsboro)
The Copper Flat mine in the Hillsboro district, east of
Silver City is an example of a porphyry copper deposit,
among other related deposit types. Known critical minerals
in the district include Te, As, Bi, Mg, Mn, and Zn. Copper
Flat has proven and probable reserves of 45.5Mt of ore at
a reported grade of 0.45% Cu, 0.14g/t Au, 2.3 g/t Ag and
0.0015% Mo. The district consists of Cretaceous andesites
surrounded by Paleozoic sedimentary rocks and Quaternary
alluvial fan deposits. A quartz monzonite stock (74.93±0.66
Ma) with a breccia pipe is located in the center of the dis-
trict and a series of latite dikes radiate outwards from the
quartz monzonite. The quartz monzonite porphyry and the
latite dikes are co-genetic. Replacement deposits, which
occur near the porphyry deposit, are also genetically related
to porphyry deposits. The Copper Flat porphyry copper
deposit consists of Cu, Au, Mo, and Ag disseminations
and quartz veins in the breccia pipe. Propagating outward
Figure 1. Location of the Copper Flat at Hillsboro, Black
Hawk in Burro Mountains, and Carlisle-Center mine in
Steeple Rock areas, southwestern NM