4
The primary minerals found are pyrite, chalcopyrite, chal-
cocite, azurite, malachite, and cuprite. Additionally, smaller
quantities of molybdenite, galena, bornite, tetrahedrite,
sphalerite, and fluorite are present (McLemore, 2016).
Mine dumps and tailings were sampled for this project.
The Kelly Mine, Magdalena District, Socorro County
The Kelly Mine is located in the Magdalena mining dis-
trict in Socorro County, central New Mexico. The dis-
trict has had significant lead, zinc, and silver production.
The Magdalena district consists predominantly of tilted
and faulted carboniferous sedimentary rocks, overlying
Precambrian basement rocks and volcanic formations
mainly (Titley, 1959). In 1903, zinc carbonate ore became
a dominant resource, particularly after the introduction
of milling processes for sulfide ores. The main production
from the district includes lead, zinc, and smaller quanti-
ties of copper, gold, and silver (Loughlin and Koschmann,
1949). During the period of 1866 to 1970, the Magdalena
district produced more than $46,000,000 of Zn, Pb, Cu,
Ag, Mn, Au, and perlite (McLemore, 2017).
The Kelly limestone layer is the primary host for ore
deposits due to replacement processes along faults and frac-
tures. Structural faulting in the district, including major
longitudinal and transverse faults, significantly influenced
the localization and distribution of ores. Replacement
deposits of zinc and lead minerals, often forming along
networks of minor faults and bedding planes within the
Kelly limestone, were the main sources of ore (Loughlin
and Koschmann, 1949). Mine dumps were sampled for
this project.
PURPOSE
The purpose of this research is to provide comprehensive
data on mine wastes from the Black Hawk district (Grant
County), Magdalena district (Socorro County), and
Hillsboro districts (Sierra County) in New Mexico. This
includes a detailed characterization and estimation of the
critical minerals potential. Additionally, it focuses on deter-
mining the acid-generating potential of the mine waste
rock piles, which is essential for assessing environmental
impacts. Another goal of this study is also to offer valuable
information to support the planning and development of
future mining operations.
MATERIALS AND METHODS
Sampling and Sample Preparation
Following the USGS sampling procedures, large features
with varying characteristics, such as color or radioactivity,
are divided into separate sampling units (McLemore and
Owen, 2024). For example, Black Hawk mine wastes rock
piles have been subdivided by different radioactivity levels.
Once units are identified, each is subdivided into around
30 cells for composite sampling using markers. Samples are
sieved, air-dried if necessary, and homogenized for analysis.
Oversized material from waste rock piles may require addi-
tional processing to collect representative chips. Soil sam-
ples were collected and separated as fine (2mm) and coarse
(2mm). Figure 5 shows the Black Hawk mine waste sam-
ple locations.
At Copper Flat mine tailings, a 3-foot pit was dug to
sample along a vertical profile. The surface of the profile
was cleaned with a small trowel. Observations like varia-
tions in lithology such as color, thickness, texture, and grain
size are recorded in a field notebook. Samples are carefully
collected by scraping directly into labeled bags or clean
containers to prevent cross-contamination between litholo-
gies (Figure 6).
Petrography and Mineralogy
Mineralogy of selected samples was determined by exam-
ining under a microscope and using X-ray diffraction
(XRD) analysis. XRD analysis was performed on either
whole rock or mineral separates on a PANalytical X- Pert
PRO ® diffractometer at the NMBGMR XRD Diffraction
Laboratory. Analyses were conducted using 45 kV X-ray
beam tension and 40 mA X-ray beam current. XRD scans
were identified using X’Pert HighScore Plus ® software,
which identifies intensity peaks and matches patterns to a
Powder Diffraction File database. XRD data will be avail-
able in the final report.
Figure 5. Black Hawk district mine waste composite sample
locations
The primary minerals found are pyrite, chalcopyrite, chal-
cocite, azurite, malachite, and cuprite. Additionally, smaller
quantities of molybdenite, galena, bornite, tetrahedrite,
sphalerite, and fluorite are present (McLemore, 2016).
Mine dumps and tailings were sampled for this project.
The Kelly Mine, Magdalena District, Socorro County
The Kelly Mine is located in the Magdalena mining dis-
trict in Socorro County, central New Mexico. The dis-
trict has had significant lead, zinc, and silver production.
The Magdalena district consists predominantly of tilted
and faulted carboniferous sedimentary rocks, overlying
Precambrian basement rocks and volcanic formations
mainly (Titley, 1959). In 1903, zinc carbonate ore became
a dominant resource, particularly after the introduction
of milling processes for sulfide ores. The main production
from the district includes lead, zinc, and smaller quanti-
ties of copper, gold, and silver (Loughlin and Koschmann,
1949). During the period of 1866 to 1970, the Magdalena
district produced more than $46,000,000 of Zn, Pb, Cu,
Ag, Mn, Au, and perlite (McLemore, 2017).
The Kelly limestone layer is the primary host for ore
deposits due to replacement processes along faults and frac-
tures. Structural faulting in the district, including major
longitudinal and transverse faults, significantly influenced
the localization and distribution of ores. Replacement
deposits of zinc and lead minerals, often forming along
networks of minor faults and bedding planes within the
Kelly limestone, were the main sources of ore (Loughlin
and Koschmann, 1949). Mine dumps were sampled for
this project.
PURPOSE
The purpose of this research is to provide comprehensive
data on mine wastes from the Black Hawk district (Grant
County), Magdalena district (Socorro County), and
Hillsboro districts (Sierra County) in New Mexico. This
includes a detailed characterization and estimation of the
critical minerals potential. Additionally, it focuses on deter-
mining the acid-generating potential of the mine waste
rock piles, which is essential for assessing environmental
impacts. Another goal of this study is also to offer valuable
information to support the planning and development of
future mining operations.
MATERIALS AND METHODS
Sampling and Sample Preparation
Following the USGS sampling procedures, large features
with varying characteristics, such as color or radioactivity,
are divided into separate sampling units (McLemore and
Owen, 2024). For example, Black Hawk mine wastes rock
piles have been subdivided by different radioactivity levels.
Once units are identified, each is subdivided into around
30 cells for composite sampling using markers. Samples are
sieved, air-dried if necessary, and homogenized for analysis.
Oversized material from waste rock piles may require addi-
tional processing to collect representative chips. Soil sam-
ples were collected and separated as fine (2mm) and coarse
(2mm). Figure 5 shows the Black Hawk mine waste sam-
ple locations.
At Copper Flat mine tailings, a 3-foot pit was dug to
sample along a vertical profile. The surface of the profile
was cleaned with a small trowel. Observations like varia-
tions in lithology such as color, thickness, texture, and grain
size are recorded in a field notebook. Samples are carefully
collected by scraping directly into labeled bags or clean
containers to prevent cross-contamination between litholo-
gies (Figure 6).
Petrography and Mineralogy
Mineralogy of selected samples was determined by exam-
ining under a microscope and using X-ray diffraction
(XRD) analysis. XRD analysis was performed on either
whole rock or mineral separates on a PANalytical X- Pert
PRO ® diffractometer at the NMBGMR XRD Diffraction
Laboratory. Analyses were conducted using 45 kV X-ray
beam tension and 40 mA X-ray beam current. XRD scans
were identified using X’Pert HighScore Plus ® software,
which identifies intensity peaks and matches patterns to a
Powder Diffraction File database. XRD data will be avail-
able in the final report.
Figure 5. Black Hawk district mine waste composite sample
locations