2
Rare earth elements (REE) and other critical minerals
are essential in most of our electronic devices, such as cell
phones, laptops, computer chips, batteries, magnets, wind
turbines, hybrid/electric cars, etc. (Committee on Critical
Mineral Impacts of the U.S. Economy, 2008 Long et al.,
2010 McLemore, 2011 McLemore and Gysi, 2023).
Other technologies are being developed like solar panels,
water purification, desalination, magnetic refrigeration,
and even more efficient light bulbs that require REE and
other critical elements in their manufacture. A variety of
minerals (Mg, REE, Co, Li, etc.) are required to manufac-
ture batteries and some of these critical minerals are found
in and even produced from New Mexico (Figure 2), includ-
ing the mine wastes from previous mines.
Mine wastes have the potential to contain critical min-
erals, especially since the actual mineral production was
generally for precious and base metals and not critical min-
erals. Therefore, any critical minerals that are found in the
mineral deposit also would be found in the mine wastes
(mine waste dumps, tailings, slags, etc.). Although some of
these critical minerals are located in New Mexico, they have
not been important exploration targets in the past because
demand has been met economically elsewhere, mostly from
China. However, with the projected increase in demand
for critical minerals and the potential lack of available pro-
duction from China and other countries, the New Mexico
deposits including mine wastes are being re-examined for
their critical mineral potential, and several areas of mill tail-
ings are undergoing current exploration.
Not only are these data required to delineate favorable
mine wastes for the USGS project, but identification and
examination of critical minerals is a high priority of the
NMBGMR. This project is important to the state of New
Mexico because critical mineral resources must be identi-
fied before land exchanges, withdrawals or other land-use
decisions are made by government officials. Future mining
of potential critical minerals deposits will directly benefit
the economy of New Mexico. Possible re-mining of mine
wastes could clean up these sites or pay for reclamation.
Furthermore, this project will allow training of the next
generation of younger, professional geologists and students
in economic and reclamation geology by the PIs. We plan
to evaluate typical environmental characteristics of the mine
wastes (acid base accounting, pH, leaching tests, etc.) of the
mine features, because these evaluations will be required to
obtain permits and provide a safe work environment dur-
ing mining, reclamation, and/or waste reprocessing.
The purposes of this project are 1) to test sampling pro-
tocols of mine wastes in a variety of mine features (waste
rock piles, stock piles, tailings, pit lakes, etc.), 2) to deter-
mine the potential for critical minerals in mine wastes
in New Mexico, and 3) compare results between mining
districts and types of deposits. Previous sampling of mine
wastes in mining districts in New Mexico are compared to
new sampling for the USGS mine waste project.
DESCRIPTION OF AREAS SAMPLED
The NMBGMR has been working on mine wastes since
the 1950s. Samples have been collected for chemical anal-
yses and other characterization data from several mining
districts throughout New Mexico as part of prior projects:
1) an inventory and characterization of mine features and
evaluation of mine wastes as part of the New Mexico AML
project (geoinfo.nmt.edu/hazards/mines/aml/home.html),
2) a study on uranium transport, uranium source character-
istics, and uranium legacy issues in New Mexico (EPSCoR,
geoinfo.nmt.edu/geoscience/research/home.cfml?id=81&
project=Uranium+Transport+and+Sources+in+New
+Mexico+A+fiveyear+EPSCoR+program), 3) an assess-
ment on the effects of the Gold King mine spill on the
Animas and San Juan Rivers in northern New Mexico, and
4) specific mining district studies. More recently, three dis-
tricts in New Mexico were selected for sampling and testing
procedures for the USGS Earth MRI mine waste project.
Samples discussed in this paper were collected from
several districts in New Mexico, as summarized in Table 1
Figure 1. Map of mining districts in New Mexico that have
critical minerals. Coal fields are not shown. Other areas in
New Mexico, such as high-magnesium dolomites, lithium-
bearing playas, and coal fields, are not found in specific
mining districts and also have potential for critical minerals
(CM)
Rare earth elements (REE) and other critical minerals
are essential in most of our electronic devices, such as cell
phones, laptops, computer chips, batteries, magnets, wind
turbines, hybrid/electric cars, etc. (Committee on Critical
Mineral Impacts of the U.S. Economy, 2008 Long et al.,
2010 McLemore, 2011 McLemore and Gysi, 2023).
Other technologies are being developed like solar panels,
water purification, desalination, magnetic refrigeration,
and even more efficient light bulbs that require REE and
other critical elements in their manufacture. A variety of
minerals (Mg, REE, Co, Li, etc.) are required to manufac-
ture batteries and some of these critical minerals are found
in and even produced from New Mexico (Figure 2), includ-
ing the mine wastes from previous mines.
Mine wastes have the potential to contain critical min-
erals, especially since the actual mineral production was
generally for precious and base metals and not critical min-
erals. Therefore, any critical minerals that are found in the
mineral deposit also would be found in the mine wastes
(mine waste dumps, tailings, slags, etc.). Although some of
these critical minerals are located in New Mexico, they have
not been important exploration targets in the past because
demand has been met economically elsewhere, mostly from
China. However, with the projected increase in demand
for critical minerals and the potential lack of available pro-
duction from China and other countries, the New Mexico
deposits including mine wastes are being re-examined for
their critical mineral potential, and several areas of mill tail-
ings are undergoing current exploration.
Not only are these data required to delineate favorable
mine wastes for the USGS project, but identification and
examination of critical minerals is a high priority of the
NMBGMR. This project is important to the state of New
Mexico because critical mineral resources must be identi-
fied before land exchanges, withdrawals or other land-use
decisions are made by government officials. Future mining
of potential critical minerals deposits will directly benefit
the economy of New Mexico. Possible re-mining of mine
wastes could clean up these sites or pay for reclamation.
Furthermore, this project will allow training of the next
generation of younger, professional geologists and students
in economic and reclamation geology by the PIs. We plan
to evaluate typical environmental characteristics of the mine
wastes (acid base accounting, pH, leaching tests, etc.) of the
mine features, because these evaluations will be required to
obtain permits and provide a safe work environment dur-
ing mining, reclamation, and/or waste reprocessing.
The purposes of this project are 1) to test sampling pro-
tocols of mine wastes in a variety of mine features (waste
rock piles, stock piles, tailings, pit lakes, etc.), 2) to deter-
mine the potential for critical minerals in mine wastes
in New Mexico, and 3) compare results between mining
districts and types of deposits. Previous sampling of mine
wastes in mining districts in New Mexico are compared to
new sampling for the USGS mine waste project.
DESCRIPTION OF AREAS SAMPLED
The NMBGMR has been working on mine wastes since
the 1950s. Samples have been collected for chemical anal-
yses and other characterization data from several mining
districts throughout New Mexico as part of prior projects:
1) an inventory and characterization of mine features and
evaluation of mine wastes as part of the New Mexico AML
project (geoinfo.nmt.edu/hazards/mines/aml/home.html),
2) a study on uranium transport, uranium source character-
istics, and uranium legacy issues in New Mexico (EPSCoR,
geoinfo.nmt.edu/geoscience/research/home.cfml?id=81&
project=Uranium+Transport+and+Sources+in+New
+Mexico+A+fiveyear+EPSCoR+program), 3) an assess-
ment on the effects of the Gold King mine spill on the
Animas and San Juan Rivers in northern New Mexico, and
4) specific mining district studies. More recently, three dis-
tricts in New Mexico were selected for sampling and testing
procedures for the USGS Earth MRI mine waste project.
Samples discussed in this paper were collected from
several districts in New Mexico, as summarized in Table 1
Figure 1. Map of mining districts in New Mexico that have
critical minerals. Coal fields are not shown. Other areas in
New Mexico, such as high-magnesium dolomites, lithium-
bearing playas, and coal fields, are not found in specific
mining districts and also have potential for critical minerals
(CM)