5
A composite sample of the mine waste is collected after
sample units have been identified in a particular mine
feature. Composite samples of waste rock piles were col-
lected, using procedures developed by Munroe (1999) and
the U.S. Geological Survey (USGS) (Smith et al., 2000
Smith, 2007 McLemore et al., 2014 USGS 2023 memo).
This type of sampling is developed by the USGS and poses
no stability or erosion risks of the waste rock piles or tail-
ings. Each sampling unit should be subdivided into at least
30 cells of roughly equal area. To do this, flags/markers are
placed equidistant from each other forming a rough grid,
where the flag/maker represents the center of each cell. GPS
locations should also be recorded simultaneously, while
placing flags/markers or while removing flags/markers after
sampling. The overburden or overlying surface material (i.e.,
leaves, grass, roots, cover material of tailings, etc.) is first
removed. Collect the desired volume into the required sieve
size (e.g., 4 mm for waste rock piles), and sieve into a single
decontaminated bucket or bag, making sure to homogenize
as you sample. Finally, all the composite samples should be
thoroughly homogenized again and then transferred into
appropriately labeled sample containers.
Drill core samples are collected from existing drill core.
Core is generally described (logged) and photographed
before sampling. Only ½ of the core is split or sawed, with
the remaining core left in the box undisturbed. If the core
has already been sampled, then only ¼ is removed. A note
with your name, project, date, and purpose of sampling is
stored in the box where the sample was taken from.
Some general precautions in sampling include the fol-
lowing. All equipment should be cleaned to prevent cross-
contamination of the sample. Sampling tools (buckets,
sampling bags, shovels, trowels, and sieves) should be con-
structed of materials suitable for environmental sampling
(typically stainless steel, plastic, or aluminum). Devices
plated with chrome or other materials should not be used
as they can introduce contaminants to the samples. All
equipment used for sampling should be rinsed with deion-
ized water and air-dried prior to use. Wear disposable gloves
while sieving to avoid contamination.
The samples are transported from the field to
NMBGMR, where each sample is prepared for analyses.
Selected samples are cut and chips sent for preparation of
polished thin sections. The prepared samples are then sent
to a laboratory for chemical analyses. NMBGMR standards
are submitted blind to the commercial laboratory with each
sample batch to assure analytical quality.
Geochemical Analyses
Geochemical data are a critical part of geologic mapping
and for evaluation for critical mineral resources central to
the mission of Earth MRI. Geochemical analyses of samples
collected for this study were determined by the USGS labo-
ratory and by ALS Laboratory (description of methods can
be found at ALS Geochemistry Fee Schedule USD (2).pdf
and in future reports). Samples were submitted to the lab-
oratories where sample preparation occurred. Duplicate
samples and standards were analyzed and uncertainty of
analyses is generally 5%. Specific analytical methods for
each element and additional quality assurance and qual-
ity control (QA/QC) are available on request. Chemical
plots were created using ioGAS-64 (ioGAS ™ -REFLEX
(reflexnow.com). Chemical analyses will be presented in
future reports.
Petrography and Mineralogy
Hand sample descriptions of both sawed samples and thin
sections were entered into the project’s SQLS database.
Polished thin sections of selected samples of the igneous,
altered, and mineralized rocks were made by Quality Thin
Sections. Thin sections were scanned in both plane and
plane polarized light, and selected photomicrographs were
taken. Mineralogy of selected samples was determined by
visual and petrographic, X-ray diffraction (XRD), and elec-
tron microprobe methods.
X-ray diffraction (XRD) analysis was performed
on either whole rock or mineral separates performed
on a PANalytical X- Pert PRO ® diffractometer at the
NMBGMR X-ray 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 available in the final report. Petrographic
descriptions, including mineralogy and texture, of thin sec-
tions using plane, plane polarized, and reflective light were
entered into the SQLS database.
PRELIMINARY RESULTS
Mineralogy
Common minerals hosting the critical minerals in these
rocks include clay minerals, zircon, and rutile/anatase, as
determined from petrographic and XRD analyses.
Chemistry
Results of chemical analyses are shown in Figures 5–11.
A composite sample of the mine waste is collected after
sample units have been identified in a particular mine
feature. Composite samples of waste rock piles were col-
lected, using procedures developed by Munroe (1999) and
the U.S. Geological Survey (USGS) (Smith et al., 2000
Smith, 2007 McLemore et al., 2014 USGS 2023 memo).
This type of sampling is developed by the USGS and poses
no stability or erosion risks of the waste rock piles or tail-
ings. Each sampling unit should be subdivided into at least
30 cells of roughly equal area. To do this, flags/markers are
placed equidistant from each other forming a rough grid,
where the flag/maker represents the center of each cell. GPS
locations should also be recorded simultaneously, while
placing flags/markers or while removing flags/markers after
sampling. The overburden or overlying surface material (i.e.,
leaves, grass, roots, cover material of tailings, etc.) is first
removed. Collect the desired volume into the required sieve
size (e.g., 4 mm for waste rock piles), and sieve into a single
decontaminated bucket or bag, making sure to homogenize
as you sample. Finally, all the composite samples should be
thoroughly homogenized again and then transferred into
appropriately labeled sample containers.
Drill core samples are collected from existing drill core.
Core is generally described (logged) and photographed
before sampling. Only ½ of the core is split or sawed, with
the remaining core left in the box undisturbed. If the core
has already been sampled, then only ¼ is removed. A note
with your name, project, date, and purpose of sampling is
stored in the box where the sample was taken from.
Some general precautions in sampling include the fol-
lowing. All equipment should be cleaned to prevent cross-
contamination of the sample. Sampling tools (buckets,
sampling bags, shovels, trowels, and sieves) should be con-
structed of materials suitable for environmental sampling
(typically stainless steel, plastic, or aluminum). Devices
plated with chrome or other materials should not be used
as they can introduce contaminants to the samples. All
equipment used for sampling should be rinsed with deion-
ized water and air-dried prior to use. Wear disposable gloves
while sieving to avoid contamination.
The samples are transported from the field to
NMBGMR, where each sample is prepared for analyses.
Selected samples are cut and chips sent for preparation of
polished thin sections. The prepared samples are then sent
to a laboratory for chemical analyses. NMBGMR standards
are submitted blind to the commercial laboratory with each
sample batch to assure analytical quality.
Geochemical Analyses
Geochemical data are a critical part of geologic mapping
and for evaluation for critical mineral resources central to
the mission of Earth MRI. Geochemical analyses of samples
collected for this study were determined by the USGS labo-
ratory and by ALS Laboratory (description of methods can
be found at ALS Geochemistry Fee Schedule USD (2).pdf
and in future reports). Samples were submitted to the lab-
oratories where sample preparation occurred. Duplicate
samples and standards were analyzed and uncertainty of
analyses is generally 5%. Specific analytical methods for
each element and additional quality assurance and qual-
ity control (QA/QC) are available on request. Chemical
plots were created using ioGAS-64 (ioGAS ™ -REFLEX
(reflexnow.com). Chemical analyses will be presented in
future reports.
Petrography and Mineralogy
Hand sample descriptions of both sawed samples and thin
sections were entered into the project’s SQLS database.
Polished thin sections of selected samples of the igneous,
altered, and mineralized rocks were made by Quality Thin
Sections. Thin sections were scanned in both plane and
plane polarized light, and selected photomicrographs were
taken. Mineralogy of selected samples was determined by
visual and petrographic, X-ray diffraction (XRD), and elec-
tron microprobe methods.
X-ray diffraction (XRD) analysis was performed
on either whole rock or mineral separates performed
on a PANalytical X- Pert PRO ® diffractometer at the
NMBGMR X-ray 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 available in the final report. Petrographic
descriptions, including mineralogy and texture, of thin sec-
tions using plane, plane polarized, and reflective light were
entered into the SQLS database.
PRELIMINARY RESULTS
Mineralogy
Common minerals hosting the critical minerals in these
rocks include clay minerals, zircon, and rutile/anatase, as
determined from petrographic and XRD analyses.
Chemistry
Results of chemical analyses are shown in Figures 5–11.