Bradley S. Van Gosen
William M. Benzel
Heather A. Lowers
Kate M. Campbell
20201104
Mineralogical analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona, USA
tabular digital data; a CSV format file; files in portable data format (pdf)
Denver, CO
U.S. Geological Survey
Additional information about Originators: Bradley S. Van Gosen, https://orcid.org/0000-0003-4214-3811 ; William M. Benzel, https://orcid.org/0000-0002-4085-1876 ; Heather A. Lowers, https://orcid.org/0000-0001-5360-9264 ; Kate M. Campbell, https://orcid.org/0000-0002-8715-5544
https://doi.org/10.5066/P9F745JX
This data release compiles the X-ray diffraction and electron microscopy analyses of drill core samples collected by the U.S. Geological Survey that were selected to typify the uranium-copper ore bodies of the Canyon deposit. The deposit is hosted by a solution-collapse breccia pipe, in which mineralization exists from about 650 to 2,100 ft (200 to 640 m) below the surface (Mathisen and others, 2017), located about 6.1 miles (10 km) south-southeast of Tusayan, Arizona, at latitude 35.88333 North, longitude -112.09583 West (datum WGS 1984). Energy Fuels Inc., owner and operator of the property, has conducted extensive drilling into the Canyon deposit that delineated the extent and uranium and copper content of the ore bodies. Mining facilities, including a shaft, have been developed by Energy Fuels at the deposit. As of October 2020, they await favorable economic conditions to resume mining operations and recover the ore.
On a site visit in February 2018, Energy Fuels generously allowed the authors (U.S. Geological Survey geologists) to examine and sample drill cores of mineralized portions of the Canyon deposit. Thirty-five samples were collected, which were chosen primarily as representative intervals of high-grade uranium, copper, and associated sulfide mineralization. An earlier-published data release (Van Gosen and others, 2020) provides the geochemical analyses of the 35 samples for 63 elements. X-ray diffraction (XRD) analyses were performed on 28 of these samples to examine their mineralogy. The raw data from these XRD analyses are also provided in Van Gosen and others (2020). This data release provides a mineralogical interpretation of the XRD data.
This data release summarizes the mineralogy of the drill core samples, based on interpretation of the XRD analyses (28 samples) and observations by scanning electron microscopy. From the XRD data, mineralogy was determined using specialized software and user interpretation of the software's selections, which are detailed in the section on process description below. Polished thin sections cut from 21 of the Canyon drill core samples were examined using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) to identify the ore minerals and observe their relationships at high magnification. The EDS vendor's auto identification algorithm was used for peak assignments; the user did not attempt to verify every peak identification. The spectra for each EDS measurement are provided in separate documents in Portable Data Format (pdf), one document for each of the 21 samples that were examined by SEM-EDS. The interpreted mineral phase(s), which is based solely on the judgement of the user, is given below each spectrum. XRD and SEM-EDS analyses identified uraninite (U oxide) as the uranium ore mineral, which is intergrown with at least a dozen identified sulfide minerals, within a gangue matrix of mainly quartz and lesser amounts of clay minerals, dolomite, calcite, barite, and potassium feldspar.
The Canyon deposit is similar to numerous other uranium deposits hosted by solution-collapse breccia pipes in the Grand Canyon region of northwest Arizona. The uranium-copper deposits occur within matrix-supported, vertical columns of breccia (a "breccia pipe") that formed by solution and collapse of sedimentary strata (Wenrich, 1985; Alpine, 2010). The breccia pipes average about 300 ft (90 m) in diameter and can extend vertically for as much as 3,000 ft (900 m), from their base in the Mississippian Redwall Limestone to as stratigraphically high as the Triassic Chinle Formation. The regions north, south, and east of the Grand Canyon host hundreds of solution-collapse breccia pipes (Van Gosen and others, 2016). Six decades of exploration across the region has found that most of these breccia pipes are not mineralized or substantially mineralized, and only a small percentage of the breccia pipes contain ore-grade uranium deposits. The mineralized breccia pipes contain concentrations of uranium, arsenic, copper, silver, lead, zinc, cobalt, and nickel minerals (Wenrich, 1985), which is reflected in this data set of Canyon deposit samples.
The geology of the Canyon deposit is most thoroughly described by Mathisen and others (2017), a NI 43-101 report prepared for Energy Fuels. The Canyon pipe has an average diameter of about 200 ft (61 m), but narrows to about 80 ft (24 m) in the primary ore zones, which are at the horizons of the Coconino Sandstone and the Hermit Formation. The uranium oxide-copper sulfide mineralization has its highest concentrations at these stratigraphic horizons and in concentric zones of fractures that bound the breccia column along its contact with the intact sedimentary strata. Based on 130 diamond holes totaling nearly 80,000 ft of drilling, Mathisen and others (2017) calculated a mineral resource estimate for the Canyon deposit (effective date of June 17, 2017) as uranium resources, with a Measured Resource of 6,000 tons at an average grade of 0.43 percent U oxide for a total of 56,000 pounds U oxide; an Indicated Resource of 132,000 tons at an average grade of 0.90 percent U oxide for a total of 2,378,000 pounds U oxide; and an Inferred Resource of 18,000 tons at an average grade of 0.38 percent U oxide for a total of 134,000 pounds U oxide. Additionally, the breccia pipe contains copper resources, determined by Mathisen and others (2017) to contain a Measured Resource of 6,000 tons at an average grade of 9.29 percent Cu for a total of 1,203,000 pounds Cu; an Indicated Resource of 94,000 tons at an average grade of 5.70 percent Cu for a total of 10,736,000 pounds Cu; and an Inferred Resource of 5,000 tons at an average grade of 5.90 percent Cu for a total of 570,000 pounds of Cu. While the high uranium content of the Canyon deposit is not unusual for the orebodies of the breccia pipe deposits of the Grand Canyon region, the copper content of the Canyon deposit appears to be anomalously high. Energy Fuels is investigating methods to recover both the copper and the uranium during the processing of the Canyon deposit ores.
References cited above:
Alpine, A.E., ed., 2010, Hydrological, geological, and biological site characterization of breccia pipe uranium deposits in northern Arizona: U.S. Geological Survey Scientific Investigations Report 2010-5025, 353 p., 1 plate, scale 1:375,000, available at http://pubs.usgs.gov/sir/2010/5025/
Mathisen, M.B., Wilson, Valerie, and Woods, J.L., 2017, Technical report on the Canyon mine, Coconino County, Arizona, U.S.A.: NI 43-101 Report, prepared by Roscoe Postle Associates Inc. for Energy Fuels Resources (USA) Inc., dated October 6, 2017, 139 p., accessed December 20, 2019, at http://www.energyfuels.com/canyon-mine
Van Gosen, B.S., Benzel, W.M., and Campbell, K.M., 2020, Geochemical and X-ray diffraction analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona: U.S. Geological Survey data release, https://doi.org/10.5066/P9UUILQI
Van Gosen, B.S., Johnson, M.R., and Goldman, M.A., 2016, Three GIS datasets defining areas permissive for the occurrence of uranium-bearing, solution-collapse breccia pipes in northern Arizona and southeast Utah: U.S. Geological Survey data release, https://dx.doi.org/10.5066/F76D5R3Z
Wenrich, K.J., 1985, Mineralization of breccia pipes in northern Arizona: Economic Geology, v. 80, no. 6, p. 1722-1735, https://doi.org/10.2113/gsecongeo.80.6.1722
This data set is a compilation of X-ray Diffraction and electron microscopy analyses of drill core samples collected by the U.S. Geological Survey, which were selected from ore zones of the Canyon uranium deposit. These data are made available for use in geologic, exploration, and environmental background studies.
2018
2018
Time of sample collection
Not planned
-112.0958
-112.0958
35.8833
35.8833
ISO 19115 Topic Category
geoscientificinformation
USGS Thesaurus
geology
economic geology
energy resources
metallic mineral resources
mineral resources
mineralogy
x-ray diffraction
none
uranium
copper
mine
Canyon mine
GGGSC
Geology, Geophysics, and Geochemistry Science Center
Mineral Resources Program
MRP
U.S. Geological Survey
USGS
XRD
breccia pipe
USGS Metadata Identifier
USGS:5f8dc8e382ce32418791fec9
Geographic Names Information System (GNIS)
United States
Arizona
Coconino County
Grand Canyon
Tusayan
none
USA
northwest Arizona
GEOLEX database, available at https://ngmdb.usgs.gov/Geolex/search
Redwall Limestone
Hermit Formation
Coconino Sandstone
Chinle Formation
USGS Thesaurus: Time Periods
Mississippian
Permian
Triassic
None. Please see 'Distribution Info' for details
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Bradley S Van Gosen
U.S. Geological Survey
mailing address
Box 25046, Mail Stop 973
Denver
CO
80225-0046
United States
303-236-1566
bvangose@usgs.gov
The U.S. Geological Survey Mineral Resources Program (MRP) provided funding for this work.
Environment as of Metadata Creation: Microsoft Windows 10, MS Excel, Adobe PDF
The X-ray Diffraction and SEM-EDS data in this report are analyses of rock (drill core) samples collected in support of mineral deposit research projects of the U.S. Geological Survey (USGS). Attribute fields and values were reviewed and checked for accuracy and consistency of terms.
This data set was derived from rock (drill core) samples collected by U.S. Geological Survey (USGS) geologists and analyzed at laboratories of the USGS. All samples were subject to the same sample preparation protocol and same analytical protocols. The procedures used to analyze the samples are explained in the Process Description section below. The X-ray Diffraction and SEM-EDS analyses were performed by U.S. Geological Survey geologists.
Note: Because of the heterogeneous character of the breccia mineral deposits, the chemistry obtained from one split of an individual sample, which is provided in Van Gosen and others (2020), may not align well with the mineralogy as determined by XRD from a separate split of the sample.
This data set provides the X-ray diffraction analyses of 28 rock (drill core) samples. The data set provides brief descriptive information for each sample. Additionally, polished sections of 21 of the samples were examined and analyzed by SEM-EDS to determine mineral phases and observe their relationships.
The deposit location was recorded using a hand-held GPS receiver using the WGS84 datum. The location determined by GPS should be accurate to the nearest latitude or longitude second, or good to the nearest 10,000th of a degree latitude (11 meters) or longitude (8.7 meters).
No formal vertical (elevation) accuracy tests were conducted.
For the X-ray Diffraction analyses, three grams of sample were ground to pass through a 250-mesh (~58 microns) sieve and side packed into mounts. Scans were collected on a PANalytical X'Pert Pro MPD diffractometer with Bragg-Bertano optics using copper radiation. The samples were scanned using the following set up: PANalytical X'Pert Pro - MPD X-ray Diffractometer; Theta/Theta geometry; Cu long-fine-focus X-ray tube (Ni filtered); and a X'celerator solid state "strip" detector. Instrument conditions are 45 kV, 40 mA; 15 mm beam mask; ½° anti-scatter slit; ¼° divergence slit; ½° receiving anti-scatter slit; ¼° receiving divergence slit; step size 0.0167 degrees in continuous scan mode; scan range of 4 to 80 degrees two-theta; and a sample spinner on a scan rate of 1 degree per minute. Identification of mineral phases was done with Material Data Inc. (MDI®) Jade (V 2010) search-match software using the International Center for Diffraction Database (ICDD®) "2019 PDF®-4". Semi-quantitative mineral estimates were calculated using MDI Whole Pattern Fit software which simultaneously calculates a whole pattern fit and a Rietveld refinement of the minerals. Reference minerals are selected from the database, some of which are "structure" references that represent perfect crystals of the mineral and other entries are real world mineral specimens. Each of these cards contain a full crystallographic description of the mineral. A calculated model of the observed pattern is produced by non-linear, least-squares optimization. The calculations, performed by the software, involve the application of various parameters to improve the fit of the model to the observed data. Modeling parameters include background reduction, profile fitting, and lattice constants which iterates minimizing a residual error between the calculated X-ray diffraction pattern from the selected references in comparison to the measured scan of the sample. All data were normalized to 100 percent based on the identified minerals.
Polished thin sections cut from 21 of the samples were examined using a scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) to identify the ore minerals and observe their relationships at high magnification. The EDS vendor's auto identification algorithm was used for peak assignments; the user did not attempt to verify every peak identification. The spectra for each EDS measurement are provided in separate documents in Portable Data Format (PDF; readable by Adobe Acrobat), one document for each of the 21 samples that were examined by SEM-EDS. The interpreted mineral phase(s), based solely on the judgement of the user, is given below each spectrum.
20201020
The Canyon deposit and mine is located at latitude 35.88333 north, longitude -112.09583 west (datum of WGS84).
Point
0.0001
0.0001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.0
298.257223563
Canyon_deposit_core_samples_XRD_mineralogy.csv [.xlsx]>
A dataset containing the interpretive results of X-ray diffraction analyses of rock samples, described by the data dictionary, Canyon_deposit_core_samples_XRD_mineralogy_DataDictionary.csv.
U.S. Geological Survey
A data dictionary, Canyon_deposit_core_samples_XRD_mineralogy_DataDictionary.csv, describing the entities and attributes for the results of the X-ray diffraction analyses of the samples.
Canyon_deposit_core_samples_XRD_mineralogy_DataDictionary.csv
File "SEM_EDS_sample_analyses.zip" is a compressed (zipped) folder containing 21 files in portable data format (PDF). Each PDF shows the SEM-EDS results of systematic examination of a polished thin section cut from each of the 21 selected samples. Each image in each PDF files displays the location of the acquired EDS spectra; the spectra for each location follow each image in chronological order.
SEM_EDS_sample_analyses.zip
ScienceBase
U.S. Geological Survey
mailing and physical
Building 810, Mail Stop 302, Denver Federal Center
Denver
CO
80225
USA
1-888-275-8747
sciencebase@usgs.gov
https://www.sciencebase.gov/catalog/item/5f8dc8e382ce32418791fec9
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
CSV; JPG; PDF; XLSX; XML; ZIP
none
Comma-separated values text file; Joint Photographic Experts Group raster image; Adobe Portable Document Format file; Microsoft Excel spreadsheet; Extensible Markup Language file; Zip archive
X-ray diffraction interpretations in csv format; X-ray diffraction interpretations in xlsx format; Data dictionary for X-ray diffraction interpretations in csv format; Scanning electron microscope images in jpg format; Mineralogy interpretations of SEM-EDS spectra in pdf format, contained in a zip archive; Metadata in xml format.
Use a file extraction software such as WinZip, 7zip, Peazip
24.5
http://doi.org/10.5066/P9F745JX
none
User will require software capable of opening text files; software capable of opening image files; software capable of opening an Excel spreadsheet; software capable of decompressing a zip archive; Adobe Acrobat Reader of other software capable of opening a pdf
20201104
Bradley S Van Gosen
U.S. Geological Survey
mailing and physical address
Box 25046, Denver Federal Center, Mail Stop 973
Denver
Colorado
80225
United States of America
1-303-236-1566
1-303-236-3200
bvangose@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
none
none