M. Christopher Jenkins, PhD
Chris Jenkins is located at GMEG Science Center in Spokane, WA. Chris received a MSc in Earth Science from the University of Toronto in 2017 and a PhD in Earth Science from Carleton University in 2021. Since joining the USGS in 2016, Chris specializes in studying magmatic ore deposits using igneous petrology, numerical modeling, and geostatistics.
Professional Experience
2022 - Present, Mendenhall Postdoctoral Fellow, Geology Minerals Energy and Geophysics Science Center, Spokane, WA.
2016 - 2022, Physical science technician, Geology Minerals Energy and Geophysics Science Center, Spokane, WA.
Education and Certifications
PhD Earth Sciences, Carleton University, 2021
MSc Earth Sciences, University of Toronto, 2017
BSc Geology, Eastern Washington University, 2015
Affiliations and Memberships*
2014 - Present: Society of Economic Geologists
2014 - Present: American Mineralogical Society
2013 - Present: Geological Society of America
Science and Products
National assessment of Ni, Co, V, Cr, and PGE associated with mafic/ultramafic magmatic mineral systems
Many minerals critical for modern society are found only in a few places in the world. U.S. reliance on minerals imported from other countries can cause supply chain vulnerabilities. This project aims to evaluate critical commodities associated with mafic and ultramafic igneous rocks and highlight areas with mineral potential.
Geochemistry, olivine chemistry, microXRF chemical maps, and isotope geochemistry of komatiitic volcanic rocks and U-Pb geochronology of metasedimentary rocks from the Bradley Peak and South Pass greenstone terranes, Wyoming Province Geochemistry, olivine chemistry, microXRF chemical maps, and isotope geochemistry of komatiitic volcanic rocks and U-Pb geochronology of metasedimentary rocks from the Bradley Peak and South Pass greenstone terranes, Wyoming Province
Bradley Peak and South Pass are two ca. 2.7 Ga greenstone terranes in the Archean Wyoming Province, USA that contain mafic-ultramafic metavolcanic rocks. This dataset contains five Comma Separated Value (CSV) files of tabular data, a data dictionary for tabular data (Data_Dictionary.csv), a shapefile with sample locations, and microXRF images. Wholerock_geochemistry.csv includes whole...
Geochemistry of rocks and rock fabric data near the hanging wall contact to the Reef Package, Stillwater Complex, Montana, USA Geochemistry of rocks and rock fabric data near the hanging wall contact to the Reef Package, Stillwater Complex, Montana, USA
The Reef Package is a sequence of coarse-grained cumulates that host the J-M Reef Pd-Pt deposit in the Stillwater Complex of Montana. The top of the Reef Package marks the top of economic-grade platinum-group element mineralization and is identified by a distinct change in rock fabric, from the coarse-grained rocks of the Reef Package to finer-grained cumulates in the hanging wall. This...
Titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world Titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world
This data release includes four .csv files and one Esri shapefile which contain data on titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world. Some of the data was used to create a grade and tonnage model for titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions. Only deposits with reported...
Missouri Breaks Project, Montana - Digitized aeromagnetic data Missouri Breaks Project, Montana - Digitized aeromagnetic data
From February 12 to March 8, 1981, EG and G Geometrics conducted an aeromagnetic survey in Montana for Anaconda Copper Company. A Piper Navajo aircraft was used to conducted the survey. The survey was flown along north-south flightlines spaced 660 feet at a nominal height of 450 feet above the terrain. Five uniformly spaced east-west tie-lines were also flown. During processing, the...
Filter Total Items: 14
Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA
Exploration continues for contact-style Ni-Cu sulfide and chromitite-associated PGE mineralization in ultramafic rocks of the Stillwater Complex. At the Iron and Chrome Mountain areas, massive sulfides occur along the complex’s footwall contact and anomalous concentrations of PGE+Au are associated with the three lowermost chromitite seams. Southeast of Chrome Mountain, magmatic layering...
Authors
Allen Andersen, Michael Jenkins
Petrogenesis and mineralization potential of spinifex komatiitic basalts in the Bradley Peak greenstone terrane, Wyoming Province Petrogenesis and mineralization potential of spinifex komatiitic basalts in the Bradley Peak greenstone terrane, Wyoming Province
Komatiitic volcanic rocks are important hosts of Ni sulfide mineralization and record early Earth evolution; however, those in the well-studied Archean Wyoming Province have received little attention. Here, we elucidate the timing and petrogenesis of the Bradley Peak komatiitic volcanic rocks using field and textural observations, geochronology, and geochemistry. Detrital and igneous...
Authors
Lisa Zieman, Michael Jenkins, Jacob Poletti
Origin of the high Pd/Pt ratio of the J-M Reef, Stillwater Complex Montana USA Origin of the high Pd/Pt ratio of the J-M Reef, Stillwater Complex Montana USA
The J-M Reef of the Stillwater Complex exhibits a high and consistent Pd/Pt ratio (~3.8). This ratio results from the equilibration of an immiscible sulfide liquid with a relatively high Pd/Pt silicate melt rather than an unusually Pd- and Pt-enriched parental melt. Numerical modeling suggests that the original silicate melt contained typical mantle-derived concentrations of Pd and Pt (...
Authors
Michael Jenkins, William Smith
Petrogenesis and mineralization potential of the Bradley Peak komatiitic basalts, Wyoming Province Petrogenesis and mineralization potential of the Bradley Peak komatiitic basalts, Wyoming Province
The ca. 2.72 Ga Bradley Peak greenstone terrane in the Wyoming Province contains spinifex- and cumulate-textured komatiitic volcanic rocks that may host Ni-Cu-PGE sulfide mineralization. New whole rock geochemistry classifies these rocks as Al-undepleted komatiitic basalts derived from a parental melt with ~17 wt. % MgO. Isotopic data (Sm-Nd, Re-Os) and REE profiles suggest a plume...
Authors
Lisa Zieman, Michael Jenkins, Michael L. Zientek, Jacob Poletti, Alan D. Rooney
Assimilation of reduced carbon triggers platinum alloy saturation in mafic and ultramafic magmas Assimilation of reduced carbon triggers platinum alloy saturation in mafic and ultramafic magmas
It is generally observed that magmatic sulfide ores have higher ratios of Pd/Pt than the mantle-like values of their parental magmas. This discrepancy has defied simple explanation because the partitioning behavior of both elements between sulfide and silicate liquids is very similar. Assimilation of sulfur- and carbon-rich country rocks by mafic and ultramafic magmas is considered a...
Authors
Ying Zhou Li, William Smith, Michael Jenkins, Zhuosen Yao, James Mungall
Layered intrusions in the Precambrian: Observations and perspectives Layered intrusions in the Precambrian: Observations and perspectives
Layered intrusions are plutonic bodies of cumulates that form by the crystallization of mantle-derived melts. These intrusions are characterized by igneous layering distinguishable by shifts in mineralogy, texture, or composition. Layered intrusions have been fundamental to our understanding of igneous petrology; however, it is their status as important repositories of critical metals –...
Authors
William Smith, Michael Jenkins, Claudia Augustin, Ville Virtanen, Zoja Vukmanovic, Brian O’Driscoll
Geochemistry of Archean komatiitic greenstone terranes of the Wyoming Province: Implications for geodynamic setting and mineralization Geochemistry of Archean komatiitic greenstone terranes of the Wyoming Province: Implications for geodynamic setting and mineralization
No abstract available.
Authors
Lisa Zieman, Jacob Poletti, Michael Jenkins
A multi-methodological approach: Combining textural observations and geochronology to study the J-M Reef Package and its Hanging Wall, Stillwater Complex, Montana A multi-methodological approach: Combining textural observations and geochronology to study the J-M Reef Package and its Hanging Wall, Stillwater Complex, Montana
No abstract available.
Authors
Michael Jenkins, Sam Corson, Ennis Geraghty, S.L. Kamo, Heather Lowers, James Mungall
Unifying the Neoarchean Lac des Iles Complex and implications for the petrogenesis of Pd-enriched noritic breccia pipes in ancient arcs Unifying the Neoarchean Lac des Iles Complex and implications for the petrogenesis of Pd-enriched noritic breccia pipes in ancient arcs
No abstract available.
Authors
William Smith, L. Fay, M.L. Djon, Michael Jenkins, Y. Lin, Z. Yao, James Mungall
Melting at the base of the J-M Reef Package, Stillwater Complex Melting at the base of the J-M Reef Package, Stillwater Complex
No abstract available.
Authors
Michael Jenkins, Stephen J. Barnes
A novel origin for PGE reefs: A case study of the J-M Reef A novel origin for PGE reefs: A case study of the J-M Reef
The origin of meter scale stratiform layers of disseminated sulfides in enriched platinum group element (PGE) tenors and grades, called reef-type deposits, are the world’s most significant source of PGEs. Their origin in layered mafic intrusions remains debated, but in general, most researchers favor an orthomagmatic origin for reef-type deposits and agree that their formation requires...
Authors
Michael Jenkins, James Mungall, Michael L. Zientek, Gelu Costin, Zhuo-sen Yao
Origin of the J-M Reef and Lower Banded series, Stillwater Complex, Montana, USA Origin of the J-M Reef and Lower Banded series, Stillwater Complex, Montana, USA
The origin and parental magma for layered cumulates in the Lower Banded series (LBS) and the J-M Reef Pd-Pt deposit of the Stillwater Complex remains poorly constrained. We present whole-rock lithogeochemistry and mineral chemistry from LBS rocks collected from drill holes and surface samples from the Mountain View area of the complex that in total span nearly the entirety of the LBS...
Authors
Michael Jenkins, James Mungall, Michael L. Zientek, Gelu Costin, Zhuo-sen Yao
Science and Products
National assessment of Ni, Co, V, Cr, and PGE associated with mafic/ultramafic magmatic mineral systems
Many minerals critical for modern society are found only in a few places in the world. U.S. reliance on minerals imported from other countries can cause supply chain vulnerabilities. This project aims to evaluate critical commodities associated with mafic and ultramafic igneous rocks and highlight areas with mineral potential.
Geochemistry, olivine chemistry, microXRF chemical maps, and isotope geochemistry of komatiitic volcanic rocks and U-Pb geochronology of metasedimentary rocks from the Bradley Peak and South Pass greenstone terranes, Wyoming Province Geochemistry, olivine chemistry, microXRF chemical maps, and isotope geochemistry of komatiitic volcanic rocks and U-Pb geochronology of metasedimentary rocks from the Bradley Peak and South Pass greenstone terranes, Wyoming Province
Bradley Peak and South Pass are two ca. 2.7 Ga greenstone terranes in the Archean Wyoming Province, USA that contain mafic-ultramafic metavolcanic rocks. This dataset contains five Comma Separated Value (CSV) files of tabular data, a data dictionary for tabular data (Data_Dictionary.csv), a shapefile with sample locations, and microXRF images. Wholerock_geochemistry.csv includes whole...
Geochemistry of rocks and rock fabric data near the hanging wall contact to the Reef Package, Stillwater Complex, Montana, USA Geochemistry of rocks and rock fabric data near the hanging wall contact to the Reef Package, Stillwater Complex, Montana, USA
The Reef Package is a sequence of coarse-grained cumulates that host the J-M Reef Pd-Pt deposit in the Stillwater Complex of Montana. The top of the Reef Package marks the top of economic-grade platinum-group element mineralization and is identified by a distinct change in rock fabric, from the coarse-grained rocks of the Reef Package to finer-grained cumulates in the hanging wall. This...
Titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world Titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world
This data release includes four .csv files and one Esri shapefile which contain data on titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions and massif anorthosite intrusions from around the world. Some of the data was used to create a grade and tonnage model for titanium-vanadium deposits hosted in mafic-ultramafic layered intrusions. Only deposits with reported...
Missouri Breaks Project, Montana - Digitized aeromagnetic data Missouri Breaks Project, Montana - Digitized aeromagnetic data
From February 12 to March 8, 1981, EG and G Geometrics conducted an aeromagnetic survey in Montana for Anaconda Copper Company. A Piper Navajo aircraft was used to conducted the survey. The survey was flown along north-south flightlines spaced 660 feet at a nominal height of 450 feet above the terrain. Five uniformly spaced east-west tie-lines were also flown. During processing, the...
Filter Total Items: 14
Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA Noble and base metal distribution and processes affecting ore tenors in the disrupted lower stratigraphy of the Stillwater Complex, USA
Exploration continues for contact-style Ni-Cu sulfide and chromitite-associated PGE mineralization in ultramafic rocks of the Stillwater Complex. At the Iron and Chrome Mountain areas, massive sulfides occur along the complex’s footwall contact and anomalous concentrations of PGE+Au are associated with the three lowermost chromitite seams. Southeast of Chrome Mountain, magmatic layering...
Authors
Allen Andersen, Michael Jenkins
Petrogenesis and mineralization potential of spinifex komatiitic basalts in the Bradley Peak greenstone terrane, Wyoming Province Petrogenesis and mineralization potential of spinifex komatiitic basalts in the Bradley Peak greenstone terrane, Wyoming Province
Komatiitic volcanic rocks are important hosts of Ni sulfide mineralization and record early Earth evolution; however, those in the well-studied Archean Wyoming Province have received little attention. Here, we elucidate the timing and petrogenesis of the Bradley Peak komatiitic volcanic rocks using field and textural observations, geochronology, and geochemistry. Detrital and igneous...
Authors
Lisa Zieman, Michael Jenkins, Jacob Poletti
Origin of the high Pd/Pt ratio of the J-M Reef, Stillwater Complex Montana USA Origin of the high Pd/Pt ratio of the J-M Reef, Stillwater Complex Montana USA
The J-M Reef of the Stillwater Complex exhibits a high and consistent Pd/Pt ratio (~3.8). This ratio results from the equilibration of an immiscible sulfide liquid with a relatively high Pd/Pt silicate melt rather than an unusually Pd- and Pt-enriched parental melt. Numerical modeling suggests that the original silicate melt contained typical mantle-derived concentrations of Pd and Pt (...
Authors
Michael Jenkins, William Smith
Petrogenesis and mineralization potential of the Bradley Peak komatiitic basalts, Wyoming Province Petrogenesis and mineralization potential of the Bradley Peak komatiitic basalts, Wyoming Province
The ca. 2.72 Ga Bradley Peak greenstone terrane in the Wyoming Province contains spinifex- and cumulate-textured komatiitic volcanic rocks that may host Ni-Cu-PGE sulfide mineralization. New whole rock geochemistry classifies these rocks as Al-undepleted komatiitic basalts derived from a parental melt with ~17 wt. % MgO. Isotopic data (Sm-Nd, Re-Os) and REE profiles suggest a plume...
Authors
Lisa Zieman, Michael Jenkins, Michael L. Zientek, Jacob Poletti, Alan D. Rooney
Assimilation of reduced carbon triggers platinum alloy saturation in mafic and ultramafic magmas Assimilation of reduced carbon triggers platinum alloy saturation in mafic and ultramafic magmas
It is generally observed that magmatic sulfide ores have higher ratios of Pd/Pt than the mantle-like values of their parental magmas. This discrepancy has defied simple explanation because the partitioning behavior of both elements between sulfide and silicate liquids is very similar. Assimilation of sulfur- and carbon-rich country rocks by mafic and ultramafic magmas is considered a...
Authors
Ying Zhou Li, William Smith, Michael Jenkins, Zhuosen Yao, James Mungall
Layered intrusions in the Precambrian: Observations and perspectives Layered intrusions in the Precambrian: Observations and perspectives
Layered intrusions are plutonic bodies of cumulates that form by the crystallization of mantle-derived melts. These intrusions are characterized by igneous layering distinguishable by shifts in mineralogy, texture, or composition. Layered intrusions have been fundamental to our understanding of igneous petrology; however, it is their status as important repositories of critical metals –...
Authors
William Smith, Michael Jenkins, Claudia Augustin, Ville Virtanen, Zoja Vukmanovic, Brian O’Driscoll
Geochemistry of Archean komatiitic greenstone terranes of the Wyoming Province: Implications for geodynamic setting and mineralization Geochemistry of Archean komatiitic greenstone terranes of the Wyoming Province: Implications for geodynamic setting and mineralization
No abstract available.
Authors
Lisa Zieman, Jacob Poletti, Michael Jenkins
A multi-methodological approach: Combining textural observations and geochronology to study the J-M Reef Package and its Hanging Wall, Stillwater Complex, Montana A multi-methodological approach: Combining textural observations and geochronology to study the J-M Reef Package and its Hanging Wall, Stillwater Complex, Montana
No abstract available.
Authors
Michael Jenkins, Sam Corson, Ennis Geraghty, S.L. Kamo, Heather Lowers, James Mungall
Unifying the Neoarchean Lac des Iles Complex and implications for the petrogenesis of Pd-enriched noritic breccia pipes in ancient arcs Unifying the Neoarchean Lac des Iles Complex and implications for the petrogenesis of Pd-enriched noritic breccia pipes in ancient arcs
No abstract available.
Authors
William Smith, L. Fay, M.L. Djon, Michael Jenkins, Y. Lin, Z. Yao, James Mungall
Melting at the base of the J-M Reef Package, Stillwater Complex Melting at the base of the J-M Reef Package, Stillwater Complex
No abstract available.
Authors
Michael Jenkins, Stephen J. Barnes
A novel origin for PGE reefs: A case study of the J-M Reef A novel origin for PGE reefs: A case study of the J-M Reef
The origin of meter scale stratiform layers of disseminated sulfides in enriched platinum group element (PGE) tenors and grades, called reef-type deposits, are the world’s most significant source of PGEs. Their origin in layered mafic intrusions remains debated, but in general, most researchers favor an orthomagmatic origin for reef-type deposits and agree that their formation requires...
Authors
Michael Jenkins, James Mungall, Michael L. Zientek, Gelu Costin, Zhuo-sen Yao
Origin of the J-M Reef and Lower Banded series, Stillwater Complex, Montana, USA Origin of the J-M Reef and Lower Banded series, Stillwater Complex, Montana, USA
The origin and parental magma for layered cumulates in the Lower Banded series (LBS) and the J-M Reef Pd-Pt deposit of the Stillwater Complex remains poorly constrained. We present whole-rock lithogeochemistry and mineral chemistry from LBS rocks collected from drill holes and surface samples from the Mountain View area of the complex that in total span nearly the entirety of the LBS...
Authors
Michael Jenkins, James Mungall, Michael L. Zientek, Gelu Costin, Zhuo-sen Yao
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government