Research Interests and Projects
The scope of my research is to make contributions toward a better understanding of fundamental earth processes. This includes: how economically significant gold and silver deposits form; understanding the sources of metal(loid)s in these deposits; deciphering how complex plate tectonic configurations (e.g., shallow slab subduction, slab edges, and adjoining strike-slip faults) interact to generate some of the largest volcanoes on Earth; volcanic and sedimentary records of terrane accretion; and the interplay between intraplate volcanism and lithospheric extension.
These research efforts also provide teaching tools for students. At KSU, I mentor graduate and undergraduate students. Since I was a graduate student, I have mentored undergraduate research projects and believe that undergraduate research is a critical component of an undergraduate education, because it leads to learning science. Doing research also demonstrates skills for future employers or school. Our research usually involves field and laboratory work, thus the students I mentor are exposed to foundational techniques in both settings. I try to foster a multidisciplinary environment. The best research I've been involved with is multidisciplinary; people with different perspectives and backgrounds working together = better outcomes and science.
Recent research support includes the National Science Foundation, National Aeronautics and Space Administration, Geological Society of America, Society of Economic Geologists, American Association of Petroleum Geologists, Newmont Mining Co., the American Federation of Mineralogical Societies, and Kansas State University.
The scope of my research is to make contributions toward a better understanding of fundamental earth processes. This includes: how economically significant gold and silver deposits form; understanding the sources of metal(loid)s in these deposits; deciphering how complex plate tectonic configurations (e.g., shallow slab subduction, slab edges, and adjoining strike-slip faults) interact to generate some of the largest volcanoes on Earth; volcanic and sedimentary records of terrane accretion; and the interplay between intraplate volcanism and lithospheric extension.
These research efforts also provide teaching tools for students. At KSU, I mentor graduate and undergraduate students. Since I was a graduate student, I have mentored undergraduate research projects and believe that undergraduate research is a critical component of an undergraduate education, because it leads to learning science. Doing research also demonstrates skills for future employers or school. Our research usually involves field and laboratory work, thus the students I mentor are exposed to foundational techniques in both settings. I try to foster a multidisciplinary environment. The best research I've been involved with is multidisciplinary; people with different perspectives and backgrounds working together = better outcomes and science.
Recent research support includes the National Science Foundation, National Aeronautics and Space Administration, Geological Society of America, Society of Economic Geologists, American Association of Petroleum Geologists, Newmont Mining Co., the American Federation of Mineralogical Societies, and Kansas State University.
Large igneous provinces and "hotspot tracks"
We are currently studying <8 Ma mafic-intermediate volcanism primarily in the upper Wind River Basin, Wyoming (southeast of Yellowstone national park; includes Lava Mountain, WY - work has been in collaboration with Dave Adams) and in nearby parts of Wyoming, Idaho, and Montana (e.g., Centennial Mountains region). These igneous rocks are "off-track" volcanic products that lie adjacent to a hotspot track (e.g., Snake River Plain-Yellowstone; SRPY), yet are out-of-sequence with the main phases of SRPY hotspot track silicic age progression. Why do they exist? How can igneous products like these identify hotspots and related volcanism and hotspot tracks? What kind of mantle and crustal reservoirs were involved in their petrogenesis? This project is funded by the National Science Foundation.
Ongoing work to better understand other aspects of the Cenozoic evolution of the Pacific Northwest/northern Great Basin (U.S.A.). This is focused on mid-Miocene flood basalt volcanism and coeval rhyolite eruptions (e.g., Columbia River/Steens Basalt, etc.) in the Oregon-Idaho-Nevada tristate region, as well as in northeastern Nevada. We are currently trying to understand the petrogenesis, intensive variables, and relationship with regional/local extensional tectonism and Yellowstone hotspot of the crystal-rich Jarbidge Rhyolite (in collaboration with Ben Ellis [ETH Zurich] and Bill Hames [Auburn U.]). How does rhyolite magma with ~40-50% by volume crystals, actually erupt? Are these lavas erupted rhyolite magma mush? Other related work includes studying <12 Ma basalts of the Owyhee Plateau (OR-NV-ID), and the tectonic and significance and petrogenesis of Oligo-Miocene arc(?) magmatism across the northern Great Basin/southern Oregon Plateau that directly preceded the Columbia River-Steens flood basalt event.
Collaborative work with Richard Hanson (TCU), Bob Puckett, and Stan Mertzman (Franklin and Marshall College) has been focused on studying Cambrian mafic-intermediate lavas and intrusive bodies exposed in the southern Oklahoma aulacogen (SOA). The chemical and petrogenetic characteristics of this thick package of lavas is poorly understood and our work has verified that the SOA is indeed a large igneous province (there are rhyolites too!), on par with others across Earth, and also helped ongoing geophysical studies in the region focused on petroleum exploration. This work has been highlighted as the November 2011 LIP of the month by the IAVCEI large igneous province commission and papers published in Lithos.
Subduction zone processes
Collaborative work with Jeff Trop (Bucknell U.), Jeff Benowitz (UA-Fairbanks), and Paul Layer (UA-Fairbanks) is focused on understanding the evolution of the Cenozoic Wrangell arc, Alaska and its relationships to shallow slab subduction and transform faulting at an arc-transform junction. Our work has provided constraints on how volcanic arcs can form adjacent to slab edges, a tectonic setting that was not usually associated with subduction and volcanic arc formation. Other Alaska-based work is focused on Cretaceous arc magmatism (e.g., Chisana arc) and terrane accretion in south-central Alaska, as well new work on deciphering the petrogenesis of <1 Ma monogenetic volcanism in southern AK (e.g., volcanoes that formed, until our work, in what was thought to be an amagmatic, flat-slab setting). The Wrangell project was funded by the National Science Foundation. See the project webpage for updates.
Through our work on magmatism associated with both extensional tectonics and subduction, I’ve become fascinated with how volcanism can be used to help decipher the post-subduction transition to extension in mountain belts and how that’s recognized in the upper plate, especially in the volcanic record. As a result, another new project centers on a package of ~35-16 Ma volcanics (e.g., Dillon volcanics) that erupted just after the cessation of Laramide compression and continued through the onset of widespread Basin and Range extension in SW MT ca. ~20-15 Ma.
Ore deposit research: metal(loid)s, critical minerals and sustainability
Work in northern NV, southeastern OR, and southwestern ID focused on understanding the regional mid-Miocene magmatism associated with the inception of the Yellowstone hotspot, including the timing and petrogenesis of mafic through silicic units in local/regional contexts, and the relationship between local/regional magmatism, precious metal mineralization (e.g., gold and silver), and the onset of Basin and Range extension. Collaborative work with Jim Saunders and Bill Hames (Auburn University) has been focused in the Owyhee Mts. (ID), on studying the relationship between coeval mid-Miocene precious metal mineralization and magmatism in the northern Great Basin. This project was funded by the National Science Foundation.
I have expanded aspects of this project to address similar issues (e.g., sources of metals and relationships to mafic magmas focused on copper isotopes and copper behavior in basaltic magmas) across the region in collaboration with Ryan Mathur (Juniata College) and also general copper isotope systematics in mafic-intermediate magmas, in collaboration with Pamela Kempton (Kansas State). Another offshoot of this work is focused on understanding metal(loid) partitioning in epithermal sinter deposits. Are sinters viable Au-Ag resources? Do sinter deposits host evidence for transportation and deposition of metal(loid) nanoparticles? Also I have supervised projects dealing with the correlation and petrogenesis of Eocene ash-flow tuffs in the northern Great Basin that are spatially and temporally associated with Carlin-type gold mineralization.
The work my colleagues and I have undertaken on links between epithermal Au-Ag deposits and mafic magmas, has spurred interest in other aspects of ores, critical minerals, and implications for energy sustainability. Lithium is still the primary resource needed for most new batteries, thus I plan to evaluate Li abundance in Cenozoic rhyolite ash flow tuffs and lavas along the Snake River plain and the ID-OR-NV tristate region. Some of these rhyolites have substantial enrichments in other incompatible trace elements, and they should be Li-rich. This work will focus on glass chemistry and also possibly melt inclusions, and is directly applicable to Li resources. Models for the highest grade Li deposits in the northern Great Basin are centered on leaching of Li from rhyolites into clays deposited in hydrologically closed basins. Identifying other Li-rich rhyolites associated with extensional (or caldera-formed) lacustrine strata is key to this exploration model.
Other projects: Kimberlites; detrital muscovite chemistry; the Picuris Orogeny
The bedrock geology of Kansas is far more exciting than many people might think. In fact, there are kimberlites exposed within 20 miles of Manhattan and we nearly lie over the mid-continent rift! I am working with Pamela Kempton, Claudia Adam, and Kansas State students to better understand the petrogenesis of these kimberlites- why are they present in Kansas? In 2018-19, I received a Big 12 Faculty Fellowship to work with Graham Andrews (West Virginia) on applying kimberlite emplacement models, based mostly on physical characteristics, to kimberlites in Kansas and Pennsylvania.
Other work includes: 1) using detrital muscovite chemistry, muscovite geochronology, and clastic sedimentology to understand impacts of Appalachian Devonian mountain-building on climate and tetrapod evolution (with Jeff Trop, Jeff Benowitz), and; 2) whole rock chemical constraints on the provenance of Proterozoic plutonic clasts from New Mexico (with Mary Beth Gray and Chris Daniel) and how these link to magmatism associated with the ~1.4 Ga Picuris Orogeny.
We are currently studying <8 Ma mafic-intermediate volcanism primarily in the upper Wind River Basin, Wyoming (southeast of Yellowstone national park; includes Lava Mountain, WY - work has been in collaboration with Dave Adams) and in nearby parts of Wyoming, Idaho, and Montana (e.g., Centennial Mountains region). These igneous rocks are "off-track" volcanic products that lie adjacent to a hotspot track (e.g., Snake River Plain-Yellowstone; SRPY), yet are out-of-sequence with the main phases of SRPY hotspot track silicic age progression. Why do they exist? How can igneous products like these identify hotspots and related volcanism and hotspot tracks? What kind of mantle and crustal reservoirs were involved in their petrogenesis? This project is funded by the National Science Foundation.
Ongoing work to better understand other aspects of the Cenozoic evolution of the Pacific Northwest/northern Great Basin (U.S.A.). This is focused on mid-Miocene flood basalt volcanism and coeval rhyolite eruptions (e.g., Columbia River/Steens Basalt, etc.) in the Oregon-Idaho-Nevada tristate region, as well as in northeastern Nevada. We are currently trying to understand the petrogenesis, intensive variables, and relationship with regional/local extensional tectonism and Yellowstone hotspot of the crystal-rich Jarbidge Rhyolite (in collaboration with Ben Ellis [ETH Zurich] and Bill Hames [Auburn U.]). How does rhyolite magma with ~40-50% by volume crystals, actually erupt? Are these lavas erupted rhyolite magma mush? Other related work includes studying <12 Ma basalts of the Owyhee Plateau (OR-NV-ID), and the tectonic and significance and petrogenesis of Oligo-Miocene arc(?) magmatism across the northern Great Basin/southern Oregon Plateau that directly preceded the Columbia River-Steens flood basalt event.
Collaborative work with Richard Hanson (TCU), Bob Puckett, and Stan Mertzman (Franklin and Marshall College) has been focused on studying Cambrian mafic-intermediate lavas and intrusive bodies exposed in the southern Oklahoma aulacogen (SOA). The chemical and petrogenetic characteristics of this thick package of lavas is poorly understood and our work has verified that the SOA is indeed a large igneous province (there are rhyolites too!), on par with others across Earth, and also helped ongoing geophysical studies in the region focused on petroleum exploration. This work has been highlighted as the November 2011 LIP of the month by the IAVCEI large igneous province commission and papers published in Lithos.
Subduction zone processes
Collaborative work with Jeff Trop (Bucknell U.), Jeff Benowitz (UA-Fairbanks), and Paul Layer (UA-Fairbanks) is focused on understanding the evolution of the Cenozoic Wrangell arc, Alaska and its relationships to shallow slab subduction and transform faulting at an arc-transform junction. Our work has provided constraints on how volcanic arcs can form adjacent to slab edges, a tectonic setting that was not usually associated with subduction and volcanic arc formation. Other Alaska-based work is focused on Cretaceous arc magmatism (e.g., Chisana arc) and terrane accretion in south-central Alaska, as well new work on deciphering the petrogenesis of <1 Ma monogenetic volcanism in southern AK (e.g., volcanoes that formed, until our work, in what was thought to be an amagmatic, flat-slab setting). The Wrangell project was funded by the National Science Foundation. See the project webpage for updates.
Through our work on magmatism associated with both extensional tectonics and subduction, I’ve become fascinated with how volcanism can be used to help decipher the post-subduction transition to extension in mountain belts and how that’s recognized in the upper plate, especially in the volcanic record. As a result, another new project centers on a package of ~35-16 Ma volcanics (e.g., Dillon volcanics) that erupted just after the cessation of Laramide compression and continued through the onset of widespread Basin and Range extension in SW MT ca. ~20-15 Ma.
Ore deposit research: metal(loid)s, critical minerals and sustainability
Work in northern NV, southeastern OR, and southwestern ID focused on understanding the regional mid-Miocene magmatism associated with the inception of the Yellowstone hotspot, including the timing and petrogenesis of mafic through silicic units in local/regional contexts, and the relationship between local/regional magmatism, precious metal mineralization (e.g., gold and silver), and the onset of Basin and Range extension. Collaborative work with Jim Saunders and Bill Hames (Auburn University) has been focused in the Owyhee Mts. (ID), on studying the relationship between coeval mid-Miocene precious metal mineralization and magmatism in the northern Great Basin. This project was funded by the National Science Foundation.
I have expanded aspects of this project to address similar issues (e.g., sources of metals and relationships to mafic magmas focused on copper isotopes and copper behavior in basaltic magmas) across the region in collaboration with Ryan Mathur (Juniata College) and also general copper isotope systematics in mafic-intermediate magmas, in collaboration with Pamela Kempton (Kansas State). Another offshoot of this work is focused on understanding metal(loid) partitioning in epithermal sinter deposits. Are sinters viable Au-Ag resources? Do sinter deposits host evidence for transportation and deposition of metal(loid) nanoparticles? Also I have supervised projects dealing with the correlation and petrogenesis of Eocene ash-flow tuffs in the northern Great Basin that are spatially and temporally associated with Carlin-type gold mineralization.
The work my colleagues and I have undertaken on links between epithermal Au-Ag deposits and mafic magmas, has spurred interest in other aspects of ores, critical minerals, and implications for energy sustainability. Lithium is still the primary resource needed for most new batteries, thus I plan to evaluate Li abundance in Cenozoic rhyolite ash flow tuffs and lavas along the Snake River plain and the ID-OR-NV tristate region. Some of these rhyolites have substantial enrichments in other incompatible trace elements, and they should be Li-rich. This work will focus on glass chemistry and also possibly melt inclusions, and is directly applicable to Li resources. Models for the highest grade Li deposits in the northern Great Basin are centered on leaching of Li from rhyolites into clays deposited in hydrologically closed basins. Identifying other Li-rich rhyolites associated with extensional (or caldera-formed) lacustrine strata is key to this exploration model.
Other projects: Kimberlites; detrital muscovite chemistry; the Picuris Orogeny
The bedrock geology of Kansas is far more exciting than many people might think. In fact, there are kimberlites exposed within 20 miles of Manhattan and we nearly lie over the mid-continent rift! I am working with Pamela Kempton, Claudia Adam, and Kansas State students to better understand the petrogenesis of these kimberlites- why are they present in Kansas? In 2018-19, I received a Big 12 Faculty Fellowship to work with Graham Andrews (West Virginia) on applying kimberlite emplacement models, based mostly on physical characteristics, to kimberlites in Kansas and Pennsylvania.
Other work includes: 1) using detrital muscovite chemistry, muscovite geochronology, and clastic sedimentology to understand impacts of Appalachian Devonian mountain-building on climate and tetrapod evolution (with Jeff Trop, Jeff Benowitz), and; 2) whole rock chemical constraints on the provenance of Proterozoic plutonic clasts from New Mexico (with Mary Beth Gray and Chris Daniel) and how these link to magmatism associated with the ~1.4 Ga Picuris Orogeny.