Ryan J McAleer, Ph.D.
Ryan J McAleer is a Research Geologist at the Florence Bascom Geoscience Center.
I am a Research Geologist at the Florence Bascom Geoscience Center in Reston, VA. I received a PhD in Geology from Indiana University in 2016. I currently run the 40Ar/39Ar geochronology, electron microprobe, and mineral separation laboratories in Reston, VA. I contribute to National Cooperative Geologic Mapping, Energy, and Mineral program projects as well as collaborative work with universities. I use detailed optical and electron petrography, metamorphic petrology, 40Ar/39Ar and U/Pb geochronology, and a variety of other analytical tools in my research. Some current research projects that I am a part of include work on:
- Determining the age of bedrock beneath the coastal plain of the southeastern U.S.
- Assessing the age and deformation mechanisms along the Blue Ridge Thrust
- The age(s) of the Petersburg Granite
- Causes and uses of photoluminesence in zircon
- Coupled substitution in sphalerite with a focus on germanium
- The age and origin of manganese oxide deposits in Virginia.
Professional Experience
2016-present, Research Geologist, USGS, Reston, VA
2011-2015, Graduate Student, Indiana University, Bloomington, IN
2011-2015, SCEP/Pathways student appointment, USGS, Reston, VA
2007-2010, Geologist, USGS, Reston, VA
Education and Certifications
Ph.D. Metamorphic Petrology, Indiana University, 2016 (Advisor: Bob Wintsch)
M.S. Geology, 2006 (Advisor: Jim Spotila)
B.S. Geology, 2004 (Senior Thesis Advisor: Terry Engelder)
Affiliations and Memberships*
2016-present, Mineralogical Society of America
2011-present, Geological Society of America
2019-present, Microscopy Society of America/Microanalysis Society
Science and Products
Filter Total Items: 27
Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA) Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations...
Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA) Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the...
40Ar/39Ar data from the Janub Metamorphic Complex, Southern Jordan 40Ar/39Ar data from the Janub Metamorphic Complex, Southern Jordan
This data release includes 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Janub Metamorphic Complex in Southern Jordan. Rock samples were collected by Hind Ghanem of the University of Jordan. Muscovite-rich microcores were drilled from a polished thick section of a deformed granitoid and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon...
40Ar/39Ar isotopic data and electron microprobe data from muscovite in the Sukari gold deposit, Egypt 40Ar/39Ar isotopic data and electron microprobe data from muscovite in the Sukari gold deposit, Egypt
This data release includes electron microprobe and 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Sukari gold deposit in the Eastern Desert of Egypt. Rock samples were collected by Basem Zoheir--Benha University/University of Kiel. Muscovite from a polished thick section of sericitized wall rock was analyzed by electron probe microanalysis at the U.S. Geological...
Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A. Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.
Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A. Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared...
Filter Total Items: 55
Deformation-induced graphitization and muscovite recrystallization in a ductile fault zone Deformation-induced graphitization and muscovite recrystallization in a ductile fault zone
A suite of slate samples collected along a 2 km transect crossing the Lishan fault in central Taiwan were evaluated to assess the role of ductile deformation in natural graphitization at lower greenschist facies metamorphic conditions. The process of natural aromatization, or graphitization, of an organic precursor is well established as a thermally driven process; however, experimental...
Authors
Martha Stokes, Aaron M. Jubb, Ryan J. McAleer, David Bish, Robert Wintsch
Insights into glendonite formation from the upper Oligocene Sagavanirktok Formation, North Slope, Alaska Insights into glendonite formation from the upper Oligocene Sagavanirktok Formation, North Slope, Alaska
The type locality for the upper Oligocene Nuwok Member of the Sagavanirktok Formation (Carter Creek, North Slope, Alaska, USA) contains abundant occurrence of glendonite, a pseudomorph after the calcium carbonate mineral ikaite, which typically forms in the shallow subsurface of cold marine sediments. The region during the time of Nuwok Member deposition was located at a high latitude...
Authors
John W. Counts, Madeleine Vickers, Martha Stokes, Whittney Spivey, Kristina Frank Gardner, Jean Self-Trail, Jared T. Gooley, Ryan J. McAleer, Aaron M. Jubb, David W. Houseknecht, Richard O. Lease, Neil Patrick Griffis, Martin S. Vickers, Kasia Sliwinska, Hannah Gail Dooley Tompkins, Adam M. Hudson
Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus Ocean, Blue Ridge, VA–NC–TN Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus Ocean, Blue Ridge, VA–NC–TN
Recent field and geochronological studies in eight 7.5-minute quadrangles near Mount Rogers in Virginia, North Carolina and Tennessee recognize (1) important stratigraphic and structural relationships for the Neoproterozoic Mount Rogers and Konnarock Formations, and the northeast end of the Mountain City window; (2) the separation of Mesoproterozoic rocks of the Blue Ridge into three age...
Authors
Arthur J. Merschat, Ryan J. McAleer, Christopher S. Holm-Denoma, C. Scott Southworth
Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam
The extrusion tectonic model for the southeastern margin of the Himalayan orogeny links the crustal shear activity along the Red River Shear Zone (RRSZ) to the opening of the South China Sea (SCS). The Day Nui Con Voi (DNCV) metamorphic massif in northern Vietnam strikes NW-SE, is bounded by the RRSZ to the south and continues along the strike where it meets the SCS. The DNCV is thus a...
Authors
Thi-Hue Dinh, Meng-Wan Yeh, Tung-Yi Lee, Michael J. Kunk, Robert P. Wintsch, Ryan J. McAleer
Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA
Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic...
Authors
Mark W. Carter, Ryan J. McAleer, Christopher S. Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy
Elucidating the molecular structure of sedimentary organic matter (SOM) is key to understanding petroleum generation processes, as well as ancient sedimentary environments. SOM structure is primarily controlled by biogenic source material (e.g., marine vs. terrigenous), depositional conditions, and subsurface thermal history. Additional factors, e.g., strain, may also impact the...
Authors
Aaron M. Jubb, Martha Stokes, Ryan J. McAleer, Paul C. Hackley, Eoghan Dillion, Jing Qu
Non-USGS Publications**
Berger, A.L., Gulick, S.P., Spotila, J.A., Upton, P., Jaeger, J.M., Chapman, J.B., Worthington, L.A., Pavlis, T.L., Ridgway, K.D., Willems, B.A. and McAleer, R.J., 2008. Quaternary tectonic response to intensified glacial erosion in an orogenic wedge. Nature Geoscience, 1(11), p.793.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 27
Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA) Molecular-scale speciation of germanium and copper within sphalerite from Central Tennessee mining district (TN), Red Dog mining district (AK), and Metaline mining district (WA)
Oxidation state and bonding environment of Ge and Cu in ZnS and Zn mineral concentrates from a variety of sources [Central Tennessee mining district (TN), Metaline mining district, (WA), and Red Dog mine (AK)] were determined by linear combination fits from x-ray absorption spectroscopy (XAS) analysis. Sphalerites from the East Tennessee mining district contained Ge in concentrations...
Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA) Trace element composition and molecular-scale speciation characterization of sphalerite from Central and East Tennessee mining districts, Red Dog mining district (AK), and Metaline mining district (WA)
Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the...
40Ar/39Ar data from the Janub Metamorphic Complex, Southern Jordan 40Ar/39Ar data from the Janub Metamorphic Complex, Southern Jordan
This data release includes 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Janub Metamorphic Complex in Southern Jordan. Rock samples were collected by Hind Ghanem of the University of Jordan. Muscovite-rich microcores were drilled from a polished thick section of a deformed granitoid and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon...
40Ar/39Ar isotopic data and electron microprobe data from muscovite in the Sukari gold deposit, Egypt 40Ar/39Ar isotopic data and electron microprobe data from muscovite in the Sukari gold deposit, Egypt
This data release includes electron microprobe and 40Ar/39Ar collected at the U.S. Geological Survey for samples from the Sukari gold deposit in the Eastern Desert of Egypt. Rock samples were collected by Basem Zoheir--Benha University/University of Kiel. Muscovite from a polished thick section of sericitized wall rock was analyzed by electron probe microanalysis at the U.S. Geological...
Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A. Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Mineral abundances within bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S.A., were determined by Mineral Liberation Analysis (MLA) and X-Ray Diffraction (XRD). Data and methods reported are part of a research study published below in the 'Related External Resources' section.
Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A. Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Oxidation state and bonding environment of Ge in minerals within mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined by linear combination fits from x-ray absorption near edge spectroscopy (XANES) analysis. Ge content in quartz within these wastes was determined using XANES edge steps, and Ge content in sphalerite was compared...
Filter Total Items: 55
Deformation-induced graphitization and muscovite recrystallization in a ductile fault zone Deformation-induced graphitization and muscovite recrystallization in a ductile fault zone
A suite of slate samples collected along a 2 km transect crossing the Lishan fault in central Taiwan were evaluated to assess the role of ductile deformation in natural graphitization at lower greenschist facies metamorphic conditions. The process of natural aromatization, or graphitization, of an organic precursor is well established as a thermally driven process; however, experimental...
Authors
Martha Stokes, Aaron M. Jubb, Ryan J. McAleer, David Bish, Robert Wintsch
Insights into glendonite formation from the upper Oligocene Sagavanirktok Formation, North Slope, Alaska Insights into glendonite formation from the upper Oligocene Sagavanirktok Formation, North Slope, Alaska
The type locality for the upper Oligocene Nuwok Member of the Sagavanirktok Formation (Carter Creek, North Slope, Alaska, USA) contains abundant occurrence of glendonite, a pseudomorph after the calcium carbonate mineral ikaite, which typically forms in the shallow subsurface of cold marine sediments. The region during the time of Nuwok Member deposition was located at a high latitude...
Authors
John W. Counts, Madeleine Vickers, Martha Stokes, Whittney Spivey, Kristina Frank Gardner, Jean Self-Trail, Jared T. Gooley, Ryan J. McAleer, Aaron M. Jubb, David W. Houseknecht, Richard O. Lease, Neil Patrick Griffis, Martin S. Vickers, Kasia Sliwinska, Hannah Gail Dooley Tompkins, Adam M. Hudson
Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus Ocean, Blue Ridge, VA–NC–TN Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus Ocean, Blue Ridge, VA–NC–TN
Recent field and geochronological studies in eight 7.5-minute quadrangles near Mount Rogers in Virginia, North Carolina and Tennessee recognize (1) important stratigraphic and structural relationships for the Neoproterozoic Mount Rogers and Konnarock Formations, and the northeast end of the Mountain City window; (2) the separation of Mesoproterozoic rocks of the Blue Ridge into three age...
Authors
Arthur J. Merschat, Ryan J. McAleer, Christopher S. Holm-Denoma, C. Scott Southworth
Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam Extrusion tectonism of Indochina reassessed: constraints from 40Ar/39Ar geochronology from the Day Nui Con Voi metamorphic massif, Vietnam
The extrusion tectonic model for the southeastern margin of the Himalayan orogeny links the crustal shear activity along the Red River Shear Zone (RRSZ) to the opening of the South China Sea (SCS). The Day Nui Con Voi (DNCV) metamorphic massif in northern Vietnam strikes NW-SE, is bounded by the RRSZ to the south and continues along the strike where it meets the SCS. The DNCV is thus a...
Authors
Thi-Hue Dinh, Meng-Wan Yeh, Tung-Yi Lee, Michael J. Kunk, Robert P. Wintsch, Ryan J. McAleer
Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA
Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic...
Authors
Mark W. Carter, Ryan J. McAleer, Christopher S. Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy Mapping ancient sedimentary organic matter molecular structure at nanoscales using optical photothermal infrared spectroscopy
Elucidating the molecular structure of sedimentary organic matter (SOM) is key to understanding petroleum generation processes, as well as ancient sedimentary environments. SOM structure is primarily controlled by biogenic source material (e.g., marine vs. terrigenous), depositional conditions, and subsurface thermal history. Additional factors, e.g., strain, may also impact the...
Authors
Aaron M. Jubb, Martha Stokes, Ryan J. McAleer, Paul C. Hackley, Eoghan Dillion, Jing Qu
Non-USGS Publications**
Berger, A.L., Gulick, S.P., Spotila, J.A., Upton, P., Jaeger, J.M., Chapman, J.B., Worthington, L.A., Pavlis, T.L., Ridgway, K.D., Willems, B.A. and McAleer, R.J., 2008. Quaternary tectonic response to intensified glacial erosion in an orogenic wedge. Nature Geoscience, 1(11), p.793.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*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