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
Evidence for strain induced graphitization across 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 strain energy in natural graphitization at greenschist facies metamorphic conditions. Scanning electron microscope (SEM) imaging documents phyllosilicate and quartz replacement textures consistent cleavage development via dissolution-precipitation proces
40Ar/39Ar data from the Gidami gold deposit, Egypt
This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from the Gidami gold deposit in the Eastern Desert of Egypt. Rock samples were collected by Basem Zoheir--Benha University/University of Kiel. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laborator
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.
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 using XANE
Elemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publi
Electron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-sili
40Ar/39Ar data from the Old Mine Park area, Trumbull, Connecticut
This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from Old Mine Park Area, Trumbull, Connecticut. Mineral samples were collected by Robert Wintsch and Harold Moritz. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. The
Photoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies
The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge
Bedrock geologic map of the Crown Point quadrangle, Essex County, New York, and Addison County, Vermont
The bedrock geology of the 7.5-minute Crown Point quadrangle consists of deformed and metamorphosed Mesoproterozoic gneisses of the Adirondack Highlands unconformably overlain by weakly deformed lower Paleozoic sedimentary rocks of the Champlain Valley. The Mesoproterozoic rocks occur on the eastern edge of the Adirondack Highlands and represent an extension of the Grenville Province of Laurentia.
Filter Total Items: 39
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 granitic rocks. T
Authors
Mark W. Carter, Ryan J. McAleer, Christopher 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
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 molecular structur
Authors
Aaron M. Jubb, Martha (Rebecca) Stokes, Ryan J. McAleer, Paul C. Hackley, Eoghan Dillion, Jing Qu
A novel non-destructive workflow for examining germanium and co-substituents in ZnS
A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of s
Authors
Sarah M. Hayes, Ryan J. McAleer, Nadine M. Piatak, Sarah Jane White, Robert R. Seal
The Sukari gold deposit, Egypt: Geochemical and geochronological constraints on the ore genesis and implications for regional exploration
The Sukari gold deposit (>15 Moz Au) in the Eastern Desert of Egypt is hosted by a deformed granitoid stock (Sukari tonalite-trondhjemite intrusion) and mainly occurs as a network of crosscutting sulfide-bearing quartz (± carbonate) veins and intensely sulfidized-silicified-sericitized wall rock. Emplacement of the Sukari intrusion into a tectonized Neoproterozoic accretionary complex was controll
Authors
Basem Zoheir, Astrid Holzheid, Armin Zeh, Ryan J. McAleer, Mohamed El-Behairy, Ulrich Schwarz-Schampera, Torsten Graupner, David Lentz, Fahui Xiong
Vein-type gold formation during late extensional collapse of the Eastern Desert, Egypt: the Gidami deposit
Orogenic gold deposits, though construed to focused fluid flow during orogenesis, commonly post-date the main accretionary events. Several lines of evidence indicate that orogenic gold formation in the Arabian–Nubian Shield continued through the orogen collapse stage and associated rapid exhumation and thermal re-equilibration. The Gidami gold deposit in the Eastern Desert of Egypt is associated w
Authors
Basem Zoheir, Ryan J. McAleer, Matthew Steele-MacInnis, Armin Zeh, Wyatt M. Bain, Spencer Poulette
Germanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral
Germanium (Ge) is a metal used in emerging energy technologies, communications, and defense, and has been deemed critical by the United States due to its essential applications and scarce supply. Germanium is recovered as a byproduct of zinc (Zn) sulfides, and mining and processing of these materials lead to waste that could act both as a source of extractable Ge and a source for exposure to human
Authors
Sarah Jane White, Nadine M. Piatak, Ryan J. McAleer, Sarah M. Hayes, Robert R. Seal, Laurel A. Schaider, James P. Shine
U-Pb and fission-track data from zircon and apatite resolve latest- and post-Alleghanian thermal histories along the Fall Line of the Atlantic margin of the southeastern United States
Although the Atlantic continental margin of the eastern United States is an archetypal passive margin, episodes of rejuvenation following continental breakup are increasingly well documented. To better constrain this history of rejuvenation along the southern portion of this continental margin, we present zircon U-Pb (ZUPb) age, zircon fission-track (ZFT) age, apatite U-Pb (AUPb) age, and apatite
Authors
William H. Craddock, Paul O'Sullivan, Ryan J. McAleer
Evaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of hydrogen from water, organic-rich (22 wt% total organic carbon, TOC) mudrock samples from the Eocene lac
Authors
Paul C. Hackley, Aaron M. Jubb, Patrick L. Smith, Ryan J. McAleer, Brett J. Valentine, Javin J. Hatcherian, Palma J. Botterell, Justin E. Birdwell
Geology & mineralogy of the Old Mine Park area Trumbull Connecticut
Old Mine Park, in the northern Trumbull area (also known as Long Hill) of southwestern Connecticut, is a recreation area encompassing the mineral-rich hill of “Saganawamps” and owned by the Town of Trumbull. Most of its 72 acres are wooded, rocky and undeveloped but it is surrounded by dense infrastructure and transportation, residential, retail, and commercial development (Figure 1). It preserves
Authors
Harold Moritz, Robert P. Wintsch, Bill Devlin, Ryan J. McAleer, Shinae Lee, SookJu Kim, Keewook Yi
Stop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia
Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained gra
Authors
Mark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. Owens
Diagenetic barite-pyrite-wurtzite formation and redox signatures in Triassic mudstone, Brooks Range, northern Alaska
Mineralogical and geochemical studies of interbedded black and gray mudstones in the Triassic part of the Triassic-Jurassic Otuk Formation (northern Alaska) document locally abundant barite and pyrite plus diverse redox signatures. These strata, deposited in an outer shelf setting at paleolatitudes of ~45 to 60°N, show widespread sedimentological evidence for bioturbation. Barite occurs preferenti
Authors
John F. Slack, Ryan J. McAleer, Wayne (Pat) Shanks, Julie A. Dumoulin
Formation of miarolitic-class, segregation-type pegmatites in the Taishanmiao batholith, China: The role of pressure fluctuations and volatile exsolution during pegmatite formation in a closed, isochoric system
The Taishanmiao granitic batholith, located in the Eastern Qinling Orogen in Henan Province, China, contains numerous small (mostly tens of centimeters in maximum dimension) bodies exhibiting textures and mineralogy characteristics of simple quartz and alkali feldspar pegmatites. Analysis of melt inclusions (MI) and fluid inclusions (FI) in pegmatitic quartz, combined with Rhyolite-MELTS modeling
Authors
Yabin Yuan, Lowell Moore, Ryan J. McAleer, Shunda Yuan, Hegen Ouyang, Harvey E. Belkin, Jingwen Mao, Matthew D. Sublett Jr., Robert J. Bodnar
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
- Data
Evidence for strain induced graphitization across 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 strain energy in natural graphitization at greenschist facies metamorphic conditions. Scanning electron microscope (SEM) imaging documents phyllosilicate and quartz replacement textures consistent cleavage development via dissolution-precipitation proces40Ar/39Ar data from the Gidami gold deposit, Egypt
This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from the Gidami gold deposit in the Eastern Desert of Egypt. Rock samples were collected by Basem Zoheir--Benha University/University of Kiel. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) LaboratorMineral 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.
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 using XANEElemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Elemental concentrations for bulk and size-fractionated mine waste from sampled historical waste piles from the Tar Creek Superfund Site, Oklahoma, U.S. were determined after dissolution via acid digests or a sodium peroxide fusion. Elemental concentrations were determined for the leachate from a simulated rainwater leach of mine wastes. Data and methods reported are part of a research study publiElectron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-sili40Ar/39Ar data from the Old Mine Park area, Trumbull, Connecticut
This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from Old Mine Park Area, Trumbull, Connecticut. Mineral samples were collected by Robert Wintsch and Harold Moritz. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. ThePhotoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies
The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge - Maps
Bedrock geologic map of the Crown Point quadrangle, Essex County, New York, and Addison County, Vermont
The bedrock geology of the 7.5-minute Crown Point quadrangle consists of deformed and metamorphosed Mesoproterozoic gneisses of the Adirondack Highlands unconformably overlain by weakly deformed lower Paleozoic sedimentary rocks of the Champlain Valley. The Mesoproterozoic rocks occur on the eastern edge of the Adirondack Highlands and represent an extension of the Grenville Province of Laurentia. - Multimedia
- Publications
Filter Total Items: 39
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 granitic rocks. TAuthorsMark W. Carter, Ryan J. McAleer, Christopher Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. VazquezMapping 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 molecular structurAuthorsAaron M. Jubb, Martha (Rebecca) Stokes, Ryan J. McAleer, Paul C. Hackley, Eoghan Dillion, Jing QuA novel non-destructive workflow for examining germanium and co-substituents in ZnS
A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of sAuthorsSarah M. Hayes, Ryan J. McAleer, Nadine M. Piatak, Sarah Jane White, Robert R. SealThe Sukari gold deposit, Egypt: Geochemical and geochronological constraints on the ore genesis and implications for regional exploration
The Sukari gold deposit (>15 Moz Au) in the Eastern Desert of Egypt is hosted by a deformed granitoid stock (Sukari tonalite-trondhjemite intrusion) and mainly occurs as a network of crosscutting sulfide-bearing quartz (± carbonate) veins and intensely sulfidized-silicified-sericitized wall rock. Emplacement of the Sukari intrusion into a tectonized Neoproterozoic accretionary complex was controllAuthorsBasem Zoheir, Astrid Holzheid, Armin Zeh, Ryan J. McAleer, Mohamed El-Behairy, Ulrich Schwarz-Schampera, Torsten Graupner, David Lentz, Fahui XiongVein-type gold formation during late extensional collapse of the Eastern Desert, Egypt: the Gidami deposit
Orogenic gold deposits, though construed to focused fluid flow during orogenesis, commonly post-date the main accretionary events. Several lines of evidence indicate that orogenic gold formation in the Arabian–Nubian Shield continued through the orogen collapse stage and associated rapid exhumation and thermal re-equilibration. The Gidami gold deposit in the Eastern Desert of Egypt is associated wAuthorsBasem Zoheir, Ryan J. McAleer, Matthew Steele-MacInnis, Armin Zeh, Wyatt M. Bain, Spencer PouletteGermanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral
Germanium (Ge) is a metal used in emerging energy technologies, communications, and defense, and has been deemed critical by the United States due to its essential applications and scarce supply. Germanium is recovered as a byproduct of zinc (Zn) sulfides, and mining and processing of these materials lead to waste that could act both as a source of extractable Ge and a source for exposure to humanAuthorsSarah Jane White, Nadine M. Piatak, Ryan J. McAleer, Sarah M. Hayes, Robert R. Seal, Laurel A. Schaider, James P. ShineU-Pb and fission-track data from zircon and apatite resolve latest- and post-Alleghanian thermal histories along the Fall Line of the Atlantic margin of the southeastern United States
Although the Atlantic continental margin of the eastern United States is an archetypal passive margin, episodes of rejuvenation following continental breakup are increasingly well documented. To better constrain this history of rejuvenation along the southern portion of this continental margin, we present zircon U-Pb (ZUPb) age, zircon fission-track (ZFT) age, apatite U-Pb (AUPb) age, and apatiteAuthorsWilliam H. Craddock, Paul O'Sullivan, Ryan J. McAleerEvaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of hydrogen from water, organic-rich (22 wt% total organic carbon, TOC) mudrock samples from the Eocene lacAuthorsPaul C. Hackley, Aaron M. Jubb, Patrick L. Smith, Ryan J. McAleer, Brett J. Valentine, Javin J. Hatcherian, Palma J. Botterell, Justin E. BirdwellGeology & mineralogy of the Old Mine Park area Trumbull Connecticut
Old Mine Park, in the northern Trumbull area (also known as Long Hill) of southwestern Connecticut, is a recreation area encompassing the mineral-rich hill of “Saganawamps” and owned by the Town of Trumbull. Most of its 72 acres are wooded, rocky and undeveloped but it is surrounded by dense infrastructure and transportation, residential, retail, and commercial development (Figure 1). It preservesAuthorsHarold Moritz, Robert P. Wintsch, Bill Devlin, Ryan J. McAleer, Shinae Lee, SookJu Kim, Keewook YiStop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia
Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained graAuthorsMark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. OwensDiagenetic barite-pyrite-wurtzite formation and redox signatures in Triassic mudstone, Brooks Range, northern Alaska
Mineralogical and geochemical studies of interbedded black and gray mudstones in the Triassic part of the Triassic-Jurassic Otuk Formation (northern Alaska) document locally abundant barite and pyrite plus diverse redox signatures. These strata, deposited in an outer shelf setting at paleolatitudes of ~45 to 60°N, show widespread sedimentological evidence for bioturbation. Barite occurs preferentiAuthorsJohn F. Slack, Ryan J. McAleer, Wayne (Pat) Shanks, Julie A. DumoulinFormation of miarolitic-class, segregation-type pegmatites in the Taishanmiao batholith, China: The role of pressure fluctuations and volatile exsolution during pegmatite formation in a closed, isochoric system
The Taishanmiao granitic batholith, located in the Eastern Qinling Orogen in Henan Province, China, contains numerous small (mostly tens of centimeters in maximum dimension) bodies exhibiting textures and mineralogy characteristics of simple quartz and alkali feldspar pegmatites. Analysis of melt inclusions (MI) and fluid inclusions (FI) in pegmatitic quartz, combined with Rhyolite-MELTS modelingAuthorsYabin Yuan, Lowell Moore, Ryan J. McAleer, Shunda Yuan, Hegen Ouyang, Harvey E. Belkin, Jingwen Mao, Matthew D. Sublett Jr., Robert J. BodnarNon-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