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Amy Gilmer, PhD

I am an igneous petrologist interested in the role magmatic processes play in driving plate tectonics, building mountains, forming of volcanic belts and their associated geologic hazards, and forming hydrothermal ore deposits. 

My research is focused on the evolution of magmatic systems. I study extinct systems, using exposures to explore internal processes driving magma, analogous to the plumbing systems feeding active volcanoes. I combine field geology, geochronology, geochemistry, and petrology to constrain conditions of magmatic storage and differentiation that result in either eruption or pluton emplacement and help us understand the larger architecture of magmatic systems. 

 

Professional Experience

  • Research Geologist (2018-present)

  • Postdoctoral Fellow, U.S. Geological Survey (2017-2018)

  • Geologist, Virginia Division of Geology and Mineral Resources (2001-2012)

Education and Certifications

  • Ph.D., Geological Science, University of Bristol (2016)

  • M.S., Geological Science, The University of Texas at Austin (2001)

  • B.S., Geology, College of William and Mary (1999)

Science and Products

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USGS Geochron: A database of USGS geochronological and thermochronological data

The U.S. Geological Survey (USGS) has developed an updated geochronology database (USGS Geochron) to include geochronology summary and analytical data created or funded by the USGS.
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Geosciences and Environmental Change Science Center
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USGS Geochron: A database of USGS geochronological and thermochronological data

The U.S. Geological Survey (USGS) has developed an updated geochronology database (USGS Geochron) to include geochronology summary and analytical data created or funded by the USGS.
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Mt. Ouray, Colorado with aspen colors

Geologic Framework of the Intermountain West

The Geologic Framework of the Intermountain West (IMW) Project is creating a seamless, integrated, geologic map database that spans the Intermountain West region. The database will serve enhanced geologic map data to support geoscience research, environmental and resource assessments, and the communication of geologic information for all U.S. Geological Survey stakeholders. This innovative...
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Geosciences and Environmental Change Science Center
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Geologic Framework of the Intermountain West

The Geologic Framework of the Intermountain West (IMW) Project is creating a seamless, integrated, geologic map database that spans the Intermountain West region. The database will serve enhanced geologic map data to support geoscience research, environmental and resource assessments, and the communication of geologic information for all U.S. Geological Survey stakeholders. This innovative...
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USGS science for a changing world logo

Serving the U.S. Geological Survey’s geochronological data

Geochronological data provide essential information necessary for understanding the timing of geologic processes and events, as well as quantifying rates and timescales key to geologic mapping, mineral and energy resource and hazard assessments. The USGS’s National Geochronological Database (NGDB) contains over 30,000 radiometric ages, but no formal update has occurred in over 20 years. This proj
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Community for Data Integration (CDI)
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Serving the U.S. Geological Survey’s geochronological data

Geochronological data provide essential information necessary for understanding the timing of geologic processes and events, as well as quantifying rates and timescales key to geologic mapping, mineral and energy resource and hazard assessments. The USGS’s National Geochronological Database (NGDB) contains over 30,000 radiometric ages, but no formal update has occurred in over 20 years. This proj
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Looking north towards Ute Mountain, New Mexico

Cenozoic Landscape Evolution of the Southern Rocky Mountains

The Cenozoic Landscape Evolution of the Southern Rocky Mountains Project is a multi-year investigation funded by the National Cooperative Geologic Mapping Program. This project utilizes a combination of geologic mapping, geophysical surveys, basin modeling, and structural, neotectonic, geomorphic, volcanic, stratigraphic, and geochronologic studies to better understand the geologic landscape of...
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Geosciences and Environmental Change Science Center
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Cenozoic Landscape Evolution of the Southern Rocky Mountains

The Cenozoic Landscape Evolution of the Southern Rocky Mountains Project is a multi-year investigation funded by the National Cooperative Geologic Mapping Program. This project utilizes a combination of geologic mapping, geophysical surveys, basin modeling, and structural, neotectonic, geomorphic, volcanic, stratigraphic, and geochronologic studies to better understand the geologic landscape of...
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Data release of zircon U-Pb geochronology and whole-rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada, and Wyoming

This U.S. Geological Survey (USGS) data release provides zircon U-Pb geochronology and whole rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada and Wyoming. The drill core samples were obtained from the USGS Core Research Center in Denver, Colorado. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement te
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Geosciences and Environmental Change Science Center

Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota

This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic history, a
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Geology, Minerals, Energy, and Geophysics Science Center

Data release of monazite and xenotime geochronology for Proterozoic rocks in central Colorado and monazite and zircon geochronology and whole-rock isotope geochemistry fo a Proterozoic drill core sample from western Colorado

This U.S. Geological Survey (USGS) data release provides monazite and xenotime geochronology from Proterozoic rocks collected from outcrop in central Colorado and whole rock isotope geochemistry, and zircon and monazite geochronology from a Proterozoic rock sampled from a drill core from western Colorado. The drill core sample was collected from the 1 Paradox Valley injection core near Bedrock, CO
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Geology, Minerals, Energy, and Geophysics Science Center

Zircon U-Pb geochronology and whole rock geochemistry for pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado

This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data and zircon U-Pb geochronology and trace element concentrations for samples from pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado. Samples were collected in order to constrain the evolution of the pre-ignimbrite m
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Geosciences and Environmental Change Science Center

Bedrock geologic map database for the Durango 1-degree x 2-degree quadrangle, southern Colorado: Contributions to the National Geologic Map

This data release presents geologic map data for the bedrock geology of the Durango 1-degree by 2-degree quadrangle. Geologic mapping incorporates new interpretive contributions and compilation from published geologic map data sources primarily ranging from 1:24,000 to 1:50,000 scale. Much of the geology incorporated from published geologic maps is adjusted based on digital elevation model and nat
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Geosciences and Environmental Change Science Center

Data Release of Geochemical, Geochronologic, and Isotopic Data for Precambrian to Cenozoic Rocks from Colorado, New Mexico, Utah, and Wyoming

This U.S. Geological Survey (USGS) data release includes whole rock geochemical and isotopic data, and uranium-lead isotopic data collected by both Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods for rocks in Colorado, Wyoming, Utah, and New Mexico.
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Geosciences and Environmental Change Science Center

Zircon U-Pb data for Proterozoic rocks in southwestern Colorado and rocks from drill core from Wyoming, Montana, and Nebraska

This U.S. Geological Survey (USGS) data release provides U-Pb zircon data and geochronology for Proterozoic rocks in the Needle Mountains of southwestern Colorado and for Proterozoic rocks sampled from drill cores from Wyoming, Montana, and Nebraska. Samples from the Needle Mountains were collected in order to constrain the polyphase tectonic evolution of the area. Drill core samples are part of a
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

Data release of geochemistry and geochronology for Proterozoic rocks in southwestern Colorado and rocks from drill core from Colorado, North Dakota, Nevada, Wyoming, Montana, and Nebraska

This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data, mineral chemistry, and monazite and xenotime geochronology for Proterozoic rocks in the Needle Mountains of southwestern Colorado and for Proterozoic rocks sampled from drill cores from Colorado, North Dakota, Nevada, Wyoming, Montana, and Nebraska. Samples from the Needle Mountain
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Geosciences and Environmental Change Science Center

USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data (ver. 2.0, September 2023)

USGS Geochron is a database of geochronological and thermochronological dates and data. The data set contains published ages, dates, analytical information, sample metadata including location, and source citations. The following analytical techniques are represented in the data set: 40Ar/39Ar, K-Ar, U-Th-Pb, Sm-Nd, Rb-Sr, Lu-Hf, fission track, and luminescence. This data set incorporates data prev
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Community for Data Integration (CDI), Geosciences and Environmental Change Science Center

Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico

This geologic map depicts and briefly describes geologic units underlying Petroglyph National Monument and immediately adjacent areas in Bernalillo County, New Mexico. The Monument is underlain dominantly by Quaternary basalts of the Albuquerque Volcanoes volcanic field, a series of basin-filling volcanic flows and associated vents from a monogenetic volcanic highland along the eastern margin of t
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center

Geologic map of Petroglyph National Monument and vicinity, Bernalillo County, New Mexico

This geologic map depicts and briefly describes geologic units underlying Petroglyph National Monument and immediately adjacent areas in Bernalillo County, New Mexico. The Monument is underlain dominantly by Quaternary basalts of the Albuquerque Volcanoes volcanic field, a series of basin-filling volcanic flows and associated vents from a monogenetic volcanic highland along the eastern margin of t
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Geosciences and Environmental Change Science Center

Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen

The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria modeling and t
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Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda (Kate) Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez
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Geosciences and Environmental Change Science Center, Geology, Geophysics, and Geochemistry Science Center

Heterogeneous multi-stage accretionary orogenesis — Evidence from the Gunnison block in the Yavapai Province, southwest USA

Proterozoic rocks exposed in the southwestern U.S.A. represent one of the best examples of crustal growth by arc-related magmatism and accretionary orogenesis. Within the Southwest the 1.8–1.7 Ga Yavapai Province is widely regarded as a classic example of juvenile arc crust, however 1.8–2.5 Ga inherited zircon and Nd and Hf model ages have been recognized near Gunnison in central Colorado. These d
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Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Karl E. Karlstrom, Amanda (Kate) Souders, Jorge A. Vazquez, Wayne R. Premo
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Geosciences and Environmental Change Science Center

Geochemical evidence for evolving Proterozoic crustal thickness and orogenic styles in southwestern Laurentia

It has long been challenging for researchers to track the crustal thickness and mode(s) of crustal modification in ancient convergent margins, limiting evaluation of the tectonic styles and processes that modify continental crust during orogenesis. We present trace element igneous geochemical crustal thickness proxies that quantitatively track the crustal thickness evolution of the long-lived Prot
Authors
Ian William Hillenbrand, Karl E. Karlstrom, Michael L. Williams, Amy K. Gilmer, Wayne R. Premo, Peter B Davis
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Geosciences and Environmental Change Science Center

Monazite and xenotime petrochronologic constraints on four Proterozoic tectonic episodes and ca. 1705 Ma age of the Uncompahgre Formation, southwestern Colorado, USA

The Proterozoic tectonic evolution of the south-western USA remains incompletely understood due to limited constraints on the timing and conditions of the tectono-metamorphic phases and depositional age of metasedimentary successions. We integrated multi-scale compositional mapping, petrologic modeling, and in situ geochronology to constrain pressure-temperature-time paths from samples of Paleopro
Authors
Ian William Hillenbrand, Michael L. Williams, Karl E. Karlstrom, Amy K. Gilmer, Heather A. Lowers, Michael J. Jercinovic, Kaitlyn Suarez, Amanda (Kate) Souders
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Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

Community for data integration 2019 project report

The U.S. Geological Survey Community for Data Integration annually supports small projects focusing on data integration for interdisciplinary research, innovative data management, and demonstration of new technologies. This report provides a summary of the 14 projects supported in fiscal year 2019 and outlines their goals, activities, and accomplishments. Proposals in 2019 were encouraged to addre
Authors
Amanda N. Liford, Caitlin M. Andrews, Aparna Bamzai, Joseph A. Bard, David S. Blehert, John B. Bradford, Wesley M. Daniel, Sara L. Caldwell Eldridge, Frank Engel, Jason A. Ferrante, Amy K. Gilmer, Margaret E. Hunter, Jeanne M. Jones, Benjamin Letcher, Frances L. Lightsom, Richard R. McDonald, Leah E. Morgan, Sasha C. Reed, Leslie Hsu
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Ecosystems Mission Area, Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Science Analytics and Synthesis (SAS) Program, Volcano Hazards Program, Community for Data Integration (CDI), Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, National Wildlife Health Center, Oklahoma-Texas Water Science Center, Southwest Biological Science Center, Volcano Science Center, Western Geographic Science Center, Wetland and Aquatic Research Center , Woods Hole Coastal and Marine Science Center, Science Data Management

Revised age and regional correlations of Cenozoic strata on Bat Mountain, Death Valley region, California, USA, from zircon U-Pb geochronology of sandstones and ash-fall tuffs

Basin analysis and tectonic reconstructions of the Cenozoic history of the Death Valley region, California, USA, are hindered by a lack of volcanic (tuff) age control in many stratigraphic successions exposed in the Grapevine and Funeral Mountains of California, USA. Although maximum depositional ages (MDAs) interpreted from detrital zircon U-Pb data may be a promising alternative to volcanic ages
Authors
Theresa Maude Schwartz, Amanda (Kate) Souders, Jens-Erik Lundstern, Amy K. Gilmer, Ren A. Thompson
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center

The Seamless Integrated Geologic Mapping (SIGMa) extension to the Geologic Map Schema (GeMS)

Geologic maps are the fundamental building blocks of surface and subsurface three-dimensional geologic framework models of the Earth’s crust. However, as the production and availability of geologic map databases continues to increase, inconsistent data models and the lack of synthesized, national geologic map data at scales appropriate for informed decision making negatively affect the functional
Authors
Kenzie J. Turner, Jeremiah B. Workman, Joseph Colgan, Amy K. Gilmer, Margaret E. Berry, Samuel Johnstone, Kathleen F. Warrell, Marieke Dechesne, D. Paco VanSistine, Ren A. Thompson, Adam M. Hudson, Kristine L. Zellman, Donald S. Sweetkind, Chester A. Ruleman
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Geosciences and Environmental Change Science Center

Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountain volcanic field, Colorado, USA

The Oligocene Platoro caldera complex of the San Juan volcanic locus in Colorado (USA) features numerous exposed plutons both within the caldera and outside its margins, enabling investigation of the timing and evolution of postcaldera magmatism. Intrusion whole-rock geochemistry and phenocryst and/or mineral trace element compositions coupled with new zircon U-Pb geo-chronology and zircon in situ
Authors
Amy K. Gilmer, Ren A. Thompson, Peter W. Lipman, Jorge A. Vazquez, Amanda (Kate) Souders
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National Cooperative Geologic Mapping Program, Volcano Hazards Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center

Duration of hydrothermal alteration and mineralization of the Don Manuel porphyry copper system, central Chile

The Don Manuel porphyry copper system, located in the Miocene–Pliocene metallogenic belt of central Chile, contains spatially zoned alteration styles common to other porphyry copper deposits including extensive potassic alteration, propylitic alteration, localized sericite-chlorite alteration and argillic alteration but lacks pervasive hydrolytic alteration typical of some deposits. It is one of t
Authors
Amy K. Gilmer, R. Stephen J. Sparks, Dan N. Barfod, Emily Brugge, Catherine Annen, Ian Parkinson
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Geosciences and Environmental Change Science Center

Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado)

Many eroded calderas expose associated postcollapse plutons, but detailed fieldwork‐supported studies have rarely focused on the internal structure that can contribute to understanding of emplacement dynamics. The Alamosa River monzonite pluton is a postcollapse intrusion at the Platoro caldera complex that erupted six large ignimbrites between 30.2 and 28.8 Ma in the Southern Rocky Mountains volc
Authors
Filip Tomek, Amy K. Gilmer, M. S. Petronis, Peter W. Lipman, M. S. Foucher
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center

A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system

Establishing temporal constrains on major volcanic eruptions is limited by the precision of existing geochronometers. Prior work on the La Garita caldera, created by the eruption of the Fish Canyon Tuff, failed to resolve temporal differences between pre-, syn-, and post-collapse eruptive units. Here, we report 40Ar/39Ar geochronologic data supporting a ca. 100 ka eruptive history of the La Garita
Authors
Leah E. Morgan, Samuel Johnstone, Amy K. Gilmer, Michael A. Cosca, Ren A. Thompson
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National Cooperative Geologic Mapping Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

Non-USGS Publications**

Gilmer, A.K., Sparks, R.S.J., Rust, A.C., Tapster, Simon, Webb, A.D., and Barfod, D.N., Geology of the Don Manuel igneous complex, central Chile: Implications for igneous processes in porphyry copper systems:GSA Bulletin, 129 (7-8): 920–946.
Blundy, J., Mavrogenes, J., Tattitch, B., Sparks, S., and Gilmer, A. 2015, Generation of porphyry copper deposits by gas-brine reaction in volcanic arcs: Nature Geoscience, 8, 235-240.
Pratt, T.L., Horton, J.W., Spears, D.B., Gilmer, A.K., and McNamara, D.E., 2014, The 2011 Virginia Mw 5.8 earthquake: Insights from seismic reflection imaging into the influence of older structures on eastern US seismicity: Geological Society of America Special Papers, 509, SPE509-16.
Shah, A.K., Horton, J.W., Burton, W.C., Spears, D.B., and Gilmer, A.K., 2014, Subsurface geologic features of the 2011 central Virginia earthquakes revealed by airborne geophysics: Geological Society of America Special Papers, 509, SPE509-17.
Gilmer, A.K., Kyle, J.R., Connelly, J.N., and Mathur, R.D., and Henry, CD., 2003, Extension of Laramide magmatism in southwestern North America into Trans-Pecos Texas: Geology, v. 31, no. 5, p. 447-450.

**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.

Intermountain West Seamless Geologic Map Explorer

The Intermountain West Seamless Geologic Map Explorer is an interactive mapping application that hosts surficial and bedrock geologic data layers for a transect from the Rio Grande rift to the Basin and Range. 

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Geosciences and Environmental Change Science Center

USGS Geochron Database Explorer

This Web Application is a tool for viewing, exploring, and downloading the "USGS Geochron: A Database of Geochronological and Thermochronological Dates and Data" Data Release.

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Geosciences and Environmental Change Science Center

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