I joined the USGS GEC Science Center in Denver, Colorado in 2017. I am 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.
I am working on the Geologic Framework of the Intermountain West Project investigating the ignimbrites and post-caldera intrusions of the Platoro caldera complex and how they relate to the San Juan magma reservoir, Rio Grande extension-related magmatism, and ore deposition in the region.
Before joining the USGS, my research focused on the primary magmatic features and petrogenesis of the Don Manuel igneous complex and associated porphyry copper system in the Andean Cordillera of central Chile. I also worked for the Virginia Division of Geology and Mineral Resources conducting mineral resource assessments and geologic mapping in the Virginia Blue Ridge, Piedmont, and Coastal Plain.
Science and Products
Geologic Framework of the Intermountain West
Serving the U.S. Geological Survey’s geochronological data
Cenozoic Landscape Evolution of the Southern Rocky Mountains
Geologic map of Petroglyph National Monument and vicinity, Bernalillo County, New Mexico
Duration of hydrothermal alteration and mineralization of the Don Manuel porphyry copper system, central Chile
Geologic map of Petroglyph National Monument and vicinity, Bernalillo County, New Mexico
Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado)
A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system
Pre-USGS Publications
Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico
Science and Products
- Science
Geologic Framework of the Intermountain West
The Geologic Framework of the Intermountain West project was launched with the goal of producing a new digital geologic map database and 3D geologic model of a transect from the Rio Grande rift to the Basin and Range, based on a synthesis of existing geologic maps with new targeted new mapping, subsurface data, and other data sets. This database will integrate disparate map data, resolve...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 projCenozoic 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... - Maps
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 - Publications
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 tGeologic 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 tProtracted 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 volcA 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 GaritaPre-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. - Data
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