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Joseph Colgan

I study magmatism and deformation of the earth’s crust, and how these processes influence the formation and distribution of natural resources and geologic hazards. This work involves geologic mapping at different scales, interpretation of subsurface and geophysical data, and laboratory analyses to determine the age and composition of rocks and minerals.

Professional Experience

  • 2014 - present     Research Geologist, USGS, Denver CO

  • 2009 - 2014         Research Geologist, USGS, Menlo Park CA

  • 2006 - 2009         Mendenhall Postdoctoral Fellow, USGS, Menlo Park CA

  • 1999 - 2005         Teaching and Research Assistant, Stanford University, Stanford CA

  • 1998 - 1999         Earth Science Intern, USGS, Menlo Park CA

Education and Certifications

  • 2005      Ph.D., Geological & Environmental Sciences, Stanford University, Stanford CA

  • 1998      B.A., Geology, Carleton College, Northfield MN

Honors and Awards

  • 2012 - Presidential Early Career Award in Science and Engineering (PECASE)

Science and Products

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Precambrian bedrock and Paleozoic sedimentary cover in the upper Midwest

National Bedrock Geology

Accessible, up-to-date information about the Nation’s bedrock geology is necessary to support infrastructure development, natural resource management, mineral assessments, water quality, and earth science research. The National Bedrock Geology task will construct a continuous digital geologic map of pre-Quaternary rocks and deposits across the United States at National scale, to fulfill the USGI...
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Geosciences and Environmental Change Science Center
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National Bedrock Geology

Accessible, up-to-date information about the Nation’s bedrock geology is necessary to support infrastructure development, natural resource management, mineral assessments, water quality, and earth science research. The National Bedrock Geology task will construct a continuous digital geologic map of pre-Quaternary rocks and deposits across the United States at National scale, to fulfill the USGI...
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View toward Blanca Peak, Colorado

National Geologic Synthesis

The National Cooperative Geologic Mapping Program (NCGMP) Strategic Plan of 2020 calls for the creation of a “variable-scale, national, integrated 2D and 3D geologic-framework model that enables the seamless construction of geologic maps within user-defined regions of interest across the United States by the year 2030” (USGS Open-File Report 2021-1013*). Congress recently directed NCGMP to “bring...
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center
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National Geologic Synthesis

The National Cooperative Geologic Mapping Program (NCGMP) Strategic Plan of 2020 calls for the creation of a “variable-scale, national, integrated 2D and 3D geologic-framework model that enables the seamless construction of geologic maps within user-defined regions of interest across the United States by the year 2030” (USGS Open-File Report 2021-1013*). Congress recently directed NCGMP to “bring...
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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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Zircon U-Pb age and trace element data for igneous rocks in the Cortez area, Nevada

The Cortez region in north-central Nevada hosts the second largest concentration of Carlin-type gold deposits in Nevada. The origin of these deposits is debated, and major questions remain concerning the role of magmatism in their formation. To understand the Mesozoic and Cenozoic magmatic history of the Cortez region, twenty-one samples of igneous rocks ranging from Jurassic to Eocene were sample
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Geosciences and Environmental Change Science Center

Thermochronologic data from the southern Stillwater Range, Nevada

This dataset contains apatite and zircon U-Th(He)data, 4He/3He thermochronologic data, and apatite fission-track data from the southern Stillwater Range, Nevada
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center

Geochemical and geochronologic data from the Stillwater Range, Clan Alpine, and Desatoya Mountains, Nevada

This dataset contains argon-argon and U-Pb geochronologic data collected from igneous rocks in the Stillwater Range, Clan Alpine, and Desatoya Mountains, western Nevada, USA.
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Geosciences and Environmental Change Science Center

Data to accompany U.S. Geological Survey Data Series 1099: Petrographic, geochemical and geochronologic data for Cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada

This dataset is the assembled analytical results of geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada. Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during geologic map
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Geochemical and geochronologic data from the Hall Creek caldera, Toiyabe Range, Nevada

The magmatic, tectonic, and topographic evolution of what is now the northern Great Basin remains controversial, notably the temporal and spatial relation between magmatism and extensional faulting. This controversy is exemplified in the northern Toiyabe Range of central Nevada, where previous geologic mapping suggested the presence of a caldera that sourced the late Eocene (34.0 mega-annum [Ma])
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Geosciences and Environmental Change Science Center

Geologic map of the Caetano caldera, Lander and Eureka counties, Nevada

The Eocene (34 Ma) Caetano caldera in north-central Nevada offers an exceptional opportunity to study the physical and petrogenetic evolution of a large (20 km by 10–18 km pre-extensional dimensions) silicic magma chamber, from precursor magmatism to caldera collapse and intrusion of resurgent plutons. Caldera-related rocks shown on this map include two units of crystal-rich intracaldera tu

Map showing inventory and regional susceptibility for Holocene debris flows, and related fast-moving landslides in the conterminous United States

Introduction Debris flows, debris avalanches, mud flows and lahars are fast-moving landslides that occur in a wide variety of environments throughout the world. They are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. This map represents a significant effort to compile the locations of known debris flows in
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Natural Hazards, Landslide Hazards, Geologic Hazards Science Center
Filter Total Items: 34

The National Cooperative Geologic Mapping Program’s U.S. GeoFramework Initiative — Delivering a digital database of geologic map information by 2030

The U.S. Geological Survey's National Cooperative Geologic Mapping Program's U.S. GeoFramework Initiative responds to Congressional direction to implement the National Geologic Map Database Phase Three. The U.S. GeoFramework Initiative aims to create and deliver a new digital geologic framework of the United States by 2030. This Fact Sheet outlines the collaborations needed and plans taken to achi
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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
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Geosciences and Environmental Change Science Center

Detrital zircon record of magmatism and sediment dispersal across the North American Cordilleran arc system (28-48°N)

As zircon U-Pb geochronology has become a leading method in sediment provenance studies and basin analysis over the past 20 years, the volume of detrital zircon data made available in published literature has enabled researchers to go beyond source-to-sink provenance studies to explore increasingly complex geologic problems. In this review, we utilize the growing body of detrital zircon data acqui
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National Cooperative Geologic Mapping Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

Why did Great Basin Eocene magmatism generate Carlin-type gold deposits when extensive Jurassic to Middle Miocene magmatism did not? Lessons from the Cortez Region, Northern Nevada, USA

No abstract available.
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Geology, Minerals, Energy, and Geophysics Science Center

Timing of Cenozoic extension in the southern Stillwater Range and Dixie Valley, Nevada

The Dixie Valley fault bounds the east side of the Stillwater Range in west‐central Nevada and last ruptured in 1954. Offset basalts indicate that slip began more recently than ~14 Ma, and prior work has interpreted the southern segment as an active low‐angle normal fault. Oligocene igneous rocks in the southern Stillwater Range were steeply tilted during large‐magnitude extension prior to ~14 Ma.
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National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center

Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada

Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts of west-central Nevada. In the Tonopah mining district, volcanic rocks include the Mizpah Trachyte, Fraction Tuff, and Oddie Rhyolite; in the Di
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada

The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during geologic map
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Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center

Oxygen isotopic investigation of silicic magmatism in the Stillwater caldera complex, Nevada: Generation of large-volume, low-δ18O rhyolitic tuffs and assessment of their regional context in the Great Basin of the western United States

Successive caldera-forming eruptions from ca. 30 to 25 Ma generated a large nested caldera complex in western Nevada that was subsequently dissected by Basin and Range extension, providing extraordinary cross-sectional views through diverse volcanic and plutonic rocks. A high-resolution oxygen isotopic study was conducted on units that represent all major parts of the Job Canyon, Louderback Mounta
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Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Interpretation of low‐temperature thermochronometer ages from tilted normal fault blocks

Low‐temperature thermochronometry is widely used to measure the timing and rate of slip on normal faults. Rates are often derived from suites of footwall thermochronometer samples, but regression of age vs. structural depth fails to account for the trajectories of samples during fault slip. We demonstrate that in rotating fault blocks, regression of age‐depth data is susceptible to significant err
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Insights into the emplacement of upper-crustal plutons and their relationship to large silicic calderas, from field relationships, geochronology, and zircon trace element geochemistry in the Stillwater – Clan Alpine caldera complex, western Nevada, USA

Geologic mapping, new U-Pb zircon ages, and new and published 40Ar/39Ar sanidine ages document the timing and extent of Oligocene magmatism in the southern Stillwater Range and Clan Alpine Mountains of western Nevada, where Miocene extension has exposed at least six nested silicic calderas and underlying granitic plutons to crustal depths locally ≥ 9 km. Both caldera-forming rhyolitic tuffs and un
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Groundwater and Streamflow Information Program, Geosciences and Environmental Change Science Center

Eruptive history, geochronology, and post-eruption structural evolution of the late Eocene Hall Creek Caldera, Toiyabe Range, Nevada

The magmatic, tectonic, and topographic evolution of what is now the northern Great Basin remains controversial, notably the temporal and spatial relation between magmatism and extensional faulting. This controversy is exemplified in the northern Toiyabe Range of central Nevada, where previous geologic mapping suggested the presence of a caldera that sourced the late Eocene (34.0 mega-annum [Ma])
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Groundwater and Streamflow Information Program, Geosciences and Environmental Change Science Center

Probing the volcanic-plutonic connection and the genesis of crystal-rich rhyolite in a deeply dissected supervolcano in the Nevada Great Basin: Source of the late Eocene Caetano Tuff

Late Cenozoic faulting and large-magnitude extension in the Great Basin of the western USA has created locally deep windows into the upper crust, permitting direct study of volcanic and plutonic rocks within individual calderas. The Caetano caldera in north–central Nevada, formed during the mid-Tertiary ignimbrite flare-up, offers one of the best exposed and most complete records of caldera magmat
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Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Non-USGS Publications**

Henry, C.D., Bell, J.W., John, D.A., and Colgan, J.P., 2013, Preliminary geologic map of the West Gate quadrangle, Churchill County, Nevada: Nevada Bureau of Mines and Geology Open-File Report 13-9, scale 1:24,000.
Henry, C.D., Hinz, N.H., Faulds, J.E., Colgan, J.P., John, D.A., Brooks, E.R., Cassel, E.J., Garside, L.J., Davis, D.A., and Castor, S.B., 2012, Eocene–Early Miocene paleotopography of the Sierra Nevada–Great Basin–Nevadaplano based on widespread ash-flow tuffs and paleovalleys: Geosphere, v. 8, p. 1–27, doi:10.1130/GES00727.1.
Colgan, J.P., Wyld, S.J., and Wright, J., 2010, Geologic map of the Vicksburg Canyon 7.5’ quadrangle, Humboldt County, Nevada: Nevada Bureau of Mines and Geology Map M169, scale 1:24,000.
Lerch, D.W., Klemperer, S.L., Egger, A.E., Colgan, J.P., and Miller, E.L., 2009, The northwestern margin of the Basin and Range Province, part 1: Reflection profiling of the moderate-angle (35°) Surprise Valley Fault: Tectonophysics, v. 488(1–4), p. 143–149, doi:10.1016/j.tecto.2009.05.028.
Mattinson, C.G., Colgan, J.P., Metcalf, J.R., Miller E.L., and Wooden, J.L., 2007, Late Cretaceous to Paleocene metamorphism and magmatism in the Funeral Mountains metamorphic core complex, Death Valley, California, in Cloos, M., Carlson, W.D., Gilbert, M.C., Liou, J.G., and Sorensen, S.S., eds., Convergent Margin Terranes and Associated Regions: A Tribute to W.G. Ernst: Geological Society of America Special Paper 419, p. 205–223, doi:10.1130/2006.2419(11).
Lerch, D.W., Klemperer, S.L., Glen, J.M.G., Ponce, D.A., Miller, E.L., and Colgan, J.P., 2007, Crustal structure of the northwestern Basin and Range Province and its transition to unextended volcanic plateaus: Geochemistry, Geophysics, and Geosystems, v. 8, doi:10.1029/2006GC001429.
Colgan, J.P., Dumitru, T.A., Reiners, P.W., Wooden, J.L., and Miller, E.L., 2006, Cenozoic tectonic evolution of the Basin and Range Province in northwestern Nevada: American Journal of Science, v. 306(8), p. 616–654.
Colgan, J.P., Dumitru, T.A., McWilliams, M.O., and Miller, E.L., 2006, Timing of Cenozoic volcanism and Basin and Range extension in northwestern Nevada: new constraints from the northern Pine Forest Range: Geological Society of America Bulletin, v. 118(1-2), p. 126–139, doi:10.1130/B25681.1.
Colgan, J.P., Dumitru, T.A., and Miller, E.L., 2004, Diachroneity of Basin and Range faulting and Yellowstone hotpsot volcanism in northwestern Nevada: Geology, v. 32(2), p. 121–124, doi:10.1130/G20037.1.

**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