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
Filter Total Items: 19
Bedrock geologic map database for the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado Bedrock geologic map database for the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado
This data release presents geologic map data for the bedrock geology of the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado. 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...
Digital database of the previously published geologic map of the Boulder-Fort Collins-Greeley area, Colorado Digital database of the previously published geologic map of the Boulder-Fort Collins-Greeley area, Colorado
This digital map shows the geographic extent of rock stratigraphic units (formations) as compiled by Colton in 1976 under the Front Range Urban Corridor Geology Program. Colton used his own geologic mapping and previously published geologic maps to compile one map having a single classification of geologic units. The resulting published color paper map (USGS Map I-855-G, Colton, 1978)...
Digital database of the previously published geologic map of the greater Denver area, Front Range Urban Corridor, Colorado Digital database of the previously published geologic map of the greater Denver area, Front Range Urban Corridor, Colorado
This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient...
Bedrock geologic map database for the Durango 1-degree x 2-degree quadrangle, southern Colorado: Contributions to the National Geologic Map (ver. 2.0, June 2024) Bedrock geologic map database for the Durango 1-degree x 2-degree quadrangle, southern Colorado: Contributions to the National Geologic Map (ver. 2.0, June 2024)
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...
Digital database of the previously published bedrock geologic map showing thickness of overlying Quaternary deposits, Grand Island quadrangle, Nebraska and Kansas Digital database of the previously published bedrock geologic map showing thickness of overlying Quaternary deposits, Grand Island quadrangle, Nebraska and Kansas
This digital data release contains geospatial data for the 1:250,000 scale geologic map of the Grand Island 1 degree by 2 degree quadrangle, Nebraska, originally published by Dreeszen and others (1973). The database includes line and polygon features depicting the extent of the Miocene Ogallala Formation and underlying Cretaceous rocks. The original map also included shaded patches...
Digital database of the previously published geologic map of the O'Neill 1x2 degree quadrangle, Nebraska Digital database of the previously published geologic map of the O'Neill 1x2 degree quadrangle, Nebraska
This digital data release contains geospatial data for the geologic map of the O’Neill 1 degree by 2 degree geologic map in Nebraska, originally published in 2008 by R.E. Diffendal and others. The original map consists of a 1:250,000 scale map plate with a “stack unit” structure showing multiple overlying units, as well as several roughly 1:750,000 scale maps in an accompanying pamphlet...
Filter Total Items: 41
Detrital zircon record of magmatism and sediment dispersal across the North American Cordilleran arc system (28-48°N) 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...
Authors
Theresa Maude Schwartz, Kathleen D. Surpless, Joseph P. Colgan, Samuel Johnstone, Christopher S. Holm-Denoma
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 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.
Authors
Christopher D. Henry, David A. John, Matt T. Heizler, Robert W. Leonardson, Joseph P. Colgan, Kathryn E. Watts, Michael W. Ressel, Brian L. Cousens
Timing of Cenozoic extension in the southern Stillwater Range and Dixie Valley, Nevada 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...
Authors
Joseph P. Colgan, Samuel Johnstone, David L. Shuster
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada 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...
Authors
Edward A. du Bray, David A. John, Joseph P. Colgan, Peter G. Vikre, Michael A. Cosca, Leah E. Morgan
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada 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...
Authors
Edward A. du Bray, David A. John, Peter G. Vikre, Joseph P. Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-Denoma
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 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...
Authors
Kathryn E. Watts, David A. John, Joseph P. Colgan, Christopher D. Henry, Ilya N. Bindeman, John W. Valley
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
Filter Total Items: 19
Bedrock geologic map database for the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado Bedrock geologic map database for the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado
This data release presents geologic map data for the bedrock geology of the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado. 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...
Digital database of the previously published geologic map of the Boulder-Fort Collins-Greeley area, Colorado Digital database of the previously published geologic map of the Boulder-Fort Collins-Greeley area, Colorado
This digital map shows the geographic extent of rock stratigraphic units (formations) as compiled by Colton in 1976 under the Front Range Urban Corridor Geology Program. Colton used his own geologic mapping and previously published geologic maps to compile one map having a single classification of geologic units. The resulting published color paper map (USGS Map I-855-G, Colton, 1978)...
Digital database of the previously published geologic map of the greater Denver area, Front Range Urban Corridor, Colorado Digital database of the previously published geologic map of the greater Denver area, Front Range Urban Corridor, Colorado
This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient...
Bedrock geologic map database for the Durango 1-degree x 2-degree quadrangle, southern Colorado: Contributions to the National Geologic Map (ver. 2.0, June 2024) Bedrock geologic map database for the Durango 1-degree x 2-degree quadrangle, southern Colorado: Contributions to the National Geologic Map (ver. 2.0, June 2024)
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...
Digital database of the previously published bedrock geologic map showing thickness of overlying Quaternary deposits, Grand Island quadrangle, Nebraska and Kansas Digital database of the previously published bedrock geologic map showing thickness of overlying Quaternary deposits, Grand Island quadrangle, Nebraska and Kansas
This digital data release contains geospatial data for the 1:250,000 scale geologic map of the Grand Island 1 degree by 2 degree quadrangle, Nebraska, originally published by Dreeszen and others (1973). The database includes line and polygon features depicting the extent of the Miocene Ogallala Formation and underlying Cretaceous rocks. The original map also included shaded patches...
Digital database of the previously published geologic map of the O'Neill 1x2 degree quadrangle, Nebraska Digital database of the previously published geologic map of the O'Neill 1x2 degree quadrangle, Nebraska
This digital data release contains geospatial data for the geologic map of the O’Neill 1 degree by 2 degree geologic map in Nebraska, originally published in 2008 by R.E. Diffendal and others. The original map consists of a 1:250,000 scale map plate with a “stack unit” structure showing multiple overlying units, as well as several roughly 1:750,000 scale maps in an accompanying pamphlet...
Filter Total Items: 41
Detrital zircon record of magmatism and sediment dispersal across the North American Cordilleran arc system (28-48°N) 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...
Authors
Theresa Maude Schwartz, Kathleen D. Surpless, Joseph P. Colgan, Samuel Johnstone, Christopher S. Holm-Denoma
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 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.
Authors
Christopher D. Henry, David A. John, Matt T. Heizler, Robert W. Leonardson, Joseph P. Colgan, Kathryn E. Watts, Michael W. Ressel, Brian L. Cousens
Timing of Cenozoic extension in the southern Stillwater Range and Dixie Valley, Nevada 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...
Authors
Joseph P. Colgan, Samuel Johnstone, David L. Shuster
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada 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...
Authors
Edward A. du Bray, David A. John, Joseph P. Colgan, Peter G. Vikre, Michael A. Cosca, Leah E. Morgan
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada 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...
Authors
Edward A. du Bray, David A. John, Peter G. Vikre, Joseph P. Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-Denoma
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 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...
Authors
Kathryn E. Watts, David A. John, Joseph P. Colgan, Christopher D. Henry, Ilya N. Bindeman, John W. Valley
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.