Cynthia Dusel-Bacon
Cynthia Dusel-Bacon is a Scientist Emerita in the Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, California. Since 1975 she has worked to decipher the geology, geologic setting of syngenetic and epigenetic mineral deposits, and tectonic history of east-central Alaska.
Cynthia Dusel-Bacon joined the USGS Branch of Alaskan Geology, headquartered in Menlo Park, California, in 1975. In 1977, during her third field season of geologic mapping in east-central Alaska, she was mauled by a black bear and lost both arms as a result of her injuries. Her disability has not kept her from enjoying a long and productive career that includes fieldwork in Alaska, petrologic studies, and publication of results.
Research Focus
Dusel-Bacon’s studies have involved deciphering the geologic and tectonic history of east-central Alaska utilizing geologic mapping, metamorphic petrology, whole-rock geochemistry, trace-element tectonic fingerprinting of (meta)igneous rocks, and geochronology (U-Pb zircon,40Ar-39Ar, and apatite fission track data) generated by collaborating scientists. Her studies also have included correlation of regional events in east-central Alaska with those in the western Canadian Cordillera; the age, character, and tectonic setting of submarine, syngenetic, hydrothermal mineral deposits (both volcanic- and sedimentary-hosted); and compilation of a Metamorphic Facies Map of Alaska.
Education
- San Jose State University, BA, Geology, 1975
- San Jose State University, Secondary Teaching Credential (Spanish), 1969
- University of California Santa Barbara, BA, Spanish, 1968
Professional Experience
- 2014 – Scientist Emerita, U.S. Geological Survey, Menlo Park, California
- 1980 – 2014 Research Geologist, U.S. Geological Survey, Menlo Park, California
- 1975 – 1979 Physical Science Technician, Branch of Alaskan Geology, U.S. Geological Survey, Menlo Park, California
Affiliations
- 1974 – Geological Society of America (Fellow since 2005, former Associate Editor GSA Bulletin)
- 1980 – Mineralogical Society of America
- 1980 – American Geophysical Union
- 1996 – Geological Association of Canada
- 1998 – Society of Economic Geologists
Honors
- US Department of the Interior Meritorious Service Award, 2011
- Outstanding Handicapped Federal Employee (1 of 10) for 1981
Science and Products
Sulfide Electron Microprobe Analyses and Petrography of Mineralized Samples from the Stratabound Sheep Creek Sediment-Hosted Zn-Pb-Ag-Sn Prospect, and SHRIMP U-Pb Zircon Data for Metaigneous Rocks in the Bonnifield Mining District, Healy Quadrangle, AK
This data set contains 99 electron microprobe analyses of cassiterite, chalcopyrite, galena, pyrite, sphalerite, and tetrahedrite from seven Sheep Creek drill core samples and one outcrop; and a table that describes the textures, mineralogy, and rock type of 15 thin sections of Sheep Creek drill core and observations from our study and from drill core logging by industry. These data were...
New U-Pb Geochronology and Geochemistry of Paleozoic Metaigneous Rocks from Western Yukon and Eastern Alaska
This data release contains three tables of U-Pb zircon isotopic data generated from analyses of 40 metaplutonic and metavolcanic rocks from the Yukon-Tanana Upland of western Yukon and east-central Alaska and one sample from southern Yukon. One of the tables also reports U-Pb data for two titanite analyses for one of the samples. U-Pb zircon ages from analyzed samples range from 363.5...
Geologic map of the Kechumstuk fault zone in the Mount Veta area, Fortymile mining district, east-central Alaska
This map was developed by the U.S. Geological Survey Mineral Resources Program to depict the fundamental geologic features for the western part of the Fortymile mining district of east-central Alaska, and to delineate the location of known bedrock mineral prospects and their relationship to rock types and structural features.This geospatial map database presents a 1:63,360-scale geologic...
Filter Total Items: 51
New U-Pb geochronology and geochemistry of Paleozoic metaigneous rocks from western Yukon and eastern Alaska, cross-border synthesis, and implications for tectonic models
The tectonic evolution of and relation between the Yukon-Tanana terrane and the Lake George assemblage, as well as other associated tectonic assemblages in western Yukon and eastern Alaska, have been debated for decades. The Yukon-Tanana terrane is widely considered to be an allochthonous rifted fragment derived from the Laurentian continental margin, whereas the Lake George assemblage...
Authors
Cynthia Dusel-Bacon, James K. Mortensen
Sulphide petrology and ore genesis of the stratabound Sheep Creek sediment-hosted Zn–Pb–Ag–Sn prospect, and U–Pb zircon constraints on the timing of magmatism in the northern Alaska Range
The Sheep Creek prospect is a stratabound Zn–Pb–Ag–Sn massive sulfide occurrence in the Bonnifield mining district, northern Alaska Range. The prospect is within a quartz–sericite–graphite–chlorite schist unit associated with Devonian carbonaceous and siliceous metasedimentary rocks. Volcanogenic massive sulfide (VMS) deposits in the district are hosted in felsic metavolcanic rocks (362...
Authors
Cynthia Dusel-Bacon, John N. Aleinikoff, Suzanne Paradise, John F. Slack
Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska
We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the...
Authors
Cynthia Dusel-Bacon, Christopher S. Holm-Denoma, James V. Jones, John N. Aleinikoff, James K. Mortensen
Apatite fission-track evidence for regional exhumation in the subtropical Eocene, block faulting, and localized fluid flow in east-central Alaska
The origin and antiquity of the subdued topography of the Yukon–Tanana Upland (YTU), the physiographic province between the Denali and Tintina faults, are unresolved questions in the geologic history of interior Alaska and adjacent Yukon. We present apatite fission-track (AFT) results for 33 samples from the 2300 km2 western Fortymile district in the YTU in Alaska and propose an...
Authors
Cynthia Dusel-Bacon, Charles R. Bacon, Paul B. O'Sullivan, Warren C. Day
Mesozoic magmatism and timing of epigenetic Pb-Zn-Ag mineralization in the western Fortymile mining district, east-central Alaska: Zircon U-Pb geochronology, whole-rock geochemistry, and Pb isotopes
The Mesozoic magmatic history of the North American margin records the evolution from a more segmented assemblage of parautochthonous and allochthonous terranes to the more cohesive northern Cordilleran orogenic belt. We characterize the setting of magmatism, tectonism, and epigenetic mineralization in the western Fortymile mining district, east-central Alaska, where parautochthonous and...
Authors
Cynthia Dusel-Bacon, J.N. Aleinkoff, W. C. Day, J.K. Mortensen
The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska
Dissected caldera structures expose thick intracaldera tuff and, uncommonly, cogenetic shallow plutons, while remnants of correlative outflow tuffs deposited on the pre-eruption ground surface record elements of ancient landscapes. The Middle Fork caldera encompasses a 10 km × 20 km area of rhyolite welded tuff and granite porphyry in east-central Alaska, ∼100 km west of the Yukon border...
Authors
Charles R. Bacon, Cynthia Dusel-Bacon, John N. Aleinikoff, John F. Slack
Geochemistry, petrography, and zircon U-Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon-Tanana terrane
We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and...
Authors
Cynthia Dusel-Bacon, Warren C. Day, John N. Aleinikoff
Studies by the U.S. Geological Survey in Alaska, 2011
The collection of papers that follow continues the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. This series represents new and sometimes-preliminary findings that are of interest to Earth scientists in academia, government, and industry; to land and resource managers; and to the general public. The reports...
Authors
Julie A. Dumoulin, Cynthia Dusel-Bacon
History of earthquakes and tsunamis along the eastern Aleutian-Alaska megathrust, with implications for tsunami hazards in the California Continental Borderland
During the past several years, devastating tsunamis were generated along subduction zones in Indonesia, Chile, and most recently Japan. Both the Chile and Japan tsunamis traveled across the Pacific Ocean and caused localized damage at several coastal areas in California. The question remains as to whether coastal California, in particular the California Continental Borderland, is...
Authors
Holly F. Ryan, Roland E. von Huene, Ray E. Wells, David W. Scholl, Stephen Kirby, Amy E. Draut
Volcanogenic massive sulfide occurrence model
Volcanogenic massive sulfide deposits, also known as volcanic-hosted massive sulfide, volcanic-associated massive sulfide, or seafloor massive sulfide deposits, are important sources of copper, zinc, lead, gold, and silver (Cu, Zn, Pb, Au, and Ag). These deposits form at or near the seafloor where circulating hydrothermal fluids driven by magmatic heat are quenched through mixing with...
Authors
W.C. Pat Shanks, Randolph A. Koski, Dan L. Mosier, Klaus J. Schulz, Lisa A. Morgan, John F. Slack, W. Ian Ridley, Cynthia Dusel-Bacon, Robert R. Seal, Nadine M. Piatak
Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska
Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in...
Authors
Cynthia Dusel-Bacon, Nora K. Foley, John E. Slack, Alan E. Koenig, Robert L. Oscarson
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element...
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans
Science and Products
Sulfide Electron Microprobe Analyses and Petrography of Mineralized Samples from the Stratabound Sheep Creek Sediment-Hosted Zn-Pb-Ag-Sn Prospect, and SHRIMP U-Pb Zircon Data for Metaigneous Rocks in the Bonnifield Mining District, Healy Quadrangle, AK
This data set contains 99 electron microprobe analyses of cassiterite, chalcopyrite, galena, pyrite, sphalerite, and tetrahedrite from seven Sheep Creek drill core samples and one outcrop; and a table that describes the textures, mineralogy, and rock type of 15 thin sections of Sheep Creek drill core and observations from our study and from drill core logging by industry. These data were...
New U-Pb Geochronology and Geochemistry of Paleozoic Metaigneous Rocks from Western Yukon and Eastern Alaska
This data release contains three tables of U-Pb zircon isotopic data generated from analyses of 40 metaplutonic and metavolcanic rocks from the Yukon-Tanana Upland of western Yukon and east-central Alaska and one sample from southern Yukon. One of the tables also reports U-Pb data for two titanite analyses for one of the samples. U-Pb zircon ages from analyzed samples range from 363.5...
Geologic map of the Kechumstuk fault zone in the Mount Veta area, Fortymile mining district, east-central Alaska
This map was developed by the U.S. Geological Survey Mineral Resources Program to depict the fundamental geologic features for the western part of the Fortymile mining district of east-central Alaska, and to delineate the location of known bedrock mineral prospects and their relationship to rock types and structural features.This geospatial map database presents a 1:63,360-scale geologic...
Filter Total Items: 51
New U-Pb geochronology and geochemistry of Paleozoic metaigneous rocks from western Yukon and eastern Alaska, cross-border synthesis, and implications for tectonic models
The tectonic evolution of and relation between the Yukon-Tanana terrane and the Lake George assemblage, as well as other associated tectonic assemblages in western Yukon and eastern Alaska, have been debated for decades. The Yukon-Tanana terrane is widely considered to be an allochthonous rifted fragment derived from the Laurentian continental margin, whereas the Lake George assemblage...
Authors
Cynthia Dusel-Bacon, James K. Mortensen
Sulphide petrology and ore genesis of the stratabound Sheep Creek sediment-hosted Zn–Pb–Ag–Sn prospect, and U–Pb zircon constraints on the timing of magmatism in the northern Alaska Range
The Sheep Creek prospect is a stratabound Zn–Pb–Ag–Sn massive sulfide occurrence in the Bonnifield mining district, northern Alaska Range. The prospect is within a quartz–sericite–graphite–chlorite schist unit associated with Devonian carbonaceous and siliceous metasedimentary rocks. Volcanogenic massive sulfide (VMS) deposits in the district are hosted in felsic metavolcanic rocks (362...
Authors
Cynthia Dusel-Bacon, John N. Aleinikoff, Suzanne Paradise, John F. Slack
Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska
We report eight new U-Pb detrital zircon ages for quartzose metasedimentary rocks from four lithotectonic units of parautochthonous North America in east-central Alaska: the Healy schist, Keevy Peak Formation, and Sheep Creek Member of the Totatlanika Schist in the northern Alaska Range, and the Butte assemblage in the northwestern Yukon-Tanana Upland. Excepting 1 of 3 samples from the...
Authors
Cynthia Dusel-Bacon, Christopher S. Holm-Denoma, James V. Jones, John N. Aleinikoff, James K. Mortensen
Apatite fission-track evidence for regional exhumation in the subtropical Eocene, block faulting, and localized fluid flow in east-central Alaska
The origin and antiquity of the subdued topography of the Yukon–Tanana Upland (YTU), the physiographic province between the Denali and Tintina faults, are unresolved questions in the geologic history of interior Alaska and adjacent Yukon. We present apatite fission-track (AFT) results for 33 samples from the 2300 km2 western Fortymile district in the YTU in Alaska and propose an...
Authors
Cynthia Dusel-Bacon, Charles R. Bacon, Paul B. O'Sullivan, Warren C. Day
Mesozoic magmatism and timing of epigenetic Pb-Zn-Ag mineralization in the western Fortymile mining district, east-central Alaska: Zircon U-Pb geochronology, whole-rock geochemistry, and Pb isotopes
The Mesozoic magmatic history of the North American margin records the evolution from a more segmented assemblage of parautochthonous and allochthonous terranes to the more cohesive northern Cordilleran orogenic belt. We characterize the setting of magmatism, tectonism, and epigenetic mineralization in the western Fortymile mining district, east-central Alaska, where parautochthonous and...
Authors
Cynthia Dusel-Bacon, J.N. Aleinkoff, W. C. Day, J.K. Mortensen
The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska
Dissected caldera structures expose thick intracaldera tuff and, uncommonly, cogenetic shallow plutons, while remnants of correlative outflow tuffs deposited on the pre-eruption ground surface record elements of ancient landscapes. The Middle Fork caldera encompasses a 10 km × 20 km area of rhyolite welded tuff and granite porphyry in east-central Alaska, ∼100 km west of the Yukon border...
Authors
Charles R. Bacon, Cynthia Dusel-Bacon, John N. Aleinikoff, John F. Slack
Geochemistry, petrography, and zircon U-Pb geochronology of Paleozoic metaigneous rocks in the Mount Veta area of east-central Alaska: implications for the evolution of the westernmost part of the Yukon-Tanana terrane
We report the results of new mapping, whole-rock major, minor, and trace-element geochemistry, and petrography for metaigneous rocks from the Mount Veta area in the westernmost part of the allochthonous Yukon–Tanana terrane (YTT) in east-central Alaska. These rocks include tonalitic mylonite gneiss and mafic metaigneous rocks from the Chicken metamorphic complex and the Nasina and...
Authors
Cynthia Dusel-Bacon, Warren C. Day, John N. Aleinikoff
Studies by the U.S. Geological Survey in Alaska, 2011
The collection of papers that follow continues the series of U.S. Geological Survey (USGS) investigative reports in Alaska under the broad umbrella of the geologic sciences. This series represents new and sometimes-preliminary findings that are of interest to Earth scientists in academia, government, and industry; to land and resource managers; and to the general public. The reports...
Authors
Julie A. Dumoulin, Cynthia Dusel-Bacon
History of earthquakes and tsunamis along the eastern Aleutian-Alaska megathrust, with implications for tsunami hazards in the California Continental Borderland
During the past several years, devastating tsunamis were generated along subduction zones in Indonesia, Chile, and most recently Japan. Both the Chile and Japan tsunamis traveled across the Pacific Ocean and caused localized damage at several coastal areas in California. The question remains as to whether coastal California, in particular the California Continental Borderland, is...
Authors
Holly F. Ryan, Roland E. von Huene, Ray E. Wells, David W. Scholl, Stephen Kirby, Amy E. Draut
Volcanogenic massive sulfide occurrence model
Volcanogenic massive sulfide deposits, also known as volcanic-hosted massive sulfide, volcanic-associated massive sulfide, or seafloor massive sulfide deposits, are important sources of copper, zinc, lead, gold, and silver (Cu, Zn, Pb, Au, and Ag). These deposits form at or near the seafloor where circulating hydrothermal fluids driven by magmatic heat are quenched through mixing with...
Authors
W.C. Pat Shanks, Randolph A. Koski, Dan L. Mosier, Klaus J. Schulz, Lisa A. Morgan, John F. Slack, W. Ian Ridley, Cynthia Dusel-Bacon, Robert R. Seal, Nadine M. Piatak
Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska
Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in...
Authors
Cynthia Dusel-Bacon, Nora K. Foley, John E. Slack, Alan E. Koenig, Robert L. Oscarson
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element...
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans