View southwest of Garfield Peak and Eagle Crags above Chaski Bay. Cliffs at caldera rim are andesite of Applegate Peak (unit aa; ca. 210-270 ka), overlain by two thin flows of andesite of Garfield Peak at top center (unit ag; 224 ±9 ka). Talus rests on flat top of massive slide block that consists of altered lavas of units aa, ak(?), and db(?).
Charles R Bacon, PhD
Current Research Interests Petrology, geochemistry, physical volcanology, and eruptive histories of calderas, emphasizing detailed study of Crater Lake, Oregon, and Veniaminof and Aniakchak caldera volcanoes, Alaska Peninsula. General interest in volcanic and magmatic processes. Secondary Ion Mass Spectrometry applied to geologic and biologic materials. Landscape evolution in interior Alaska.
Professional Experience
Senior Research Geologist Emeritus, U.S. Geological Survey, October 2014–present.
Research Geologist with USGS in Menlo Park 1975–2014, Senior Scientist 2004–2014
Research Associate, Lawrence Berkeley Laboratory, 1975
Co-Director, USGS–Stanford Ion Microprobe Laboratory (SUMAC), October 2008-September 2014
Geologic mapping of Quaternary volcanic fields and caldera volcanoes in California, Oregon, and Alaska
Isotope geochemistry of magmatic systems
Microbeam chemical analysis by electron and ion microprobe applied to igneous rocks and biological materials
Physical volcanology of products of explosive eruptions
Petrologic and geochemical research on volcanic rocks and magmatic processes
Mentorship/Outreach
Research and Teaching Assistantships, University of California, Berkeley, 1970-74
Visiting Professor, California Institute of Technology, winter term 1988
Education and Certifications
University of California, Berkeley, PhD, Geology, 1975
Stanford University, BS, Geology, 1970
Affiliations and Memberships*
Member, Geochemical Society, International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI)
NAS/NRC Continental Scientific Drilling Committee, 1983-86
USGS Geologic Division Science Advisory Committee, 1988-89, Chair 1990-91
NSF Petrology and Geochemistry Panel, 1994-97
AGU VGP Section Nominating Committee, 1996, Chair 1998
MSA Fellows Committee, 1997-99; MSA Nominating Committee, 2007-2009
Associate Editor, Geological Society of America Bulletin, 1985-90
Associate Editor, American Mineralogist, 1989-92
Editorial Board, Geology, 1993-95
Editorial Board, Journal of Volcanology and Geothermal Research, 1998-2007
Board of Directors, Berkeley Geochronology Center, 2009-present.
Honors and Awards
Fellow, American Geophysical Union, Mineralogical Society of America, Geological Society of America
President-elect, Volcanology, Geochemistry, and Petrology Section of the American Geophyscial Union, 7/02-6/04; President, 7/04-6/06
IAVCEI quadrennial L.R. Wager Medal, 1987
AGU VGP Section N.L. Bowen Award, 1999
USGS Shoemaker Awards for Communication Product Excellence, 2002, 2004
US Department of the Interior Meritorious Service Award, 2004
U.S. Department of the Interior Superior Service Award, 2009 (from National Park Service)
Science and Products
Filter Total Items: 94
The ~400 yr B.P. eruption of Half Cone, a post-caldera composite cone within Aniakchak caldera, Alaska Peninsula
Aniakchak volcano is a historically active caldera located on the central Alaska Peninsula.
The largest eruption from Aniakchak since the ~3,400 yr B.P. caldera-forming eruption
occurred ~400 yr B.P. from Half Cone volcano, an intracaldera composite cone on the
northwest floor of the Aniakchak caldera that was largely destroyed by the eruption. The
~400 yr B.P. eruption produced a widely dispersed
Authors
Brandon Browne, Christina A. Neal, Charles R. Bacon
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Volcanoes of subduction-related magmatic arcs occur in a variety of crustal tectonic regimes, including where active faults indicate arc-normal extension. The Cascades arc volcano Mount Mazama overlaps on its west an ∼10-km-wide zone of ∼north-south–trending normal faults. A lidar (light detection and ranging) survey of Crater Lake National Park, reveals several previously unrecognized faults west
Authors
Charles R. Bacon, Joel E. Robinson
Presentation of the Dana Medal of the Mineralogical Society of America for 2017 to Thomas W. Sisson
I have the pleasure of introducing Thomas W. Sisson, the Mineralogical Society of America Dana Medalist for 2017. Tom is known for his scientific rigor and landmark publications that have contributed to a diverse spectrum of fields closely tied to the mineralogical sciences. He is particularly recognized for his work on magma differentiation and the role of water in subduction-related magmatism. B
Authors
Charles R. Bacon
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
These field-trip guides were written for the occasion of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial scientific assembly in Portland, Oregon, in August 2017. The guide to Mount Mazama and Crater Lake caldera is an updated and expanded version of the guide (Bacon, 1989) for part of an earlier IAVCEI trip to the southern Cascade Range. The
Authors
Charles R. Bacon, Julie M. Donnelly-Nolan, Robert A. Jensen, Heather M. Wright
Surface morphology of caldera-forming eruption deposits revealed by lidar mapping of Crater Lake National Park, Oregon- Implications for emplacement and surface modification
Large explosive eruptions of silicic magma can produce widespread pumice fall, extensive ignimbrite sheets, and collapse calderas. The surfaces of voluminous ignimbrites are rarely preserved or documented because most terrestrial examples are heavily vegetated, or severely modified by post-depositional processes. Much research addresses the internal sedimentary characteristics, flow processes, and
Authors
Joel E. Robinson, Charles R. Bacon, Jon J. Major, Heather M. Wright, James W. Vallance
Geologic field trip guide to Mount Mazama and Crater Lake Caldera, Oregon
Crater Lake partly fills one of the most spectacular calderas of the world—an 8 by 10 kilometer (km) basin more than 1 km deep formed by collapse of the Mount Mazama volcano during a rapid series of explosive eruptions ~7,700 years ago. Having a maximum depth of 594 meters (m), Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 squar
Authors
Charles R. Bacon, Heather M. Wright
Oxygen and U-Th isotopes and the timescales of hydrothermal exchange and melting in granitoid wall rocks at Mount Mazama, Crater Lake, Oregon
We report new whole rock U-Th and in-situ oxygen isotope compositions for partially melted (0–50 vol% melt), low-δ18O Pleistocene granitoid blocks ejected during the ∼7.7 ka caldera-forming eruption of Mt. Mazama (Crater Lake, Oregon). The blocks are interpreted to represent wall rocks of the climactic magma chamber that, prior to eruption, experienced variable amounts of exchange with meteoric hy
Authors
Meagan E. Ankney, Charles R. Bacon, John W. Valley, Brian L. Beard, Clark M. Johnson
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 exhumation model t
Authors
Cynthia Dusel-Bacon, Charles R. Bacon, Paul B. O'Sullivan, Warren C. Day
Memorial to Robert Leland Smith 1920-2016
Robert L. Smith, renowned volcanologist and distinguished scientist with the U.S. Geological Survey (USGS), was a world authority on ash-flow tuffs, silicic volcanism, and caldera structures. Bob died peacefully in Sacramento, California, June 17, 2016, a few days short of his ninety-sixth birthday. His publications on ash flows and their deposits brought about an international revolution in under
Authors
Charles R. Bacon
Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes
A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective contro
Authors
Kurt P. Kowalski, Charles W. Bacon, Wesley A. Bickford, Heather A. Braun, Keith Clay, Michele Leduc-Lapierre, Elizabeth Lillard, Melissa K. McCormick, Eric Nelson, Monica Torres, James W. C. White, Douglas A. Wilcox
The effect of pressurized magma chamber growth on melt migration and pre-caldera vent locations through time at Mount Mazama, Crater Lake, Oregon
The pattern of eruptions at long-lived volcanic centers provides a window into the co-evolution of crustal magma transport, tectonic stresses, and unsteady magma generation at depth. Mount Mazama in the Oregon Cascades has seen variable activity over the last 400 ky, including the 50 km3 climactic eruption at ca. 7.7 ka that produced Crater Lake caldera. The physical mechanisms responsible for the
Authors
Leif Karlstrom, Heather M. Wright, Charles R. Bacon
Postglacial eruptive history, geochemistry, and recent seismicity of Aniakchak volcano, Alaska Peninsula
Aniakchak is a Pleistocene to Holocene composite volcano of the Alaska–Aleutian arc that suffered at least one caldera-forming eruption in postglacial time and last erupted in 1931. The oldest recognized postglacial eruption, Aniakchak I, produced andesite ignimbrite ca. 9,500–7,500 14C yr B.P. Subsequently, a vent northeast of the summit issued dacite–rhyodacite magma ca. 7,000 14C yr B.P. mainly
Authors
Charles R. Bacon, Christina A. Neal, Thomas P. Miller, Robert G. McGimsey, Christopher J. Nye
Under trees and water at Crater Lake National Park, Oregon
Crater Lake partially fills the caldera that formed approximately 7,700 years ago during the eruption of a 12,000-ft-high volcano known as Mount Mazama. The caldera-forming, or climactic, eruption of Mount Mazama devastated the surrounding landscape, left a thick deposit of pumice and ash in adjacent valleys, and spread a blanket of volcanic ash as far away as southern Canada. Prior to the climact
Geologic map of Mount Mazama and Crater Lake Caldera, Oregon, including the database for the geologic map of Mount Mazama and Crater Lake Caldera, Oregon
Crater Lake partly fills one of the most spectacular calderas of the world, an 8-by-10-km basin more than 1 km deep formed by collapse of the volcano known as Mount Mazama (fig. 1) during a rapid series of explosive eruptions about 7,700 years ago. Having a maximum depth of 594 m, Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 km
Crater Lake revealed
Around 500,000 people each year visit Crater Lake National Park in the Cascade Range of southern Oregon. Volcanic peaks, evergreen forests, and Crater Lake’s incredibly blue water are the park’s main attractions. Crater Lake partially fills the caldera that formed approximately 7,700 years ago by the eruption and subsequent collapse of a 12,000-foot volcano called Mount Mazama. The caldera-forming
Crater Lake, Chaski Bay. Talus slope sits on flat top of massive sl...
Crater Lake, Chaski Bay. Talus slope sits on flat top of massive sl...
View southwest of Garfield Peak and Eagle Crags above Chaski Bay. Cliffs at caldera rim are andesite of Applegate Peak (unit aa; ca. 210-270 ka), overlain by two thin flows of andesite of Garfield Peak at top center (unit ag; 224 ±9 ka). Talus rests on flat top of massive slide block that consists of altered lavas of units aa, ak(?), and db(?).
Science and Products
Filter Total Items: 94
The ~400 yr B.P. eruption of Half Cone, a post-caldera composite cone within Aniakchak caldera, Alaska Peninsula
Aniakchak volcano is a historically active caldera located on the central Alaska Peninsula.
The largest eruption from Aniakchak since the ~3,400 yr B.P. caldera-forming eruption
occurred ~400 yr B.P. from Half Cone volcano, an intracaldera composite cone on the
northwest floor of the Aniakchak caldera that was largely destroyed by the eruption. The
~400 yr B.P. eruption produced a widely dispersed
Authors
Brandon Browne, Christina A. Neal, Charles R. Bacon
Postglacial faulting near Crater Lake, Oregon, and its possible association with the Mazama caldera-forming eruption
Volcanoes of subduction-related magmatic arcs occur in a variety of crustal tectonic regimes, including where active faults indicate arc-normal extension. The Cascades arc volcano Mount Mazama overlaps on its west an ∼10-km-wide zone of ∼north-south–trending normal faults. A lidar (light detection and ranging) survey of Crater Lake National Park, reveals several previously unrecognized faults west
Authors
Charles R. Bacon, Joel E. Robinson
Presentation of the Dana Medal of the Mineralogical Society of America for 2017 to Thomas W. Sisson
I have the pleasure of introducing Thomas W. Sisson, the Mineralogical Society of America Dana Medalist for 2017. Tom is known for his scientific rigor and landmark publications that have contributed to a diverse spectrum of fields closely tied to the mineralogical sciences. He is particularly recognized for his work on magma differentiation and the role of water in subduction-related magmatism. B
Authors
Charles R. Bacon
Overview for geologic field-trip guides to Mount Mazama, Crater Lake Caldera, and Newberry Volcano, Oregon
These field-trip guides were written for the occasion of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial scientific assembly in Portland, Oregon, in August 2017. The guide to Mount Mazama and Crater Lake caldera is an updated and expanded version of the guide (Bacon, 1989) for part of an earlier IAVCEI trip to the southern Cascade Range. The
Authors
Charles R. Bacon, Julie M. Donnelly-Nolan, Robert A. Jensen, Heather M. Wright
Surface morphology of caldera-forming eruption deposits revealed by lidar mapping of Crater Lake National Park, Oregon- Implications for emplacement and surface modification
Large explosive eruptions of silicic magma can produce widespread pumice fall, extensive ignimbrite sheets, and collapse calderas. The surfaces of voluminous ignimbrites are rarely preserved or documented because most terrestrial examples are heavily vegetated, or severely modified by post-depositional processes. Much research addresses the internal sedimentary characteristics, flow processes, and
Authors
Joel E. Robinson, Charles R. Bacon, Jon J. Major, Heather M. Wright, James W. Vallance
Geologic field trip guide to Mount Mazama and Crater Lake Caldera, Oregon
Crater Lake partly fills one of the most spectacular calderas of the world—an 8 by 10 kilometer (km) basin more than 1 km deep formed by collapse of the Mount Mazama volcano during a rapid series of explosive eruptions ~7,700 years ago. Having a maximum depth of 594 meters (m), Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 squar
Authors
Charles R. Bacon, Heather M. Wright
Oxygen and U-Th isotopes and the timescales of hydrothermal exchange and melting in granitoid wall rocks at Mount Mazama, Crater Lake, Oregon
We report new whole rock U-Th and in-situ oxygen isotope compositions for partially melted (0–50 vol% melt), low-δ18O Pleistocene granitoid blocks ejected during the ∼7.7 ka caldera-forming eruption of Mt. Mazama (Crater Lake, Oregon). The blocks are interpreted to represent wall rocks of the climactic magma chamber that, prior to eruption, experienced variable amounts of exchange with meteoric hy
Authors
Meagan E. Ankney, Charles R. Bacon, John W. Valley, Brian L. Beard, Clark M. Johnson
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 exhumation model t
Authors
Cynthia Dusel-Bacon, Charles R. Bacon, Paul B. O'Sullivan, Warren C. Day
Memorial to Robert Leland Smith 1920-2016
Robert L. Smith, renowned volcanologist and distinguished scientist with the U.S. Geological Survey (USGS), was a world authority on ash-flow tuffs, silicic volcanism, and caldera structures. Bob died peacefully in Sacramento, California, June 17, 2016, a few days short of his ninety-sixth birthday. His publications on ash flows and their deposits brought about an international revolution in under
Authors
Charles R. Bacon
Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes
A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective contro
Authors
Kurt P. Kowalski, Charles W. Bacon, Wesley A. Bickford, Heather A. Braun, Keith Clay, Michele Leduc-Lapierre, Elizabeth Lillard, Melissa K. McCormick, Eric Nelson, Monica Torres, James W. C. White, Douglas A. Wilcox
The effect of pressurized magma chamber growth on melt migration and pre-caldera vent locations through time at Mount Mazama, Crater Lake, Oregon
The pattern of eruptions at long-lived volcanic centers provides a window into the co-evolution of crustal magma transport, tectonic stresses, and unsteady magma generation at depth. Mount Mazama in the Oregon Cascades has seen variable activity over the last 400 ky, including the 50 km3 climactic eruption at ca. 7.7 ka that produced Crater Lake caldera. The physical mechanisms responsible for the
Authors
Leif Karlstrom, Heather M. Wright, Charles R. Bacon
Postglacial eruptive history, geochemistry, and recent seismicity of Aniakchak volcano, Alaska Peninsula
Aniakchak is a Pleistocene to Holocene composite volcano of the Alaska–Aleutian arc that suffered at least one caldera-forming eruption in postglacial time and last erupted in 1931. The oldest recognized postglacial eruption, Aniakchak I, produced andesite ignimbrite ca. 9,500–7,500 14C yr B.P. Subsequently, a vent northeast of the summit issued dacite–rhyodacite magma ca. 7,000 14C yr B.P. mainly
Authors
Charles R. Bacon, Christina A. Neal, Thomas P. Miller, Robert G. McGimsey, Christopher J. Nye
Under trees and water at Crater Lake National Park, Oregon
Crater Lake partially fills the caldera that formed approximately 7,700 years ago during the eruption of a 12,000-ft-high volcano known as Mount Mazama. The caldera-forming, or climactic, eruption of Mount Mazama devastated the surrounding landscape, left a thick deposit of pumice and ash in adjacent valleys, and spread a blanket of volcanic ash as far away as southern Canada. Prior to the climact
Geologic map of Mount Mazama and Crater Lake Caldera, Oregon, including the database for the geologic map of Mount Mazama and Crater Lake Caldera, Oregon
Crater Lake partly fills one of the most spectacular calderas of the world, an 8-by-10-km basin more than 1 km deep formed by collapse of the volcano known as Mount Mazama (fig. 1) during a rapid series of explosive eruptions about 7,700 years ago. Having a maximum depth of 594 m, Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 km
Crater Lake revealed
Around 500,000 people each year visit Crater Lake National Park in the Cascade Range of southern Oregon. Volcanic peaks, evergreen forests, and Crater Lake’s incredibly blue water are the park’s main attractions. Crater Lake partially fills the caldera that formed approximately 7,700 years ago by the eruption and subsequent collapse of a 12,000-foot volcano called Mount Mazama. The caldera-forming
Crater Lake, Chaski Bay. Talus slope sits on flat top of massive sl...
Crater Lake, Chaski Bay. Talus slope sits on flat top of massive sl...
View southwest of Garfield Peak and Eagle Crags above Chaski Bay. Cliffs at caldera rim are andesite of Applegate Peak (unit aa; ca. 210-270 ka), overlain by two thin flows of andesite of Garfield Peak at top center (unit ag; 224 ±9 ka). Talus rests on flat top of massive slide block that consists of altered lavas of units aa, ak(?), and db(?).
View southwest of Garfield Peak and Eagle Crags above Chaski Bay. Cliffs at caldera rim are andesite of Applegate Peak (unit aa; ca. 210-270 ka), overlain by two thin flows of andesite of Garfield Peak at top center (unit ag; 224 ±9 ka). Talus rests on flat top of massive slide block that consists of altered lavas of units aa, ak(?), and db(?).
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government