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Jorge Vazquez

Jorge Vazquez is a Research Geologist in the Geology, Minerals, Energy and Geophysics Science Center and specializes in uranium-series geochronology, isotope geochemistry, and volcanic geology. Presently he is the acting Center Director for GMEG Science Center.

Education and Certifications

  • Ph.D. UC Los Angeles

  • M.S. Northern Arizona

  • B.S. CSU Los Angeles

Science and Products

link
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
By
Community for Data Integration (CDI)
link

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
Learn More

Data release of zircon U-Pb geochronology and whole-rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada, and Wyoming

This U.S. Geological Survey (USGS) data release provides zircon U-Pb geochronology and whole rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada and Wyoming. The drill core samples were obtained from the USGS Core Research Center in Denver, Colorado. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement te
By
Geosciences and Environmental Change Science Center

Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota

This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic history, a
By
Geology, Minerals, Energy, and Geophysics Science Center

Data release of monazite and xenotime geochronology for Proterozoic rocks in central Colorado and monazite and zircon geochronology and whole-rock isotope geochemistry fo a Proterozoic drill core sample from western Colorado

This U.S. Geological Survey (USGS) data release provides monazite and xenotime geochronology from Proterozoic rocks collected from outcrop in central Colorado and whole rock isotope geochemistry, and zircon and monazite geochronology from a Proterozoic rock sampled from a drill core from western Colorado. The drill core sample was collected from the 1 Paradox Valley injection core near Bedrock, CO
By
Geology, Minerals, Energy, and Geophysics Science Center

Zircon U-Pb geochronology and whole rock geochemistry for pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado

This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data and zircon U-Pb geochronology and trace element concentrations for samples from pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado. Samples were collected in order to constrain the evolution of the pre-ignimbrite m
By
Geosciences and Environmental Change Science Center

Tabular geochronologic, geochemical, and isotopic data from igneous rocks in the Lane Mountain area, San Bernardino County, California

This dataset provides geochronologic, geochemical, and isotopic data for selected igneous rock samples collected in the Lane Mountain area about 20 kilometers northeast of Barstow, California. Uranium-lead (U-Pb) zircon geochronologic and whole-rock geochemical data were obtained for 62 samples of which 28 are from Permian to Triassic plutonic rocks and dikes, 24 are from Late Jurassic plutonic ro
By
National Cooperative Geologic Mapping Program

Tabular geochronologic and geochemical data from metasedimentary and associated rocks in the Lane Mountain area, San Bernardino County, California

This dataset provides geochronologic and geochemical data for selected metasedimentary and associated rock samples collected in the Lane Mountain area about 20 kilometers northwest of Barstow, California. Geochronologic data were obtained for 24 samples, and geochemical data were obtained for 5 of these. The dataset consists of four tables in csv (comma separated values) format: (1) sample localit
By
Geology, Minerals, Energy, and Geophysics Science Center

Whole Rock Geochemistry and Uranium Lead Isotopic Data from the Dinwiddie Terrane, Virginia, USA

This data release includes whole rock geochemical data, and uranium-lead isotopic data collected by both Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods. Whole rock geochemistry was collected by Activation Laboratories in Ancaster, Ontario. LA-ICP-MS data was collected at the PLASMA at the USG
By
Florence Bascom Geoscience Center

Zircon Trace Element Data for Igneous Units Related to Mineralization in the Eastern Yukon-Tanana Upland and nearby areas, Eastern Alaska

From 2017-2019, framework metallogenic studies were completed in the eastern Yukon-Tanana upland in eastern Alaska. Numerous previously undated plutons known or suspected to contain components of porphyry, epithermal, and intrusion-related gold systems and associated deposit types were sampled for age and zircon trace element determinations between the Black Mountain area and the Yukon border, nor
By
Alaska Science Center

Zircon U-Pb data for volcanic ash beds in the Barstow Formation, California probe data 2022

Zircon grains separated from altered ash beds were analyzed to better understand the ages of the beds. Isotopic analyses for U-Pb geochronology and trace element geochemistry were performed simultaneously by secondary ion mass spectrometry using the Stanford-USGS SHRIMP-RG ion microprobe housed at Stanford University, USA. Analyses followed the analytical protocol and data acquisition conditions d
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Photoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies

The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge
By
Florence Bascom Geoscience Center, Bascom ARgon Dating (BARD) Laboratory

Geochronologic data from xenoliths near the Stillwater Complex, Montana

The Archean Stillwater Complex, a layered ultramafic-to-mafic intrusion, is exposed along the northern side of the Beartooth Mountains in Montana. To the north of the Stillwater outcrops, a gravity anomaly is located where Phanerozoic rocks may unconformably overlie the complex. These Phanerozoic rocks are intruded by Cretaceous plutons that have gabbroid inclusions that look like metamorphosed ro
By
Geology, Minerals, Energy, and Geophysics Science Center

Geologic map of the Providence Mountains in parts of the Fountain Peak and adjacent 7.5' quadrangles, San Bernardino County, California

IntroductionThe Providence Mountains are in the eastern Mojave Desert about 60 km southeast of Baker, San Bernardino County, California. This range, which is noted for its prominent cliffs of Paleozoic limestone, is part of a northeast-trending belt of mountainous terrain more than 100 km long that also includes the Granite Mountains, Mid Hills, and New York Mountains. Providence Mountains State R
By
Geology, Minerals, Energy, and Geophysics Science Center
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River, looking for an area that can yield samples suitable for 40Ar/39Ar geochronology.  USGS photo by Jorge Vazquez, June 2017.

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River, looking for an area that can yield samples suitable for 40Ar/39Ar geochronology.  USGS photo by Jorge Vazquez, June 2017.

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Big Pine Volcanic Field, California, from southwest cinder cone, wi...
Big Pine Volcanic Field, CA, from SW cinder cone
Big Pine Volcanic Field, CA, from SW cinder cone
Big Pine Volcanic Field, California, from southwest cinder cone, wi...

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, California, from southwest cinder cone, with US Route 395 and Owens River in view

By
Natural Hazards Mission Area, Volcano Hazards Program
Big Pine Volcanic Field, California, from southwest cinder cone, wi...

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, California, from southwest cinder cone, with US Route 395 and Owens River in view

By
Natural Hazards Mission Area, Volcano Hazards Program
Filter Total Items: 51

A Bayesian age from dispersed plagioclase and zircon dates in the Los Chocoyos ash, Central America

The eruption that produced the modern Atitlán caldera in Guatemala has a Volcanic Explosivity Index (VEI) greater than 8, making it the largest of the Quaternary in the Central American Volcanic Arc (CAVA). It generated ∼1220 km3 (730 km3 dense rock equivalent) of dispersed rhyolitic ash and unwelded pyroclastic flow deposits known as the Los Chocoyos ash. Despite its scale, the age of the Los Cho
Authors
Alec Baudry, Bradley S. Singer, Brian Jicha, Christine E. Jilly-Rehak, Jorge A. Vazquez, C. Brenhin Keller
By
Geology, Minerals, Energy, and Geophysics Science Center

Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen

The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria modeling and t
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda (Kate) Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez
By
Geosciences and Environmental Change Science Center, Geology, Geophysics, and Geochemistry Science Center

Heterogeneous multi-stage accretionary orogenesis — Evidence from the Gunnison block in the Yavapai Province, southwest USA

Proterozoic rocks exposed in the southwestern U.S.A. represent one of the best examples of crustal growth by arc-related magmatism and accretionary orogenesis. Within the Southwest the 1.8–1.7 Ga Yavapai Province is widely regarded as a classic example of juvenile arc crust, however 1.8–2.5 Ga inherited zircon and Nd and Hf model ages have been recognized near Gunnison in central Colorado. These d
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Karl E. Karlstrom, Amanda (Kate) Souders, Jorge A. Vazquez, Wayne R. Premo
By
Geosciences and Environmental Change Science Center

Geochronology and mapping constraints on the time-space evolution of the igneous and hydrothermal systems in the Taurus Cu-Mo district, eastern Alaska

The Taurus porphyry Cu-Mo district contains four mineralized porphyry centers in the eastern interior of Alaska. All four centers were emplaced during a magmatic episode that spanned from ca. 72 to 67 Ma, with seven distinct igneous suites. Each igneous suite resulted in hydrothermal alteration and mineralization, with younger pulses overprinting older pulses. Each magmatic-hydrothermal system is
Authors
Douglas C. Kreiner, Christopher Holm-Denoma, Laura Pianowski, Zachary Flood, David J. Stevenson, Garth E. Graham, Jorge A. Vazquez, Robert A Creaser
By
Mineral Resources Program, Alaska Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA

Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic granitic rocks. T
Authors
Mark W. Carter, Ryan J. McAleer, Christopher Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
By
Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center, Florence Bascom Geoscience Center

Geochronologic and geochemical data from metasedimentary and associated rocks in the Lane Mountain area, San Bernardino County, California

Eugeoclinal metasedimentary and metavolcanic rocks in the Lane Mountain area, California, are considered part of the El Paso terrane, which is commonly thought to have been displaced several hundred kilometers (km) southeastward from its place of origin during late Paleozoic truncation of the North American continental margin. Uranium-lead dating of detrital zircons from this area was undertaken t
Authors
Paul Stone, M. Robinson Cecil, Howard J. Brown, Jorge A. Vazquez
By
Geology, Minerals, Energy, and Geophysics Science Center

Ages of the granitic basement of Long Valley Caldera, California, USA, and siting of the Quaternary granite-rhyolite pluton

The leucogranitic crystal-mush pluton beneath the iconic Long Valley Caldera, California, USA, released >820 km3 of crystal-poor Pleistocene rhyolite, which was hosted by numerous Mesozoic granitic plutons, only a few of which had been dated until now. Reported here are U-Pb zircon ages, determined by sensitive high-resolution ion microprobe−reverse geometry (SHRIMP-RG), for 11 circumcaldera grani
Authors
Edward Hildreth, Judith E. Fierstein, Jorge A. Vazquez
By
Volcano Hazards Program, Volcano Science Center

Post-Early Miocene silicic volcanism in the northern Mojave Desert, California

Silicic volcanism that postdates widespread early Miocene volcanism in the Mojave Desert is underappreciated. We compiled age, petrographic, and geochemical data for volcanic rocks in a wide swath of the desert south of the Garlock fault using an age threshold of post-18.8 Ma, approximately the limit of the earlier Miocene volcanism as marked by the eruption of the widespread Peach Spring Tuff. In
Authors
David M. Miller, Phillip B Gans, Tracey J. Felger, Jorge A. Vazquez
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Stop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia

Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained gra
Authors
Mark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. Owens
By
Florence Bascom Geoscience Center

Geochronologic, isotopic, and geochemical data from pre-Cretaceous plutonic rocks in the Lane Mountain area, San Bernardino County, California

Pre-Cretaceous, predominantly dioritic plutonic rocks in the Lane Mountain area, California, intrude metasedimentary and metavolcanic rocks considered part of the El Paso terrane. New geochronologic (uranium-lead zircon), geochemical, and isotopic data provide a reliable basis for dividing these pre-Cretaceous plutonic rocks into two mappable suites of Permian–Triassic and Late Jurassic ages. The
Authors
Paul Stone, Howard J. Brown, M. Robinson Cecil, Robert J. Fleck, Jorge A. Vazquez, John A. Fitzpatrick
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Zircon geochronology and geochemistry of Quaternary rhyolite domes of the Coso volcanic field, Inyo County, California

The Quaternary Coso volcanic field (CVF) is a compositionally bimodal volcanic field located within a releasing bend along the eastern range-front Sierra Nevada fault zone in California's southern Owens Valley. The erupted products of CVF silicic magmatism since ~1 Ma comprise 38 high-silica rhyolite domes, with the volumetric majority (~99%) of rhyolite emplaced within the past ~300 ka. The CVF h
Authors
Seth D. Burgess, Matthew Coble, Jorge A. Vazquez
By
Volcano Hazards Program, Volcano Science Center

Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountain volcanic field, Colorado, USA

The Oligocene Platoro caldera complex of the San Juan volcanic locus in Colorado (USA) features numerous exposed plutons both within the caldera and outside its margins, enabling investigation of the timing and evolution of postcaldera magmatism. Intrusion whole-rock geochemistry and phenocryst and/or mineral trace element compositions coupled with new zircon U-Pb geo-chronology and zircon in situ
Authors
Amy K. Gilmer, Ren A. Thompson, Peter W. Lipman, Jorge A. Vazquez, Amanda (Kate) Souders
By
National Cooperative Geologic Mapping Program, Volcano Hazards Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center

Science and Products

link
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
By
Community for Data Integration (CDI)
link

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
Learn More

Data release of zircon U-Pb geochronology and whole-rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada, and Wyoming

This U.S. Geological Survey (USGS) data release provides zircon U-Pb geochronology and whole rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada and Wyoming. The drill core samples were obtained from the USGS Core Research Center in Denver, Colorado. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement te
By
Geosciences and Environmental Change Science Center

Data release of isotope geochemistry, mineral chemistry, and geochronology for a Proterozoic paragneiss sampled from drill core from North Dakota

This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic history, a
By
Geology, Minerals, Energy, and Geophysics Science Center

Data release of monazite and xenotime geochronology for Proterozoic rocks in central Colorado and monazite and zircon geochronology and whole-rock isotope geochemistry fo a Proterozoic drill core sample from western Colorado

This U.S. Geological Survey (USGS) data release provides monazite and xenotime geochronology from Proterozoic rocks collected from outcrop in central Colorado and whole rock isotope geochemistry, and zircon and monazite geochronology from a Proterozoic rock sampled from a drill core from western Colorado. The drill core sample was collected from the 1 Paradox Valley injection core near Bedrock, CO
By
Geology, Minerals, Energy, and Geophysics Science Center

Zircon U-Pb geochronology and whole rock geochemistry for pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado

This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data and zircon U-Pb geochronology and trace element concentrations for samples from pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado. Samples were collected in order to constrain the evolution of the pre-ignimbrite m
By
Geosciences and Environmental Change Science Center

Tabular geochronologic, geochemical, and isotopic data from igneous rocks in the Lane Mountain area, San Bernardino County, California

This dataset provides geochronologic, geochemical, and isotopic data for selected igneous rock samples collected in the Lane Mountain area about 20 kilometers northeast of Barstow, California. Uranium-lead (U-Pb) zircon geochronologic and whole-rock geochemical data were obtained for 62 samples of which 28 are from Permian to Triassic plutonic rocks and dikes, 24 are from Late Jurassic plutonic ro
By
National Cooperative Geologic Mapping Program

Tabular geochronologic and geochemical data from metasedimentary and associated rocks in the Lane Mountain area, San Bernardino County, California

This dataset provides geochronologic and geochemical data for selected metasedimentary and associated rock samples collected in the Lane Mountain area about 20 kilometers northwest of Barstow, California. Geochronologic data were obtained for 24 samples, and geochemical data were obtained for 5 of these. The dataset consists of four tables in csv (comma separated values) format: (1) sample localit
By
Geology, Minerals, Energy, and Geophysics Science Center

Whole Rock Geochemistry and Uranium Lead Isotopic Data from the Dinwiddie Terrane, Virginia, USA

This data release includes whole rock geochemical data, and uranium-lead isotopic data collected by both Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Sensitive High Resolution Ion Microprobe-Reverse Geometry (SHRIMP-RG) methods. Whole rock geochemistry was collected by Activation Laboratories in Ancaster, Ontario. LA-ICP-MS data was collected at the PLASMA at the USG
By
Florence Bascom Geoscience Center

Zircon Trace Element Data for Igneous Units Related to Mineralization in the Eastern Yukon-Tanana Upland and nearby areas, Eastern Alaska

From 2017-2019, framework metallogenic studies were completed in the eastern Yukon-Tanana upland in eastern Alaska. Numerous previously undated plutons known or suspected to contain components of porphyry, epithermal, and intrusion-related gold systems and associated deposit types were sampled for age and zircon trace element determinations between the Black Mountain area and the Yukon border, nor
By
Alaska Science Center

Zircon U-Pb data for volcanic ash beds in the Barstow Formation, California probe data 2022

Zircon grains separated from altered ash beds were analyzed to better understand the ages of the beds. Isotopic analyses for U-Pb geochronology and trace element geochemistry were performed simultaneously by secondary ion mass spectrometry using the Stanford-USGS SHRIMP-RG ion microprobe housed at Stanford University, USA. Analyses followed the analytical protocol and data acquisition conditions d
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Photoluminescence Imaging of Whole Zircon Grains on a Petrographic Microscope - An Underused Aide for Geochronologic Studies

The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most ge
By
Florence Bascom Geoscience Center, Bascom ARgon Dating (BARD) Laboratory

Geochronologic data from xenoliths near the Stillwater Complex, Montana

The Archean Stillwater Complex, a layered ultramafic-to-mafic intrusion, is exposed along the northern side of the Beartooth Mountains in Montana. To the north of the Stillwater outcrops, a gravity anomaly is located where Phanerozoic rocks may unconformably overlie the complex. These Phanerozoic rocks are intruded by Cretaceous plutons that have gabbroid inclusions that look like metamorphosed ro
By
Geology, Minerals, Energy, and Geophysics Science Center

Geologic map of the Providence Mountains in parts of the Fountain Peak and adjacent 7.5' quadrangles, San Bernardino County, California

IntroductionThe Providence Mountains are in the eastern Mojave Desert about 60 km southeast of Baker, San Bernardino County, California. This range, which is noted for its prominent cliffs of Paleozoic limestone, is part of a northeast-trending belt of mountainous terrain more than 100 km long that also includes the Granite Mountains, Mid Hills, and New York Mountains. Providence Mountains State R
By
Geology, Minerals, Energy, and Geophysics Science Center
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River
A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River, looking for an area that can yield samples suitable for 40Ar/39Ar geochronology.  USGS photo by Jorge Vazquez, June 2017.

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River

A geologist examples a basaltic lava flow along the Madison River, looking for an area that can yield samples suitable for 40Ar/39Ar geochronology.  USGS photo by Jorge Vazquez, June 2017.

By
Volcano Science Center, Yellowstone Volcano Observatory, Yellowstone
Big Pine Volcanic Field, California, from southwest cinder cone, wi...
Big Pine Volcanic Field, CA, from SW cinder cone
Big Pine Volcanic Field, CA, from SW cinder cone
Big Pine Volcanic Field, California, from southwest cinder cone, wi...

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, California, from southwest cinder cone, with US Route 395 and Owens River in view

By
Natural Hazards Mission Area, Volcano Hazards Program
Big Pine Volcanic Field, California, from southwest cinder cone, wi...

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, CA, from SW cinder cone

Big Pine Volcanic Field, California, from southwest cinder cone, with US Route 395 and Owens River in view

By
Natural Hazards Mission Area, Volcano Hazards Program
Filter Total Items: 51

A Bayesian age from dispersed plagioclase and zircon dates in the Los Chocoyos ash, Central America

The eruption that produced the modern Atitlán caldera in Guatemala has a Volcanic Explosivity Index (VEI) greater than 8, making it the largest of the Quaternary in the Central American Volcanic Arc (CAVA). It generated ∼1220 km3 (730 km3 dense rock equivalent) of dispersed rhyolitic ash and unwelded pyroclastic flow deposits known as the Los Chocoyos ash. Despite its scale, the age of the Los Cho
Authors
Alec Baudry, Bradley S. Singer, Brian Jicha, Christine E. Jilly-Rehak, Jorge A. Vazquez, C. Brenhin Keller
By
Geology, Minerals, Energy, and Geophysics Science Center

Paleoproterozoic reworking of Archean crust and extreme back-arc metamorphism in the enigmatic southern Trans-Hudson orogen

The crustal evolution of the southernmost ∼2000–1800 Ma Trans-Hudson orogen (THO) is enigmatic due to burial by Phanerozoic sediments. We provide new insights through petrochronologic analysis of a paragneiss drill core sample. Detrital zircon age peaks at 2625, 2340, and 1880 Ma and Hf isotopes suggest Paleoproterozoic arc development proximal to Archean source(s). Phase equilibria modeling and t
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Amanda (Kate) Souders, Michael J. Jercinovic, Heather A. Lowers, Jorge A. Vazquez
By
Geosciences and Environmental Change Science Center, Geology, Geophysics, and Geochemistry Science Center

Heterogeneous multi-stage accretionary orogenesis — Evidence from the Gunnison block in the Yavapai Province, southwest USA

Proterozoic rocks exposed in the southwestern U.S.A. represent one of the best examples of crustal growth by arc-related magmatism and accretionary orogenesis. Within the Southwest the 1.8–1.7 Ga Yavapai Province is widely regarded as a classic example of juvenile arc crust, however 1.8–2.5 Ga inherited zircon and Nd and Hf model ages have been recognized near Gunnison in central Colorado. These d
Authors
Ian William Hillenbrand, Amy K. Gilmer, Michael L. Williams, Karl E. Karlstrom, Amanda (Kate) Souders, Jorge A. Vazquez, Wayne R. Premo
By
Geosciences and Environmental Change Science Center

Geochronology and mapping constraints on the time-space evolution of the igneous and hydrothermal systems in the Taurus Cu-Mo district, eastern Alaska

The Taurus porphyry Cu-Mo district contains four mineralized porphyry centers in the eastern interior of Alaska. All four centers were emplaced during a magmatic episode that spanned from ca. 72 to 67 Ma, with seven distinct igneous suites. Each igneous suite resulted in hydrothermal alteration and mineralization, with younger pulses overprinting older pulses. Each magmatic-hydrothermal system is
Authors
Douglas C. Kreiner, Christopher Holm-Denoma, Laura Pianowski, Zachary Flood, David J. Stevenson, Garth E. Graham, Jorge A. Vazquez, Robert A Creaser
By
Mineral Resources Program, Alaska Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA

Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic granitic rocks. T
Authors
Mark W. Carter, Ryan J. McAleer, Christopher Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
By
Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center, Florence Bascom Geoscience Center

Geochronologic and geochemical data from metasedimentary and associated rocks in the Lane Mountain area, San Bernardino County, California

Eugeoclinal metasedimentary and metavolcanic rocks in the Lane Mountain area, California, are considered part of the El Paso terrane, which is commonly thought to have been displaced several hundred kilometers (km) southeastward from its place of origin during late Paleozoic truncation of the North American continental margin. Uranium-lead dating of detrital zircons from this area was undertaken t
Authors
Paul Stone, M. Robinson Cecil, Howard J. Brown, Jorge A. Vazquez
By
Geology, Minerals, Energy, and Geophysics Science Center

Ages of the granitic basement of Long Valley Caldera, California, USA, and siting of the Quaternary granite-rhyolite pluton

The leucogranitic crystal-mush pluton beneath the iconic Long Valley Caldera, California, USA, released >820 km3 of crystal-poor Pleistocene rhyolite, which was hosted by numerous Mesozoic granitic plutons, only a few of which had been dated until now. Reported here are U-Pb zircon ages, determined by sensitive high-resolution ion microprobe−reverse geometry (SHRIMP-RG), for 11 circumcaldera grani
Authors
Edward Hildreth, Judith E. Fierstein, Jorge A. Vazquez
By
Volcano Hazards Program, Volcano Science Center

Post-Early Miocene silicic volcanism in the northern Mojave Desert, California

Silicic volcanism that postdates widespread early Miocene volcanism in the Mojave Desert is underappreciated. We compiled age, petrographic, and geochemical data for volcanic rocks in a wide swath of the desert south of the Garlock fault using an age threshold of post-18.8 Ma, approximately the limit of the earlier Miocene volcanism as marked by the eruption of the widespread Peach Spring Tuff. In
Authors
David M. Miller, Phillip B Gans, Tracey J. Felger, Jorge A. Vazquez
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Stop 3 – The Petersburg “Granite” redefined: Recognition and implications of Silurian to Devonian rocks in central-eastern Virginia

Introduction Although the Petersburg Granite had long been in practical use as a building stone since the 1830s (Watson, 1906; 1907; 1910; Darton, 1911; Steidtmann, 1945), it was first formally defined as a geologic unit by Anna Jonas on the 1928 geologic map of Virginia. Anna Jonas defined this unit as a Precambrian coarse-grained porphyritic biotite granite that was intruded by finer grained gra
Authors
Mark W. Carter, Ryan J. McAleer, Marcie Occhi, Christopher Holm-Denoma, Jorge A. Vazquez, Brent E. Owens
By
Florence Bascom Geoscience Center

Geochronologic, isotopic, and geochemical data from pre-Cretaceous plutonic rocks in the Lane Mountain area, San Bernardino County, California

Pre-Cretaceous, predominantly dioritic plutonic rocks in the Lane Mountain area, California, intrude metasedimentary and metavolcanic rocks considered part of the El Paso terrane. New geochronologic (uranium-lead zircon), geochemical, and isotopic data provide a reliable basis for dividing these pre-Cretaceous plutonic rocks into two mappable suites of Permian–Triassic and Late Jurassic ages. The
Authors
Paul Stone, Howard J. Brown, M. Robinson Cecil, Robert J. Fleck, Jorge A. Vazquez, John A. Fitzpatrick
By
National Cooperative Geologic Mapping Program, Geology, Minerals, Energy, and Geophysics Science Center

Zircon geochronology and geochemistry of Quaternary rhyolite domes of the Coso volcanic field, Inyo County, California

The Quaternary Coso volcanic field (CVF) is a compositionally bimodal volcanic field located within a releasing bend along the eastern range-front Sierra Nevada fault zone in California's southern Owens Valley. The erupted products of CVF silicic magmatism since ~1 Ma comprise 38 high-silica rhyolite domes, with the volumetric majority (~99%) of rhyolite emplaced within the past ~300 ka. The CVF h
Authors
Seth D. Burgess, Matthew Coble, Jorge A. Vazquez
By
Volcano Hazards Program, Volcano Science Center

Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountain volcanic field, Colorado, USA

The Oligocene Platoro caldera complex of the San Juan volcanic locus in Colorado (USA) features numerous exposed plutons both within the caldera and outside its margins, enabling investigation of the timing and evolution of postcaldera magmatism. Intrusion whole-rock geochemistry and phenocryst and/or mineral trace element compositions coupled with new zircon U-Pb geo-chronology and zircon in situ
Authors
Amy K. Gilmer, Ren A. Thompson, Peter W. Lipman, Jorge A. Vazquez, Amanda (Kate) Souders
By
National Cooperative Geologic Mapping Program, Volcano Hazards Program, Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center
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