Geologic Framework of the Intermountain West
Active
By Geosciences and Environmental Change Science Center
October 4, 2019
The Geologic Framework of the Intermountain West (IMW) Project conducts 1:24,000- to 1:100,000-scale geologic mapping to support framework geologic investigations. The IMW project is prioritizing development of a seamless, integrated geologic map database in targeted areas of the Intermountain West region of the United States that host substantial mineral, energy, water, and industrial material resources critical for economic development, energy independence, and national security. The database synthesizes new and existing geologic map data into a spatially consistent geologic framework, serving the compiled geologic map data at scales ranging from 1:100,000 to 1:50,000. This innovative geologic map database improves queryability of map unit information that benefits private, indigenous, and public lands stakeholders by supporting informed decisions addressing resource assessments, exploration and extraction, and is foundational data to geoscience research. The database utilizes modern data delivery through web-hosted feature service layers that support advanced GIS data users. Geologic map data is more accessible to the public using the Intermountain West Geologic Map Explorer.
The stratigraphic framework that underpins the geologic map database is constructed dynamically using a process-based, time-dependent, hierarchical classification of geologic map units. Development of this framework requires thorough understanding of the complicated geologic history of the Intermountain West region, much of which remains inconsistently mapped, and accordingly, poorly understood. To fill critical knowledge gaps, topically focused research groups within the IMW Project investigate the various tectonic, magmatic, stratigraphic, and geomorphic processes that have shaped the Intermountain West region and created resources critical to the nation’s security and economic future. This stratigraphic framework and data structure is designed to simplify use of the map data in complex resource and hazard management applications.
The Intermountain West Seamless Geologic Map Explorer is now live!
The Intermountain West Seamless Geologic Map Explorer is now live!
The USGS Geochron Database Explorer is now live!
The USGS Geochron Database Explorer is now live!
Geologic Framework of the Intermountain West Project Working Groups
Filter Total Items: 36
Preliminary detrital zircon data for Upper Cretaceous to Paleocene strata of the Crazy Mountains basin, Montana Preliminary detrital zircon data for Upper Cretaceous to Paleocene strata of the Crazy Mountains basin, Montana
This document includes sandstone provenance data for Upper Cretaceous to Paleocene strata preserved in the Crazy Mountains Basin of western Montana, USA. The dataset includes detrital zircon data for six samples from the Upper Cretaceous Hoppers Formation (1 sample), Upper Cretaceous Billman Creek Formation (1 sample), and Paleocene Fort Union Formation (4 samples). Detrital zircon data...
Measured sections and paleocurrent data from fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations, Raton Basin, Colorado-New Mexico, USA Measured sections and paleocurrent data from fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations, Raton Basin, Colorado-New Mexico, USA
This document provides two data sets that characterize outcrops of fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations of the Raton Basin of Colorado-New Mexico, USA. First, the dataset includes stratigraphic sections measured through fluvial deposits of the Raton and Poison Canyon Formations (ten unique .tif files), currently exposed in roadside...
Thermochronologic data from the southern Stillwater Range, Nevada Thermochronologic data from the southern Stillwater Range, Nevada
This dataset contains apatite and zircon U-Th(He)data, 4He/3He thermochronologic data, and apatite fission-track data from the southern Stillwater Range, Nevada
Digital subsurface data of Paleozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis Digital subsurface data of Paleozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis
The Upper Colorado River Basin has a drainage area of about 113,500 square miles in western Colorado, eastern Utah, southwestern Wyoming, northeastern Arizona, and northwestern New Mexico. In the 1980’s and 1990’s, the Upper Colorado River Basin was a study area under of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program (Sun and Johnston, 1994; Sun and Weeks...
Digital subsurface data of Mesozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis Digital subsurface data of Mesozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis
The Upper Colorado River Basin has a drainage area of about 113,500 square miles in western Colorado, eastern Utah, southwestern Wyoming, northeastern Arizona, and northwestern New Mexico. In the 1980's and 1990's, the Upper Colorado River Basin was a study area under of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program (Sun and Johnston, 1994; Sun and Weeks...
Data release for Geologic Map of the Homestake Reservoir 7.5' quadrangle, Lake, Pitkin, and Eagle Counties, Colorado Data release for Geologic Map of the Homestake Reservoir 7.5' quadrangle, Lake, Pitkin, and Eagle Counties, Colorado
The Homestake Reservoir 7.5' quadrangle lies at the northwestern end of the Upper Arkansas Valley, and headwaters of the Arkansas River, and the Roaring Fork, Fryingpan, and Eagle Rivers of the Colorado River system. The quadrangle lies within tectonic provinces of the 1.4 Ga Picuris Orogeny, the late Paleozoic Ancestral Rockies, Late Cretaceous-Paleocene Laramide orogeny, Oligocene to...
Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico
This geologic map depicts and briefly describes geologic units underlying Petroglyph National Monument and immediately adjacent areas in Bernalillo County, New Mexico. The Monument is underlain dominantly by Quaternary basalts of the Albuquerque Volcanoes volcanic field, a series of basin-filling volcanic flows and associated vents from a monogenetic volcanic highland along the eastern...
Digital data for three-dimensional geologic framework model of the Rio San Jose groundwater basin, New Mexico Digital data for three-dimensional geologic framework model of the Rio San Jose groundwater basin, New Mexico
This data release contains a geospatial database related to a digital 3D geologic framework of the Rio San Jose watershed, New Mexico. The geospatial database contains two main data elements: (1) input data to the 3D framework model; (2) interpolated elevations and thicknesses of stratigraphic units as a cellular array. Input surface and subsurface data for 18 stratigraphic units have...
Data release for Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications Data release for Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
This dataset includes tables of 3He-isotopic data used to calculate surface exposure ages for samples of basalt, and U- and Th-isotopic data used to calculate uranium-series age estimates (230Th/U method) and initial 234U/238U activity ratios for samples of pedogenic carbonate formed in soils on alluvial fans in the San Luis Valley, Colorado, USA. These data are included in the...
Argon geochronology data for La Garita caldera Argon geochronology data for La Garita caldera
This dataset accompanies publication 'A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system', in review in Geology, which analyzed eruptive products from the La Garita caldera.
Data release of geospatial map database, argon geochronology and geochemistry data for: Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado Data release of geospatial map database, argon geochronology and geochemistry data for: Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado
This dataset accompanies publication "Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado". Data presented here include the digital geologic database, 40Ar/39Ar geochronology and major and trace element chemistry from lava flows and an ignimbrite. The geologic database includes spatial feature classes and non-spatial tables that collectively contain...
Argon data for Poncha Pass Geologic Map Argon data for Poncha Pass Geologic Map
This dataset was collected by Leah E. Morgan and Michael A. Cosca in the Argon Geochronology Laboratory of the USGS in Denver, Colorado in 2015. The dataset contains full raw argon isotopic data for samples presented in: Geologic Map of the Poncha Map Area, Chaffee, Fremont, and Saguache Counties, Colorado.
Filter Total Items: 31
No results found.
Below are publications associated with the Geologic Framework of the Intermountain West Project.
Filter Total Items: 39
Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountain volcanic field, Colorado, USA 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...
Authors
Amy K. Gilmer, Ren A. Thompson, Peter W. Lipman, Jorge A. Vazquez, Amanda Souders
Beach placer mineral deposits along localized paleoshorelines of the western Interior Seaway, upper cretaceous Fox Hills sandstone, eastern Denver Basin, Colorado Beach placer mineral deposits along localized paleoshorelines of the western Interior Seaway, upper cretaceous Fox Hills sandstone, eastern Denver Basin, Colorado
Beach placers deposited within the Fox Hills Sandstone along the eastern flank of the Denver Basin contain minerals deemed critical in 2018 by the U.S. Department of the Interior. These marine beach placers, or paleoplacers, were deposited in the Late Cretaceous along the western edge of the retreating Western Interior Seaway (WIS). Preliminary investigations determined that these...
Authors
Michael K O’Keeffe, Marieke Dechesne, Matthew J. Morgan, Stephen M Keller, Katherina Pfaff, Asha Mahatma, Alexander I Peretyatko
The grass is not always greener on the other side: Seasonal reversal of vegetation greenness in aspect-driven semiarid ecosystems The grass is not always greener on the other side: Seasonal reversal of vegetation greenness in aspect-driven semiarid ecosystems
Our current understanding of semiarid ecosystems is that they tend to display higher vegetation greenness on polar-facing slopes (PFS) than on equatorial-facing slopes (EFS). However, recent studies have argued that higher vegetation greenness can occur on EFS during part of the year. To assess whether this seasonal reversal of aspect-driven vegetation is a common occurrence, we...
Authors
Nikul Kumari, Patricia M. Saco, Jose F. Rodriguez, Samuel Johnstone, Ankur Srivastava, Kwok P. Chun, Omer Yetemen
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
Dilution and propagation of provenance trends in sand and mud: Geochemistry and detrital zircon geochronology of modern sediment from central California (U.S.A.) Dilution and propagation of provenance trends in sand and mud: Geochemistry and detrital zircon geochronology of modern sediment from central California (U.S.A.)
Integrated, multi-method provenance studies of siliciclastic sedimentary deposits are increasingly used to reconstruct the history of source-to-sink transport, paleogeography, and tectonics. Invariably, analysis of large-scale depositional systems must confront issues regarding how to best sample the system and adequately cope with the details of sediment mixing. Potential biases...
Authors
Matthew A. Malkowski, Glenn R. Sharman, Samuel Johnstone, Marty J. Grove, Dave L. Kimbrough, Stephen A. Graham
A new stratigraphic framework and constraints for the position of the Paleocene-Eocene boundary in the rapidly subsiding Hanna Basin, Wyoming A new stratigraphic framework and constraints for the position of the Paleocene-Eocene boundary in the rapidly subsiding Hanna Basin, Wyoming
The Paleocene–Eocene strata of the rapidly subsiding Hanna Basin give insights in sedimentation patterns and regional paleogeography during the Laramide orogeny and across the climatic event at the Paleocene–Eocene Thermal Maximum (PETM). Abundant coalbeds and carbonaceous shales of the fluvial, paludal, and lacustrine strata of the Hanna Formation offer a different depositional setting...
Authors
Marieke Dechesne, Ellen D Currano, Regan E Dunn, Pennilyn Higgins, Joseph Hartman, Kevin R Chamberlain, Christopher S. Holm-Denoma
Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, USA Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, USA
Much progress has been made in recent years towards a set of recognition criteria for river discharge variability in river channel deposits, and thus sedimentary proxies for precipitation variability. Despite this progress, there is currently no consensus on how different styles of discharge variability are reflected in river sedimentary records, and whether variable-discharge river...
Authors
Kristine L. Zellman, Piret Plink-Bjorklund, Henry Fricke
Orogenic recycling of detrital zircons characterizes age distributions of North American Cordilleran strata Orogenic recycling of detrital zircons characterizes age distributions of North American Cordilleran strata
Detrital zircon (DZ) analysis has become the standard tool for source‐to‐sink sediment routing studies at many spatial and temporal scales. In North American source‐to‐sink studies, DZ distributions are commonly classified according to the presence/absence and proportions of DZ age groups associated with North American crustal provinces as well as peri‐Gondwanan and Cordilleran terranes...
Authors
Theresa Maude Schwartz, Robert K. Schwartz, A.L. Weislogel
Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado) Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado)
Many eroded calderas expose associated postcollapse plutons, but detailed fieldwork‐supported studies have rarely focused on the internal structure that can contribute to understanding of emplacement dynamics. The Alamosa River monzonite pluton is a postcollapse intrusion at the Platoro caldera complex that erupted six large ignimbrites between 30.2 and 28.8 Ma in the Southern Rocky...
Authors
Filip Tomek, Amy K. Gilmer, M. S. Petronis, Peter W. Lipman, M. S. Foucher
Plant and insect herbivore community variation across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming Plant and insect herbivore community variation across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming
Ecosystem function and stability are highly affected by internal and external stressors. Utilizing paleobotanical data gives insight into the evolutionary processes an ecosystem undergoes across long periods of time, allowing for a more complete understanding of how plant and insect herbivore communities are affected by ecosystem imbalance. To study how plant and insect herbivore...
Authors
Lauren E Schmidt, Regan E Dunn, Jason J Mercer, Marieke Dechesne, Ellen D Currano
Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
The Rio Grande is the fourth longest river in North America extending over 3,000 km from the Rocky Mountains to the Gulf of Mexico. The Pleistocene evolution of this river from individual subbasins into a coalesced fluvial system has been long debated. Herein, we constrain the middle Pleistocene evolution of the northernmost and largest Rio Grande basin, the San Luis basin, and the...
Authors
Chester A. Ruleman, Adam M. Hudson, Ren A. Thompson, Daniel P. Miggins, James B. Paces, Brent M. Goehring
A stratigraphic approach to inferring depositional ages from detrital geochronology data A stratigraphic approach to inferring depositional ages from detrital geochronology data
With the increasing use of detrital geochronology data for provenance analyses, we have also developed new constraints on the age of otherwise undateable sedimentary deposits. Because a deposit can be no older than its youngest mineral constituent, the youngest defensible detrital mineral age defines the maximum depositional age of the sampled bed. Defining the youngest `defensible' age...
Authors
Samuel Johnstone, Theresa M. Schwartz, Christopher S. Holm-Denoma
The Geologic Framework of the Intermountain West (IMW) Project conducts 1:24,000- to 1:100,000-scale geologic mapping to support framework geologic investigations. The IMW project is prioritizing development of a seamless, integrated geologic map database in targeted areas of the Intermountain West region of the United States that host substantial mineral, energy, water, and industrial material resources critical for economic development, energy independence, and national security. The database synthesizes new and existing geologic map data into a spatially consistent geologic framework, serving the compiled geologic map data at scales ranging from 1:100,000 to 1:50,000. This innovative geologic map database improves queryability of map unit information that benefits private, indigenous, and public lands stakeholders by supporting informed decisions addressing resource assessments, exploration and extraction, and is foundational data to geoscience research. The database utilizes modern data delivery through web-hosted feature service layers that support advanced GIS data users. Geologic map data is more accessible to the public using the Intermountain West Geologic Map Explorer.
The stratigraphic framework that underpins the geologic map database is constructed dynamically using a process-based, time-dependent, hierarchical classification of geologic map units. Development of this framework requires thorough understanding of the complicated geologic history of the Intermountain West region, much of which remains inconsistently mapped, and accordingly, poorly understood. To fill critical knowledge gaps, topically focused research groups within the IMW Project investigate the various tectonic, magmatic, stratigraphic, and geomorphic processes that have shaped the Intermountain West region and created resources critical to the nation’s security and economic future. This stratigraphic framework and data structure is designed to simplify use of the map data in complex resource and hazard management applications.
The Intermountain West Seamless Geologic Map Explorer is now live!
The Intermountain West Seamless Geologic Map Explorer is now live!
The USGS Geochron Database Explorer is now live!
The USGS Geochron Database Explorer is now live!
Geologic Framework of the Intermountain West Project Working Groups
Filter Total Items: 36
Preliminary detrital zircon data for Upper Cretaceous to Paleocene strata of the Crazy Mountains basin, Montana Preliminary detrital zircon data for Upper Cretaceous to Paleocene strata of the Crazy Mountains basin, Montana
This document includes sandstone provenance data for Upper Cretaceous to Paleocene strata preserved in the Crazy Mountains Basin of western Montana, USA. The dataset includes detrital zircon data for six samples from the Upper Cretaceous Hoppers Formation (1 sample), Upper Cretaceous Billman Creek Formation (1 sample), and Paleocene Fort Union Formation (4 samples). Detrital zircon data...
Measured sections and paleocurrent data from fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations, Raton Basin, Colorado-New Mexico, USA Measured sections and paleocurrent data from fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations, Raton Basin, Colorado-New Mexico, USA
This document provides two data sets that characterize outcrops of fluvial deposits of the Upper Cretaceous-Paleogene Raton and Poison Canyon Formations of the Raton Basin of Colorado-New Mexico, USA. First, the dataset includes stratigraphic sections measured through fluvial deposits of the Raton and Poison Canyon Formations (ten unique .tif files), currently exposed in roadside...
Thermochronologic data from the southern Stillwater Range, Nevada Thermochronologic data from the southern Stillwater Range, Nevada
This dataset contains apatite and zircon U-Th(He)data, 4He/3He thermochronologic data, and apatite fission-track data from the southern Stillwater Range, Nevada
Digital subsurface data of Paleozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis Digital subsurface data of Paleozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis
The Upper Colorado River Basin has a drainage area of about 113,500 square miles in western Colorado, eastern Utah, southwestern Wyoming, northeastern Arizona, and northwestern New Mexico. In the 1980’s and 1990’s, the Upper Colorado River Basin was a study area under of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program (Sun and Johnston, 1994; Sun and Weeks...
Digital subsurface data of Mesozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis Digital subsurface data of Mesozoic rocks in the Upper Colorado River Basin in Wyoming, Utah, Colorado, Arizona, and New Mexico from USGS Regional Aquifer System Analysis
The Upper Colorado River Basin has a drainage area of about 113,500 square miles in western Colorado, eastern Utah, southwestern Wyoming, northeastern Arizona, and northwestern New Mexico. In the 1980's and 1990's, the Upper Colorado River Basin was a study area under of the U.S. Geological Survey's Regional Aquifer-System Analysis (RASA) program (Sun and Johnston, 1994; Sun and Weeks...
Data release for Geologic Map of the Homestake Reservoir 7.5' quadrangle, Lake, Pitkin, and Eagle Counties, Colorado Data release for Geologic Map of the Homestake Reservoir 7.5' quadrangle, Lake, Pitkin, and Eagle Counties, Colorado
The Homestake Reservoir 7.5' quadrangle lies at the northwestern end of the Upper Arkansas Valley, and headwaters of the Arkansas River, and the Roaring Fork, Fryingpan, and Eagle Rivers of the Colorado River system. The quadrangle lies within tectonic provinces of the 1.4 Ga Picuris Orogeny, the late Paleozoic Ancestral Rockies, Late Cretaceous-Paleocene Laramide orogeny, Oligocene to...
Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico Data Release for Geologic Map of Petroglyph National Monument and Vicinity, Bernalillo County, New Mexico
This geologic map depicts and briefly describes geologic units underlying Petroglyph National Monument and immediately adjacent areas in Bernalillo County, New Mexico. The Monument is underlain dominantly by Quaternary basalts of the Albuquerque Volcanoes volcanic field, a series of basin-filling volcanic flows and associated vents from a monogenetic volcanic highland along the eastern...
Digital data for three-dimensional geologic framework model of the Rio San Jose groundwater basin, New Mexico Digital data for three-dimensional geologic framework model of the Rio San Jose groundwater basin, New Mexico
This data release contains a geospatial database related to a digital 3D geologic framework of the Rio San Jose watershed, New Mexico. The geospatial database contains two main data elements: (1) input data to the 3D framework model; (2) interpolated elevations and thicknesses of stratigraphic units as a cellular array. Input surface and subsurface data for 18 stratigraphic units have...
Data release for Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications Data release for Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
This dataset includes tables of 3He-isotopic data used to calculate surface exposure ages for samples of basalt, and U- and Th-isotopic data used to calculate uranium-series age estimates (230Th/U method) and initial 234U/238U activity ratios for samples of pedogenic carbonate formed in soils on alluvial fans in the San Luis Valley, Colorado, USA. These data are included in the...
Argon geochronology data for La Garita caldera Argon geochronology data for La Garita caldera
This dataset accompanies publication 'A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system', in review in Geology, which analyzed eruptive products from the La Garita caldera.
Data release of geospatial map database, argon geochronology and geochemistry data for: Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado Data release of geospatial map database, argon geochronology and geochemistry data for: Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado
This dataset accompanies publication "Geologic map of the San Antonio Mountain area, northern New Mexico and southern Colorado". Data presented here include the digital geologic database, 40Ar/39Ar geochronology and major and trace element chemistry from lava flows and an ignimbrite. The geologic database includes spatial feature classes and non-spatial tables that collectively contain...
Argon data for Poncha Pass Geologic Map Argon data for Poncha Pass Geologic Map
This dataset was collected by Leah E. Morgan and Michael A. Cosca in the Argon Geochronology Laboratory of the USGS in Denver, Colorado in 2015. The dataset contains full raw argon isotopic data for samples presented in: Geologic Map of the Poncha Map Area, Chaffee, Fremont, and Saguache Counties, Colorado.
Filter Total Items: 31
No results found.
Below are publications associated with the Geologic Framework of the Intermountain West Project.
Filter Total Items: 39
Postcaldera intrusive magmatism at the Platoro caldera complex, Southern Rocky Mountain volcanic field, Colorado, USA 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...
Authors
Amy K. Gilmer, Ren A. Thompson, Peter W. Lipman, Jorge A. Vazquez, Amanda Souders
Beach placer mineral deposits along localized paleoshorelines of the western Interior Seaway, upper cretaceous Fox Hills sandstone, eastern Denver Basin, Colorado Beach placer mineral deposits along localized paleoshorelines of the western Interior Seaway, upper cretaceous Fox Hills sandstone, eastern Denver Basin, Colorado
Beach placers deposited within the Fox Hills Sandstone along the eastern flank of the Denver Basin contain minerals deemed critical in 2018 by the U.S. Department of the Interior. These marine beach placers, or paleoplacers, were deposited in the Late Cretaceous along the western edge of the retreating Western Interior Seaway (WIS). Preliminary investigations determined that these...
Authors
Michael K O’Keeffe, Marieke Dechesne, Matthew J. Morgan, Stephen M Keller, Katherina Pfaff, Asha Mahatma, Alexander I Peretyatko
The grass is not always greener on the other side: Seasonal reversal of vegetation greenness in aspect-driven semiarid ecosystems The grass is not always greener on the other side: Seasonal reversal of vegetation greenness in aspect-driven semiarid ecosystems
Our current understanding of semiarid ecosystems is that they tend to display higher vegetation greenness on polar-facing slopes (PFS) than on equatorial-facing slopes (EFS). However, recent studies have argued that higher vegetation greenness can occur on EFS during part of the year. To assess whether this seasonal reversal of aspect-driven vegetation is a common occurrence, we...
Authors
Nikul Kumari, Patricia M. Saco, Jose F. Rodriguez, Samuel Johnstone, Ankur Srivastava, Kwok P. Chun, Omer Yetemen
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
Dilution and propagation of provenance trends in sand and mud: Geochemistry and detrital zircon geochronology of modern sediment from central California (U.S.A.) Dilution and propagation of provenance trends in sand and mud: Geochemistry and detrital zircon geochronology of modern sediment from central California (U.S.A.)
Integrated, multi-method provenance studies of siliciclastic sedimentary deposits are increasingly used to reconstruct the history of source-to-sink transport, paleogeography, and tectonics. Invariably, analysis of large-scale depositional systems must confront issues regarding how to best sample the system and adequately cope with the details of sediment mixing. Potential biases...
Authors
Matthew A. Malkowski, Glenn R. Sharman, Samuel Johnstone, Marty J. Grove, Dave L. Kimbrough, Stephen A. Graham
A new stratigraphic framework and constraints for the position of the Paleocene-Eocene boundary in the rapidly subsiding Hanna Basin, Wyoming A new stratigraphic framework and constraints for the position of the Paleocene-Eocene boundary in the rapidly subsiding Hanna Basin, Wyoming
The Paleocene–Eocene strata of the rapidly subsiding Hanna Basin give insights in sedimentation patterns and regional paleogeography during the Laramide orogeny and across the climatic event at the Paleocene–Eocene Thermal Maximum (PETM). Abundant coalbeds and carbonaceous shales of the fluvial, paludal, and lacustrine strata of the Hanna Formation offer a different depositional setting...
Authors
Marieke Dechesne, Ellen D Currano, Regan E Dunn, Pennilyn Higgins, Joseph Hartman, Kevin R Chamberlain, Christopher S. Holm-Denoma
Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, USA Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, USA
Much progress has been made in recent years towards a set of recognition criteria for river discharge variability in river channel deposits, and thus sedimentary proxies for precipitation variability. Despite this progress, there is currently no consensus on how different styles of discharge variability are reflected in river sedimentary records, and whether variable-discharge river...
Authors
Kristine L. Zellman, Piret Plink-Bjorklund, Henry Fricke
Orogenic recycling of detrital zircons characterizes age distributions of North American Cordilleran strata Orogenic recycling of detrital zircons characterizes age distributions of North American Cordilleran strata
Detrital zircon (DZ) analysis has become the standard tool for source‐to‐sink sediment routing studies at many spatial and temporal scales. In North American source‐to‐sink studies, DZ distributions are commonly classified according to the presence/absence and proportions of DZ age groups associated with North American crustal provinces as well as peri‐Gondwanan and Cordilleran terranes...
Authors
Theresa Maude Schwartz, Robert K. Schwartz, A.L. Weislogel
Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado) Protracted multipulse emplacement of a post-resurgent pluton: The case of Platoro caldera complex (Southern Rocky Mountain volcanic field, Colorado)
Many eroded calderas expose associated postcollapse plutons, but detailed fieldwork‐supported studies have rarely focused on the internal structure that can contribute to understanding of emplacement dynamics. The Alamosa River monzonite pluton is a postcollapse intrusion at the Platoro caldera complex that erupted six large ignimbrites between 30.2 and 28.8 Ma in the Southern Rocky...
Authors
Filip Tomek, Amy K. Gilmer, M. S. Petronis, Peter W. Lipman, M. S. Foucher
Plant and insect herbivore community variation across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming Plant and insect herbivore community variation across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming
Ecosystem function and stability are highly affected by internal and external stressors. Utilizing paleobotanical data gives insight into the evolutionary processes an ecosystem undergoes across long periods of time, allowing for a more complete understanding of how plant and insect herbivore communities are affected by ecosystem imbalance. To study how plant and insect herbivore...
Authors
Lauren E Schmidt, Regan E Dunn, Jason J Mercer, Marieke Dechesne, Ellen D Currano
Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: Process, timing, and downstream implications
The Rio Grande is the fourth longest river in North America extending over 3,000 km from the Rocky Mountains to the Gulf of Mexico. The Pleistocene evolution of this river from individual subbasins into a coalesced fluvial system has been long debated. Herein, we constrain the middle Pleistocene evolution of the northernmost and largest Rio Grande basin, the San Luis basin, and the...
Authors
Chester A. Ruleman, Adam M. Hudson, Ren A. Thompson, Daniel P. Miggins, James B. Paces, Brent M. Goehring
A stratigraphic approach to inferring depositional ages from detrital geochronology data A stratigraphic approach to inferring depositional ages from detrital geochronology data
With the increasing use of detrital geochronology data for provenance analyses, we have also developed new constraints on the age of otherwise undateable sedimentary deposits. Because a deposit can be no older than its youngest mineral constituent, the youngest defensible detrital mineral age defines the maximum depositional age of the sampled bed. Defining the youngest `defensible' age...
Authors
Samuel Johnstone, Theresa M. Schwartz, Christopher S. Holm-Denoma