Ralph Shroba
Ralph Shroba is a Scientist Emeritus with the Geosciences and Environmental Change Science Center
Science and Products
Filter Total Items: 42
Revised preliminary geologic map of the Storm King Mountain quadrangle, Garfield County, Colorado Revised preliminary geologic map of the Storm King Mountain quadrangle, Garfield County, Colorado
No abstract available.
Authors
Bruce Bryant, R. R. Shroba, Anne E. Harding
Soil relative dating of moraine and outwash-terrace sequences in the northern part of the upper Arkansas Valley, central Colorado, U.S.A. Soil relative dating of moraine and outwash-terrace sequences in the northern part of the upper Arkansas Valley, central Colorado, U.S.A.
Profile development indices for soils developed in moraines and outwash near Twin Lakes and in outwash near Leadville support the correlation of moraines with subdued morphology and two high outwash terraces with the Bull Lake glaciation (ca. 130-160 ka) and the correlation of hummocky moraines and two low outwash terraces with the Pinedale glaciation (ca. 14-47 ka). Elsewhere in the...
Authors
Alan R. Nelson, Ralph R. Shroba
Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado
The Rifle quadrangle extends from the Grand Hogback monocline into the southeastern part of the Piceance basin. In the northeastern part of the map area, the Wasatch Formation is nearly vertical, and over a distance of about 1 km, the dip decreases sharply from about 70-85o to about 15-30o toward the southwest. No evidence of a fault in this zone of sharp change in dip is observed but...
Authors
R. R. Shroba, R. B. Scott
Revised preliminary geologic map of the New Castle Quadrangle, Garfield County, Colorado Revised preliminary geologic map of the New Castle Quadrangle, Garfield County, Colorado
No abstract available.
Authors
R. B. Scott, R. R. Shroba
Preliminary geologic map of the Capulin Quadrangle, Alamosa and Conejos counties, Colorado Preliminary geologic map of the Capulin Quadrangle, Alamosa and Conejos counties, Colorado
No abstract available.
Authors
R. R. Shroba, R. A. Thompson
Filter Total Items: 26
Geologic Map of The Volcanoes Quadrangle, Bernalillo and Sandoval Counties, New Mexico Geologic Map of The Volcanoes Quadrangle, Bernalillo and Sandoval Counties, New Mexico
This geologic map, in support of the U.S. Geological Survey Middle Rio Grande Basin Geologic Mapping Project, shows the spatial distribution of surficial deposits, lava flows, and related sediments of the Albuquerque volcanoes, upper Santa Fe Group sediments, faults, and fault-related structural features. These deposits are on, along, and beneath the Llano de Albuquerque (West Mesa) west...
Geologic map of the Denver West 30' x 60' quadrangle, north-central Colorado Geologic map of the Denver West 30' x 60' quadrangle, north-central Colorado
The Denver West quadrangle extends east-west across the entire axis of the Front Range, one of numerous uplifts in the Rocky Mountain region in which Precambrian rocks are exposed. The history of the basement rocks in the Denver West quadrangle is as old as 1,790 Ma. Along the east side of the range, a sequence of sedimentary rocks as old as Pennsylvanian, but dominated by Cretaceous-age...
Geologic map of the Clark Peak quadrangle, Jackson and Larimer Counties, Colorado Geologic map of the Clark Peak quadrangle, Jackson and Larimer Counties, Colorado
The Clark Peak quadrangle encompasses the southern end of the Medicine Bow Mountains and the northernmost end of the Mummy Range. The Continental Divide traverses the map area and Highway 14 cross the Divide at Cameron Pass, in the southeastern corner of the map. Approximately the eastern half of the map, and a few areas to the west, are underlain by Early Proterozoic plutonic and...
Geologic map of the La Mesita Negra SE Quadrangle, Bernalillo County, New Mexico Geologic map of the La Mesita Negra SE Quadrangle, Bernalillo County, New Mexico
Geologic mapping, in support of the USGS Middle Rio Grande Basin Geologic Mapping Project, shows the spatial distribution of artificial-fill, alluvial, colluvial, and eolian deposits, lava flows and related sediments of the Albuquerque volcanoes, and upper Santa Fe Group sediments. These deposits are on, beneath, and along the West Mesa (Llano de Albuquerque) just west of Albuquerque...
Geologic map of the Horse Mountain Quadrangle, Garfield County, Colorado Geologic map of the Horse Mountain Quadrangle, Garfield County, Colorado
New 1:24,000-scale geologic map of the Horse Mountain 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, summarizes available geologic information for the quadrangle. It provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of the southwest flank of the White River uplift. Bedrock strata...
Science and Products
Filter Total Items: 42
Revised preliminary geologic map of the Storm King Mountain quadrangle, Garfield County, Colorado Revised preliminary geologic map of the Storm King Mountain quadrangle, Garfield County, Colorado
No abstract available.
Authors
Bruce Bryant, R. R. Shroba, Anne E. Harding
Soil relative dating of moraine and outwash-terrace sequences in the northern part of the upper Arkansas Valley, central Colorado, U.S.A. Soil relative dating of moraine and outwash-terrace sequences in the northern part of the upper Arkansas Valley, central Colorado, U.S.A.
Profile development indices for soils developed in moraines and outwash near Twin Lakes and in outwash near Leadville support the correlation of moraines with subdued morphology and two high outwash terraces with the Bull Lake glaciation (ca. 130-160 ka) and the correlation of hummocky moraines and two low outwash terraces with the Pinedale glaciation (ca. 14-47 ka). Elsewhere in the...
Authors
Alan R. Nelson, Ralph R. Shroba
Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado Revised preliminary geologic map of the Rifle Quadrangle, Garfield County, Colorado
The Rifle quadrangle extends from the Grand Hogback monocline into the southeastern part of the Piceance basin. In the northeastern part of the map area, the Wasatch Formation is nearly vertical, and over a distance of about 1 km, the dip decreases sharply from about 70-85o to about 15-30o toward the southwest. No evidence of a fault in this zone of sharp change in dip is observed but...
Authors
R. R. Shroba, R. B. Scott
Revised preliminary geologic map of the New Castle Quadrangle, Garfield County, Colorado Revised preliminary geologic map of the New Castle Quadrangle, Garfield County, Colorado
No abstract available.
Authors
R. B. Scott, R. R. Shroba
Preliminary geologic map of the Capulin Quadrangle, Alamosa and Conejos counties, Colorado Preliminary geologic map of the Capulin Quadrangle, Alamosa and Conejos counties, Colorado
No abstract available.
Authors
R. R. Shroba, R. A. Thompson
Filter Total Items: 26
Geologic Map of The Volcanoes Quadrangle, Bernalillo and Sandoval Counties, New Mexico Geologic Map of The Volcanoes Quadrangle, Bernalillo and Sandoval Counties, New Mexico
This geologic map, in support of the U.S. Geological Survey Middle Rio Grande Basin Geologic Mapping Project, shows the spatial distribution of surficial deposits, lava flows, and related sediments of the Albuquerque volcanoes, upper Santa Fe Group sediments, faults, and fault-related structural features. These deposits are on, along, and beneath the Llano de Albuquerque (West Mesa) west...
Geologic map of the Denver West 30' x 60' quadrangle, north-central Colorado Geologic map of the Denver West 30' x 60' quadrangle, north-central Colorado
The Denver West quadrangle extends east-west across the entire axis of the Front Range, one of numerous uplifts in the Rocky Mountain region in which Precambrian rocks are exposed. The history of the basement rocks in the Denver West quadrangle is as old as 1,790 Ma. Along the east side of the range, a sequence of sedimentary rocks as old as Pennsylvanian, but dominated by Cretaceous-age...
Geologic map of the Clark Peak quadrangle, Jackson and Larimer Counties, Colorado Geologic map of the Clark Peak quadrangle, Jackson and Larimer Counties, Colorado
The Clark Peak quadrangle encompasses the southern end of the Medicine Bow Mountains and the northernmost end of the Mummy Range. The Continental Divide traverses the map area and Highway 14 cross the Divide at Cameron Pass, in the southeastern corner of the map. Approximately the eastern half of the map, and a few areas to the west, are underlain by Early Proterozoic plutonic and...
Geologic map of the La Mesita Negra SE Quadrangle, Bernalillo County, New Mexico Geologic map of the La Mesita Negra SE Quadrangle, Bernalillo County, New Mexico
Geologic mapping, in support of the USGS Middle Rio Grande Basin Geologic Mapping Project, shows the spatial distribution of artificial-fill, alluvial, colluvial, and eolian deposits, lava flows and related sediments of the Albuquerque volcanoes, and upper Santa Fe Group sediments. These deposits are on, beneath, and along the West Mesa (Llano de Albuquerque) just west of Albuquerque...
Geologic map of the Horse Mountain Quadrangle, Garfield County, Colorado Geologic map of the Horse Mountain Quadrangle, Garfield County, Colorado
New 1:24,000-scale geologic map of the Horse Mountain 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, summarizes available geologic information for the quadrangle. It provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of the southwest flank of the White River uplift. Bedrock strata...