Cal Ruleman
Current Research:
Neotectonics of the northern Rio Grande rift between Taos, New Mexico and Leadville, Colorado
Geomorphic evolution and timing of basin integration in the San Luis Valley, Colorado and New Mexico
Rates of bedrock canyon incision along the Rio Grande, New Mexico
Timing late Pleistocene glacial maximum and rates of deglaciation, central Colorado
Biography
Education
1999:B.A., University of Montana, Missoula
2002:M.S., Montana State University, Bozeman
Professional Society Memberships
1996-Present: Geological Society of America
2000-Present: Colorado Scientific Society
Professional Experience
2000-2002: USGS student intern
2002-2004: U.S. Peace Corp Volunteer, Suriname, South America
2004-2007: Geologist, USGS contractor and private sector
2007-Present: Research Geologist, USGS
Science and Products
Neotectonics and geomorphic evolution of the northwestern arm of the Yellowstone Tectonic Parabola: Controls on intra-cratonic extensional regimes, southwest Montana
The catastrophic Hebgen Lake earthquake of 18 August 1959 (MW 7.3) led many geoscientists to develop new methods to better understand active tectonics in extensional tectonic regimes that address seismic hazards. The Madison Range fault system and adjacent Hebgen Lake–Red Canyon fault system provide an intermountain active tectonic analog for...
Ruleman, Chester A.; Larsen, Mort; Stickney, Michael C. Late Miocene-Pleistocene evolution of a Rio Grande rift subbasin, Sunshine Valley-Costilla Plain, San Luis Basin, New Mexico and Colorado
The Sunshine Valley-Costilla Plain, a structural subbasin of the greater San Luis Basin of the northern Rio Grande rift, is bounded to the north and south by the San Luis Hills and the Red River fault zone, respectively. Surficial mapping, neotectonic investigations, geochronology, and geophysics demonstrate that the structural, volcanic, and...
Ruleman, C.A.; Thompson, R.A.; Shroba, R.R.; Anderson, M.; Drenth, B.J.; Rotzien, J.; Lyon, J.
Geologic map of the Mount Sherman 7.5' quadrangle, Lake and Park Counties, Colorado
The Mount Sherman 7.5- minute quadrangle is located along the crest of the Mosquito Range in between Leadville and Fairplay, Colorado. There are eleven 13,000-foot peaks and one fourteener, Mount Sherman, within the quadrangle. General elevations range from 10,400–14,036 feet (3,200–4,278 meters). The western half of the quadrangle primarily...
Bohannon, Robert G.; Ruleman, Chester A. Identifying buried segments of active faults in the northern Rio Grande Rift using aeromagnetic, LiDAR,and gravity data, south-central Colorado, USA
Combined interpretation of aeromagnetic and LiDAR data builds on the strength of the aeromagnetic method to locate normal faults with significant offset under cover and the strength of LiDAR interpretation to identify the age and sense of motion of faults. Each data set helps resolve ambiguities in interpreting the other. In addition, gravity data...
Grauch, V.J.S.; Ruleman, Chester A.
Geologic map of the Bailey 30' x 60' quadrangle, North-Central Colorado
The Bailey, Colo. 1:100,000-scale quadrangle lies within two physiographic and geologic provinces in central Colorado: 1) the Front Range and 2) South Park. Most of the Front Range is composed of Proterozoic rocks ranging in age from 1,790 Ma to 1,074 Ma. Along the eastern flanks and within the Denver Basin, sedimentary rocks ranging from...
Ruleman, Chester A.; Bohannon, Robert G.; Bryant, Bruce; Shroba, Ralph R.; Premo, Wayne R. Neotectonic inversion of the Hindu Kush-Pamir mountain region
The Hindu Kush-Pamir region of southern Asia is one of Earth's most rapidly deforming regions and it is poorly understood. This study develops a kinematic model based on active faulting in this part of the Trans-Himalayan orogenic belt. Previous studies have described north-verging thrust faults and some strike-slip faults, reflected in the...
Ruleman, C.A.
Geologic Map of the Sulphur Mountain Quadrangle, Park County, Colorado
The main structural element in the Sulphur Mountain quadrangle is the Elkhorn thrust. This northwest-trending fault is the southernmost structure that bounds the west side of the Late Cretaceous and early Tertiary Front Range basement-rock uplift. The Elkhorn thrust and the Williams Range thrust that occurs in the Dillon area north of the...
Bohannon, Robert G.; Ruleman, Chester A.
Geologic Map of the Elkhorn Quadrangle, Park County, Colorado
The Elkhorn thrust is defined by the juxtaposition of Early and Middle Proterozoic metamorphic and igneous rocks against Mesozoic and Tertiary rocks. Within the mapped area, an imbricate frontal thrust system juxtaposes Upper Cretaceous rocks against Paleocene rocks of the South Park Formation. In the southeastern section of the quadrangle, Middle...
Ruleman, Chester A.; Bohannon, Robert G.
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...
Kellogg, Karl S.; Ruleman, Chester A.; Shroba, Ralph R.; Braddock, William A. 2007 Rocky Mountain Section Friends of the Pleistocene Field Trip - Quaternary Geology of the San Luis Basin of Colorado and New Mexico, September 7-9, 2007
Prologue Welcome to the 2007 Rocky Mountain Cell Friends of the Pleistocene Field Trip, which will concentrate on the Quaternary geology of the San Luis Basin of Colorado and New Mexico. To our best knowledge, Friends of the Pleistocene (FOP) has never run a trip through the San Luis Basin, although former trips in the region reviewed the '...
Machette, Michael N.; Coates, Mary-Margaret; Johnson, Margo L. Map and Database of Probable and Possible Quaternary Faults in Afghanistan
The U.S. Geological Survey (USGS) with support from the U.S. Agency for International Development (USAID) mission in Afghanistan, has prepared a digital map showing the distribution of probable and suspected Quaternary faults in Afghanistan. This map is a key component of a broader effort to assess and map the country's seismic hazards. Our...
Ruleman, C.A.; Crone, A.J.; Machette, M.N.; Haller, K.M.; Rukstales, K.S.