Mark Hudson is a Research Geologist with the Geosciences and Environmental Change Science Center
Over a long career with the U.S. Geological Survey, I have had to opportunity to conduct a variety of basic and applied research studies applying techniques from structural geology/tectonics, geologic mapping, paleomagnetism/rock magnetism, karst geology, and hydrogeology. These studies have been conducted in the Basin and Range, Rio Grande rift, and southern Rocky Mountains provinces of the West and the Ozark Plateaus-Ouachita Mountains provinces of the southern midcontinent.
Professional Experience
2001 - present, Project Chief and Research Geologist, U.S. Geological Survey; Denver, CO
1987 - 2000, Research Geologist, U.S. Geological Survey; Denver, CO
Education and Certifications
Colorado School of Mines, Golden, CO - Ph.D., 1988, major - Geology, minor - Geophysics
Colorado School of Mines, Golden, CO - M.S., 1983, major - Geology
Arkansas Tech University, Russellville, AR - B.S., 1980, major - Geology, minor - Mathematics
Science and Products
Filter Total Items: 24
Evaporite tectonism in the lower Roaring Fork River valley, west-central Colorado
Evaporite tectonism in the lower Roaring Fork River valley in west-central Colorado has caused regional subsidence of a differentially downdropped area in the southern part of the Carbondale collapse center during the late Cenozoic. A prominent topographic depression coincides with this collapse area, and drainage patterns within the collapse area contrast sharply with those outside of it. Miocene
Eagle collapse center: Interpretation of evidence for late Cenozoic evaporite-related deformation in the Eagle River basin, Colorado
Evaporite tectonism resulted in deformation and collapse over an area of ~2500 km2 that is referred to as the Eagle collapse center. The collapse center includes much of the Eagle and Colorado River drainage basins between Vail, Dotsero, and McCoy, Colorado. The volume loss of evaporitic rocks by dissolution in the collapse center is estimated to be nearly 1700 km33 . Before ca. 10 Ma, Miocene bas
Geophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications
Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The region has been loosely divided into six domains based on structural style and overall geophysical character. For each domain, the subsurface tectonic and magmatic features that have been in
Style and age of late Oligocene-early Miocene deformation in the southern Stillwater Range, west central Nevada: Paleomagnetism, geochronology, and field relations
Paleomagnetic and geochronologic data combined with geologic mapping tightly restrict the timing and character of a late Oligocene to early Miocene episode of large magnitude extension in the southern Stillwater Range and adjacent regions of west central Nevada. The southern Stillwater Range was the site of an Oligocene to early Miocene volcanic center comprising (1) 28.3 to 24.3 Ma intracaldera a
Paleomagnetism and rotation constraints for the middle Miocene southwestern Nevada volcanic field
Middle Miocene rocks of the southwestern Nevada volcanic field (SWNVF) lie across the projection of the Walker Lane belt within the Basin and Range province and thus provide an interesting opportunity to test for late Cenozoic vertical-axis rotation. Paleomagnetic data from individual ash flow sheets document no significant relative vertical-axis rotation among localities within central SWNVF, an
Source of anomalous magnetization in an area of hydrocarbon potential: Petrologic evidence from the Jurassic Preuss Sandstone, Wyoming-Idaho thrust belt
The Jurassic Preuss Sandstone, which crops out in the central part of the Wyoming-Idaho thrust belt on trend with a hydrocarbon-producing region to the south, has been previously identified as the source of anomalous magnetization in the area. Elsewhere, anomalous magnetization in sedimentary rocks near hydrocarbon accumulations has been attributed to hydrocarbon-engendered magnetic minerals, but
Paleomagnetic evidence for the timing of collapse and resurgence of the Lake City Caldera, San Juan Mountains, Colorado
Rocks of the 23.1‐m.y.‐old Lake City caldera consist of the compositionally zoned Sunshine Peak Tuff, postcollapse intracaldera lava flows, and resurgent quartz syenite intrusions. Declinations of reversely magnetized (I = −45° to −75°) Sunshine Peak Tuff change from easterly (D = 93°–130°) throughout most of the tuff to southerly (D = 195°–207°) within the late eruptive phases. The postcollapse l
Iron-titanium oxide minerals and magnetic susceptibility anomalies in the Mariano Lake-Lake Valley cores-Constraints on conditions of uranium mineralization in the Morrison Formation, San Juan Basin, New Mexico
Petrographic study of the Mariano Lake-Lake Valley cores reveals three distinct zones of postdepositional alteration of detrital Fe-Ti (iron-titanium) oxide minerals in the Westwater Canyon Member of the Upper Jurassic Morrison Formation. In the uranium-bearing and adjacent portions of the Westwater Canyon, these detrital Fe-Ti oxide minerals have been thoroughly altered by leaching of iron. Strat
Paleomagnetic and petrologic evidence bearing on the age and origin of uranium deposits in the Permian Cutler Formation, Lisbon Valley, Utah
An approximate age for uranium deposits in red beds of the Permian Cutler Formation, Lisbon Valley salt anticline, Utah, was obtained using paleomagnetic techniques. Progressive thermal demagnetization of samples of mineralized sandstone isolates stable magnetization components having high (≳400 °C) unblocking temperatures that define a tilt-corrected mean direction of D = 358.1°, I = 65.5°, α95 =
Filter Total Items: 13
Geologic map of the Ponca quadrangle, Newton, Boone, and Carroll Counties, Arkansas
This digital geologic map compilation presents new polygon
(i.e., geologic map unit contacts), line (i.e., fault, fold
axis, and structure contour), and point (i.e., structural
attitude, contact elevations) vector data for the Ponca 7 1/2'
quadrangle in northern Arkansas. The map database, which is at
1:24,000-scale resolution, provides geologic coverage of an
Science and Products
- Publications
Filter Total Items: 24
Evaporite tectonism in the lower Roaring Fork River valley, west-central Colorado
Evaporite tectonism in the lower Roaring Fork River valley in west-central Colorado has caused regional subsidence of a differentially downdropped area in the southern part of the Carbondale collapse center during the late Cenozoic. A prominent topographic depression coincides with this collapse area, and drainage patterns within the collapse area contrast sharply with those outside of it. MioceneEagle collapse center: Interpretation of evidence for late Cenozoic evaporite-related deformation in the Eagle River basin, Colorado
Evaporite tectonism resulted in deformation and collapse over an area of ~2500 km2 that is referred to as the Eagle collapse center. The collapse center includes much of the Eagle and Colorado River drainage basins between Vail, Dotsero, and McCoy, Colorado. The volume loss of evaporitic rocks by dissolution in the collapse center is estimated to be nearly 1700 km33 . Before ca. 10 Ma, Miocene basGeophysical framework of the southwestern Nevada volcanic field and hydrogeologic implications
Gravity and magnetic data, when integrated with other geophysical, geological, and rock-property data, provide a regional framework to view the subsurface geology in the southwestern Nevada volcanic field. The region has been loosely divided into six domains based on structural style and overall geophysical character. For each domain, the subsurface tectonic and magmatic features that have been inStyle and age of late Oligocene-early Miocene deformation in the southern Stillwater Range, west central Nevada: Paleomagnetism, geochronology, and field relations
Paleomagnetic and geochronologic data combined with geologic mapping tightly restrict the timing and character of a late Oligocene to early Miocene episode of large magnitude extension in the southern Stillwater Range and adjacent regions of west central Nevada. The southern Stillwater Range was the site of an Oligocene to early Miocene volcanic center comprising (1) 28.3 to 24.3 Ma intracaldera aPaleomagnetism and rotation constraints for the middle Miocene southwestern Nevada volcanic field
Middle Miocene rocks of the southwestern Nevada volcanic field (SWNVF) lie across the projection of the Walker Lane belt within the Basin and Range province and thus provide an interesting opportunity to test for late Cenozoic vertical-axis rotation. Paleomagnetic data from individual ash flow sheets document no significant relative vertical-axis rotation among localities within central SWNVF, anSource of anomalous magnetization in an area of hydrocarbon potential: Petrologic evidence from the Jurassic Preuss Sandstone, Wyoming-Idaho thrust belt
The Jurassic Preuss Sandstone, which crops out in the central part of the Wyoming-Idaho thrust belt on trend with a hydrocarbon-producing region to the south, has been previously identified as the source of anomalous magnetization in the area. Elsewhere, anomalous magnetization in sedimentary rocks near hydrocarbon accumulations has been attributed to hydrocarbon-engendered magnetic minerals, butPaleomagnetic evidence for the timing of collapse and resurgence of the Lake City Caldera, San Juan Mountains, Colorado
Rocks of the 23.1‐m.y.‐old Lake City caldera consist of the compositionally zoned Sunshine Peak Tuff, postcollapse intracaldera lava flows, and resurgent quartz syenite intrusions. Declinations of reversely magnetized (I = −45° to −75°) Sunshine Peak Tuff change from easterly (D = 93°–130°) throughout most of the tuff to southerly (D = 195°–207°) within the late eruptive phases. The postcollapse lIron-titanium oxide minerals and magnetic susceptibility anomalies in the Mariano Lake-Lake Valley cores-Constraints on conditions of uranium mineralization in the Morrison Formation, San Juan Basin, New Mexico
Petrographic study of the Mariano Lake-Lake Valley cores reveals three distinct zones of postdepositional alteration of detrital Fe-Ti (iron-titanium) oxide minerals in the Westwater Canyon Member of the Upper Jurassic Morrison Formation. In the uranium-bearing and adjacent portions of the Westwater Canyon, these detrital Fe-Ti oxide minerals have been thoroughly altered by leaching of iron. StratPaleomagnetic and petrologic evidence bearing on the age and origin of uranium deposits in the Permian Cutler Formation, Lisbon Valley, Utah
An approximate age for uranium deposits in red beds of the Permian Cutler Formation, Lisbon Valley salt anticline, Utah, was obtained using paleomagnetic techniques. Progressive thermal demagnetization of samples of mineralized sandstone isolates stable magnetization components having high (≳400 °C) unblocking temperatures that define a tilt-corrected mean direction of D = 358.1°, I = 65.5°, α95 = - Science
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- Maps
Filter Total Items: 13
Geologic map of the Ponca quadrangle, Newton, Boone, and Carroll Counties, Arkansas
This digital geologic map compilation presents new polygon (i.e., geologic map unit contacts), line (i.e., fault, fold axis, and structure contour), and point (i.e., structural attitude, contact elevations) vector data for the Ponca 7 1/2' quadrangle in northern Arkansas. The map database, which is at 1:24,000-scale resolution, provides geologic coverage of an