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Research about Mesa County, Colorado

Source-linked reports with geographic coverage including Mesa County, Colorado.

18 recordsLinked to original sources
USGS2025

Reduction of red bed sedimentary rocks in connection with energy metal ore formation: A case study from the Sinbad seep, Mesa County, Colorado

The Paradox Basin’s Sinbad seep is a modern analog for ancient bleaching of red bed sediments by introduced alkaline, reducing brines. This bleaching, involving reductive alteration of former red beds, is essential ground preparation that enables the altered rocks to trap Cu, U, and V from later oxidized fluids, forming ore deposits. Study of Sinbad thus offers insights into these metallic mineralization processes in the Paradox and other sedimentary basins. The Sinbad seep occurs where shallow groundwater interacts with organic-rich petroleum source rocks, flows up a fault, and discharges into Salt Creek. Ratios of Na/Cl, Na/Br, and Cl/Br, plus high sulfate concentrations, indicate that the salinity of the seep water originated from dissolution of halite and gypsum during topographically driven flow of meteoric water across a diapir of the Pennsylvanian Paradox Formation, rather than from deep basinal brines. In contact with the organic-rich shales of the Paradox, these SO 4 -rich waters become reduced through bacterial reduction, producing H 2 S. The waters react with red beds of the Permian Cutler Formation, causing pervasive bleaching. The bleaching at Sinbad is characterized by iron-conservative reduction of ferric iron in diagenetic hematite and detrital ilmenite and magnetite to Fe sulfides. The ferrous iron is retained in these sulfides likely as sorbed Fe. Associated alteration includes precipitation of quartz and feldspar overgrowths, partial dissolution of detrital quartz and feldspar caused by pressure solution, formation of clay and authigenic rutile, and precipitation of carbonate and gypsum. The Fe sulfides rapidly degenerate to a mixture of jarosite and iron oxides on weathering at the surface. Among the major-oxide elements and most trace elements, there is no statistical difference between unbleached and bleached samples. The exceptions are uranium and sulfur, which are somewhat greater in bleached samples. Fission track radiography illuminates that uranium is preferentially concentrated in iron oxide cements, iron sorbed into detrital clasts, and finely disseminated iron oxide in illite cement in bleached samples. A leaching experiment suggests that uranium may be more easily available for mobilization from rocks that have undergone bleaching alteration, making them potential U sources. In addition, bleached rocks form effective traps for U, V, and some Cu mineralization.

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USGS2002

Geologic map of the Grand Junction Quadrangle, Mesa County, Colorado

This 1:24,000-scale geologic map of the Grand Junction 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of the junction of the Colorado River and the Gunnison River. Bedrock strata include the Upper Cretaceous Mancos Shale through the Lower Jurassic Wingate Sandstone units. Below the Mancos Shale, which floors the Grand Valley, the Upper and Lower(?)Cretaceous Dakota Formation and the Lower Cretaceous Burro Canyon Formation hold up much of the resistant northeast- dipping monocline along the northeast side of the Uncompahgre uplift. The impressive sequence of Jurassic strata below include the Brushy Basin, Salt Wash, and Tidwell Members of the Upper Jurassic Morrison Formation, the Middle Jurassic Wanakah Formation and informal 'board beds' unit and Slick Rock Member of the Entrada Formation, and the Lower Jurassic Kayenta Formation and Wingate Sandstone. The Upper Triassic Chinle Formation and Early Proterozoic meta-igneous gneiss and migmatitic meta- sedimentary rocks, which are exposed in the Colorado National Monument quadrangle to the west, do not crop out here. The monoclinal dip slope of the northeastern margin of the Uncompahgre uplift is apparently a Laramide structural feature. Unlike the southwest-dipping, high-angle reverse faults in the Proterozoic basement and s-shaped fault- propagation folds in the overlying strata found in the Colorado National Monument 7.5' quadrangle along the front of the uplift to the west, the monocline in the map area is unbroken except at two localities. One locality displays a small asymmetrical graben that drops strata to the southwest. This faulted character of the structure dies out to the northwest into an asymmetric fault-propagation fold that also drops strata to the southwest. Probably both parts of this structure are underlain by a northeast-dipping high-angle reverse fault. The other locality displays a second similar asymmetric fold. No evidence of post-Laramide tilting or uplift exists here, but the antecedent Unaweep Canyon, only 30 km to the south-southwest of the map area, provides clear evidence of Late Cenozoic, if not Pleistocene, uplift. The major geologic hazards in the area include large landslides associated with the dip-slope-underlain, smectite-rich Brushy Basin Member of the Morrison Formation and overlying Dakota and Burro Canyon Formations. Active landslides affect the southern bank of the Colorado River where undercutting by the river and smectitic clays in the Mancos trigger landslides. The Wanakah, Morrison, and Dakota Formations and the Mancos Shale create a significant hazard to houses and other structures by containing expansive smectitic clay. In addition to seasonal spring floods associated with the Colorado and Gunnison Rivers, a serious flash flood hazard associated with sudden summer thunderstorms threatens the intermittent washes that drain the dip slope of the monocline.

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USGS2001

Geologic map of Colorado National Monument and adjacent areas, Mesa County, Colorado

New 1:24,000-scale geologic mapping in the Colorado National Monument Quadrangle and adjacent areas, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of and data for the stratigraphy, structure, geologic hazards in the area from the Colorado River in Grand Valley onto the Uncompahgre Plateau. The plateau drops abruptly along northwest-trending structures toward the northeast 800 m to the Redlands area and the Colorado River in Grand Valley. In addition to common alluvial and colluvial deposits, surficial deposits include Holocene and late Pleistocene charcoal-bearing valley-fill deposits, late to middle Pleistocene river-gravel terrace deposits, Holocene to middle Pleistocene younger, intermediate, and old fan-alluvium deposits, late to middle Pleistocene local gravel deposits, Holocene to late Pleistocene rock-fall deposits, Holocene to middle Pleistocene young and old landslide deposits, Holocene to late Pleistocene sheetwash deposits and eolian deposits, and Holocene Cienga-type deposits. Only the lowest part of the Upper Cretaceous Mancos Shale is exposed in the map area near the Colorado River. The Upper and Lower? Cretaceous Dakota Formation and the Lower Cretaceous Burro Canyon Formation form resistant dipslopes in the Grand Valley and a prominent ridge on the plateau. Less resistant strata of the Upper Jurassic Morrison Formation consisting of the Brushy Basin, Salt Wash, and Tidwell Members form slopes on the plateau and low areas below the mountain front of the plateau. The Middle Jurassic Wanakah Formation nomenclature replaces the previously used Summerville Formation. Because an upper part of the Middle Jurassic Entrada Formation is not obviously correlated with strata found elsewhere, it is therefore not formally named; however, the lower rounded cliff former Slickrock Member is clearly present. The Lower Jurassic silica-cemented Kayenta Formation forms the cap rock for the Lower Jurassic carbonate-cemented Wingate Sandstone, which forms the impressive cliffs of the monument. The Upper Triassic Chinle Formation was deposited on the eroded and weathered Middle Proterozoic meta-igneous gneiss, pegmatite dikes, and migmatitic gneiss. Structurally the area is deceptively challenging. Nearly flat-lying strata on the plateau are folded by northwest-trending fault-propagation folds into at least two S-shaped folds along the mountain front of the plateau. Strata under Grand Valley dip at about 6 degrees to the northeast. In the absence of local evidence, the uplifted plateau is attributed to Laramide deformation by dated analogous structures elsewhere in the Colorado Plateau. The major exposed fault records high-angle reverse relationships in the basement rocks but dissipates strain as a triangular zone of distributed microfractures and cataclastic flow into overlying Mesozoic strata that absorb the fault strain, leaving only folds. Evidence for younger, probably late Pliocene or early Pleistocene, uplift does exist at the antecedent Unaweep Canyon south and east of the map area. To what degree this younger deformation affected the map area is unknown. Several geologic hazards affect the area. Middle and late Pleistocene landslides involving the smectite-bearing Brushy Basin Member of the Morrison Formation are extensive on the plateau and common in the Redlands below the plateau. Expansive clay in the Brushy Basin and other strata create foundation stability problems for roads and homes. Flash floods create a serious hazard to people on foot in narrow canyons in the monument and to homes close to water courses downstream from narrow restrictions close to the monument boundary.

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USGS1954

Geology of the Juanita Arch quadrangle, Mesa county, Colorado

The Juanita Arch quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore ro large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstone of favorable construction.

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USGS1953

Geology of the Calamity Mesa quadrangle, Mesa county, Colorado

The Calamity Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks the range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

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USGS1953

Geology of the Gateway quadrangle, Mesa county Colorado

The Gateway quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

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USGS1953

Geology of the Pine Mountain quadrangle, Mesa county, Colorado

The Pine Mountain quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from Paleozoic to Quaternary. Over mush of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in sizer from irregular masses containing only a few ton of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

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USGS1952

Carnotite resources of Club Mesa, Montrose County, Colorado

Club Mesa is 1 mile west of Uravan, Montrose County, Colo. About 200,000 short tons of carnotite ore containing an estimated 0.45 percent U 3 O 8 and 2.1 percent V 2 O 5 has been mined from the mesa. This production represents about one-fifth of the carnotite ore mined from the Colorado Plateau. All the principal deposits on the mesa are in the main ore-bearing sandstone which is in the top part of the Salt Wash sandstone member of the Jurassic Morrison formation. The deposits are in tabular masses of uneven thickness lying more or less parallel to the enclosing strata. The ore consists mainly of sandstone impregnated with carnotite and vanadiferous clay minerals. The sandstone near the deposits is generally over 30 feet in thickness, contains noticeable quantities of carbon, and vivid patches of limonite (?) stain. Also near ore deposits, the mudstone in contact with the sandstone is altered from red to gray or green through a thickness of 3 or 4 feet. Certain linear features of the ore bodies and of favorable parts of the main ore-bearing sandstone offer clues by their orientation to extensions of known ore bodies and of favorable ground. These features on Club Mesa trend mostly east to northeast. Between March 6, 1948, and January 22, 1952, the U.S. Geological Survey drilled 651 holes for a total of 167,495 feet. As a result of this drilling, 18 deposits were discovered and partly outlined. These range in size from 200 to 55,000 short tons of indicated ore reserves and are in layers 1 foot or more thick containing 0.10 percent or more U 3 O 8 or 1.0 percent or more V 2 O 5 . About 85 percent of this ore is in public land; the remainder is in claims owned by the United States Vanadium Co. Reserves in deposits known from drill holes or exposures are classed as indicated or inferred, and those in deposits that are predicted solely on geologic evidence are classed as potential. The tons of indicated and inferred reserves and the pounds of contained U 3 O 8 and V 2 O 5 are summarized in table 1. These reserves are subdivided also by thickness and grade cutoffs. At the higher grade cutoff, reserve figures express approximately the tonnage and grade of material that might actually be mined from these deposits under 1951 conditions. Indicated and inferred reserves of this type total 198,000 short tons, averaging 0.35 percent U 3 O 8 and 1.8 percent V 2 O 5, and contain 1,1,372,000 pounds of U 3 O 8 and 7,260,000 pounds of V 2 O 5. These reserves are based on Geological Survey drilling. Potential reserves are predicted to total about 40,000 short tons, averaging about 0.35 percent U 3 O 8 and 1.9 percent V 2 O 5 . No additional exploration on Club Mesa is planned by the Geological Survey, but exploration by private companies is recommended.

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USGS1952

Carnotite resources of Outlaw Mesa, Mesa County, Colorado

The U.S. Geological Survey explored Outlaw Mesa for carnotite deposits from 1949 through 1951 with 1,302 diamond-drill holes that totaled 222,150 feet. Total production from Outlaw Mesa from 1914 through 1951 was about 30,000 short tons of carnotite ore, having an estimated grade of about 0.40 percent U3O8 and 1.7 percent V205. The known carnotite deposits are in a number of sandstone lenses in the upper part of the Salt Wash sandstone member of the Jurassic Morrison formation. The deposits are mainly impregnations of sandstone by carnotite and vanadium-bearing clay minerals. Commonly, the deposits are irregular tabular layers or pod-like or crescentic masses ("rolls") connected by thin layers of mineralized rock. The deposits and rolls have a dominant northeasterly trend. Useful criteria for recognizing-sandstone that might contain mineralized rock are: (1) thick, light-brown sandstone, (2) gray mudstone at the base of and in this sandstone, and (3) abundant carbonaceous material. The indicated and inferred reserves of carnotite-bearing material, and the pounds of contained U308 and V205 are summarized in table 1. Potential reserves, whose existence is based on geologic evidence alone, are estimated to total about 80,000 short tones, averaging about 0.35 percent U308 and 1.5percent V205. No further exploration by the Geological Survey is planned; however, additional drilling by private operators is recommended, particularly in ground underlain by mineralized rock.

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USGS1952

Preliminary report on diamond-drill exploration on Outlaw Mesa, Mesa County, Colorado

Outlaw Mesa is northeast of the Dolores River, about 10 miles southeast of Gateway, Mesa County, Colo. It is an oval-shaped area of about 17 square miles lying mostly within T. 50 N., R. 17 W«, and T. 50 No, R. 18 W., New Mexico principal meridian. The area is accessible by three unimproved roads from Colorado Highway 141. The altitude of the mesa ranges from about 5,500 feet to over 7,000 feet. Total production from Outlaw Mesa from 1914 to 1949 was about 4,000 tons of carnotite ore, having an estimated grade of about 0.50 percent U30Q and 2.5 percent V 2 O 5 . The production from 1949 to October 1951 was about 18,000 tons, having an estimated grade of about 0.35 percent U 3 O 8 and 1.6 percent V 2 O 5 . About 80 percent of the production from 1949 to October 1951 was from deposits discovered by U. S. Geological Survey diamond-drilling in public land, now leased to the Climax Uranium Co. A more complete history of mining and production OE Outlaw Mesa has been given in earlier reports. The results of Geological Survey exploration on Outlaw Mesa are summarized in this preliminary report. A final and more comprehensive report will be transmitted later. No additional drilling is planned.

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USGS1951

Carnotite resources of the Calamity group area, Mesa County, Colorado

The Calamity group area, which includes 28 unpatented Government claims and enclosed fractions of public domain, lies along the east rim of Calamity Mesa, Mesa County, Colo. From 1915 through 1944, about 10,000 tons of carnotite ore, averaging about 1.0 percent U 3 O 8 and 2.5 percent V 2 O 5 , was produced from mines in this group (tons in this report are short tons). Production from this area from August 1949 to January 1, 1951, totaled 8,100 tons of ore with an average grade of 0.36 percent U 3 O 8 and 1.66 percent V 2 O 5 , containing about 58,600 pounds of U 3 O 8 and 268,000 pounds of V 2 O 5.

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USGS1951

Preliminary report on the correlation between gamma-ray logs and permeability logs of the ore-bearing sandstone in the Morrison Formation Calamity Mesa, Mesa County, Colorado

A study of the hydrologic properties and geologic relations of the ore-bearing sandstone in the Salt Wash sandstone member of the Morrison formation has been undertaken because uranium and vanadium are believed to have been introduced into the sandstone by circulating ground water. This report describes the geologic and hydrologic characteristics of the ore-bearing sandstone as determined in the core samples from three diamond-drill holes on Calamity Mesa, Mesa County, Colo., and correlates these data with localized gamma-ray activity detected in the three drill holes. These data are illustrated on figure 1 by the combined geologic, permeability, porosity, and gamma-ray logs. This study is part of the program of geologic studies on the Colorado Plateau conducted by the Geological Survey on behalf of the Atomic Energy Commission. This preliminary report describing the results of this study has benefited from the suggestions and criticisms of L. B. Riley of the Geological Survey.

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