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Title: Reconnaissance of Colorado Front Range bogs for uranium and other elements

Abstract

Alpine bogs form along spring-fed valley floors and in steam drainages restricted by moraines, slides, and beaver dams. The bogs are generally young (Holocene) and contain a few tens of centimeters to several meters of peat and organic-rich muck. Organic matter has a great affinity for cations such as uranium; the geochemical enrichment factor between the peats and uraniferous ground water can approach 10,000 to 1. Because the bog sediments are geologically young, the uranium is in gross disequilibrium and has low radioactivity, thus it is undetectable by ground and aerial gamma surveys. Communities that derive a part of their water supplies from drainages containing uraniferous bogs face a potential health threat because the uranium is loosely bound and may easily be remobilized by ground water moving through the bogs. Reconnaissance sampling of bogs was conducted in the Colorado Front Range from the South Park area to the Colorado-Wyoming state line. Several bogs have uranium concentrations of 1000-3000 ppm, but most bogs have uranium concentrations in the 10-100 ppm range. Zinc concentrations of 100-1000 ppm are found in some bogs and many other metallic elements are present in concentrations between 10 and 100 ppm. Concentrations between 100 and 1000 ppmmore » of some of the rare earth elements (e.g., Ce, La, Nd, Yb) were found in the Cripple Creek area.« less

Authors:
; ;
Publication Date:
Research Org.:
Geological Survey, Reston, VA
OSTI Identifier:
5862779
Report Number(s):
CONF-870915-
Journal ID: CODEN: AABUD; TRN: 88-001091
Resource Type:
Conference
Resource Relation:
Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States); Journal Volume: 71:8; Conference: American Association of Petroleum Geologists Rocky Mountain Section meeting, Boise, ID, USA, 13 Sep 1987
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; COLORADO; URANIUM DEPOSITS; EXPLORATION; GEOCHEMICAL SURVEYS; RARE EARTHS; ZINC; ELEMENTS; FEDERAL REGION VIII; GEOLOGIC DEPOSITS; METALS; MINERAL RESOURCES; NORTH AMERICA; RESOURCES; SURVEYS; USA; 050100* - Nuclear Fuels- Reserves, Exploration, & Mining

Citation Formats

Owen, D.E., Schumann, R.R., and Otton, J.K. Reconnaissance of Colorado Front Range bogs for uranium and other elements. United States: N. p., 1987. Web.
Owen, D.E., Schumann, R.R., & Otton, J.K. Reconnaissance of Colorado Front Range bogs for uranium and other elements. United States.
Owen, D.E., Schumann, R.R., and Otton, J.K. 1987. "Reconnaissance of Colorado Front Range bogs for uranium and other elements". United States. doi:.
@article{osti_5862779,
title = {Reconnaissance of Colorado Front Range bogs for uranium and other elements},
author = {Owen, D.E. and Schumann, R.R. and Otton, J.K.},
abstractNote = {Alpine bogs form along spring-fed valley floors and in steam drainages restricted by moraines, slides, and beaver dams. The bogs are generally young (Holocene) and contain a few tens of centimeters to several meters of peat and organic-rich muck. Organic matter has a great affinity for cations such as uranium; the geochemical enrichment factor between the peats and uraniferous ground water can approach 10,000 to 1. Because the bog sediments are geologically young, the uranium is in gross disequilibrium and has low radioactivity, thus it is undetectable by ground and aerial gamma surveys. Communities that derive a part of their water supplies from drainages containing uraniferous bogs face a potential health threat because the uranium is loosely bound and may easily be remobilized by ground water moving through the bogs. Reconnaissance sampling of bogs was conducted in the Colorado Front Range from the South Park area to the Colorado-Wyoming state line. Several bogs have uranium concentrations of 1000-3000 ppm, but most bogs have uranium concentrations in the 10-100 ppm range. Zinc concentrations of 100-1000 ppm are found in some bogs and many other metallic elements are present in concentrations between 10 and 100 ppm. Concentrations between 100 and 1000 ppm of some of the rare earth elements (e.g., Ce, La, Nd, Yb) were found in the Cripple Creek area.},
doi = {},
journal = {AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)},
number = ,
volume = 71:8,
place = {United States},
year = 1987,
month = 8
}

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  • The authors recovered sediment cores 3.1 m long from Blue Lake ([approximately]37m water depth, [approximately]3,445m a.s.l., 40[degree]5 minutes 20 seconds N, 105[degree]37 minutes 08 seconds W) and 2.7m long from Lake Dorothy ([approximately]35m water depth, [approximately]3,675m a.s.l., 40[degree]00 minutes 46 seconds N, 105[degree]41 minutes 11 seconds W). A light-weight percussion coring system suspended from perlon ropes was used because of sediment thicknesses, water depths, and ski-backpacking requirements. Lake ice provided a stable coring platform. One purpose of the project is provision of a high-resolution record of environmental change in the subalpine/alpine ecotone during the Holocene, under the auspices of themore » Niwot Ridge Long-Term Ecological Research program. The sediment cores also provide minimum-limiting radiocarbon ages for deglaciation of cirques and the deposits that impound their tarns. Here the authors report on this second purpose. The Blue Lake core bottomed in sandy, gray, inorganic sediment, presumably glacial diamict. A bulk sample from 2.8--2.9m depth yielded a conventional radiocarbon age of 12,275[+-]345 yrs BP. Thus, ice retreated from the site by 12 ka. Since 12 ka both glacial and rock-glacial sediments have been deposited upvalley; some of these events may be recognized in the core. In contrast, the Lake Dorothy core did not penetrate gray inorganic diamict and is entirely organic-rich. A bulk sample from 2.65--2.7m depth yielded a conventional radiocarbon age of 10,910 [+-] 320 yrs BP. Thus, the moraines impounding the lake are 2--3 times older than suggested by a combination of relative-age methods and one radiocarbon age from surface sediments.« less
  • Aeromagnetic and aeroradioactivity data acquired along 1-mile spaced flight lines at 400 ft above terrain during the DOE-NURE program have been compiled to provide a synoptic overview of the Colorado Front Range between 38[degree] and 41[degree] N. These data constitute one of the largest blocks of systematically collected data of this type in the US. Features related to surface geology clearly shown on the aeromagnetic map include major northeast-trending Precambrian shear zones, trends of steeply dipping foliation (but not foliation with shallow dip), and a variety of Proterozoic, Mesozoic and Tertiary plutons, some of which show hitherto unrecognized internal subdivisions.more » A conspicuous north-south trending discontinuity in the western part of the Precambrian core of the range does not correlate closely with surface geology and may be related to downward steepening of east-dipping Laramide thrust faults that bound the Precambrian rocks along the west side of the range. Seismic and/or gravity data may help test this interpretation. The aeroradioactivity maps show many details of the outcropping plutons, including major differences in U, Th, K contents of plutons of the same general age, subtle compositional gradients within individuals plutons, and the location of individual intrusive centers in the Pikes Peak batholith. Distribution of alluvium derived from high U-Th plutons and trends of Tertiary paleovalleys containing high-U ash-flow tuffs are also locally evident. Compilations of geophysical data of this type and scale provide an invaluable overview for studies of regional tectonics, structure, and plutonism in crystalline terranes, even where surface geology is reasonably well known.« less
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  • An important aspect of the US Department of Energy's Atmospheric Studies in Complex Terrain (ASCOT) program is the development and evaluation of numerical models that predict transport and diffusion of pollutants in complex terrain. Operational mesoscale modeling of the transport of pollutants in complex terrain will become increasingly practical as computational costs decrease and additional data from high-resolution remote sensing instrumentation networks become available during the 1990s. Four-dimensional data assimilation (4DDA) techniques are receiving a great deal of attention recently not only to improve the initial conditions of mesoscale forecast models, but to create high-quality four-dimensional mesoscale analysis fields thatmore » can be used as input to air-quality models. In this study, a four-dimensional data assimilation technique based on Newtonian relaxation is incorporated into the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) and evaluated using data taken from one experiment of the 1991 ASCOT field study along the front range of the Rockies in Colorado. The main objective of this study is to compare the observed surface concentrations with those predicted by a Lagrangian particle dispersion model and to demonstrate the effect of data assimilation on the simulated plume. In contrast to pervious studies in which the smallest horizontal grid spacing was 10 km (Stauffer and Seaman, 1991) and 8 km (Yamada and Hermi, 1991), data assimilation is applied in this study to domains with a horizontal grid spacing as small as 1 km.« less