Robert Zielinski
Robert Zielinski is currently an emeritus-volunteer with the uranium research group in Denver. He serves as an advisor/reviewer/mentor and provides support of field work, sample archiving, web page development, and the uranium research group library.
Robert Zielinski is a research chemist (retired-emeritus) in the USGS Central Energy Resources Team in Denver, Colorado. He earned a B.A. in chemistry from Rutgers University in 1967 and a Ph.D. in geochemistry from M.I.T. in 1972. He was awarded a National Research Council Postdoctoral Fellowship with the USGS from 1972-1973, and accepted a permanent research position in 1974. His research interests include the use of trace-element geochemistry and isotopic measurements to describe natural geologic processes and to evaluate the environmental impacts of energy resource development.
Robert Zielinski originally applied his expertise in trace-element geochemistry to better understand natural processes such as igneous rock petrogenesis, trace element mobility during alteration and weathering of volcanic rocks, uranium source rock evaluation, and uranium uptake in wetlands. More recently he has used trace elements and various stable and radiogenic isotopes to evaluate the environmental impacts of excess nutrients in the Everglades, historic uranium mining in the western U.S., historic coal mining in Colorado, and oil and gas development at various sites throughout the U.S. including two USGS research sites in Osage County, Oklahoma. Sampled media have included drill cores, soil, lake sediments, surface water, ground water, peat, coal fly ash, mine waste rock, and living vegetation. He is a recognized expert on the geochemistry of uranium and its decay products and on the use of uranium and radium isotopes to identify environmental impacts from anthropogenic sources of pollution such as uranium mill tailings, abandoned uranium mines and mine waste, radium-rich oilfield scales, and U-bearing phosphate fertilizers.
Dr. Zielinski is first author of 65 scientific publications and has presented a similar number of talks at national and international scientific meetings. He has served as a Project Chief, Section Leader, and coordinator of research. He served for thirteen years as an Associate Editor for Applied Geochemistry.
Currently he is an emeritus-volunteer with the uranium research group in Denver. He serves as an advisor/reviewer/mentor and provides support of field work, sample archiving, web page development, and the uranium research group library.
Science and Products
Tuffaceous sediments as source rocks for uranium: A case study of the White River Formation, Wyoming
The mobility and distribution of heavy metals during the formation of first cycle red beds
Leachability of uranium and other elements from freshly erupted volcanic ash
Instrumental neutron activation analyses of Cenozoic volcanic rocks, phenocrysts, and associated intrusions from the southern Rocky Mountains and adjacent areas
Leaching characteristics of ash from the May 18, 1980, eruption of Mount St. Helens Volcano, Washington
Margaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.
The mobility of uranium and other elements during alteration of rhyolite ash to montmorillonite: A case study in the Troublesome Formation, Colorado, U.S.A.
Uraniferous opal, Virgin Valley, Nevada: conditions of formation and implications for uranium exploration
Water-soluble material on aerosols collected within volcanic eruption clouds ( Fuego, Pacaya, Santiaguito, Guatamala).
The chemical and isotopic record of rock-water interaction in the Sherman Granite, Wyoming and Colorado
Leachability of uranium and other elements from freshly erupted volcanic ash
Uranium contents of glassy and devitrified andesites and dacites, Mount Mazama, Oregon
Science and Products
- Data
- Publications
Filter Total Items: 84
Tuffaceous sediments as source rocks for uranium: A case study of the White River Formation, Wyoming
Fine-grained tuffaceous sediments of the White River Formation (Oligocene) are evaluated as a possible source of uranium for the sedimentary uranium deposits of Wyoming. The evaluation is based upon a model in which volcanic glass is considered to be a major host of uranium and thorium and in which uranium and silica are released during alteration of glass to montmorillonite. The evaluation schemeAuthorsR. A. ZielinskiThe mobility and distribution of heavy metals during the formation of first cycle red beds
Holocene-Pliocene sequence sampled in northern Baja California. Geochemical data supported by petrographic, X-ray, and SEM observations of mineralogical transformations, fission-track radiography, and uranium decay series measurements. Results indicate that metal content of the studied samples is inherited from constituent detrital minerals and that reddening of whole-rock samples does not promoteAuthorsR. A. Zielinski, S. Bloch, T.R. WalkerLeachability of uranium and other elements from freshly erupted volcanic ash
A study of leaching of freshly erupted basaltic and dacitic air-fall ash and bomb fragment samples, unaffected by rain, shows that glass dissolution is the dominant process by which uranium is initially mobilized from air-fall volcanic ash. Si, Li, and V are also preferentially mobilized by glass dissolution. Gaseous transfer followed by fixation of soluble uranium species on volcanic-ash particleAuthorsD. B. Smith, R. A. Zielinski, W.I. RoseInstrumental neutron activation analyses of Cenozoic volcanic rocks, phenocrysts, and associated intrusions from the southern Rocky Mountains and adjacent areas
No abstract available.AuthorsPeter W. Lipman, H. R. Bowman, R. Knight, Hugh T. Millard, J.S. Pallister, K. Street, H. Wollenberg, R. A. ZielinskiLeaching characteristics of ash from the May 18, 1980, eruption of Mount St. Helens Volcano, Washington
Leaching of freshly erupted air-fall ash, unaffected by rain, from the May 18, 1.980,eruption of Mount St. Helens volcano, Washington, shows that Ca 2+, Na+, Mg+, SO4 2-, and Cl- are the predominant chemical species released on first exposure of the ash to water. Extremely high correlation of Ca with SO4 and Na with Cl in water leachates suggests the presence of CaSO4 and NaCl salts on the ash. ThAuthorsDavid Burl Smith, Robert A. Zielinski, Howard E. TaylorMargaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.
Margaritasite, (Cs,K,H3O)2(UO2)2V2O8.nH2O (where Cs > K, H3O and n approx 1), a 10.514, b 8.425, c 7.25 A, beta 106.01o, P21/a, Z = 2, is a newly recognized uranium ore mineral named for the Margaritas deposit, Pena Blanca uranium district, Chihuahua, Mexico, at which it was discovered. A Cs-rich analogue of carnotite, margaritasite is the natural equivalent of synthetic Cs-uranyl vanadate (A.M. 4AuthorsK. J. Wenrich, P. J. Modreski, R. A. Zielinski, J. L. SeeleyThe mobility of uranium and other elements during alteration of rhyolite ash to montmorillonite: A case study in the Troublesome Formation, Colorado, U.S.A.
An unusual occurrence of juxtaposed glassy and clay-altered ash was sampled to estimate the degree and type of element mobility during alteration of glass to montmorillonite. The results are particularly interesting in that major mobilization of uranium is indicated. Closely spaced samples of glassy and montmorillonitic ash were collected from the same 20-50 cm thick stratigraphic horizon in the TAuthorsR. A. ZielinskiUraniferous opal, Virgin Valley, Nevada: conditions of formation and implications for uranium exploration
Uraniferous, fluorescent opal, which occurs in tuffaceous sedimentary rocks at Virgin Valley, Nevada, records the temperature and composition of uranium-rich solutions as well as the time of uranium-silica coprecipitation. Results are integrated with previous geologic and geochronologic data for the area to produce a model for uranium mobility that may be used to explore for uranium deposits in siAuthorsR. A. ZielinskiWater-soluble material on aerosols collected within volcanic eruption clouds ( Fuego, Pacaya, Santiaguito, Guatamala).
In Feb. and March of 1978, filter samplers mounted on an aircraft were used to collect the aerosol fraction of the eruption clouds from three active Guatemalan volcanoes (Fuego, Pacaya, and Santiaguito). The elements dissolved in the aqueous extracts represent components of water-soluble material either formed directly in the eruption cloud or derived from interaction of ash particles and aerosolAuthorsD. B. Smith, R. A. Zielinski, W.I. Rose, B.J. HuebertThe chemical and isotopic record of rock-water interaction in the Sherman Granite, Wyoming and Colorado
Chemical, isotopic, radiographic, and rock-leaching data are combined to describe the effects of rock-water interactions in core samples of petrographically fresh, 1.43 b.y.-old Sherman Granite. The data serve to identify sensitive indicators of incipient alteration and to estimate the degree, pathways, and timing of element mobilization. Unfractured core samples of Sherman Granite are remarkablyAuthorsR. A. Zielinski, Z. E. Peterman, J. S. Stuckless, J.N. Rosholt, Ignatius T. NkomoLeachability of uranium and other elements from freshly erupted volcanic ash
A study of leaching of freshly erupted basaltic and dacitic air-fall ash and bomb fragment samples, unaffected by rain, shows that glass dissolution is the dominant orocess by which uranium is initially mobilized from air-fall volcanic ash. Si, Li, and V are also Preferentially mobilized by glass dissolution. Gaseous transfer followed by fixation of soluble uranium species on volcanic-ash particleAuthorsDavid B. Smith, Robert A. Zielinski, William I. RoseUranium contents of glassy and devitrified andesites and dacites, Mount Mazama, Oregon
By direct comparison of devitrified and granophyrically crystallized specimens with nonhydrated glassy materials from the same units, Rosholt and coworkers (Rosholt and Noble, 1969; Rosholt et al., 1971) showed that specimens of primarily crystallized but otherwise unaltered peralkaline and subalkaline rhyolite from the western United States had lost from 30 to 80 percent of the uranium that theyAuthorsD. C. Noble, W.I. Rose, Robert A. Zielinski