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
Whole rock geochemistry and comparative leachability of variably bleached and red sandstones of the Permian Cutler Formation, Mesa County, Colorado
Forty samples of outcropping rock samples were collected from the Permian Cutler Formation exposed in the Sinbad Valley, Mesa County, Colorado by USGS volunteer Jon Thorson. This sample set includes 13 pairs of co-existing red unaltered and yellow-grey bleached sandstone. The decimal latitude and longitude locations of the sample collection sites are listed in the "All_Rock_Data" worksheet in the
Location, description, and whole rock geochemistry of rocks from the Coles Hill uranium deposit and vicinity, south-central Virginia
Major-element and trace-element concentrations in 76 core samples and seven surface samples of rocks from the Coles Hill uranium deposit and vicinity, Pittsylvania County, south-central Virginia are presented as tabular digital data. The Coles Hill deposit is the largest unmined uranium deposit in the United States. The data were collected to 1) characterize the chemistry of variably uranium-miner
Stratigraphic, geochemical, and hydrologic data for the Boston Peak wetland, Larimer County, CO, USA
Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland are combined with hydrologic measurements to define the important controls on uranium (U) supply and uptake. The major source of U to the wetland is groundwater flowing through locally fractured and faulted granite gneiss of Proterozoic age. Dissolved U concentrations in f
Filter Total Items: 84
Sandstone-hosted uranium deposits of the Colorado Plateau, USA
More than 4,000 sandstone-hosted uranium occurrences host over 1.2 billion pounds of mined and in situ U3O8 throughout the Colorado Plateau. Most of the resources are in two distinct mineral systems with deposits hosted in the Triassic Chinle and Jurassic Morrison Formations. In the Chinle mineral system, base metal sulfides typically accompany mineralization. The Morrison mineral system is charac
Authors
Susan M. Hall, Bradley S. Van Gosen, Robert A. Zielinski
The Coles Hill uranium deposit, Virginia, USA: Geology, geochemistry, geochronology, and genetic model
The Coles Hill uranium deposit with an indicated resource of about 130 million lbs. of U3O8 is the largest unmined uranium deposit in the United States. The deposit is hosted in the Taconian (approximately 480 – 450 Ma) Martinsville igneous complex, which consists of the Ordovician Leatherwood Granite (granodiorite) and Silurian Rich Acres Formation (diorite). The host rock was metamorphosed to or
Authors
Susan M. Hall, J.S. Beard, Christopher J. Potter, R.J. Bodnar, Leonid A. Neymark, James B. Paces, Craig A. Johnson, G.N. Breit, Robert A. Zielinski, G. J. Aylor
Calcrete uranium deposits in the Southern High Plains, USA
The Southern High Plains (SHP) is a new and emerging U.S. uranium province. Here, uranyl vanadates form deposits in Pliocene to Pleistocene sandstone, dolomite, and limestone. Fifteen calcrete uranium occurrences are identified; two of these, the Buzzard Draw and Sulfur Springs Draw deposits, have combined in-place resources estimated at about 4 million pounds of U3O8. Ore minerals carnotite and f
Authors
Susan Hall, Bradley S. Van Gosen, James B. Paces, Robert A. Zielinski
Uranium delivery and uptake in a montane wetland, north-central Colorado, USA
Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland are combined with hydrologic measurements to define the important controls on uranium (U) supply and uptake. The major source of U to the wetland is groundwater flowing through locally fractured and faulted granite gneiss of Proterozoic age. Dissolved U concentrations in f
Authors
R. Randall Schumann, Robert A. Zielinski, James K. Otton, Michael P. Pantea, William H. Orem
Assessment of undiscovered sandstone-hosted uranium resources in the Texas Coastal Plain, 2015
The U.S. Geological Survey estimated a mean of 220 million pounds of recoverable uranium oxide (U3O8 ) remaining as potential undiscovered resources in southern Texas. This estimate used a geology-based assessment method for Tertiary sandstone-hosted uranium deposits in the Texas Coastal Plain sedimentary strata (fig.1).
Authors
Mark J. Mihalasky, Susan M. Hall, Jane M. Hammarstrom, Kathleen R. Tureck, Mark T. Hannon, George N. Breit, Robert A. Zielinski, Brent Elliott
Persistent U(IV) and U(VI) following in-situ recovery (ISR) mining of a sandstone uranium deposit, Wyoming, USA
Drill-core samples from a sandstone-hosted uranium (U) deposit in Wyoming were characterized to determine the abundance and distribution of uranium following in-situ recovery (ISR) mining with oxygen- and carbon dioxide-enriched water. Concentrations of uranium, collected from ten depth intervals, ranged from 5 to 1920 ppm. A composite sample contained 750 ppm uranium with an average oxidation st
Authors
Tanya J. Gallegos, Kate M. Campbell, Robert A. Zielinski, P.W. Reimus, J.T. Clay, N. Janot, J. J. Bargar, William Benzel
Radionuclides, trace elements, and radium residence in phosphogypsum of Jordan
Voluminous stockpiles of phosphogypsum (PG) generated during the wet process production of phosphoric acid are stored at many sites around the world and pose problems for their safe storage, disposal, or utilization. A major concern is the elevated concentration of long-lived 226Ra (half-life = 1,600 years) inherited from the processed phosphate rock. Knowledge of the abundance and mode-of-occurre
Authors
R. A. Zielinski, M. S. Al-Hwaiti, J. R. Budahn, J. F. Ranville
Geology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah - Indications of contaminant migration
The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957-68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the natur
Authors
James K. Otton, Robert A. Zielinski, Robert Horton
Distribution and mode of occurrence of radionuclides in phosphogypsum derived from Aqaba and Eshidiya Fertilizer Industry, South Jordan
Phosphogypsum (PG) is a by-product of the chemical reaction called the "wet process" whereby sulphuric acid reacts with phosphate rock (PR) to produce phosphoric acid, needed for fertilizer production. Through the wet process, some impurities naturally present in the PR become incorporated in PG, including U decay-series radionuclides, are the main important concern which could have an effect on t
Authors
M. S. Al-Hwaiti, R. A. Zielinski, J.R. Bundham, J. F. Ranville, P.E. Ross
Uranium in surface waters and sediments affected by historical mining in the Denver West 1:100,000 Quadrangle, Colorado
Geochemical sampling of 82 stream waters and 87 stream sediments within mountainous areas immediately west of Denver, Colorado, was conducted by the U.S. Geological Survey in October 1994. The primary purpose was to evaluate regionally the effects of geology and past mining on the concentration and distribution of uranium. The study area contains uranium- and thorium-rich bedrock, numerous nonecon
Authors
Robert A. Zielinski, James K. Otton, R. Randall Schumann, Laurie Wirt
Geologic controls on movement of produced-water releases at US geological survey research Site A, Skiatook lake, Osage county, Oklahoma
Highly saline produced water was released from multiple sources during oil field operations from 1913 to 1973 at the USGS research Site A on Skiatook Lake in northeastern Oklahoma. Two pits, designed to hold produced water and oil, were major sources for release of these fluids at the site. Produced water spills from these and other features moved downslope following topography and downdip by perc
Authors
James K. Otton, Robert A. Zielinski, Bruce D. Smith, Marvin M. Abbott
Mode of occurrence of arsenic in feed coal and its derivative fly ash, Black Warrior Basin, Alabama
An arsenic-rich (As = 55 ppm) bituminous feed coal from the Black Warrior Basin, Alabama and its derivative fly ash (As = 230 ppm) were selected for detailed investigation of arsenic residence and chemical forms. Analytical techniques included microbeam analysis, selective extraction, and As K-edge X-ray absorption fine-structure (XAFS) spectroscopy. Most As in the coal is contained in a generatio
Authors
R. A. Zielinski, A. L. Foster, G.P. Meeker, I. K. Brownfield
Science and Products
- Data
Whole rock geochemistry and comparative leachability of variably bleached and red sandstones of the Permian Cutler Formation, Mesa County, Colorado
Forty samples of outcropping rock samples were collected from the Permian Cutler Formation exposed in the Sinbad Valley, Mesa County, Colorado by USGS volunteer Jon Thorson. This sample set includes 13 pairs of co-existing red unaltered and yellow-grey bleached sandstone. The decimal latitude and longitude locations of the sample collection sites are listed in the "All_Rock_Data" worksheet in theLocation, description, and whole rock geochemistry of rocks from the Coles Hill uranium deposit and vicinity, south-central Virginia
Major-element and trace-element concentrations in 76 core samples and seven surface samples of rocks from the Coles Hill uranium deposit and vicinity, Pittsylvania County, south-central Virginia are presented as tabular digital data. The Coles Hill deposit is the largest unmined uranium deposit in the United States. The data were collected to 1) characterize the chemistry of variably uranium-minerStratigraphic, geochemical, and hydrologic data for the Boston Peak wetland, Larimer County, CO, USA
Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland are combined with hydrologic measurements to define the important controls on uranium (U) supply and uptake. The major source of U to the wetland is groundwater flowing through locally fractured and faulted granite gneiss of Proterozoic age. Dissolved U concentrations in f - Publications
Filter Total Items: 84
Sandstone-hosted uranium deposits of the Colorado Plateau, USA
More than 4,000 sandstone-hosted uranium occurrences host over 1.2 billion pounds of mined and in situ U3O8 throughout the Colorado Plateau. Most of the resources are in two distinct mineral systems with deposits hosted in the Triassic Chinle and Jurassic Morrison Formations. In the Chinle mineral system, base metal sulfides typically accompany mineralization. The Morrison mineral system is characAuthorsSusan M. Hall, Bradley S. Van Gosen, Robert A. ZielinskiThe Coles Hill uranium deposit, Virginia, USA: Geology, geochemistry, geochronology, and genetic model
The Coles Hill uranium deposit with an indicated resource of about 130 million lbs. of U3O8 is the largest unmined uranium deposit in the United States. The deposit is hosted in the Taconian (approximately 480 – 450 Ma) Martinsville igneous complex, which consists of the Ordovician Leatherwood Granite (granodiorite) and Silurian Rich Acres Formation (diorite). The host rock was metamorphosed to orAuthorsSusan M. Hall, J.S. Beard, Christopher J. Potter, R.J. Bodnar, Leonid A. Neymark, James B. Paces, Craig A. Johnson, G.N. Breit, Robert A. Zielinski, G. J. AylorCalcrete uranium deposits in the Southern High Plains, USA
The Southern High Plains (SHP) is a new and emerging U.S. uranium province. Here, uranyl vanadates form deposits in Pliocene to Pleistocene sandstone, dolomite, and limestone. Fifteen calcrete uranium occurrences are identified; two of these, the Buzzard Draw and Sulfur Springs Draw deposits, have combined in-place resources estimated at about 4 million pounds of U3O8. Ore minerals carnotite and fAuthorsSusan Hall, Bradley S. Van Gosen, James B. Paces, Robert A. ZielinskiUranium delivery and uptake in a montane wetland, north-central Colorado, USA
Comprehensive sampling of peat, underlying lakebed sediments, and coexisting waters of a naturally uraniferous montane wetland are combined with hydrologic measurements to define the important controls on uranium (U) supply and uptake. The major source of U to the wetland is groundwater flowing through locally fractured and faulted granite gneiss of Proterozoic age. Dissolved U concentrations in fAuthorsR. Randall Schumann, Robert A. Zielinski, James K. Otton, Michael P. Pantea, William H. OremAssessment of undiscovered sandstone-hosted uranium resources in the Texas Coastal Plain, 2015
The U.S. Geological Survey estimated a mean of 220 million pounds of recoverable uranium oxide (U3O8 ) remaining as potential undiscovered resources in southern Texas. This estimate used a geology-based assessment method for Tertiary sandstone-hosted uranium deposits in the Texas Coastal Plain sedimentary strata (fig.1).AuthorsMark J. Mihalasky, Susan M. Hall, Jane M. Hammarstrom, Kathleen R. Tureck, Mark T. Hannon, George N. Breit, Robert A. Zielinski, Brent ElliottPersistent U(IV) and U(VI) following in-situ recovery (ISR) mining of a sandstone uranium deposit, Wyoming, USA
Drill-core samples from a sandstone-hosted uranium (U) deposit in Wyoming were characterized to determine the abundance and distribution of uranium following in-situ recovery (ISR) mining with oxygen- and carbon dioxide-enriched water. Concentrations of uranium, collected from ten depth intervals, ranged from 5 to 1920 ppm. A composite sample contained 750 ppm uranium with an average oxidation stAuthorsTanya J. Gallegos, Kate M. Campbell, Robert A. Zielinski, P.W. Reimus, J.T. Clay, N. Janot, J. J. Bargar, William BenzelRadionuclides, trace elements, and radium residence in phosphogypsum of Jordan
Voluminous stockpiles of phosphogypsum (PG) generated during the wet process production of phosphoric acid are stored at many sites around the world and pose problems for their safe storage, disposal, or utilization. A major concern is the elevated concentration of long-lived 226Ra (half-life = 1,600 years) inherited from the processed phosphate rock. Knowledge of the abundance and mode-of-occurreAuthorsR. A. Zielinski, M. S. Al-Hwaiti, J. R. Budahn, J. F. RanvilleGeology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah - Indications of contaminant migration
The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957-68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the naturAuthorsJames K. Otton, Robert A. Zielinski, Robert HortonDistribution and mode of occurrence of radionuclides in phosphogypsum derived from Aqaba and Eshidiya Fertilizer Industry, South Jordan
Phosphogypsum (PG) is a by-product of the chemical reaction called the "wet process" whereby sulphuric acid reacts with phosphate rock (PR) to produce phosphoric acid, needed for fertilizer production. Through the wet process, some impurities naturally present in the PR become incorporated in PG, including U decay-series radionuclides, are the main important concern which could have an effect on tAuthorsM. S. Al-Hwaiti, R. A. Zielinski, J.R. Bundham, J. F. Ranville, P.E. RossUranium in surface waters and sediments affected by historical mining in the Denver West 1:100,000 Quadrangle, Colorado
Geochemical sampling of 82 stream waters and 87 stream sediments within mountainous areas immediately west of Denver, Colorado, was conducted by the U.S. Geological Survey in October 1994. The primary purpose was to evaluate regionally the effects of geology and past mining on the concentration and distribution of uranium. The study area contains uranium- and thorium-rich bedrock, numerous noneconAuthorsRobert A. Zielinski, James K. Otton, R. Randall Schumann, Laurie WirtGeologic controls on movement of produced-water releases at US geological survey research Site A, Skiatook lake, Osage county, Oklahoma
Highly saline produced water was released from multiple sources during oil field operations from 1913 to 1973 at the USGS research Site A on Skiatook Lake in northeastern Oklahoma. Two pits, designed to hold produced water and oil, were major sources for release of these fluids at the site. Produced water spills from these and other features moved downslope following topography and downdip by percAuthorsJames K. Otton, Robert A. Zielinski, Bruce D. Smith, Marvin M. AbbottMode of occurrence of arsenic in feed coal and its derivative fly ash, Black Warrior Basin, Alabama
An arsenic-rich (As = 55 ppm) bituminous feed coal from the Black Warrior Basin, Alabama and its derivative fly ash (As = 230 ppm) were selected for detailed investigation of arsenic residence and chemical forms. Analytical techniques included microbeam analysis, selective extraction, and As K-edge X-ray absorption fine-structure (XAFS) spectroscopy. Most As in the coal is contained in a generatioAuthorsR. A. Zielinski, A. L. Foster, G.P. Meeker, I. K. Brownfield