Time filter

Source Type

Champaign, IL, United States

Panno S.,Illinois State Geological Survey | Hackley K.,Isotech Laboratories Inc. | Locke R.,Illinois State Geological Survey | Krapac I.,Illinois State Geological Survey | And 3 more authors.
Geochimica et Cosmochimica Acta | Year: 2013

Recently, brine samples from the Cambrian-age Mount Simon Formation (the deepest, most inaccessible sedimentary rock formation of the Illinois Basin) and the overlying Ironton-Galesville Formation were collected as part of a major research effort evaluating the feasibility of sequestration of carbon dioxide in deep geologic formations. Halide and halide/cation ratios (especially Cl/Br and Na/Br ratios) from groundwater samples collected during this investigation suggest that the brines of the Cambrian-age strata formed by the evaporation of seawater well beyond the point of halite precipitation. The Cl/Br and Na/Br ratios, the presence of Mississippi-Valley-Type (MVT) ore mineralization in close proximity to the Illinois Basin, and the tectonic history of the region and the Illinois Basin suggest that components of ore-forming brines and perhaps crystalline basement brine are likely still present within the Mount Simon Formation. Halide and cation/halide ratio plots show that these brines have mixed with and have been diluted by subaerially evaporated seawater, seawater and dilute groundwater. Movement of brines out of the Mount Simon Formation and/or exchange with brines of other formations is constrained by the overlying, siltstone- and shale-rich Eau Claire Formation, a low-permeability layer.The most plausible interpretation of the halide and halide/cation ratio data is that the brines of the Cambrian-age strata were introduced to the Illinois Basin from outside of the basin, perhaps when the Illinois Basin was connected to the Arkoma (Oklahoma and Arkansas) and Black Warrior Basins (Alabama and Mississippi) via the Reelfoot Rift during Cambrian and early Ordovician time. In addition, the presence of some percentage of high NaCl, low Cl/Br brines from the crystalline basement is suggested given the geochemical relationships of the halide and cation/halide ratios and the tectonic history of the Illinois Basin. Finally, halide and cation/halide ratios determined by this investigation, and regional geochemical evidence and hydrogeologic modeling (by others) suggest that the brines of these strata probably were affected by regional hydrothermal activity during Permian time that was responsible for the MVT ore deposits of the Midwestern U.S. Thus, the brines of the deepest strata of the Illinois Basin constitute a different, more complex type of fluid than those found elsewhere in the basin. Halide and halide-cation ratios suggest that these deep brines are dominated by residual evaporitic brine (possibly originating as ore-forming brines) with dilution by seawater and dilute groundwater. Other components may include subaerially evaporated seawater and crystalline basement brines. © 2013. Source

Dai J.,Petrochina | Xia X.,GeoIsoChem Cooperation | Li Z.,Petrochina | Coleman D.D.,Isotech Laboratories Inc. | And 14 more authors.
Chemical Geology | Year: 2012

Compound-specific carbon and hydrogen isotopic compositions of three natural gas round robins were calibrated by ten laboratories carrying out more than 800 measurements including both on-line and off-line methods. Two-point calibrations were performed with international measurement standards for hydrogen isotope ratios (VSMOW and SLAP) and carbon isotope ratios (NBS 19 and L-SVEC CO 2). The consensus δ 13C values and uncertainties were derived from the Maximum Likelihood Estimation (MLE) based on off-line measurements; the consensus δ 2H values and uncertainties were derived from MLE of both off-line and on-line measurements, taking the bias of on-line measurements into account. The calibrated consensus values in ‰ relative to VSMOW and VPDB are:NG1 (coal-related gas):Methane: δ 2H VSMOW=-185.1‰±1.2‰, δ 13C VPDB=-34.18‰±0.10‰Ethane: δ 2H VSMOW=-156.3‰±1.8‰, δ 13C VPDB=-24.66‰±0.11‰Propane: δ 2H VSMOW=-143.6‰±3.3‰, δ 13C VPDB=-22.21‰±0.11‰i-Butane: δ 13C VPDB=-21.62‰±0.12‰n-Butane: δ 13C VPDB=-21.74‰±0.13‰CO 2: δ 13C VPDB=-5.00‰±0.12‰NG2 (biogas):Methane: δ 2H VSMOW=-237.0‰±1.2‰, δ 13C VPDB=-68.89‰±0.12‰NG3 (oil-related gas):Methane: δ 2H VSMOW=-167.6‰±1.0‰, δ 13C VPDB=-43.61‰±0.09‰Ethane: δ 2H VSMOW=-164.1‰±2.4‰, δ 13C VPDB=-40.24‰±0.10‰Propane: δ 2H VSMOW=-138.4‰±3.0‰, δ 13C VPDB=-33.79‰±0.09‰All of the assigned values are traceable to the international carbon isotope standard of VPDB and hydrogen isotope standard of VSMOW. © 2012 Elsevier B.V. Source

Hwang H.-H.,Illinois State Geological Survey | Panno S.V.,Illinois State Geological Survey | Hackley K.C.,Illinois State Geological Survey | Hackley K.C.,Isotech Laboratories Inc.
Environmental and Engineering Geoscience | Year: 2015

During the last decade of the twentieth century, McHenry County had the fastest-growing population in Illinois. Just north of the Chicago metropolitan area, land use in the eastern half of the county changed from row-crop agriculture to urban sprawl. Water supplies are from shallow sand and gravel aquifers and are highly vulnerable. We evaluated the change of groundwater quality in McHenry County during most of the twentieth century and identified the degree and extent of contamination, and sources, using available historic water-quality data. To evaluate historic data, we calculated background concentrations of selected ions using cumulative probability plots to identify the presence of anthropogenic contamination. Timing of groundwater contamination coincides with that of population growth and the onset of utilization of artificial N-fertilizer and road salt. Groundwater from urban areas showed greater Na+ and Cl- contents than rural areas, which reflect more extensive applications of road salt beginning in the early 1960s. Groundwater was collected for chemical and isotope analyses from selected shallow wells with historically elevated NO3- Concentration as well as from farms with livestock. The isotope data suggest N-fertilizer and soil nitrogen are the predominant sources for NO3- in shallow groundwater. Animal waste was also a source for NO3- near farms with livestock. Spatial analysis suggested that the source of NO3- in the groundwater was from surface-borne contaminants. The permeable soils and near-surface sand and gravel aquifer found in most of McHenry County provide pathways for surface contaminants to migrate into shallow ground-water. Source

Isotech Laboratories Inc. | Date: 2012-10-09

Metal containers used for collecting, trapping, retaining and shipping gases or liquids. Plastic containers used for collecting, trapping, retaining and shipping gasses or liquids for commercial or industrial use.

Isotech Laboratories Inc. | Date: 2009-09-22

Container for collecting solid or liquid samples such as soil, mud, rock, mineral, water, oil, etc., for the purpose of analysis of the contained materials and/or of the entrapped gases.

Discover hidden collaborations