ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport proc... more ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport processes in groundwaters with the purpose of modeling small scale (mm) interactions between water and rock in complex solid media. This method was used to create a simple porous media structure in which chemical reactions including sorption, dissolution and precipitation occur. A pre-existing lattice Boltzmann code developed at LANL for physical fluid flow was used as the basis for overlaying chemical exchange controls at each lattice node. Initially, Langmuir sorption isotherms were applied on open channel models varying from 10x4000 to 30x1000 nodes. The resulting breakthrough curves from these chemical slug models are compatible with analytical solutions that apply the isotherm equations on larger scales. The model was then further developed to include multiple solid compositions and dissolution and precipitation reactions to study the small scale spatial and temporal distributions of materials in porous media. Mineral nodes of varying composition which undergo specific chemical reactions can be created in the open channels or among evenly spaced blocks of solid nodes which simulate homogeneous porous media. This model structure is being used to investigate millimeter scale Sr isotopic variations observed in the K-metasomatized Lemitar Tuff from Southern New Mexico. Multiple samples of the adularia will provide an isochron age that may represent the time of K-metasomatism. Physical microsampling of this tuff has demonstrated the secondary adularia has a unique Sr isotopic characteristic (87}Sr/{86Sr near 0.727) relative to the fresh plagioclase and sanidine phenocrysts (0.709). The model is being used to discern between the possibilities of the Sr now present in the altered material originating from the surround matrix or alternatively from an outside source in the altering fluids. An outside source of Sr in the K-metasomatic groundwater would be likely with the failure of the model to recreate the correct Sr characteristic in the altered material while relying on in situ Sr from dissolution and precipitation.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), 1989
ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los ... more ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los Alamos Nuclear Microprobe. Chlorites and epidotes in basalt were analyzed from the Samail Ophiolite of Oman. Sulfide and sulfate minerals were analyzed from samples of active chimney walls from 21/degree/N. East Pacific Rise. These samples are ideal for our study because of the extensive background information available on processes and component characteristics. Initial results indicate significant differences in mobile trace elements between chlorites associated with and those distinctly separate from major stockwork flow zones, consistent with greater water-rock reaction within stockworks. Trace element concentrations across chimney walls also exhibit distinctive patterns which can be correlated with mineral/chemical zonation and possible also with variations in elemental source. 9 refs., 2 figs., 1 tab.
The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) envir... more The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) environmental cleanup site for a previous manufacturing plant that made components for the U.S. nuclear weapons arsenal. The facility was shut down in 1989 to address environmental and safety concerns, and left behind a legacy of contaminated facilities, soils, surface and ground water. In 1995, the
The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectros... more The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectroscopy technique described here can be used to classify microliter quantities of oil such as those in fluid inclusions in cements from petroleum reservoirs. It is primarily constructed to obtain synchronously scanned luminescence spectra from microscopic sized samples to characterize the organic classes of compounds that predominate. At present no other technique can so readily analyze a single oil-bearing fluid inclusion. The data collected from the technique are pertinent to evaluating systems and providing quantitative data for solving problems in oil migration and maturation determinations, oil-to-oil and oil-to-source correlations, oil degradation, and episodes and chemistry of cementation.
Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawate... more Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawater ionic strength at 350-425°C, 375-400 bars pressure and fluid/rock mass ratios of 0.5-1.0, to assess the role of temperature, basalt/diabase chemistry and texture on heavy metal and sulfur mobility during hydrothermal alteration. Alteration of basalt/diabase is characterized by cation fixation and hydrolysis reactions which show
Geological Society, London, Special Publications, 1993
Abstract The geochemical changes associated with the experimental serpentinization of peridotite ... more Abstract The geochemical changes associated with the experimental serpentinization of peridotite are due to reaction with sea water and to the growth of new mineral phases. Since the rare earth elements (REE) and Sr are primarily ensconced in clinopyroxene, it is the unreactive nature of this phase in the presence of sea water that determines the REE content, the 87Sr/86Sr and 143Nd/144Nd ratio of the experimentally produced serpentinites. Serpentinites (after lherzolite and dunite) have chondrite-normalized REE abundance patterns similar to the initial peridotite indicating that the light REE (LREE) are not selectively mobilized by peridotite-sea water interaction at 300°C. However, the serpentinites produced as a result of harzburgite-sea water experiments show an increase in LREE content. Despite the sporadic behaviour of the LREE, the 143Nd/144Nd ratios in experimentally produced serpentinites (after lherzolite and harzburgite) are identical to primary clinopyroxene in the unaltered peridotite. In contrast, a marked change in the strontium isotopic composition of the peridotites occurs during experimental serpentinization due to the growth of hydrous and Ca-rich phases which facilitates the uptake of sea water Sr. Whereas harzburgite and dunite alter to produce serpentinites with high Sr contents and 87Sr/86Sr > 0.709, lherzolites tend to alter to serpentinites with 87Sr/86Sr < 0.709. This behaviour invalidates the use of Rb-Sr data in understanding the origin of oceanic and ophiolitic peridotites, but the relative immobility of the light REE (in clinopyroxene-bearing peridotites) and the low REE content of sea water encourages the careful use of the REE and neodymium isotopes as a petrogenetic indicator for elucidating the origin of serpentinized abyssal peridotites.
... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquo... more ... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquots that were stippled onto stainless steel disks, evaporated to dryness under a heat lamp, flamed to dull red, and counted on an α-scintillation counter (Eberline Instrument Corporation ...
ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport proc... more ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport processes in groundwaters with the purpose of modeling small scale (mm) interactions between water and rock in complex solid media. This method was used to create a simple porous media structure in which chemical reactions including sorption, dissolution and precipitation occur. A pre-existing lattice Boltzmann code developed at LANL for physical fluid flow was used as the basis for overlaying chemical exchange controls at each lattice node. Initially, Langmuir sorption isotherms were applied on open channel models varying from 10x4000 to 30x1000 nodes. The resulting breakthrough curves from these chemical slug models are compatible with analytical solutions that apply the isotherm equations on larger scales. The model was then further developed to include multiple solid compositions and dissolution and precipitation reactions to study the small scale spatial and temporal distributions of materials in porous media. Mineral nodes of varying composition which undergo specific chemical reactions can be created in the open channels or among evenly spaced blocks of solid nodes which simulate homogeneous porous media. This model structure is being used to investigate millimeter scale Sr isotopic variations observed in the K-metasomatized Lemitar Tuff from Southern New Mexico. Multiple samples of the adularia will provide an isochron age that may represent the time of K-metasomatism. Physical microsampling of this tuff has demonstrated the secondary adularia has a unique Sr isotopic characteristic (87}Sr/{86Sr near 0.727) relative to the fresh plagioclase and sanidine phenocrysts (0.709). The model is being used to discern between the possibilities of the Sr now present in the altered material originating from the surround matrix or alternatively from an outside source in the altering fluids. An outside source of Sr in the K-metasomatic groundwater would be likely with the failure of the model to recreate the correct Sr characteristic in the altered material while relying on in situ Sr from dissolution and precipitation.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), 1989
ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los ... more ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los Alamos Nuclear Microprobe. Chlorites and epidotes in basalt were analyzed from the Samail Ophiolite of Oman. Sulfide and sulfate minerals were analyzed from samples of active chimney walls from 21/degree/N. East Pacific Rise. These samples are ideal for our study because of the extensive background information available on processes and component characteristics. Initial results indicate significant differences in mobile trace elements between chlorites associated with and those distinctly separate from major stockwork flow zones, consistent with greater water-rock reaction within stockworks. Trace element concentrations across chimney walls also exhibit distinctive patterns which can be correlated with mineral/chemical zonation and possible also with variations in elemental source. 9 refs., 2 figs., 1 tab.
The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) envir... more The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) environmental cleanup site for a previous manufacturing plant that made components for the U.S. nuclear weapons arsenal. The facility was shut down in 1989 to address environmental and safety concerns, and left behind a legacy of contaminated facilities, soils, surface and ground water. In 1995, the
The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectros... more The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectroscopy technique described here can be used to classify microliter quantities of oil such as those in fluid inclusions in cements from petroleum reservoirs. It is primarily constructed to obtain synchronously scanned luminescence spectra from microscopic sized samples to characterize the organic classes of compounds that predominate. At present no other technique can so readily analyze a single oil-bearing fluid inclusion. The data collected from the technique are pertinent to evaluating systems and providing quantitative data for solving problems in oil migration and maturation determinations, oil-to-oil and oil-to-source correlations, oil degradation, and episodes and chemistry of cementation.
Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawate... more Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawater ionic strength at 350-425°C, 375-400 bars pressure and fluid/rock mass ratios of 0.5-1.0, to assess the role of temperature, basalt/diabase chemistry and texture on heavy metal and sulfur mobility during hydrothermal alteration. Alteration of basalt/diabase is characterized by cation fixation and hydrolysis reactions which show
Geological Society, London, Special Publications, 1993
Abstract The geochemical changes associated with the experimental serpentinization of peridotite ... more Abstract The geochemical changes associated with the experimental serpentinization of peridotite are due to reaction with sea water and to the growth of new mineral phases. Since the rare earth elements (REE) and Sr are primarily ensconced in clinopyroxene, it is the unreactive nature of this phase in the presence of sea water that determines the REE content, the 87Sr/86Sr and 143Nd/144Nd ratio of the experimentally produced serpentinites. Serpentinites (after lherzolite and dunite) have chondrite-normalized REE abundance patterns similar to the initial peridotite indicating that the light REE (LREE) are not selectively mobilized by peridotite-sea water interaction at 300°C. However, the serpentinites produced as a result of harzburgite-sea water experiments show an increase in LREE content. Despite the sporadic behaviour of the LREE, the 143Nd/144Nd ratios in experimentally produced serpentinites (after lherzolite and harzburgite) are identical to primary clinopyroxene in the unaltered peridotite. In contrast, a marked change in the strontium isotopic composition of the peridotites occurs during experimental serpentinization due to the growth of hydrous and Ca-rich phases which facilitates the uptake of sea water Sr. Whereas harzburgite and dunite alter to produce serpentinites with high Sr contents and 87Sr/86Sr > 0.709, lherzolites tend to alter to serpentinites with 87Sr/86Sr < 0.709. This behaviour invalidates the use of Rb-Sr data in understanding the origin of oceanic and ophiolitic peridotites, but the relative immobility of the light REE (in clinopyroxene-bearing peridotites) and the low REE content of sea water encourages the careful use of the REE and neodymium isotopes as a petrogenetic indicator for elucidating the origin of serpentinized abyssal peridotites.
... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquo... more ... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquots that were stippled onto stainless steel disks, evaporated to dryness under a heat lamp, flamed to dull red, and counted on an α-scintillation counter (Eberline Instrument Corporation ...
Uploads