States

The RHIC polarized source upgrade (open access)

The RHIC polarized source upgrade

N/A
Date: October 15, 2013
Creator: A., Zelenski; Atoian, G.; Ritter, J.; Steski, D.; Davydenko, V.; Ivanov, A. et al.
Object Type: Report
System: The UNT Digital Library
Report of Foreign Research Assignment for M. M. Abraham, October 1989-September 1990 (open access)

Report of Foreign Research Assignment for M. M. Abraham, October 1989-September 1990

The traveler collaborated with M.J.M. Leask, J.M. Baker, B. Bleaney, and others at the Clarendon Laboratory, Oxford University, Oxford, UK, to Study Tetragonal rare-earth phosphates and vanadates by optical and magnetic spectroscopy. This work is related to similar studies that have been performed at ORNL by the Synthesis and Properties of Novel Materials Group in the Solid State Division.
Date: October 15, 1990
Creator: Abraham, M. M.
Object Type: Report
System: The UNT Digital Library
Biological Monitoring Program for East Fork Poplar Creek (open access)

Biological Monitoring Program for East Fork Poplar Creek

In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biologicai Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the compiex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity …
Date: October 15, 1998
Creator: Adams, S. M.; Christensen, S. W.; Greeley, M. S. Jr.; Hill, W. R.; Kszos, L. A.; McCarthy, J. F. et al.
Object Type: Report
System: The UNT Digital Library
Recent progress in inertial confinement fusion at the Lawrence Livermore Laboratory (open access)

Recent progress in inertial confinement fusion at the Lawrence Livermore Laboratory

The Shiva and Argus laser systems at Livermore have been developed to study the physics of inertial confinement fusion. Both laser system designs are predicated on the use of large aperture Nd-glass disk amplifiers and high power spatial filters. During the past year we have irradiated DT filled microshell targets with and without polymer coatings. Recently new instruments have been developed to investigate implosion dynamics and to determine the maximum fuel density achieved by these imploded fusion pellets. A series of target irradiations with thin wall microshells at 15 to 20 TW, exploding pusher designs, resulted in a maximum neutron yield of 3 x 10/sup 10/. Polymer coated microshells designed for high compression were subjected to 4 kJ for 0.2 ns and reached fuel densities of 2.0 to 3.0 gm/cm/sup 3/. Results of these and other recent experiments will be reviewed.
Date: October 15, 1979
Creator: Ahlstrom, H. G. & Manes, K. R.
Object Type: Article
System: The UNT Digital Library
Hot Electron Generation and Transport Using K(alpha) Emission (open access)

Hot Electron Generation and Transport Using K(alpha) Emission

We have conducted experiments on both the Vulcan and Titan laser facilities to study hot electron generation and transport in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40{micro}m diameter wire emulating a 40{micro}m fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of prepulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.
Date: October 15, 2009
Creator: Akli, K. U.; Stephens, R. B.; Key, M. H.; Bartal, T.; Beg, F. N.; Chawla, S. et al.
Object Type: Article
System: The UNT Digital Library
Proton Decay Studies of the Light Lu, Tm and Ho Isotopes (open access)

Proton Decay Studies of the Light Lu, Tm and Ho Isotopes

A double-sided Si-strip detector system has been installed and commissioned at the focal plane of the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility. The system can be used for heavy charged particle emission studies with half-lives as low as a few {micro}sec. In this paper the authors present identification and study of the decay properties of the five new proton emitters: {sup 140}Ho, {sup 141m}Ho, {sup 145}Tm, {sup 150m}Lu and {sup 151m}Lu.
Date: October 15, 1998
Creator: Akovali, Y.; Batchelder, J. C.; Bingham, C. R.; Davinson, T.; Ginter, T. N.; Gross, C. J. et al.
Object Type: Article
System: The UNT Digital Library
Contract 98, Appendix F self-assessment report for Fiscal Year 2003 (open access)

Contract 98, Appendix F self-assessment report for Fiscal Year 2003

This report summarizes the Ernest Orlando Lawrence Berkeley National Laboratory internal assessment of Laboratory operational and administrative performance in key support functions for Fiscal Year (FY) 2003. The report provides documentation of ongoing performance-based management and oversight processes required by the Department of Energy (DOE) to monitor, measure, and evaluate Berkeley Lab work.
Date: October 15, 2003
Creator: Albert (Editor), Rich
Object Type: Report
System: The UNT Digital Library
Dose-to-Man From SRP Waste: Sensitivity to Leaching and Rock Properties (open access)

Dose-to-Man From SRP Waste: Sensitivity to Leaching and Rock Properties

This report summarizes results of a sensitivity analysis that predicts which features of the waste form and barrier system will have the greatest impact on dose to man.
Date: October 15, 2001
Creator: Allender, J.S.
Object Type: Report
System: The UNT Digital Library
Increased oil production and reserves from improved completion techniques in the Bluebell Field, Uinta Basin, Utah. Quarterly technical progress report, July 1, 1995--September 30, 1995 (open access)

Increased oil production and reserves from improved completion techniques in the Bluebell Field, Uinta Basin, Utah. Quarterly technical progress report, July 1, 1995--September 30, 1995

The objective of this project is to increase oil production and reserves in the Uinta Basin by demonstrating improved completion techniques. Low productivity of Uinta Basin wells is caused by gross production intervals of several thousand feet that contain perforated thief zones and water-bearing zones, and unperforated oil-bearing intervals. Geologic and engineering characterization and computer simulation of the Green River and Wasatch Formations in the Bluebell field will determine reservoir heterogeneities related to fractures and depositional trends. This will be followed by drilling and recompletion of several wells to demonstrate improved completion techniques based on the reservoir characterization. Transfer of the project results will be an ongoing component of the project.
Date: October 15, 1995
Creator: Allison, E. & Morgan, C. D.
Object Type: Report
System: The UNT Digital Library
Dynamic Fiber Optic Sensors Under Intense Radioactive Environments (open access)

Dynamic Fiber Optic Sensors Under Intense Radioactive Environments

A liquid mercury target will be used as the neutron source for the proposed Spallation Neutron Source facility. This target is subjected to bombardment by short-pulse, high-energy proton beams. The intense thermal loads caused by interaction of the pulsed proton beam with the mercury create an enormous rate of temperature rise ({approximately}10{sup 7} K/s) during a very brief beam pulse ({approximately } 0.5 {micro}s). The resulting pressure waves in the mercury will interact with the walls of the mercury target and may lead to large stresses. To gain confidence in the mercury target design concept and to benchmark the computer design codes, we tested various electrical and optical sensors for measuring the transient strains on the walls of a mercury container and the pressures in the mercury. The sensors were attached on several sample mercury targets that were tested at various beam facilities: Oak Ridge Electron Linear Accelerator, Los Alamos Neutron Science Center-Weapons Neutron Research, and Brookhaven National Laboratory's Alternating Gradient Synchrotron. The effects of intense background radiation on measured signals for each sensor are described and discussed. Preliminary results of limited tests at these facilities indicate that the fiber optic sensors function well in this intense radiation environment, whereas …
Date: October 15, 1998
Creator: Allison, S. W.; Earl, D. D.; Haines, J. R. & Tsai, C. C.
Object Type: Article
System: The UNT Digital Library
Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis (open access)

Indirect-Drive Noncryogenic Double-Shell Ignition Targets for the National Ignition Facility: Design and Analysis

The central goal of the National Ignition Facility (NIF) is demonstration of controlled thermonuclear ignition. The mainline ignition target is a low-Z, single-shell cryogenic capsule designed to have weakly nonlinear Rayleigh-Taylor growth of surface perturbations. Double-shell targets are an alternative design concept that avoids the complexity of cryogenic preparation but has greater physics uncertainties associated with performance-degrading mix. A typical double-shell design involves a high-Z inner capsule filled with DT gas and supported within a low-Z ablator shell. The largest source of uncertainty for this target is the degree of highly evolved nonlinear mix on the inner surface of the high-Z shell. High Atwood numbers and feed-through of strong outer surface perturbation growth to the inner surface promote high levels of instability. The main challenge of the double-shell target designs is controlling the resulting nonlinear mix to levels that allow ignition to occur. Design and analysis of a suite of indirect-drive NIF double-shell targets with hohlraum temperatures of 200 eV and 250 eV are presented. Analysis of these targets includes assessment of two-dimensional radiation asymmetry as well as nonlinear mix. Two-dimensional integrated hohlraum simulations indicate that the x-ray illumination can be adjusted to provide adequate symmetry control in hohlraums specially …
Date: October 15, 2001
Creator: Amendt, P.; Colvin, J.; Tipton, R. E.; Hinkel, D.; Edwards, M. J.; Landen, O. L. et al.
Object Type: Article
System: The UNT Digital Library
GAMMA-RAY AND FAST NEUTRON ANNULAR STREAMING EVALUATION THROUGH SODIUM REACTOR EXPERIMENT (SRE)-MARK II CONTROL AND SAFETY ROD ASSEMBLIES (open access)

GAMMA-RAY AND FAST NEUTRON ANNULAR STREAMING EVALUATION THROUGH SODIUM REACTOR EXPERIMENT (SRE)-MARK II CONTROL AND SAFETY ROD ASSEMBLIES

An experimental program was initiated io determine the extent of fast neutron and gamma ray streaming through the SRL Mark II control and safety rods and to evaluate the adequacy of the shielding provided in these control and safety rods. The methods and procedures used to evaluate these problems are routine and proven for determining gamma-ray and fast neutron dosages using radiation sensitive films and gold foils. The final experimental results indicated that no excessive streaming of either gamma rays or fast neutrons is present above or around the SHE Mark II control and safety rods. The analytical attenuation methods used to calculate the fast neutron and gamma-ray streaming dose rates gave results that compared favorably with the experimental data. Even ihough the agreement was favorable, it cannot be concluded that these analyical methods would be equally valid for other annular geometries. Additional experimental work will be necessary in order to establish the validity for performing similar analysis, but the favorable agreement encourages the use of such methods until other methods are determined. (auth)
Date: October 15, 1959
Creator: Anderson, F. D.
Object Type: Report
System: The UNT Digital Library
[Dynamic enhanced recovery technologies]. Quarterly technical report, August 1992--October 1993 (open access)

[Dynamic enhanced recovery technologies]. Quarterly technical report, August 1992--October 1993

This paper has presented the investigation of the mechanism of geopressure occurrence, the transition of elastic properties from the hydrostatic pressured formation to the geopressured formation, and finally, a novel seismic amplitude analysis technique to map the top-of-geopresure surface. The successful application of our new technique to the Pleistocene, offshore Louisiana, Gulf of Mexico has again demonstrated that seismic attributes analyses are of importantance in the hydrocarbon exploration. There are three parts in this paper corresponding to the above discussed topics: Part I discusses mechanisms of geopressuring, and the effects of changing porosity, pressure, and fluid saturation on the elastic properties; Part II investigates the controlling factors in the geopressure transition zone, their seismic responses, and theoretical derivations of our new prediction method; and Part III demonstrates the application of the proposed method to the Pleistocene, Offshore Louisiana, Gulf of Mexico, the prediction discrpepancy between the seismic predicted top-of-geopressure and that dericed from 145 well logs, and finally, the importance of this hydrodynamic surface.
Date: October 15, 1993
Creator: Anderson, R. N.
Object Type: Report
System: The UNT Digital Library
VELOCITY BUNCHING OF HIGH-BRIGHTNESS ELECTRON BEAMS (open access)

VELOCITY BUNCHING OF HIGH-BRIGHTNESS ELECTRON BEAMS

Velocity bunching has been recently proposed as a tool for compressing electron beam pulses in modern high brightness photoinjector sources. This tool is familiar from earlier schemes implemented for bunching dc electron sources, but presents peculiar challenges when applied to high current, low emittance beams from photoinjectors. The main difficulty foreseen is control of emittance oscillations in the beam in this scheme, which can be naturally considered as an extension of the emittance compensation process at moderate energies. This paper presents two scenarios in which velocity bunching, combined with emittance control, is to play a role in nascent projects. The first is termed ballistic bunching, where the changing of relative particle velocities and positions occur in distinct regions, a short high gradient linac, and a drift length. This scenario is discussed in the context of the proposed ORION photoinjector. Simulations are used to explore the relationship between the degree of bunching, and the emittance compensation process. Experimental measurements performed at the UCLA Neptune Laboratory of the surprisingly robust bunching process, as well as accompanying deleterious transverse effects, are presented. An unanticipated mechanism for emittance growth in bends for highly momentum chirped beam was identified and studied in these experiments. The …
Date: October 15, 2004
Creator: Anderson, S. G.; Musumeci, P.; Rosenzweig, J. B.; Brown, W. J.; England, R. J.; Ferrario, M. et al.
Object Type: Article
System: The UNT Digital Library
Predictions for nuclear properties along the r-process path (open access)

Predictions for nuclear properties along the r-process path

The uniformity of different nuclear regions as a function of the number of valence protons and neutrons (counted from the nearest closed shell) has been exploited for the parameterization of calculations for nuclei far from stability within the IBA model. Predictions are given for low lying levels, E2 transition rates, and binding energies for nuclei in the r-process path in the A = 150 and A = 190 mass regions. 6 refs., 6 figs.
Date: October 15, 1987
Creator: Aprahamian, A.
Object Type: Article
System: The UNT Digital Library
Ultrasonic Velocities in Unconsolidated Sand/Clay Mixtures at Low Pressures (open access)

Ultrasonic Velocities in Unconsolidated Sand/Clay Mixtures at Low Pressures

Effective seismic interrogation of the near subsurface requires that measured parameters, such as compressional and shear velocities and attenuation, be related to important soil properties. Porosity, composition (clay content), fluid content and type are of particular interest. The ultrasonic (100-500 kHz) pulse transmission technique was used to collect data for highly attenuating materials appropriate to the vadose zone. Up to several meters of overburden were simulated by applying low uniaxial stress of 0 to about 0.1 MPa to the sample. The approach was to make baseline measurements for pure quartz sand, because the elastic properties are relatively well known except at the lowest pressures. Clay was added to modify the sample microstructure and ultrasonic measurements were made to characterize the effect of the admixed second phase. Samples were fabricated from Ottawa sand mixed with a swelling clay (Wyoming bentonite). The amount of clay added was 1 to 40% by mass. Compressional (P) velocities are low (228-483 m/s), comparable to the sound velocity in air. Shear (S) velocities are about half of the compressional velocity (120-298 m/s), but show different sensitivity to microstructure. Adding clay increases the shear amplitude dramatically with respect to P, and also changes the sensitivity of the …
Date: October 15, 1999
Creator: Aracne-Ruddle, C. M.; Bonner, B. P.; Trombino, C. N.; Hardy, E. D.; Berge, P. A.; Boro, C. O. et al.
Object Type: Article
System: The UNT Digital Library
Picosecond x-ray measurements from 100 eV to 30 keV (open access)

Picosecond x-ray measurements from 100 eV to 30 keV

Picosecond x-ray measurements relevant to the Livermore Laser Fusion Program are reviewed. Resolved to 15 picoseconds, streak camera detection capabilities extend from 100 eV to higher than 30 keV, with synchronous capabilities in the visible, near infrared, and ultraviolet. Capabilities include automated data retrieval using charge coupled devices (CCD's), absolute x-ray intensity levels, novel cathodes, x-ray mirror/reflector combinations, and a variety of x-ray imaging devices.
Date: October 15, 1980
Creator: Attwood, D.T.; Kauffman, R.L. & Stradling, G.L.
Object Type: Article
System: The UNT Digital Library
Analysis of the growth of strike-slip faults using effective medium theory (open access)

Analysis of the growth of strike-slip faults using effective medium theory

Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults …
Date: October 15, 2009
Creator: Aydin, A. & Berryman, J.G.
Object Type: Article
System: The UNT Digital Library
The MINOS long-baseline experiment at Fermilab. (open access)

The MINOS long-baseline experiment at Fermilab.

The MINOS long-baseline experiment will search for neutrino oscillations by measuring an intense {nu}{sub {mu}} beam at the end of a 730 km flight path. The 10,000 ton MINOS far detector will utilize magnetized steel plates interleaved with track chambers to reconstruct event topologies and to measure the energies of the muons, hadrons and electromagnetic showers produced by neutrino interactions. The experiment is designed to detect {nu}{sub {mu}} {r_arrow} {nu}{sub {tau}} and {nu}{sub {mu}} {r_arrow} {nu}{sub e} oscillations with {Delta}m{sup 2} {ge} 0.001 eV{sup 2} and sin{sup 2}(2{theta}) {ge} 0.01. Any oscillation signal observed can be verified and studied by several independent tests: a near/far rate comparison, the NC/CC event ratio, the CC and NC event energy spectra, and the identification of electrons and {tau} leptons. The neutrino beam can be operated in both wide-band and narrow-band configurations, allowing the detailed study oscillation phenomena. The experiment is scheduled to begin operation in 2001.
Date: October 15, 1997
Creator: Ayres, D. S.
Object Type: Article
System: The UNT Digital Library
Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials (open access)

Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials

This final report details results, conclusions, and opportunities for future effort derived from the study. The work involved combining the molecular engineering of photoactive Ti-alkoxide systems and the optical excitation of hydrolysis and condensation reactions to influence the development of the metal-oxygen-metal network at the onset of material formation. Selective excitation of the heteroleptic alkoxides, coupled with control of alkoxide local chemical environment, enabled network connectivity to be influenced and formed the basis for direct deposition and patterning of Ti-oxide-based materials. The research provided new insights into the intrinsic photoresponse and assembly of these complex, alkoxide molecules. Using a suite of electronic, vibrational, and nuclear spectroscopic probes, coupled with quantum chemical computation, the excitation wavelength and fluence dependence of molecular photoresponse and the nature of subsequent hydrolysis and condensation processes were probed in pyridine-carbinol-based Ti-alkoxides with varied counter ligand groups. Several methods for the patterning of oxide material formation were demonstrated, including the integration of this photoprocessing approach with conventional, dip-coating methodologies.
Date: October 15, 2010
Creator: B.G. Potter, Jr.
Object Type: Report
System: The UNT Digital Library
Hydrogen Production and Delivery Research (open access)

Hydrogen Production and Delivery Research

In response to DOE's Solicitation for Grant Applications DE-PS36-03GO93007, 'Hydrogen Production and Delivery Research', SRI International (SRI) proposed to conduct work under Technical Topic Area 5, Advanced Electrolysis Systems; Sub-Topic 5B, High-Temperature Steam Electrolysis. We proposed to develop a prototype of a modular industrial system for low-cost generation of H{sub 2} (<$2/kg) by steam electrolysis with anodic depolarization by CO. Water will be decomposed electrochemically into H{sub 2} and O{sub 2} on the cathode side of a high-temperature electrolyzer. Oxygen ions will migrate through an oxygen-ion-conductive solid oxide electrolyte. Gas mixtures on the cathode side (H{sub 2} + H{sub 2}O) and on the anode side (CO + CO{sub 2}) will be reliably separated by the solid electrolyte. Depolarization of the anodic process will decrease the electrolysis voltage, and thus the electricity required for H{sub 2} generation and the cost of produced H{sub 2}. The process is expected to be at least 10 times more energy-efficient than low-temperature electrolysis and will generate H{sub 2} at a cost of approximately $1-$1.5/kg. The operating economics of the system can be made even more attractive by deploying it at locations where waste heat is available; using waste heat would reduce the electricity required for …
Date: October 15, 2007
Creator: Balachov, Iouri
Object Type: Report
System: The UNT Digital Library
Risk Reduction With a Fuzzy Expert Exploration Tool (open access)

Risk Reduction With a Fuzzy Expert Exploration Tool

Incomplete or sparse information on types of data such as geologic or formation characteristics introduces a high level of risk for oil exploration and development projects. ''Expert'' systems developed and used in several disciplines and industries have demonstrated beneficial results. A state-of-the-art exploration ''expert'' tool, relying on a computerized database and computer maps generated by neural networks, is being developed through the use of ''fuzzy'' logic, a relatively new mathematical treatment of imprecise or non-explicit parameters and values. Oil prospecting risk can be reduced with the use of a properly developed and validated ''Fuzzy Expert Exploration (FEE) Tool.'' This FEE Tool can be beneficial in many regions of the U.S. by enabling risk reduction in oil and gas prospecting as well as decreased prospecting and development costs. In the 1998-1999 oil industry environment, many smaller exploration companies lacked the resources of a pool of expert exploration personnel. Downsizing, low oil prices, and scarcity of exploration funds have also affected larger companies, and will, with time, affect the end users of oil industry products in the U.S. as reserves are depleted. The FEE Tool will benefit a diverse group in the U.S., leading to a more efficient use of scarce funds, …
Date: October 15, 2003
Creator: Balch, Robert
Object Type: Report
System: The UNT Digital Library
Compatibility of SNAP Fuel and Clad Materials (open access)

Compatibility of SNAP Fuel and Clad Materials

Samples capsules containing buttons of materials of interest for SNAP fuel elements were held at temperatures up to 1600°F , in hydrogen, under a 20-tsi load for 200+ hours.
Date: October 15, 1960
Creator: Balkwill, J.K.
Object Type: Report
System: The UNT Digital Library
Low-(18)O Silicic Magmas: Why Are They So Rare? (open access)

Low-(18)O Silicic Magmas: Why Are They So Rare?

LOW-180 silicic magmas are reported from only a small number of localities (e.g., Yellowstone and Iceland), yet petrologic evidence points to upper crustal assimilation coupled with fractional crystallization (AFC) during magma genesis for nearly all silicic magmas. The rarity of 10W-l `O magmas in intracontinental caldera settings is remarkable given the evidence of intense 10W-l*O meteoric hydrothermal alteration in the subvolcanic remnants of larger caldera systems. In the Platoro caldera complex, regional ignimbrites (150-1000 km3) have plagioclase 6180 values of 6.8 + 0.1%., whereas the Middle Tuff, a small-volume (est. 50-100 km3) post-caldera collapse pyroclastic sequence, has plagioclase 8]80 values between 5.5 and 6.8%o. On average, the plagioclase phenocrysts from the Middle Tuff are depleted by only 0.3%0 relative to those in the regional tuffs. At Yellowstone, small-volume post-caldera collapse intracaldera rhyolites are up to 5.5%o depleted relative to the regional ignimbrites. Two important differences between the Middle Tuff and the Yellowstone 10W-180 rhyolites elucidate the problem. Middle Tuff magmas reached water saturation and erupted explosively, whereas most of the 10W-l 80 Yellowstone rhyolites erupted effusively as domes or flows, and are nearly devoid of hydrous phenocrysts. Comparing the two eruptive types indicates that assimilation of 10W-180 material, combined with …
Date: October 15, 1998
Creator: Balsley, Steven D. & Gregory, Robert T.
Object Type: Article
System: The UNT Digital Library