scholarly journals Zircon (U-Th)/He Thermochronologic Constraints on the Long-Term Thermal Evolution of Southern New Mexico and Western Texas

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 1-25
Author(s):  
Nathan Z. Reade ◽  
Julian M. Biddle ◽  
Jason W. Ricketts ◽  
Jeffrey M. Amato
Keyword(s):  
New Mexico ◽  
Elevated Temperatures ◽  
Thermal Evolution ◽  
Near Surface ◽  
Tectonic History ◽  
Inverse Models ◽  
Final Development ◽  
Thermal Histories ◽  
Lower Temperature ◽  
Forward And Inverse Modeling

Abstract Zircon (U-Th)/He (ZHe) dates are presented from eight samples (n=55) collected from three ranges including the Carrizo and Franklin Mountains in western Texas and the Cookes Range in southern New Mexico. ZHe dates from Proterozoic crystalline rocks range from 6 to 731 Ma in the Carrizo Mountains, 19 to 401 Ma in the Franklin Mountains, and 63 to 446 Ma in the Cookes Range, and there is a negative correlation with eU values. These locations have experienced a complex tectonic history involving multiple periods of uplift and reburial, and we use a combination of forward and inverse modeling approaches to constrain plausible thermal histories. Our final inverse models span hundreds of millions of years and multiple tectonic events and lead to the following conclusions: (1) Proterozoic exhumation occurred from 800 to 500 Ma, coinciding with the break-up of Rodinia; (2) elevated temperatures at approximately 100 Ma occurred during final development of the Bisbee basin and are a likely result of elevated heat flow in the upper crust during continental rifting; (3) a pulse of cooling associated with Laramide shortening is observed from 70 to 45 Ma in the Cooks Range and 80 to 50 Ma in the Franklin Mountains, whereas the Carrizo Mountains were largely unaffected by this event; and (4) final cooling to near-surface temperatures began 30–25 Ma at all three locations and was likely a result of Rio Grande rift extension. These data help to bridge the gap between higher and lower temperature isotopic systems to constrain complex thermal histories in tectonically mature regions.

scholarly journals Instability of the southern Canadian Shield during the late Proterozoic

2018 ◽  
Author(s):  
Kalin T. McDannell ◽  
Peter K. Zeitler ◽  
David A. Schneider
Keyword(s):  
Elevated Temperatures ◽  
Geothermal Gradient ◽  
Canadian Shield ◽  
Granitic Rocks ◽  
Deep Time ◽  
Magmatic Underplating ◽  
Thermal Histories ◽  
Lower Temperature ◽  
The Stability ◽  
Uplift And Erosion

Cratons are generally considered to comprise lithosphere that has remained tectonically quiescent for billions of years. Direct evidence for stability is mainly founded in the Phanerozoic sedimentary record and low-temperature thermochronology, but for extensive parts of Canada, earlier stability has been inferred due to the lack of an extensive rock record in both time and space. We used 40Ar/39Ar multi-diffusion domain (MDD) analysis of K-feldspar to constrain cratonic thermal histories across an intermediate (~150-350°C) temperature range in an attempt to link published high-temperature geochronology that resolves the timing of orogenesis and metamorphism with lower-temperature data suited for upper-crustal burial and unroofing histories. This work is focused on understanding the transition from Archean-Paleoproterozoic crustal growth to later intervals of stability, and how uninterrupted that record is throughout Earth’s Proterozoic “Middle Age.” Intermediate-temperature thermal histories of cratonic rocks at well-constrained localities within the southern Canadian Shield of North America challenge the stability worldview because our data indicate that these rocks were at elevated temperatures in the Proterozoic. Feldspars from granitic rocks collected at the surface cooled at rates of <0.5°C/Ma subsequent to orogenesis, seemingly characteristic of cratonic lithosphere, but modeled thermal histories suggest that at ca. 1.1-1.0 Ga these rocks were still near ~200°C – signaling either reheating, or prolonged residence at mid-crustal depths assuming a normal cratonic geothermal gradient. After 1.0 Ga, the regions we sampled then underwent further cooling such that they were at or near the surface (<< 60°C) in the early Paleozoic. Explaining mid-crustal residence at 1.0 Ga is challenging. A widespread, prolonged reheating history via burial is not supported by stratigraphic information, however assuming a purely monotonic cooling history requires at the very least 5 km of exhumation beginning at ca. 1.0 Ga. A possible explanation may be found in evidence of magmatic underplating that thickened the crust, driving uplift and erosion. The timing of this underplating coincides with Mid-Continent extension, Grenville orogenesis, and assembly of the supercontinent Rodinia. 40Ar/39Ar MDD data demonstrate that this technique can be successfully applied to older rocks and fill in a large observational gap. These data also raise questions about the evolution of cratons during the Proterozoic and the nature of cratonic stability across deep time.

scholarly journals Effect of thermal relaxation on residual stress and microstructure in the near-surface layers of dual shot peened Inconel 625

2018 ◽  
Vol 10 (10) ◽  
pp. 168781401880053
Author(s):  
Lihong Wu ◽  
Chuanhai Jiang
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Elevated Temperatures ◽  
Thermal Relaxation ◽  
Diffraction Method ◽  
Relaxation Behavior ◽  
Inconel 625 ◽  
Surface Layers ◽  
Near Surface ◽  
Subsurface Layers

Thermal relaxation behavior of residual stress and microstructure in the near-surface layers of dual shot peened Inconel alloy 625 was investigated by X-ray diffraction method. Residual stress on the top surface layer was significantly relaxed in the first 15 min at the elevated temperatures of 500°C, 600°C, and 700°C. However, there was still high maximum compressive residual stress in subsurface layers. The relaxation behavior of residual stress has contributed to the thermally activated process. The activation enthalpy Δ H and m were calculated according to the Zener–Wert–Avrami method, the values of which were 1.59 eV and 0.4934, respectively. Microstructural evaluation revealed that it was slightly changed in the near-surface layers after various isothermal treatments. Accordingly, high level of compressive residual stress and dislocation density resulted in the retained mechanical properties of dual shot peened Inconel 625, which was discussed based on the relaxation of microstructure and microhardness.

Evaporite Dissolution Relevant to the Wipp Site, Northern Delaware Basin, Southeastern New Mexico

1982 ◽  
Vol 15 ◽  
Author(s):  
Steven J. Lambert
Keyword(s):  
New Mexico ◽  
High Rate ◽  
Late Cenozoic ◽  
Time Intervals ◽  
Near Surface ◽  
Waste Isolation Pilot Plant ◽  
Delaware Basin ◽  
The Past ◽  
Geomorphic Features ◽  
Geologic Record

ABSTRACTEvaluation of the threat of natural dissolution of host evaporites to the integrity of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico has taken into consideration (1) the volume of “missing” rock salt, (2) the occurrence (or not) of characteristic dissolution brines, (3) geomorphic features, some of which are unrelated to dissolution, and (4) the time intervals over which dissolution may have been active. Even under the assumption that all “missing” halite was originally present and has been removed by dissolution, there is no evidence of active preferential removal of the lower Salado Formation halite by any geologically reasonable process. The geologic record contains evidence of dissolution in the Triassic and Jurassic; to constrain all removal of basinal halite to the late Cenozoic yields an unrealistically high rate of removal. Application to the lower Salado of a stratabound mechanism known to be active in Nash Draw, a near-surface feature within the Basin, allows a minimum survival time of 2,500,000 years to be predicted for the subsurface facility for storage of radioactive waste at WIPP. This calculation is based on an analysis of all known dissolution features in the Delaware Basin, and takes into account the wetter (pluvial) climate during the past 600,000 years.

Thermal Evolution and Electrical Properties of Rare-Earth Oxide Doped Zirconia

1988 ◽  
Vol 121 ◽  
Author(s):  
B. S. Chiou ◽  
M. Y. Lee ◽  
J. G. Duh
Keyword(s):  
Activation Energy ◽  
Rare Earth ◽  
Ionic Radius ◽  
Thermal Evolution ◽  
Rare Earth Oxide ◽  
Zirconia Ceramics ◽  
Wet Chemical ◽  
Ir Analysis ◽  
Lower Temperature ◽  
The Rare Earth

ABSTRACTSynthesized zirconia ceramics are prepared through the coprecipita-tion process. Application of the wet chemical approach is aimed at the achievement of highly sintered ceramics at lower temperature. The thermal evolution of the synthesized CeO2-ZrO2 powder is investigated with the aid of DTA and TGA measurement. The exothermic peaks on the DTA thermogram are futher identified by the IR analysis. The effect of CeO on the occurrence of the peaks is probed. For other rare-earth oxiae doped ceramics, such as Nd2O3. and Dy2O3. containing zirconia, the bulk and grain boundary resistances are evaluated by the impedance spectroscopy. The dependence of the associated activation energy in the rare-earth oxide doped zirconia is discussed with respect to the variation of the ionic radius of the rare earth constituent.

Thermomechanical models with surface processes: Low-Temperature Thermochronology predictions for model calibration

2020 ◽  
Author(s):  
Romain Beucher ◽  
Louis Moresi ◽  
Roderick Brown ◽  
Claire Mallard
Keyword(s):  
Low Temperature ◽  
Fission Track ◽  
Thermal Evolution ◽  
Surface Processes ◽  
Apatite Fission Track ◽  
Coupled Models ◽  
Passive Margins ◽  
Geomorphic Response ◽  
Mechanical Models ◽  
Thermal Histories

<p>State of the art thermo-mechanical models have become very efficient at testing scenarios of tectonic evolution but uncertainties on the rheologies and the complexity of the have so far limited the potential to quantitatively predict uplift and subsidence. Coupling thermo-mechanical models to landscape evolution models remains challenging and require careful validation and better integration of field data to prevent error in interpretation.</p><p> </p><p>Low temperature thermochronology has been extensively used to quantitatively constrain the thermal histories of rocks. It can provide important information on tectonic uplift (or subsidence) by measuring the erosional (or burial) response and can also map the spatial and temporal pattern of geomorphic response of a landscape.</p><p> </p><p>We use the temperature evolution of our coupled thermo-mechanical models with surface processes to predict Apatite fission track data (Ages and Track lengths distributions). The aim is to provide a direct means of comparison with actual empirical thermochronometric data which will allow different model scenarios and/or model parameter choices to be robustly tested.</p><p>We present a series of 3D coupled models (Underworld / Badlands) of Rifts and the associated Apatite Fission Track predicted by the thermal evolution of the rocks exhumed to the surface. We compare models predictions to existing thermochronological transects across passive margins.</p><p> </p><p>We discuss the technical challenges in obtaining sufficiently high resolution temperature field and other associated challenges that need to be addressed to satisfactory apply our model to natural examples.</p>

NEAR SURFACE GEOPHYSICS FOR THE STRUCTURAL ANALYSIS OF A MINE ROCK PILE, NORTHERN NEW MEXICO

2005 ◽  
Vol 2005 (1) ◽  
pp. 1178-1201
Author(s):  
Remke L. Van Dam ◽  
◽  
Luiza A. Gutierrez ◽  
Virginia T. McLemore ◽  
G. Ward Wilson ◽  
...  
Keyword(s):  
New Mexico ◽  
Structural Analysis ◽  
Near Surface ◽  
Rock Pile ◽  
Near Surface Geophysics

Radiation Effects in Nonmetals: Amorphization, Phase Decomposition, and Nanoparticles

1998 ◽  
Vol 540 ◽  
Author(s):  
A. Meldrum ◽  
L.A. Boatner ◽  
C.W. White ◽  
D.O. Henderson
Keyword(s):  
Ion Implantation ◽  
Electron Irradiation ◽  
Radiation Effects ◽  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Semiconductor Nanocrystals ◽  
Heavy Ion ◽  
Fused Silica ◽  
Near Surface

AbstractRadiation effects in nonmetals have been studied for well over a century by geologists, mineralogists, physicists, and materials scientists. The present work focuses on recent results of investigations of the ion-beam-induced amorphization of the ABO4 compounds – including the orthophosphates (LnPO4; Ln = lanthanides) and the orthosilicates: zircon (ZrSiO4), hafnon (HfSiO4), and thorite (ThSiO4). In the case of the orthosilicates, heavy-ion irradiation at elevated temperatures causes the precipitation of a nanocrystalline metal oxide. Electron irradiation effects in these amorphized insulating ceramics can produce localized recrystallization on a nanometer scale. Similar electron irradiation techniques were used to nucleate monodispersed compound semiconductor nanocrystals formed by ion implantation of the elemental components into fused silica. Methods for the formation of novel structural relationships between embedded nanocrystals and their hosts have been developed and the results presented here demonstrate the general flexibility of ion implantation and irradiation techniques for producing unique near-surface microstructures in ion-implanted host materials.

Deposition of Low-Stress Encapsulants on InP and GaAs

1986 ◽  
Vol 75 ◽  
Author(s):  
U. K. Chakrabarti ◽  
S. J. Pearton ◽  
H. Barz ◽  
A. R. Vonneida ◽  
K. T. Short ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Secondary Ion Mass Spectrometry ◽  
Surface Region ◽  
Near Surface ◽  
Deposition Parameters ◽  
Direct Measurements ◽  
Dopant Redistribution ◽  
Doped Glass ◽  
Phosphorus Doped ◽  
Secondary Ion

AbstractAℓN deposited by D.C. triode sputtering and spin-on, phosphorus-doped glass (PSG) layers on GaAs and InP were investigated as encapsulants. These films have similar expansion coefficients to both GaAs and InP, minimizing the amount of strain induced in the near-surface region of the underlying wafer. We have quantified this effect by direct measurements of the stress in the films and by using secondary ion mass spectrometry profiling to measure the redistribution of Cr and Fe in encapsulated GaAs and InP respectively during high temperature processing. The dopant redistribution is considerably less for the AℓN and PSG films compared to the more conventional SiO2 and Si3N4 layers. The interaction of the films with the substrate at elevated temperatures is minimal as determined by Auger profiling and the electrical properties of the surface after removal of the encapsulants. The composition of the films remains essentially constant after annealing, as measured by Rutherford backscattering, and the thickness uniformity over large wafer diameters (2″) can be excellent with close control of the deposition parameters. The activation characteristics of low dose, Si-implanted layers in GaAs using either PSG or AℓN are comparable to those obtained using capless annealing or SiO2 or Si3N4 encapsulation.

Thermal degradation of EDTA chelates in aqueous solution

1982 ◽  
Vol 60 (10) ◽  
pp. 1207-1213 ◽  
Author(s):  
Ramunas J. Motekaitis ◽  
X. B. Cox III ◽  
Patrick Taylor ◽  
Arthur E. Martell ◽  
Brad Miles ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Degradation ◽  
Elevated Temperatures ◽  
Degradation Products ◽  
Iminodiacetic Acid ◽  
Reaction Products ◽  
Degradation Rates ◽  
Lower Temperature Range ◽  
Higher Temperature ◽  
Lower Temperature

The thermal degradation of Ca(II), Mg(II), Zn(II), Fe(II), and Ni(II) chelates of EDTA was investigated in alkaline aqueous solution at elevated temperatures (230–310 °C). The kinetics of decomposition were followed by nmr, titrimetry, and spectrophotometry. Reaction products were identified through nmr and by gas chromatography. The relative order of degradation rates, as measured by the loss of EDTA, was found to be Mg(II) > Ca(II) > Zn(II) > Fe(II) > Ni(II). The main degradation products formed in the lower temperature range (~250 °C) are iminodiacetic acid, hydroxyethyliminodiacetic acid, and ethylene glycol. Higher temperature products are primarily dimethylamine and carbon dioxide. The rates of degradation of Ca(II), Mg(II), and Zn(II) EDTA chelates are considerably enhanced when either phosphate is present or a glass-lined autoclave is employed.

Microstructural Developments During Implantation of Metals

1983 ◽  
Vol 27 ◽  
Author(s):  
D. I. Potter ◽  
M. Ahmed ◽  
S. Lamond
Keyword(s):  
Chemical Composition ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Auger Spectroscopy ◽  
Phase Region ◽  
Dislocation Loops ◽  
Two Phase ◽  
Model Calculations ◽  
Near Surface ◽  
Composition Profiles

ABSTRACTThe chemical and microstructural changes caused by the direct implantation of solutes into metals are examined. The particular case involving Al+-ion implantation into nickel is treated in detail. Chemical composition profiles measured using Auger spectroscopy and Rutherford backscattering, and average near-surface chemical composition measured using an analytical electron microscope, are compared with model calculations. The microstructures that develop during implantation are investigated using transmission electron microscopy. For low fluences implanted near room temperature, these microstructures contain dislocations and dislocation loops. Dislocation loops, dislocations, and voids result from implantations at temperatures near 500°C. Higher fluences at these elevated temperatures produce precipitates when the composition of implanted solute lies in a two-phase region of the phase diagram. Implanted concentrations corresponding to intermetallic compounds produce continuous layers of these compounds. Room temperature, as compared to elevated temperature, implantation may produce the same phases at the appropriate concentrations, e.g. β'-NiAl, or different phases, depending on the relative stability of the phases involved.

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