scholarly journals Post-entrapment modification of residual inclusion pressure and its implications for Raman elastic thermobarometry

Solid Earth ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 223-240 ◽  
Author(s):  
Xin Zhong ◽  
Evangelos Moulas ◽  
Lucie Tajčmanová
Keyword(s):  
Thin Section ◽  
Pressure Field ◽  
Residual Pressure ◽  
Mineral Inclusions ◽  
Plastic Yield ◽  
Section Surface ◽  
Temperature And Pressure ◽  
Viscous Relaxation ◽  
T Path ◽  
Differential Expansion

Abstract. Residual pressure can be preserved in mineral inclusions, e.g. quartz-in-garnet, after exhumation due to differential expansion between inclusion and host crystals. Raman spectroscopy has been applied to infer the residual pressure and provides information on the entrapment temperature and pressure conditions. However, the amount of residual pressure relaxation cannot be directly measured. An underestimation or overestimation of residual pressure may lead to significant errors between calculated and actual entrapment pressure. This study focuses on three mechanisms responsible for the residual pressure modification: (1) viscous creep; (2) plastic yield; (3) proximity of inclusion to the thin-section surface. Criteria are provided to quantify how much of the expected residual pressure is modified due to these three mechanisms. An analytical solution is introduced to demonstrate the effect of inclusion depth on the residual pressure field when the inclusion is close to the thin-section surface. It is shown that for a quartz-in-garnet system, the distance between the thin-section surface and inclusion centre needs to be at least 3 times the inclusion radius to avoid pressure release. In terms of viscous creep, representative case studies on a quartz-in-garnet system show that viscous relaxation may occur from temperatures as low as 600–700 ∘C depending on the particular pressure–temperature (P–T) path and various garnet compositions. For quartz entrapped along the prograde P–T path and subject to viscous relaxation at peak T above 600–700 ∘C, its residual pressure after exhumation may be higher than predicted from its true entrapment conditions. Moreover, such a viscous resetting effect may introduce apparent overstepping of garnet nucleation that is not related to reaction affinity.

scholarly journals The relaxation of residual inclusion pressure and implications to Raman-thermobarometry

2019 ◽  
Author(s):  
Xin Zhong ◽  
Evangelos Moulas ◽  
Lucie Tajčmanová
Keyword(s):  
Thin Section ◽  
Pressure Field ◽  
Residual Pressure ◽  
Pressure Relaxation ◽  
Mineral Inclusions ◽  
Plastic Yield ◽  
Section Surface ◽  
Temperature And Pressure ◽  
T Path ◽  
Differential Expansion

Abstract. Residual pressure can be preserved in mineral inclusions, e.g. quartz-in-garnet, after exhumation due to differential expansion between inclusion and host crystals. Raman spectroscopy has been applied to infer the residual pressure and provides information on the entrapment temperature and pressure conditions. However, the amount of residual pressure relaxation cannot be directly measured. An underestimation of pressure relaxation may lead to significant errors between calculated and actual entrapment pressure. This study focuses on three mechanisms responsible for the residual-pressure relaxation: 1) viscous creep; 2) plastic yield; 3) proximity of inclusion to thin-section surface. Criteria are provided to quantify how much of the expected residual pressure is relaxed due to these three mechanisms. An analytical solution is introduced to demonstrate the effect of inclusion depth on the residual pressure field when the inclusion is close to thin-section surface. It is shown that for quartz-in-garnet system, the distance between thin-section surface and inclusion centre needs to be at least two times the inclusion radius to avoid pressure relaxation. In terms of viscous creep, representative case studies on quartz-in-garnet system show that viscous relaxation may occur from temperatures as low as 600∼700 °C depending on the particular P-T path and various garnet compositions. For quartz entrapped along the prograde P-T path and subject to viscous resetting at peak T above 600∼700 °C, its residual pressure after exhumation may be higher than predicted from its true entrapment conditions. Moreover, such a viscous resetting effect may introduce apparent overstepping of garnet nucleation that is not related to reaction affinity.

Viscous relaxation of mineral Inclusions and its implications for reaction overstepping calculations in metamorphic rocks

2020 ◽  
Author(s):  
Evangelos Moulas ◽  
Xin Zhong ◽  
Lucie Tajcmanova
Keyword(s):  
Independent Method ◽  
Metamorphic Rocks ◽  
Additional Method ◽  
Natural Systems ◽  
Long Period ◽  
Mineral Inclusions ◽  
Large Peak ◽  
Viscous Relaxation ◽  
T Path ◽  
Temperature Time

<p>Over the recent years, Raman elastic barometry has been developed as an additional method <span>to calculate</span> metamorphic conditions in natural systems. A major advantage of Raman elastic barometry is that it does not depend on thermodynamic databases and classic geobarometry methods <span>but</span> relies on mechanical calculations. As a consequence, Raman elastic barometry offers an independent method for estimating the pressure conditions <span>that prevailed at the</span> <span>time of entrapment</span> of mineral<span>s</span> du<span>ring</span> growth of their host<span>s</span>.</p><p>The di<span>fference between</span> the pressure calculated <span>using</span> elastic geobarometry and <span>that calculated by phase</span> equilibria methods has recently <span>been employed to</span> <span>estimate</span> the extent of metamorphic reaction overstepping in natural systems. <span>Quantification of</span> the <span>latter however implicitly assumes that the rheology</span> of the inclusion-host system <span>is perfectly</span> elastic. This assumption may no<span>t</span> hold at high temperatures, where viscous creep of minerals takes place.</p><p>The amount of viscous relaxation of <span>a host-inclusion</span> system is a path<span>-</span>dependent quantity which mostly depends on the temperature-time (T-t) path <span>followed</span>. <span>Here</span>, we present examples of visco-elastic relaxation of mineral inclusions and calculate the apparent reaction overstepping which results by assuming that the mechanical system is purely elastic. <span>Our modelling shows</span> that host-inclusion systems <span>that</span> experienced large peak temperatures for long period<span>s</span> of time will retain inclusion residual pressures that <span>cann</span>ot be simply related to the growth of the<span>ir hosts</span> and should <span>therefore not</span> be used for reaction overstepping calculations.</p>

scholarly journals Designing a top cooling system for an electromagnetic calorimeter

2021 ◽  
Vol 345 ◽  
pp. 00015
Author(s):  
Matěj Jeřábek ◽  
Michal Volf ◽  
Daniel Duda
Keyword(s):  
Numerical Simulation ◽  
Pressure Field ◽  
Cooling System ◽  
Flow Simulation ◽  
Electromagnetic Calorimeter ◽  
3D Flow ◽  
Commercial Software ◽  
Pressure Fields ◽  
Detailed Evaluation ◽  
Temperature And Pressure

The article describes a numerical simulation of flow in the cooling system of an electromagnetic calorimeter by analysing the temperature and pressure fields. Two fundamentally different approaches were used to analyse the pressure field - analytical 1D calculation and numerical 3D flow simulation. The article contains a detailed evaluation and description of individual analyses using the commercial software ANSYS 2020 R1.

scholarly journals Investigation and application of wellbore temperature and pressure field coupling with gas–liquid two-phase flowing

2021 ◽  
Author(s):  
Jie Zheng ◽  
Yihua Dou ◽  
Zhenzhen Li ◽  
Xin Yan ◽  
Yarong Zhang ◽  
...  
Keyword(s):  
Single Phase ◽  
Phase State ◽  
Pressure Field ◽  
Coupling Model ◽  
High Water ◽  
Two Phase ◽  
Gas Well ◽  
Single Phase State ◽  
Wellbore Temperature ◽  
Temperature And Pressure

AbstractWith the development of gas well exploitation, the calculation of wellbore with single-phase state affected by single factor cannot meet the actual needs of engineering. We need to consider the simulation calculation of complex wellbore environment under the coupling of multiphase and multiple factors, so as to better serve the petroleum industry. In view of the problem that the commonly used temperature and pressure model can only be used for single-phase state under complex well conditions, and the error is large. Combined with the wellbore heat transfer mechanism and the calculation method of pipe flow pressure drop gradient, this study analyzes the shortcomings of Ramey model and Hassan & Kabir model through transient analysis. Based on the equations of mass conservation, momentum conservation and energy conservation, and considering the interaction between fluid physical parameters and temperature and pressure, the wellbore pressure coupling model of water-bearing gas well is established, and the Newton Raphael iterative method is used for MATLAB programming. On this basis, the relationship between tubing diameter, gas production, gas–water ratio, and wellbore temperature field and pressure field in high water-bearing gas wells is discussed. The results show that the wellbore temperature pressure coupling model of high water-bearing gas well considering the coupling of gas–liquid two-phase flow wellbore temperature pressure field has higher accuracy than Ramey model and Hassan & Kabir model, and the minimum coefficients of variation of each model are 0.022, 0.037 and 0.042, respectively. Therefore, the model in this study is highly consistent with the field measured data. Therefore, the findings of this study are helpful to better calculate the wellbore temperature and pressure parameters under complex well conditions.

Contamination of thin sections, cause and elimination

1978 ◽  
Vol 36 (2) ◽  
pp. 78-79 ◽  
Author(s):  
Hilton H. Mollenhauer ◽  
D. James Morré
Keyword(s):  
Thin Section ◽  
Surface Contamination ◽  
Thin Sections ◽  
Section Surface ◽  
Extraneous Material ◽  
Possible Cause

Contamination of thin sections is a problem that has undoubtedly been experienced by most, if not all, electron microscopists. By section contamination, we refer to any extraneous material in, or on, a thin section. Section contamination is not only a nuisance to the investigator but a serious waste of time and a possible cause of image misinterpretation. Section contamination usually appears sporatically and can often be solved by changes in the fixation, embedding, or staining procedures. However, the true cause of section contamination is only occasionally identified. Four types of section contamination are described in this report along with potential causes and remedies.SURFACE CONTAMINATION is defined as any extraneous material on the surface of a section. Surface contamination occurs during the poststaining procedure and is perhaps the most common and easiest to recognize of the four section contaminations being discussed. Sections look "dirty" and the contaminating particles may be both large and dense.

Mafic granulites of the Schirmacher region, East Antarctica: fluid inclusion and geothermobarometric studies focusing on the Proterozoic evolution of the crust

1997 ◽  
Vol 88 (1) ◽  
pp. 1-17 ◽  
Author(s):  
D. Rameshwar Rao ◽  
Rajesh Sharma ◽  
N. S. Gururajan
Keyword(s):  
Fluid Inclusion ◽  
Geothermal Gradient ◽  
East Antarctica ◽  
Compositional Zoning ◽  
T Box ◽  
History Of ◽  
Mineral Data ◽  
Temperature And Pressure ◽  
T Path ◽  
General Correspondence

AbstractIn the Proterozoic complex of the Schirmacher region of East Antarctica, a retrograde pressure–temperature (P–T) history has been inferred through quantitative geothermobarometry and fluid inclusion studies of the mafic granulites. Microthermometric investigations of the fluid phases trapped in quartz and garnet identified three types of inclusions, namely, earliest pure CO2 inclusions (0·987–1·057 g cm−3), CO2–H2O inclusions and aqueous inclusions.The temperature and pressure of metamorphism have been estimated through different calibrations of geothermometers and geobarometers. The mineral reactions and compositional zoning in the minerals record P–T conditions from nearly 837 ± 26°C, 7·1±0·2 kbar to 652 ± 33°C, 5·9 ± 0·3 kbar. A good correlation between the fluid and mineral data is observed. The isochores typical of highdensity CO2 fluids fall well within the P–T box estimated by mineral thermobarometry. The abundance of primary CO2 inclusions in early metamorphic minerals (notably quartz and primary garnet) and the general correspondence between fluid and mineral P–T data indicate a ‘fluid-present’ carbonic regime for the high-grade metamorpism; however, from the present data largescale CO2 advection could not be envisaged. The subsequent stages involved a decrease in CO2 density, a progressive influx of hydrous fluids and the generation of retrograde amphibolite facies metamorphism in the area.The estimated P–T conditions of the region suggest that the rocks were metamorphosed at a depth of 19–24 km, with a geothermal gradient of c. 3°5C km−1. The estimated P–T conditions of the rocks imply a clockwise P–T–t path with a gradual decrease in temperature of around 250°C and a decrease in pressure of around 1700 bar. They have a dP/dT gradient of ≈7 ± l bar °C−1, arguing for an isobaric cooling history of the terrane under normal thickened crust after the underplating of mantle-derived material.

scholarly journals Preembedding labeling with biotinylated antibodies and subsequent visualization of the biotin groups exposed on thin sections.

1984 ◽  
Vol 32 (6) ◽  
pp. 643-648 ◽  
Author(s):  
I Nir ◽  
B G Schneider ◽  
D S Papermaster
Keyword(s):  
Thin Section ◽  
Intracellular Localization ◽  
Exposed Surface ◽  
Nonspecific Binding ◽  
Reaction Conditions ◽  
Thin Sections ◽  
Retinal Tissue ◽  
Cellular Events ◽  
Section Surface ◽  
Optimal Reaction

The feasibility of labeling cell membranes with biotinylated ligands and detecting the biotin groups on thin sections was investigated. Fixed retinal tissue was incubated with biotinyl- antiopsin . Half of the biotinyl-antibody labeled retinal tissue was incubated with avidin-ferritin (AvF) and embedded in Epon (preembedding reaction). The second half was embedded in glutaraldehyde cross-linked bovine serum albumin (BSA). Thin sections of this preparation were incubated with AvF to detect biotinyl-antibodies exposed by the sectioning (postembedding reaction). Biotin groups on the thin section surface could be readily visualized with AvF. Stereoscopic images demonstrated that the ferritin particles were localized only on the exposed surface of the thin section. The labeling was highly specific, with a very low background. Quantitative analysis was employed in order to determine the optimal reaction conditions for maximizing the labeling density with minimizing nonspecific binding. The possibility of using biotinylated molecules in the study of dynamic cellular events and for the subsequent intracellular localization of biotin on thin sections is suggested.

scholarly journals Evaluation of Natural Ventilation on Temperature and Pressure Distribution in a Road Tunnel Fire with Vertical Shaft

2015 ◽  
Vol 55 ◽  
pp. 79-85
Author(s):  
I. Benabdelaziz ◽  
M. Bouterra ◽  
Afif El Cafsi ◽  
A. Belghith
Keyword(s):  
Natural Ventilation ◽  
Pressure Field ◽  
Reduction Rate ◽  
Vertical Shaft ◽  
Road Tunnel ◽  
Urban Road ◽  
Eddy Simulation ◽  
Tunnel Fire ◽  
Large Eddy ◽  
Temperature And Pressure

This paper has analysed the influence of plug-holing on thermal and pressure field evolution in urban road tunnel fires with vertical shaft by Large Eddy Simulation (LES). Results show that the temperature reduction rate is about 70 % at the tunnel half and it increases about 80 % at the ceiling level. The pressure field is characterized by a pseudo-periodic behavior which reaches a maximum reduction rate (78 %) in case of natural ventilation. The numerical tool used is FDS (version 5).

scholarly journals Meteorological measurements and observations at Zákupy in 1718-1720

Geografie ◽  
2002 ◽  
Vol 107 (1) ◽  
pp. 1-22
Author(s):  
Rudolf Brázdil ◽  
Hubert Valášek
Keyword(s):  
Air Temperature ◽  
Surface Pressure ◽  
Wind Direction ◽  
Pressure Field ◽  
Temperature And Pressure ◽  
Meteorological Observations ◽  
Reconstructed Surface ◽  
Czech Lands

Meteorological observations of the physician Johann Carl Rost at Zákupy (north Bohemia) in the years 1718-1720, published in the overviews of meteorological observations from several European localities by a Wrocław physician Johann Kanold, are analysed. Whereas from October 1718 to December 1719 and from April to December 1720 it is only summary monthly information, from 21 December 1719 to 31 March 1720 Rost performed three times a day measurements of air temperature and pressure and observations of the wind direction and the course of the weather. These records are the object of detailed climatological analysis, completed by the reconstructed surface pressure field of these months. The summarising monthly information is compared with accessible data of Czech narrative sources. Rost's observations are so far the oldest systematic instrumental measurements in the Czech Lands.

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