Thermal mechanisms of basin formation

1982 ◽  
Vol 305 (1489) ◽  
pp. 283-294 ◽  
Keyword(s):  
Similarity Solution ◽  
Flexural Rigidity ◽  
Thermal Evolution ◽  
Sedimentary Basins ◽  
Relative Volume ◽  
Ocean Ridges ◽  
Wide Range ◽  
Subsequent Conversion ◽  
Basin Formation ◽  
Thermal Subsidence

Thermal subsidence of the sea floor explains the observed bathymetry of ocean ridges. A similarity solution for a one-dimensional cooling model successfully predicts bathymetry, heat flow and geoid anomalies under a wide range of conditions. This similarity solution can be modified to predict the thermal subsidence of sedimentary basins. For older sedimentary basins it is necessary to consider an input of heat to the base of the lithosphere that places a limit on subsidence. The similarity solution for thermal subsidence is in quite good agreement with the observed subsidence history of a variety of sedimentary basins. Some basins subside freely and in others the flexural rigidity of the elastic lithosphere inhibits subsidence. An empirical model is proposed for the conversion of kerogen to oil and the subsequent conversion of oil to gas. This model is then used in conjunction with the thermal evolution predicted by the similarity solution in order to determine the oil window and relative volume of oil as a function of the age of the basin.

Terrane provenance and amalgamation: examples from the Caledonides

1990 ◽  
Vol 331 (1620) ◽  
pp. 599-609 ◽  
Keyword(s):  
Sedimentary Basins ◽  
Fault Zones ◽  
River Systems ◽  
Pan African ◽  
Basin Formation ◽  
Laurentian Margin

The Scottish Caledonides have grown by the accretion of terranes generated somewhere along the Laurentian margin. By the time these terranes had been emplaced along the Scottish sector, they were structurally truncated then reassembled to form an incomplete collage of indirectly related tectonic elements of a destructive margin. The basement to some of these tectonic elements and the basement blocks belonging to the previously accreted Precambrian are of uncertain provenance and a source in the Pan-African craton is possible. As terranes migrate along the orogen they generate in the fault zones and on their periphery a reservoir of mature sediment. This mature sediment is produced because of the recycling produced during the generation and destruction of sedimentary basins developing during terrane translation. At each period of recycling the mature sediments are mixed with less mature sediments yielded from local uplifts generated by the new basin formation. If a large part of the orogen suffers orthogonal closure, giant river systems may form and disperse sediment across terranes. This is likely to have happened during the Devonian-Carboniferous of parts of N. Europe.

Analysis of Cu(InGa)Se2 Alloy Film Optical Properties and the Effect of Cu Off-Stoichiometry

2005 ◽  
Vol 865 ◽  
Author(s):  
P. D. Paulson ◽  
S. H. Stephens ◽  
W. N. Shafarman
Keyword(s):  
Optical Constants ◽  
Soda Lime ◽  
Alloy Film ◽  
Relative Volume ◽  
Soda Lime Glass ◽  
Distinctive Features ◽  
Glass Substrates ◽  
Wide Range ◽  
Two Phases

AbstractVariable angle spectroscopic ellipsometry has been used to characterize Cu(InGa)Se2 thin films as a function of relative Ga content and to study the effects of Cu off-stoichiometry. Uniform Cu(InGa)Se2 films were deposited on Mo-coated soda lime glass substrates by elemental evaporation with a wide range of relative Cu and Ga concentrations. Optical constants of Cu(InGa)Se2 were determined over the energy range of 0.75–C4.6 eV for films with 0 ≤ Ga/(In+Ga) ≤ 1 and used to determine electronic transition energies. Further, the changes in the optical constants and electronic transitions as a function of Cu off-stoichiometry were determined in Cu-In-Ga-Se films with Cu atomic concentration varying from 10 to 25 % and Ga/(In+Ga) = 0.3. Films with Cu in the range 16–24 % are expected to contain 2 phases so an effective medium approximation is used to model the data. This enables the relative volume fractions of the two phases, and hence composition, to be determined. Two distinctive features are observed in the optical spectra as the Cu concentration decreases. First, the fundamental bandgaps are shifted to higher energies. Second, the critical point features at higher energies become broader suggesting degradation of the crystalline quality of the material.

Analysis of Residual Stresses on the Vibration of a Circular Sensor Diaphragm with Surface Effects

2016 ◽  
Vol 33 (3) ◽  
pp. 323-329 ◽  
Author(s):  
S.-S. Zhou ◽  
S.-J. Zhou ◽  
A.-Q. Li ◽  
B.-L. Wang
Keyword(s):  
Residual Stresses ◽  
Natural Frequency ◽  
Flexural Rigidity ◽  
Plate Theory ◽  
Surface Elasticity ◽  
Surface Effects ◽  
Transition Range ◽  
Biochemical Sensors ◽  
Tension Parameter ◽  
Wide Range

AbstractResonant micro-biochemical sensors play important roles in a wide range of emerging applications to detect biochemical molecules. As the resonators of micro-biochemical sensors, the vibration characteristics of circular sensor diaphragms are important for the design of diaphragm-based resonant micro-biochemical sensors. In this paper, the influence of residual stresses on the vibration of a circular sensor diaphragm with surface effects is analyzed. Based on the Kirchhoff's plate theory and surface elasticity theory, the governing equation is presented. The material characteristic lengths for different surface effects are obtained. The influences of residual stresses on the effective flexural rigidity and natural frequency of the diaphragm with surface effects are discussed. Results show that the influence of residual stresses on the effective flexural rigidity becomes obvious with the increasing of residual stresses. The first order natural frequency increases rapidly when the tension parameter is larger than 30 for the stiffened surfaces, while for the softened surfaces the value is 10. Moreover, surface effects can influence the transition range of diaphragm from the plate behavior to membrane behavior in terms of the tension parameter. The transition range can be enlarged by the stiffened surface and be shortened by the softened surface. The analysis and results are helpful for the design of sensor diaphragm-based resonant micro-biochemical sensors and some related researches.

scholarly journals Basin formation by thermal subsidence of accretionary orogens

2015 ◽  
Vol 639 ◽  
pp. 132-143 ◽  
Author(s):  
P.J. Holt ◽  
M.B. Allen ◽  
J. van Hunen
Keyword(s):  
Basin Formation ◽  
Thermal Subsidence

Analysis of Contact Mechanics for Rotor-Bristle Interference of Brush Seal

2003 ◽  
Vol 125 (2) ◽  
pp. 414-421 ◽  
Author(s):  
R. J. Stango ◽  
H. Zhao ◽  
C. Y. Shia
Keyword(s):  
Contact Force ◽  
Flexural Rigidity ◽  
Operating Conditions ◽  
Contact Forces ◽  
Design Parameters ◽  
Attractive Alternative ◽  
Seal Design ◽  
Brush Seal ◽  
Wide Range ◽  
Deformation Mechanics

Brush seals have proven to be an attractive alternative to labyrinth seals for turbomachinery applications. This innovation in seal technology utilizes both the high temperature capability of special-alloy wire and the flexural adaptability of fibers to accommodate a wide range of operating conditions that are encountered during service. The effectiveness of the seal is principally derived from the bristles ability to endure forces imparted by both the fluid and shaft, and yet maintain contact between the filament tips and the surface of the rotor. Consequently, contact forces generated along the interface of the fiber tip and rotor are an important consideration for both the design and performance of the rotor-seal assembly. This paper focuses on evaluating brush seal forces that arise along the surface of the rotor due to the dimensional disparity or interference between the rotor-fiber. Filament tip contact forces are computed on the basis of an in-plane, large deformation mechanics analysis of a cantilever beam, and validation of the model is assessed by using an electronic balance for measuring the shear and normal force exerted by a bristle tip onto a flat, hardened surface. Formulation of the mechanics problem is briefly reviewed, and includes the effect of Coulombic friction at the interface of the fiber tip and rotor. Filament contact force is used as a basis for computing bearing stress along the fiber-rotor interface. Results are reported for a range of brush seal design parameters in order to provide a better understanding of the role that seal geometry, friction, and bristle flexural rigidity play in generating rotor contact force.

Planetary heat flow measurements

2005 ◽  
Vol 363 (1837) ◽  
pp. 2777-2791 ◽  
Author(s):  
Axel Hagermann
Keyword(s):  
Heat Flow ◽  
Thermal Evolution ◽  
Tectonic Activity ◽  
Heat Sources ◽  
Flow Measurements ◽  
Planetary Body ◽  
Ocean Ridges ◽  
Heat Engines ◽  
Rosetta Mission ◽  
History Of

The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it? Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing ‘dead balls of rock, ice or gas’ to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments.

scholarly journals Mineralogical Evolution of the Cretaceous Strata in the Songliao Basin, Northeastern China: Implications for Thermal History and Paleoenvironmental Evolution

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1101
Author(s):  
Tian Dong ◽  
Yuan Gao ◽  
He Huang ◽  
Xing Tian ◽  
Qian Yang ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Thermal History ◽  
Environmental Changes ◽  
Thermal Evolution ◽  
Sedimentary Basins ◽  
Northeastern China ◽  
Songliao Basin ◽  
Published Data ◽  
Burial Depth ◽  
Geothermal Resources

The Songliao Basin in northeastern China is one of the largest and longest-lived Cretaceous sedimentary basins enriched in petroleum and geothermal resources worldwide. Although the modern Songliao Basin has a high geothermal gradient, the geological thermal history of the basin has not been well constrained. The SK-2 drilling program, as the second stage of the International Continental Drilling Project of Cretaceous Songliao Basin, is for recovering extensive Early Cretaceous terrestrial strata and providing valuable materials for decoding the mineralogical evolution and the paleoenvironmental changes. Here, we present whole-rock and clay mineralogical analysis on 72 core samples covering 3346–5705 m of the Shahezi Formation in the SK-2 borehole. The whole-rock minerals mainly include clay minerals, quartz, plagioclase, as well as some calcite, K-feldspar, siderite, and pyrite. The clay mineral assemblages include illite, chlorite, and illite–smectite interlayer minerals. Above 4500 m, clay minerals are dominated by illite and illite–smectite interlayers. Below 4500 m, more plagioclase, K-feldspar, and calcite are present, while illite–smectite interlayers are completely replaced by illite. The whole-rock and clay mineralogical evolution of the Shahezi Formation is primarily controlled by thermal diagenesis, although paleoenvironmental change may act as a minor contribution. Combined with published data from the Upper Cretaceous in SK-1 cores, we infer that Cretaceous greenhouse climatic and environmental changes left fingerprints on whole-rock and clay mineralogical assemblages and that the Songliao Basin reached a maximum burial depth and a peak of thermal evolution at the end of the Cretaceous.

scholarly journals SILLi 1.0: A 1D Numerical Tool Quantifying the Thermal Effects of Sill Intrusions

2017 ◽  
Author(s):  
Karthik Iyer ◽  
Henrik Svensen ◽  
Daniel W. Schmid
Keyword(s):  
Thermal Effects ◽  
Thermal Evolution ◽  
Thermal Structure ◽  
Sedimentary Basins ◽  
Gas Generation ◽  
Porosity Evolution ◽  
Karoo Basin ◽  
Igneous Intrusions ◽  
User Friendly ◽  
Latent Heats

Abstract. Igneous intrusions in sedimentary basins may have a profound effect on the thermal structure and physical properties of the hosting sedimentary rocks. These include mechanical effects such as deformation and uplift of sedimentary layers, generation of overpressure, mineral reactions and porosity evolution, and fracturing and vent formation following devolatilization reactions and the generation of CO2 and CH4. The gas generation and subsequent migration and venting may have contributed to several of the past climatic changes such as the end-Permian event and the Paleocene-Eocene Thermal Maximum. Additionally, the generation and expulsion of hydrocarbons and cracking of pre-existing oil reservoirs around a hot magmatic intrusion is of significant interest to the energy industry. In this paper, we present a user-friendly 1D FEM based tool, SILLi, which calculates the thermal effects of sill intrusions on the enclosing sedimentary stratigraphy. The model is accompanied by three case studies of sills emplaced in two different sedimentary basins, the Karoo Basin in South Africa and the Vøring Basin offshore Norway. Input data for the model is the present-day well log or sedimentary column with an Excel input file and includes rock parameters such as thermal conductivity, total organic carbon (TOC) content, porosity, and latent heats. The model accounts for sedimentation and burial based on a rate calculated by the sedimentary layer thickness and age. Erosion of the sedimentary column is also included to account for realistic basin evolution. Multiple sills can be emplaced within the system with varying ages. The emplacement of a sill occurs instantaneously. The model can be applied to volcanic sedimentary basins occurring globally. The model output includes the thermal evolution of the sedimentary column through time, and the changes that take place following sill emplacement such as TOC changes, thermal maturity, and the amount of organic and carbonate-derived CO2. The TOC and vitrinite results can be readily benchmarked within the tool to present-day values measured within the sedimentary column. This allows the user to determine the conditions required to obtain results that match observables and leads to a better understanding of metamorphic processes in sedimentary basins.

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