The Experts below are selected from a list of 2028 Experts worldwide ranked by ideXlab platform
Daniel Neuville - One of the best experts on this subject based on the ideXlab platform.
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Magmas are the Largest Repositories and Carriers of Earth’s Redox Processes
Elements, 2020Co-Authors: Maria Cicconi, Charles Le Losq, Roberto Moretti, Daniel NeuvilleAbstract:Magma is the most important chemical transport agent throughout our planet. This paper provides an overview of the interplay between magma redox, major element chemistry, and crystal and volatile content, and of the influence of redox on the factors that drive Igneous system dynamics. Given the almost infinite combinations of temperature, pressure, and chemical compositions relevant to Igneous Petrology, we focus on the concepts and methods that redox geochemistry provides to understand magma formation, ascent, evolution and crystallization. Particular attention is paid to the strong and complex interplay between melt structure and chemistry, and to the influence that redox conditions have on melt properties, crystallization mechanisms and the solubility of volatile components.
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Magmas , the Largest Repositories and Carriers of Earth’s Redox Processes
Elements, 2020Co-Authors: Maria Cicconi, Charles Le Losq, Roberto Moretti, Daniel NeuvilleAbstract:Magma is the most important chemical transport agent throughout our planet. This paper provides an overview of the interplay between magma redox, major element chemistry, and crystal and volatile content, and of the influence of redox on the factors that drive Igneous system dynamics. Given the almost infinite combinations of temperature, pressure, and chemical compositions relevant to Igneous Petrology, we focus on the concepts and methods that redox geochemistry provides to understand magma formation, ascent, evolution and crystallization. Particular attention is paid to the strong and complex interplay between melt structure and chemistry, and to the influence that redox conditions have on melt properties, crystallization mechanisms and the solubility of volatile components.
Charles E. Lesher - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic and Transport Properties of Silicate Melts and Magma
The Encyclopedia of Volcanoes, 2015Co-Authors: Charles E. Lesher, Frank J. SperaAbstract:Abstract Petrogenetic problems including the generation, segregation, ascent, storage, differentiation, contamination, eruption, and solidification of magma to form volcanic and plutonic rocks can only be quantified by artful consideration of the fundamental thermodynamic and transport properties of melts and multiphase magmas. Critically important thermodynamic properties include density, heat capacity, volatile solubility, enthalpy, entropy, and volume of fusion, liquidus temperatures and the variations of all properties with temperature, pressure, and composition. Magma transport is governed by conservation of energy, momentum, and mass that depends on thermal conductivity, shear viscosity, and diffusivity (tracer, chemical and isotopic), and varies with temperature, pressure, composition, phase proportions, and shear rates in complex and interwoven ways. In this chapter magma properties are reviewed in the context of petrogenesis and transport phenomena together with underlying theory. Results are presented both graphically and in tabular form providing a survey across the dominant compositions and conditions relevant to Igneous Petrology.
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on the skaergaard intrusion and forward modeling of its liquid line of descent a reply to principles of applied experimental Igneous Petrology by morse 2008 lithos 105 pp 395 399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, Kent C BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
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On the Skaergaard intrusion and forward modeling of its liquid line of descent: A reply to “Principles of applied experimental Igneous Petrology” by Morse, 2008, Lithos 105, pp. 395−399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, C. Kent BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
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Case-Based Learning in an Upper Level Petrology Laboratory Class
Journal of Geoscience Education, 2007Co-Authors: Lara E. Heister, Charles E. LesherAbstract:We designed new laboratory exercises for undergraduate Igneous Petrology that teach the fundamentals of petrography and Petrology within the framework of tectonic environments. Our exercises are designed to promote the use of the scientific method by requiring students to collect and use data to test hypotheses and petrogenetic concepts presented in lecture. The integration of fundamental concepts of Petrology with geologic and tectonic settings, in our case drawing on the diversity found in California, allows for the introduction of more advanced material in both the laboratory and lecture portions of the course. Student written feedback and performance on exams, laboratory exercises, and final projects reflect an increased understanding of the subject matter and confidence in problem solving. This type of class structure is transportable to programs in any location, can be used for classes of reasonable size, and is an effective method to teach science classes at either an introductory or advanced level.
Peter Thy - One of the best experts on this subject based on the ideXlab platform.
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on the skaergaard intrusion and forward modeling of its liquid line of descent a reply to principles of applied experimental Igneous Petrology by morse 2008 lithos 105 pp 395 399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, Kent C BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
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On the Skaergaard intrusion and forward modeling of its liquid line of descent: A reply to “Principles of applied experimental Igneous Petrology” by Morse, 2008, Lithos 105, pp. 395−399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, C. Kent BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
Kent C Brooks - One of the best experts on this subject based on the ideXlab platform.
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on the skaergaard intrusion and forward modeling of its liquid line of descent a reply to principles of applied experimental Igneous Petrology by morse 2008 lithos 105 pp 395 399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, Kent C BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
C. Kent Brooks - One of the best experts on this subject based on the ideXlab platform.
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On the Skaergaard intrusion and forward modeling of its liquid line of descent: A reply to “Principles of applied experimental Igneous Petrology” by Morse, 2008, Lithos 105, pp. 395−399
Lithos, 2008Co-Authors: Peter Thy, Charles E. Lesher, Troels F.d. Nielsen, C. Kent BrooksAbstract:Abstract Forward modeling based on an experimental investigation successfully duplicated main features of the gabbros in the Skaergaard layered series [Thy, P., Lesher, C.E., Nielsen, T.F.D., and Brooks, C.K. 2006. Experimental constraints on the Skaergaard liquid line of descent. Lithos 92, 154–180.]. The foundation for the modeling was equilibrium melting experiments that were controlled by temperature and oxygen fugacity at low-pressure conditions. The experimental techniques and methods were chosen to represent a reasonable approximation to the inferred emplacement and crystallization conditions of the Skaergaard intrusion. The dike rocks used as starting materials define a strong differentiation trend that represents the Skaergaard liquid line of descent. This suite of dikes allowed liquidus conditions to be defined for a range of composition and temperature. The initial redox conditions were chosen based on measured and calculated estimates for the gabbros of interest. The melting experiments defined liquidus and subliquidus conditions that were used to understand crystallization of the lower and middle zones of the Skaergaard layered series, and can be extrapolated to the upper zone gabbros assuming perfect fractional crystallization. The forward modeling reproduces the cryptic variation seen in the main gabbro minerals (olivine, augite, plagioclase) well into the upper zone and provides reasonable liquidus temperatures and compositions. It can be shown that based on the assumption of Fe–Ti oxide modes in the middle and upper zones, a range of oxygen fugacity trends can be obtained. We repeat our previous conclusion that iron depletion and strong reduction in oxygen fugacity in the upper zone are only feasible for very high Fe–Ti oxide modes that exceed the experimental evidence as well as the observations from the gabbros. A strong drop in oxygen fugacity in the upper zone requires a significant sink for Fe–Ti oxides that so far has not been identified. We thus reject Morse's [Morse, S.A., 2008. Principles of applied experimental Igneous Petrology: a comment on “Experimental Constraints on the Skaergaard liquid line of descent” by Thy, Lesher, Nielsen, and Brooks, 2006, Lithos 92: 154–180. Lithos 105, pp. 395−399.] contention that we violated in our original study established principles of applied experimental Igneous Petrology. Such principles dictate that experimental and forward models are carefully tested against field observations before petrologic processes can be verified.
