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Showing 1 to 20 of 30 for “"contact metamorphism"”.
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Studies in mass transport in contact metamorphism,
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Geology and Geophysics, 1968.
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Contact metamorphism of the Lucerne pluton, Hancock Co., Maine
… with quartz. Corundum occurs at the immediate contact of the granite from the. reaction of the remaining muscovite. The Bucksport formation is recrystallized within the aureole to a purple and green gneiss. The gneissic banding is not present in the low grade calcareous rocks, and represents …
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Igneous intrusions and thermal evolution in the Raton Basin, CO-NM: contact metamorphism and coal-bed methane generation
… and petrography. Reflectance values at sill contacts are elevated over a wider zone than for dikes. Coal [delta]¹³C values increase by 1% approaching the contacts of dikes and decrease by approximately 1.5% at sills due to the addition of ¹²C-rich material such as pyrolytic carbon.Xenoliths …
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Contact metamorphism of the Mancos shale: impacts on solute release and weatherability in the East River Valley, Gothic, CO
Alteration of rocks by contact metamorphism directly impacts rock pore structure and mineralogy, potentially decreasing weathering susceptibility and altering water residence times and release rates of aqueous solutes. Mountainous catchments, which can often be metamorphosed, are important for …
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The Effects of Contact Metamorphism by Diabase Intrusion on the Carbon and Sulfur Bearing Phases in the Siltstones of the Culpeper Basin
… which is elevated near the dike-sedimentary contact and at the end of the transect. A simple illustrative model of a hypothesis of fluid flow along the bed is used to explain the observed isotopic signatures and mineralogical changes along the transect. This study highlights how models for …
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Development of novel computational techniques for phase identification and thermodynamic modeling, and a case study of contact metamorphism in the Triassic Culpeper Basin of Virginia
This dissertation develops computational techniques to aid in efficiently studying petrologic systems that would otherwise be challenging. It then focuses on a case study in which the transition from diagenesis to syn-magmatic heating led to a recrystallization and sulfur mobilization. A …
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A magmatic trigger for the Paleocene-Eocene Thermal Maximum?
… during the PETM may have been caused by contact metamorphism of organic-rich sediments. Potential terrestrial and submarine analogs are examined to determine the behavior of these elements during thermal alteration. Furthermore, geochemical evidence from sediment cores at the PETM …
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A magmatic trigger for the Paleocene-Eocene thermal maximum?
… during the PETM may have been caused by contact metamorphism of organic-rich sediments. Potential terrestrial and submarine analogs are examined to determine the behavior of these elements during thermal alteration. Furthermore, geochemical evidence from sediment cores at the PETM …
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Structural geology of the southern Silurian hills, San Bernardino County, Calif
… basic plutonic rocks, and acidic plutonic rocks. Metamorphism reaches high greenschist to low amphibolite grade with an overprint of contact metamorphism caused by the intrusion of the acidic plutonic rocks. The Riggs thrust fault separates the Pahrump Group, which is in the lower plate, from all …
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Exploring the Enstatite Chondrites: Modal Abundances, Metamorphic History, and Volatile Challenges
… formation mechanism on the parent asteroid: contact metamorphism driven by an impact melt sheet. Chapter 3 integrates bulk, in situ, and isotopic volatile measurements, demonstrating that most detected hydrogen (H) is terrestrial contamination rather than indigenous. However, modeling the H …
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Decarbonization related to continental arc magmatism as a possible mechanism for Cretaceous warming
… produced during crustal assimilation and contact metamorphism of carbonates around plutons. Bedrock maps of the North American Cordillera (a region of active continental arc magmatism during the Cretaceous), the relative locations of the carbonates, the Cretaceous plutons, and the …
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From the Appalachians to the Alps: Constraints on the Timing, Duration, and Conditions of Metamorphism at Convergent Margins
… and pressure-temperature (P-T) conditions of metamorphism provide a direct record of the physical and chemical evolution of the crust and inform our knowledge and understanding of plate tectonics. The characteristic timescales and length-scales of metamorphism vary by orders of magnitude, …
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Eo-Variscan Orogenesis in the Guilleries Massif, Catalan Coastal Ranges, Northeastern Spain Recorded by U-Th-Pb ages of Monazite Inclusions in Metamorphic Garnet
… preserve multiple rounds of deformation and metamorphism. The massif records a classic Variscan low-pressure and high-temperature metamorphic field gradient and represents part of the metamorphic core of the Variscan Orogeny. The lack of overprinting from the younger Alpine Orogeny makes the …
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A STRUCTURAL HISTORY OF THE GARNET STOCK AND ITS RELATIONSHIP TO DEFORMATION ALONG THE LEWIS AND CLARK LINE, WESTERN MONTANA
… plane of the neighboring anticline, and the contact aureole was generally confined to the syncline and the steep limb of the anticline-syncline pair. Maximum pressure and temperature of contact metamorphism is estimated at 2.8 kbar and 650°C from thermodynamic modeling of …
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A STRUCTURAL HISTORY OF THE GARNET STOCK AND ITS RELATIONSHIP TO DEFORMATION ALONG THE LEWIS AND CLARK LINE, WESTERN MONTANA
… plane of the neighboring anticline, and the contact aureole was generally confined to the syncline and the steep limb of the anticline-syncline pair. Maximum pressure and temperature of contact metamorphism is estimated at 2.8 kbar and 650°C from thermodynamic modeling of …
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Structural and petrologic aspects of the emplacement of granitoid plutons : case studies from the western margin of the Joshua Flat-Beer Creek-Pluton (White-Inyo Mountains, California) and the Flasergranitoid zone (Odenwald, Germany)
… 664 and 900 °C into a depth of c. 8 km. In the contact aureole three metamorphic zones were distinguished with decreasing distance from the pluton: the andalusite-cordierite, sillimanite, and cordierite-K-feldspar zones, respectively. The Na-in-cordierite thermometer gave c. 730 °C as the peak …
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Development of the Platreef in the northern limb of the Bushveld Complex at Sandsloot, Mokopane District, South Africa
… the Malmani Subgroup. The Platreef magma caused contact metamorphism and metasomatism of the dolomites, releasing volatiles that entered the reef. These hydrothermal fluids stripped PGE from primary sulphides and redistributed the PGE within the reef and into the metasedimentary country rocks. In …
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Petrologic and Fluid Inclusion Constraints on the Tectonic Evolution of the Manhattan Prong, Southeastern New York
… 100 million years, have superimposed contact aureoles on the Taconic regional metamorphic gradient in the northeastern Manhattan Prong and have modified the regional assemblage to different degrees. The assemblage Sil-Bt-Grt-Qtz-Pl+Ksp+Ms in regionally metamorphosed Manhattan Schist …
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Textural and Chemical Relations Among Spinel-Sapphirine-Garnet-Orthopyroxene, Salt Hill Emery Mine, Cortlandt Complex, N.Y.
Very high temperature (>900 °C) contact metamorphism and metasomatism of aluminous schist xenoliths in the mafic to ultramafic Cortlandt Complex, New York, resulted in formation of bodies of unusual Fe- and Al-oxide-rich rock called emery. During contact heating, disequilibrium thermal …
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Igneous and metamorphic processes in the Shap Granite and its aureole
… is lkm wide and 'generally displays limited contact metamorphic reactions apart from in the Blue Quarry, where higher sub—surface heat flow during the granite's intrusion resulted in localised more extreme metamorphic and some metasomatic conditions resulting in the development of garnet …
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