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Showing 1 to 7 of 7 for “"Porphyroblast growth"”.
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Relative Timing of Porphyroblast Growth and Peak Metamorphism in the Lower Granite Gorge, Grand Canyon, Arizona.
… and similar in morphology to, S2 indicating that porphyroblasts grew late or after S2 fabric development. Post-porphyroblast movements on S2 fabric involved rotation of porphyroblasts relative to matrix, shearing, and bending of S2 around porphyroblasts. Post-porphyroblast matrix coarsening …
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Microprobe dating of monazite in relation to porphyroblast growth and thermodynamic modelling P-T paths for rocks affected by prolonged orogenesis
… relative timing of distinct periods of garnet growth has been previously established through detailed microstructural analysis of foliation intersection axes (FIAs) of inclusion trails in garnet porphyroblast. Compositional mapping and in-situ microprobe analyses of monazite grains reveal that …
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Combining microstructural analysis with EPMA monazite geochronology to constrain progressive stages of orogenesis in the Appalachians
Microstructural relationships between porphyroblasts and the matrix have been frequently used to infer the relative timing of porphyroblast growth in deformed and metamorphosed terrains (Bell and Rubenach, 1983; Bell et al., 1986; Schulz, 1990; Barker, 1994; Williams, 1994). Although the …
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Structural and metamorphic evolution of the Robertson River metamorphics with pressure-temperature-deformation-time (P-T-D-t) path
… relationships of inclusion trail geometries in porphyroblasts relative to matrix foliations is vital for unravelling complex deformation and metamorphic histories in highly tectonized terranes and the approach used to thin sectioning rocks is critically important for this. Two approaches have …
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Reconciling the structural and metamorphic record of orogeny in central western New Hampshire through microstructure and garnet isopleth thermobarometry
… a previously defined relative timing scheme for porphyroblast growth that was based on Foliation Intersection Axes preserved within porphyroblast (FIA). Additionally, a tectonic model for central western New Hampshire is presented that explains several key geological features of the region that …
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Geology of the Ashe Formation between Fries and Galax, Virginia
… which strikes N 50° E and dips SE. Metamorphic porphyroblast growth of biotite, garnet, staurolite, and kyanite followed penetrative foliation development, with metamorphic grade increasing stratigraphically upward to form inverted isograds. Thrust faulting along the Fries Fault caused extensive …
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Petrology of the Taconian-Acadian Overlap Zone, Hartland Belt, Western Connecticut
… and Rowe Formations indicate that garnet porphyroblast rims equilibrated with matrix minerals at P-T conditions that are consistent with an Acadian (Devonian) metamorphic field gradient for this area. P-T conditions were calculated by simultaneously solving for a geothermometer and a …