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Showing 1 to 15 of 15 for “"Lattice Preferred Orientation"”.
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The lattice preferred orientation of olivine in Beni Bousera Ultramafic Massif, Morocco
… as areas of focused melt percolation. Lattice preferred orientation (LPO) of olivine crystals from a sample transect across one of these zones was analyzed in comparison with LPO from the surrounding host lherzolite and harzburgite. The LPO from peridotites within the zone was slightly …
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Microstructural study of two-phase marbles in simple shear
… rate of 10 -4 s -1. The microstructure, shape-preferred orientation (SPO), grain aspect ratios, lattice-preferred orientation (LPO), dislocation densities, and grain sizes were compared to the results of other studies on similar carbonates deformed in triaxial loading, torsion, and simple …
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Plagioclase preferred orientation in layered mylonites : evaluation of flow laws for the lower crust
… microstructure and the presence or absence of a lattice preferred orientation (LPO). Our analyses indicate that mylonite layers deformed at a strain rate in the range of 10-12 to 10- 11 s-1, while coarse-grained gabbro deformed at a strain rate of approximately 10-14 to 10- 13 s-1. Plagioclase in …
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Plagioclase preferred orientation in the layered mylonites : evaluation of flow laws for the lower crust
… microstructure and the presence or absence of a lattice preferred orientation (LPO). Our analyses indicate that mylonite layers deformed at a strain rate in the range of 1012 to 101 s-1, while coarse-grained gabbro deformed at a strain rate of approximately 10-14 to 1013 s-1. Plagioclase in pure …
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Seismic anisotropy and mantle flow beneath Africa and Arabia
… for the formation of the CVL, and olivine lattice preferred orientation in the upper asthenosphere associated with the northward motion of the African plate since 150 Ma, most likely causes the observed anisotropy across the Red Sea."--Abstract, page iv.</p>
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Mechanisms of Shear Zone Localization and Raman Thermobarometry in Spinel Peridotites from the Alpine Fault, New Zealand
… recrystallized grains, undulose extinction and a lattice preferred orientation. These samples also show evidence of post deformation static grain growth with polygonal grains, 120° triple junctions, and euhedral grains within larger grains of the same phase. Samples from the second locality also …
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Microstructural and crystallographic fabric analysis of stretched-pebble conglomerates in central Vermont
… to relate the development of microstructures and lattice preferred orientations to the local and regional structural settings. Additionally, the study compares the development of microstructures and lattice preferred orientations, and investigates strain heterogeneity that develops within deformed …
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3D trench-parallel flow in the subduction region and correlation with seismic anisotropy direction
… is that seismic anisotropy is caused by Lattice Preferred Orientation (LPO) of olivine minerals and that the direction of anisotropy is an indicator of the direction of mantle flow. The complex pattern of seismic anisotropy observations suggests that the flow geometry in the vicinity of …
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Seismic anisotropy in siliciclastic reservoir rocks
… parameters (e. g., crystallographic lattice preferred orientation (LPO), preferentially aligned porosity, aligned fractures and the non-random spatial distribution of mineral phases). In this study the results from scanning electron microscope-electron backscattered diffraction …
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Towards using seismic anisotropy to interpret ductile deformation in mafic lower crust
… seismic properties, finite strain and fabric orientation thus provides a useful tool in the remote sensing and interpretation of deformation in the lower crust. This thesis outlines a work-flow model by which the seismic properties of a single and representative lower crustal lithology can be …
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Shallow and deep deformation in northern Apennines region using seismological data
… important cause of seismic anisotropy is the lattice preferred orientation (LPO) of the mantle minerals as the olivine. This last is a highly anisotropic mineral and tends to align its fast crystallographic axes (a-axis) parallel to the astenospheric flow as a response to finite strain induced …
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Silicon and oxygen self-diffusion in forsterite and implications to upper-mantle rheology
(1) Silicon lattice diffusion coefficient in dry forsterite The high temperature creep of olivine is believed to be controlled by self-diffusion of olivine. However, the experimentally measured silicon diffusion coefficients (DSi) [Dohmen et al., 2002; Jaoul et al., 1981] were about 2-3 orders of …
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Field and theoretical investigations of strain localization: Effects of mineralogy, shear heating and grain size evolution on deformation in the Earth
… Hirth, 2003; Précigout and Gueydan, 2009), (3) lattice preferred orientation development (LPO) (e.g., Poirier, 1980; Tomassi et al., 2009), mixing of phases (e.g., Skemer et al., 2010a; Toy et al., 2010; Warren and Hirth, 2006) and geometrical interconnection of weak phases and materials (e.g., …
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The origins of olivine fabric transitions and their effects on seismic anisotropy in the upper mantle
… forces generated by mantle convection leads to lattice preferred orientation (LPO) of the major upper mantle mineral phases. LPO that develops in this way is thought to be the principal cause behind seismic anisotropy in the upper mantle, which can consequently be used to chart convective flow …
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A Geodynamic Investigation of Continental Rifting and Mantle Rheology: Madagascar and East African Rift case studies
… is used to calculate induced olivine aggregates'Lattice Preferred Orientation (LPO), known as seismic anisotropy. The predicted LPO isthen used to calculate synthetic seismic anisotropy, which were compared with observationsacross the island. Through a series of comparisons, we found that …