WebThe zoning shown in Fig. 8d also illustrates the mixtures of zoning types: oscillatory and complex zoning with sector zoning in some of the late-formed crystals. The X Fe values are shown in Fig. 8e and the complete EPMA data in Table 2. Sector zoning refers to a compositional difference between coeval growth sectors in a crystal. WebJul 1, 2024 · For these crystals, the variations of Ni associated with the inner depletion (∆Ni-1 ~700 ppm) is smaller than those of the outer depletion (∆Ni-2 ~ up to 900 ppm). ... compositional zoning and ...
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WebMar 29, 2007 · Compositional Zoning of the Bishop Tuff Wes Hildreth, Wes Hildreth * 1 US Geological Survey, MS-910, Menlo park, CA 94025, USA ... Schlieren are typically 10–80 mm long, several mm thick, and … WebAbstract. Zincian spinel (Zn, Fe, Mg)Al//2O//4 has been examined for compositional zoning. The samples come from fifty-two widely scattered localities, in metamorphosed …
WebNov 8, 2010 · The syn‐gold mineralisation event is hosted within the Junction shear zone and is associated with extensive quartz‐calcite ± albite ± chlorite ± pyrrhotite veining. … WebMay 1, 2024 · Compositional zoning in garnet and its modification by diffusion during pressure and temperature changes in metamorphic rocks; an approach and software. ...
WebYale Univ., Dep. Geol. and Geophys., New Haven, CT, United States WebJun 1, 2008 · The compositional zoning of plagioclase-mantled K-feldspar, defining the rapakivi texture, and of the associated quartz phenocrysts from the Paleozoic Land’s End (U.K.) and Altenberg ...
WebOct 1, 2001 · Within Zone 2, Ni reaches a maximum of 0.5 apfu before decreasing in the outer 20–40 μm. Zone-2 overgrowths also exhibit compositional polarity such that, at the (−) c-pole, overgrowths are enriched in Mg, F, Na, Ca, and Cr relative to overgrowths at the (+) c-pole that are, in turn, enriched in Al, Fe, Ni, Co, and X . Element partitioning ...
WebThe presence of zoned Fe, Mg, Ca, and Mn in the carbonate phases associated with the cracks and inclusions of the Allan Hills (ALH) 84001 meteorite provides evidence for … mcdonald\u0027s holiday pieWebJan 10, 2024 · In comparison to other hydrous phases in subduction systems, relatively little is known about compositional variations and zoning of lawsonite because it has been proposed to exhibit little compositional variation (e.g., Pawley, 1994) and because it is rarely preserved in subduction-related rocks exhumed to the Earth’s surface (Zack et al., … lgh resourcesWebMany igneous plagioclases exhibit irregular zoning consisting of corroded cores embayed and surrounded in crystallographic continuity by more sodic plagioclase. Inclusions of this sodic plagioclase within the corroded cores give the feldspar a mottled appearance and suggest the term patchy zoning for these textures. Textural evidence indicates that … lghrn50rxvWebFeb 28, 2024 · Xenotime inclusions, up to 100 μm in size, are closely spatially associated with monazites in dark apatites and interstitial spaces in cataclased apatite and magnetite ores (Fig. 8E, F). The majority of xenotime is euhedral to subhedral. Compositional zoning is indiscernible, except for larger crystals, which are weakly oscillatory zoned. lghribWebDec 1, 2008 · The compositional zoning of plagioclase-mantled K-feldspar, defining the rapakivi texture, and of the associated quartz phenocrysts from the Paleozoic Land’s End (U.K.) and Altenberg–Frauenstein (Germany) granites, and the Proterozoic Hammarudda (Finland) granite porphyry, has been investigated by laser-ablation – inductively coupled … mcdonald\\u0027s holiday pieWebNov 8, 2010 · The syn‐gold mineralisation event is hosted within the Junction shear zone and is associated with extensive quartz‐calcite ± albite ± chlorite ± pyrrhotite veining. Fluid‐inclusion analyses indicate that gold deposition occurred during the unmixing of a 400°C, moderately saline, H 2 O–CO 2 ± CH 4 fluid at pressures between 70 MPa ... lgh respiratoryWebMay 7, 2024 · Compositional zoning is observed rarely in chrome-spinel grains from slowly-cooled layered intrusions because diffusion of cations continues within the spinel to low temperatures. However, in certain circumstances, such gradational zoning of both … lgh reviews