Abstract
Phosphoran olivine (1-7 wt% P2O5) is a metastable phase known from fewer than a dozen meteoritic or terrestrial occurrences. We have thoroughly examined phosphoran olivine in the Springwater pallasite to characterize its distribution, textural relationships, and geochemistry. Phosphoran olivine is abundant in Springwater as randomly distributed millimeter-scale partial overgrowths on the P-free olivine crystals. Geochemical analyses support the substitution mechanism of P into the tetrahedral Si site with octahedral site vacancies for charge balance; observed trace element variations, on the other hand, are not related to P substitution. Element mapping reveals fine-scale oscillatory P zoning in unusual serrate patterns, indicating rapid crystal nucleation from a melt as proposed by Boesenberg and Hewins (2010) and a subsequently variable rate of crystallization. The timing of phosphoran olivine formation in Springwater is constrained to after the period of macroscopic olivine rounding but before the cooling of the metal matrix; because the phosphoran overgrowths overprint specific host grain boundary modifications, we suggest that the episode of extremely rapid cooling necessary to crystallize and preserve this rare phase may have been triggered by an additional impact to the parent body.
© 2015 by Walter de Gruyter Berlin/Boston
Artikel in diesem Heft
- Reaching new boundaries for in-situ U-Th geochronology
- Normal to inverse transition in martian spinel: Understanding the interplay between chromium, vanadium, and iron valence state partitioning through a crystal-chemical lens
- Accuracy of timescales retrieved from diffusion modeling in olivine: A 3D perspective
- Phosphoran olivine overgrowths: Implications for multiple impacts to the Main Group pallasite parent body
- Diffusion of phosphorus in olivine and molten basalt
- Oceanic lavas sampling the high-3He/4He mantle reservoir: Primitive, depleted, or re-enriched?
- U-Th baddeleyite geochronology and its significance to date the emplacement of silica undersaturated magmas
- Polycrystallinity of green rust minerals and their synthetic analogs: Implications for particle formation and reactivity in complex systems
- Fe pre-enrichment: A new method to counteract iron loss in experiments on basaltic melts
- Fe-Mg diffusion in spinel: New experimental data and a point defect model
- Age, petrochemistry, and origin of a REE-rich mineralization in the Longs Peak-St. Vrain batholith, near Jamestown, Colorado (U.S.A.)
- Laser-induced breakdown spectroscopy (LIBS) as a tool for in situ mapping and textural interpretation of lithium in pegmatite minerals
- Evidence for Nb2+ and Ta3+ in silicate melts under highly reducing conditions: A XANES study
- Elastic softening of leucite and the lack of polar domain boundaries
- New thermobarometers for martian igneous rocks, and some implications for secular cooling on Mars
- An updated calibration of the plagioclase-liquid hygrometer-thermometer applicable to basalts through rhyolites
- Water effects on the anharmonic properties of forsterite
- Synthesis and structure of a stuffed derivative of α-quartz, Mg0.5AlSiO4
- Equation of state and elasticity of the 3.65 Å phase: Implications for the X-discontinuity
- Ca-Zn solid solutions in C2/c pyroxenes: Synthesis, crystal structure, and implications for Zn geochemistry
- Aluminum environments in synthetic Ca-Tschermak clinopyroxene (CaAlAlSiO6) from Rietveld refinement, 27Al NMR, and first-principles calculations
- Trioctahedral Fe-rich micas: Relationships between magnetic behavior and crystal chemistry
- High-pressure compressibility and phase stability of Mn-dolomite (kutnohorite)
- Composition dependence of spin transition in (Mg,Fe)SiO3 bridgmanite
- Oriented multiphase needles in garnet from ultrahigh-temperature granulites, Connecticut, U.S.A.
- Solubility and solution mechanisms of chlorine and fluorine in aluminosilicate melts at high pressure and high temperature
- Volatiles in magmas related to the Campanian Ignimbrite eruption: Experiments vs. natural findings
- Aluminosilicate melts and glasses at 1 to 3 GPa: Temperature and pressure effects on recovered structural and density changes
- Role of volatiles (S, Cl, H2O) and silica activity on the crystallization of haüyne and nosean in phonolitic magmas (Eifel, Germany and Saghro, Morocco)
- P-V-T equation of state and high-pressure behavior of CaCO3 aragonite
- A possible new Al-bearing hydrous Mg-silicate (23 Å phase) in the deep upper mantle
- Synthesis of large wadsleyite single crystals by solid-state recrystallization
- Decagonite, Al71Ni24Fe5, a quasicrystal with decagonal symmetry from the Khatyrka CV3 carbonaceous chondrite
- Earth’s “missing” minerals
- Magnetite-rutile symplectite derived from ilmenite-hematite solid solution in the Xinjie Fe-Ti oxide-bearing, mafic-ultramafic layered intrusion (SW China)
- New Mineral Names
- Book Review: Arsenic: Environmental Geochemistry, Mineralogy, and Microbiology, RIMG Volume 79.
Artikel in diesem Heft
- Reaching new boundaries for in-situ U-Th geochronology
- Normal to inverse transition in martian spinel: Understanding the interplay between chromium, vanadium, and iron valence state partitioning through a crystal-chemical lens
- Accuracy of timescales retrieved from diffusion modeling in olivine: A 3D perspective
- Phosphoran olivine overgrowths: Implications for multiple impacts to the Main Group pallasite parent body
- Diffusion of phosphorus in olivine and molten basalt
- Oceanic lavas sampling the high-3He/4He mantle reservoir: Primitive, depleted, or re-enriched?
- U-Th baddeleyite geochronology and its significance to date the emplacement of silica undersaturated magmas
- Polycrystallinity of green rust minerals and their synthetic analogs: Implications for particle formation and reactivity in complex systems
- Fe pre-enrichment: A new method to counteract iron loss in experiments on basaltic melts
- Fe-Mg diffusion in spinel: New experimental data and a point defect model
- Age, petrochemistry, and origin of a REE-rich mineralization in the Longs Peak-St. Vrain batholith, near Jamestown, Colorado (U.S.A.)
- Laser-induced breakdown spectroscopy (LIBS) as a tool for in situ mapping and textural interpretation of lithium in pegmatite minerals
- Evidence for Nb2+ and Ta3+ in silicate melts under highly reducing conditions: A XANES study
- Elastic softening of leucite and the lack of polar domain boundaries
- New thermobarometers for martian igneous rocks, and some implications for secular cooling on Mars
- An updated calibration of the plagioclase-liquid hygrometer-thermometer applicable to basalts through rhyolites
- Water effects on the anharmonic properties of forsterite
- Synthesis and structure of a stuffed derivative of α-quartz, Mg0.5AlSiO4
- Equation of state and elasticity of the 3.65 Å phase: Implications for the X-discontinuity
- Ca-Zn solid solutions in C2/c pyroxenes: Synthesis, crystal structure, and implications for Zn geochemistry
- Aluminum environments in synthetic Ca-Tschermak clinopyroxene (CaAlAlSiO6) from Rietveld refinement, 27Al NMR, and first-principles calculations
- Trioctahedral Fe-rich micas: Relationships between magnetic behavior and crystal chemistry
- High-pressure compressibility and phase stability of Mn-dolomite (kutnohorite)
- Composition dependence of spin transition in (Mg,Fe)SiO3 bridgmanite
- Oriented multiphase needles in garnet from ultrahigh-temperature granulites, Connecticut, U.S.A.
- Solubility and solution mechanisms of chlorine and fluorine in aluminosilicate melts at high pressure and high temperature
- Volatiles in magmas related to the Campanian Ignimbrite eruption: Experiments vs. natural findings
- Aluminosilicate melts and glasses at 1 to 3 GPa: Temperature and pressure effects on recovered structural and density changes
- Role of volatiles (S, Cl, H2O) and silica activity on the crystallization of haüyne and nosean in phonolitic magmas (Eifel, Germany and Saghro, Morocco)
- P-V-T equation of state and high-pressure behavior of CaCO3 aragonite
- A possible new Al-bearing hydrous Mg-silicate (23 Å phase) in the deep upper mantle
- Synthesis of large wadsleyite single crystals by solid-state recrystallization
- Decagonite, Al71Ni24Fe5, a quasicrystal with decagonal symmetry from the Khatyrka CV3 carbonaceous chondrite
- Earth’s “missing” minerals
- Magnetite-rutile symplectite derived from ilmenite-hematite solid solution in the Xinjie Fe-Ti oxide-bearing, mafic-ultramafic layered intrusion (SW China)
- New Mineral Names
- Book Review: Arsenic: Environmental Geochemistry, Mineralogy, and Microbiology, RIMG Volume 79.