Phosphate Minerals in Meteorites and Lunar Rocks

Buchwald, Vagn F.

doi:10.1007/978-3-642-61736-2_5

Cited by 18 publications

(13 citation statements)

References 38 publications

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“…The oxygen fugacity of the molten core is reflected in the abundance of the oxygen-bearing phosphates found in some groups of iron meteorites (Olsen and Fredriksson, 1966;Olsen et al, 1999). Phosphate minerals are typical in group lIIAB but have never been observed in lIAB iron meteorites (Buchwald, 1975(Buchwald, , 1984Scott and Wasson, 1975). The higher nickel concentration in group IllAB compared to IIAB (Table I) is consistent with the latter forming from more reduced material.…”

Section: Accretion and Differences In Bulk Chemistry Between Groups Omentioning

confidence: 73%

“…In hexahedrites, kamacite crystals are generally larger than the specimen, whereas coarsest octahedrites have kamacite lamellae wider than 3.3 mm (Buchwald, 1975). The low nickel concentration, absence of phosphates (Buchwald, 1975(Buchwald, , 1984, and occurrence of graphite in lIAB iron meteorites suggest formation from highly reduced material.…”

Section: 1221 Group Liar Iron Meteoritesmentioning

confidence: 93%

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Iron and Stony-Iron Meteorites

Haack

McCoy²

2007

Treatise on Geochemistry

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Section: Accretion and Differences In Bulk Chemistry Between Groups Omentioning

confidence: 73%

Section: 1221 Group Liar Iron Meteoritesmentioning

confidence: 93%

Iron and Stony-Iron Meteorites

Haack

McCoy²

2007

Treatise on Geochemistry

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“…65 The stability of phosphite under H2 was determined by considering the set of reactions described on Table 1. The rate constants for reactions 10 and 11 were calculated by taking the ratio of the reaction equilibrium log 10 K values for these two reactions and dividing by reaction equilibrium log10 K values for the reactions 12-14 and then multiplying by the rate constants for these three reactions and averaging to get the values on Table 1.…”

Section: Methodsmentioning

confidence: 99%

Rethinking early Earth phosphorus geochemistry

Pasek

2008

Proc. Natl. Acad. Sci. U.S.A.

240

209

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Phosphorus is a key biologic element, and a prebiotic pathway leading to its incorporation into biomolecules has been difficult to ascertain. Most potentially prebiotic phosphorylation reactions have relied on orthophosphate as the source of phosphorus. It is suggested here that the geochemistry of phosphorus on the early Earth was instead controlled by reduced oxidation state phosphorus compounds such as phosphite (HPO 3 2؊ ), which are more soluble and reactive than orthophosphates. This reduced oxidation state phosphorus originated from extraterrestrial material that fell during the heavy bombardment period or was produced during impacts, and persisted in the mildly reducing atmosphere. This alternate view of early Earth phosphorus geochemistry provides an unexplored route to the formation of pertinent prebiotic phosphorus compounds, suggests a facile reaction pathway to condensed phosphates, and is consistent with the biochemical usage of reduced oxidation state phosphorus compounds in life today. Possible studies are suggested that may detect reduced oxidation state phosphorus compounds in ancient Archean rocks.meteorites ͉ origins of life ͉ phosphonates ͉ prebiotic ͉ redox chemistry P hosphorus (P) is a key biologic element and is the limiting reagent in many ecosystems. Phosphorus is ubiquitous in biochemistry because phosphorylated biomolecules play major roles in replication and information (as RNA and DNA), metabolism (as ATP, NADPH, and other coenzymes), and structure (as phospholipids). Several key properties of P as phosphate make it advantageous to biologic systems, including thermodynamic instability coupled with kinetic stability, charge and coordination state, and a constant oxidation state under typical redox conditions (1). These features are especially critical to the formation of large informational polymers, and hence highly relevant to the origin and development of early life. Phosphorus Geochemistry and CosmochemistryThe major forms of P in life are summarized in Fig. 1. Inorganic P compounds used by life include orthophosphate, pyrophosphate and other condensed phosphates, phosphite, hypophosphite, and phosphine. These inorganic forms are either used by organisms as sources of P for the synthesis of organic-P biomolecules or are possible metabolic by-products of P metabolism (PH 3 ). Additionally, orthophosphate acts as a buffer in many cells, keeping pH constant at Ϸ7. Organic forms of P include compounds with C-O-P linkages and compounds with C-P linkages, and both are formed from inorganic P by using enzymes.Phosphorus is a lithophile element at the redox conditions on the surface of the Earth, and hence orthophosphate is the dominant form of inorganic P on the surface of the Earth today. The concentration of orthophosphate is water-buffered by the solubility of orthophosphate minerals like apatite, Ca 5 (PO 4 ) 3 (OH,F,Cl), on the present-day Earth, and of whitlockite, Ca 9 MgH(PO 4 ) 7 , and brushite, CaHPO 4 ⅐2H 2 O, before the rise of life-mediated apatite deposition (2). Because ...

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“…. and one of phosphate minerals (Buchwald 1984). In fact, you have discovered, or been involved in the primary characterization of, five new minerals (roaldite, [Fe,Ni] VB: Yes.…”

Section: Other Iron Meteorite Researchmentioning

confidence: 99%

“…In fact, you have discovered, or been involved in the primary characterization of, five new minerals (roaldite, [Fe,Ni] VB: Yes. Perhaps I was inspired by that phosphate paper (Buchwald 1984(Buchwald ) when, in 1987 worked with corroded Santa Catherina material and discovered a beautiful blue mineral that turned out to be a nickelanalogue of viviantite. I honored the eminent Danish corrosion engineer Hans Aruep, by naming it arupite on his 60th birthday.…”

Section: Other Iron Meteorite Researchmentioning

confidence: 99%

Oral histories in meteoritics and planetary science—XXV: Vagn F. Buchwald

Sears

2014

Meteorit & Planetary Scien

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Phosphate Minerals in Meteorites and Lunar Rocks

Cited by 18 publications

References 38 publications

Iron and Stony-Iron Meteorites

Iron and Stony-Iron Meteorites

Rethinking early Earth phosphorus geochemistry

Oral histories in meteoritics and planetary science—XXV: Vagn F. Buchwald

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