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Matthew A. Pasek - One of the best experts on this subject based on the ideXlab platform.
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Geochemical Sources and Availability of Amidophosphates on the Early Earth.
Angewandte Chemie (International ed. in English), 2019Co-Authors: Clémentine Gibard, Matthew A. Pasek, Ian B. Gorrell, Eddy I. Jiménez, Terence P. Kee, Ramanarayanan KrishnamurthyAbstract:Phosphorylation of (pre)biotically relevant molecules in aqueous medium has recently been demonstrated using water-soluble diamidophosphate (DAP). Questions arise relating to the prebiotic availability of DAP and other amidophosphosphorus species on the early earth. Herein, we demonstrate that DAP and other amino-derivatives of phosphates/phosphite are generated when Fe3 P (proxy for mineral Schreibersite), condensed phosphates, and reduced oxidation state phosphorus compounds, which could have been available on early earth, are exposed to aqueous ammonia solutions. DAP is shown to remain in aqueous solution under conditions where phosphate is precipitated out by divalent metals. These results show that nitrogenated analogues of phosphate and reduced phosphite species can be produced and remain in solution, overcoming the thermodynamic barrier for phosphorylation in water, increasing the possibility that abiotic phosphorylation reactions occurred in aqueous environments on early earth.
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Schreibersite on the early earth scenarios for prebiotic phosphorylation
Geoscience frontiers, 2017Co-Authors: Matthew A. PasekAbstract:The mineral Schreibersite, (Fe,Ni)3P, provides a reactive source of phosphorus capable of forming phosphorylated molecules. These molecules may have been an important component of prebiotic chemistry, allowing their build-up and eventual commencement of autopoiesis. Discussed here are potential geochemical routes to providing Schreibersite, as a potentially important prebiotic mineral, to the Hadean Earth. Two routes are identified: delivery of phosphides by meteoritic material and the reduction of phosphates to phosphides by high-temperature, low-redox conditions. About 1–10% of all crustal phosphorus is estimated to have been in Schreibersite during the Hadean, making the long-term reaction of this mineral with organic-laden water plausible for many years. Ultimately, such conditions would have been conducive to the formation of life as we know it today.
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nucleoside phosphorylation by the mineral Schreibersite
Scientific Reports, 2015Co-Authors: Maheen Gull, Thomas M Orlando, Mike Mojica, Facundo M Fernandez, David A Gaul, Charles L Liotta, Matthew A. PasekAbstract:Phosphorylation of the nucleosides adenosine and uridine by the simple mixing and mild heating of aqueous solutions of the organic compounds with synthetic analogs of the meteoritic mineral Schreibersite, (Fe,Ni)3P under slightly basic conditions (pH ~9) is reported. These results suggest a potential role for meteoritic phosphorus in the origin and development of early life.
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investigation of Schreibersite and intrinsic oxidation products from sikhote alin seymchan and odessa meteorites and fe3p and fe2nip synthetic surrogates
Geochimica et Cosmochimica Acta, 2014Co-Authors: Claire Pirim, Matthew A. Pasek, D A Sokolov, A N Sidorov, R D Gann, Thomas M OrlandoAbstract:Abstract This work presents a comprehensive investigation of Schreibersite inclusions within iron-poor and iron-rich meteorites, and of the associated intrinsic low-temperature oxidation products observed after exposure to terrestrial weathering. First, a thermodynamic equilibrium modeling of the oxidation of Schreibersite was carried out and showed that oxidation is mostly limited to the surface in the absence of other ions and/or water. This oxidation occurs rapidly (less than a few weeks) and is mediated by the atmosphere, forming primarily iron oxides and iron phosphates. Second, detailed analyses of meteorite Schreibersite inclusions and synthetic Schreibersite surrogates (Fe 3 P and Fe 2 NiP) were performed using surface characterization techniques such as micro-Raman spectroscopy, atomic force microscopy (AFM), electrostatic force microscopy (EFM), electron microprobe analysis (EPMA), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Such thorough analyses are required as many prebiotic reactivity studies performed use meteoritic samples that have been somewhat exposed to Earth weathering. We find that, while the meteorite samples have not been introduced directly into water, they all bear significant oxidation signatures that appear to be similar for both short-term and long-term natural weathering corrosion processes. In addition, we find that synthetic Schreibersite samples have similar surface and sub-surface chemistry and are reasonable chemical proxies for natural Schreibersite. The thorough analytical studies detailed in this paper provide a chemical model for Schreibersite oxidation products.
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evidence for reactive reduced phosphorus species in the early archean ocean
Proceedings of the National Academy of Sciences of the United States of America, 2013Co-Authors: Matthew A. Pasek, Jelte P Harnmeijer, Roger Buick, Maheen Gull, Zachary AtlasAbstract:It has been hypothesized that before the emergence of modern DNA–RNA–protein life, biology evolved from an “RNA world.” However, synthesizing RNA and other organophosphates under plausible early Earth conditions has proved difficult, with the incorporation of phosphorus (P) causing a particular problem because phosphate, where most environmental P resides, is relatively insoluble and unreactive. Recently, it has been proposed that during the Hadean–Archean heavy bombardment by extraterrestrial impactors, meteorites would have provided reactive P in the form of the iron–nickel phosphide mineral Schreibersite. This reacts in water, releasing soluble and reactive reduced P species, such as phosphite, that could then be readily incorporated into prebiotic molecules. Here, we report the occurrence of phosphite in early Archean marine carbonates at levels indicating that this was an abundant dissolved species in the ocean before 3.5 Ga. Additionally, we show that Schreibersite readily reacts with an aqueous solution of glycerol to generate phosphite and the membrane biomolecule glycerol–phosphate under mild thermal conditions, with this synthesis using a mineral source of P. Phosphite derived from Schreibersite was, hence, a plausible reagent in the prebiotic synthesis of phosphorylated biomolecules and was also present on the early Earth in quantities large enough to have affected the redox state of P in the ocean. Phosphorylated biomolecules like RNA may, thus, have first formed from the reaction of reduced P species with the prebiotic organic milieu on the early Earth.
G Kurat - One of the best experts on this subject based on the ideXlab platform.
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noble gas content and isotope abundances in phases of the saint aubin ungr iron meteorite
Meteoritics & Planetary Science, 2008Co-Authors: Chikako Nishimura, Junichi Matsuda, G KuratAbstract:We analyzed the noble gas isotopes in the Fe-Ni metal and inclusions of the Saint-Aubin iron meteorite, utilizing the stepwise heating technique to separate the various components of noble gases. The light noble gases in all samples are mostly cosmogenic, with some admixture from the terrestrial atmosphere. Total abundances of noble gases in metal are one of the lowest found so far in iron meteorites and the 4He/21Ne ratio is as high as 503, suggesting that the Saint-Aubin iron meteorite was derived from a very large meteoroid in space. The exposure ages obtained from cosmogenic 3He were 916 Ma. Saint-Aubin is very peculiar because it contains very large chromite crystals, whichlike the metalcontain only cosmogenic and atmospheric noble gases. The noble gases in all the samples do not reveal any primordial components. The only exception is the 1000 °C fraction of Schreibersite which contained about 5% of the Xe-HL component. The Xe-Q and the El Taco Xe components were not found and only the Xe-HL is present in this fraction. Some presolar diamond, the only carrier for the HL component known today, must have been available during growth of the Schreibersite. However, it is also possible that this excess is due to the addition of cosmogenic and fission components. In this case, all the primordial components are masked (or lost) by the later events such as cosmic-ray irradiation, heating, and radioactive decay.
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noble gases in metal and Schreibersite of the acuna iiiab iron meteorite
Meteoritics & Planetary Science, 1996Co-Authors: Junichi Matsuda, Keisuke Nagao, G KuratAbstract:— We measured abundances and isotopic compositions of noble gases in metal and Schreibersite of the Acuna (IIIAB) iron meteorite. The concentrations of noble gases in Acuna metal are very low compared to those reported so far for other iron meteorites. The isotopic ratios of He, Ne and Ar indicate that they are mostly of cosmogenic origin. Cosmogenic components are even present in Kr and Xe, which could not have been produced from Fe, Ni and P and are probably due to the spallation of trace elements of higher masses. The high 4He/21Ne ratio of 420 in Acuna metal indicates that the samples were at a deep position within a very large meteoroid. The exposure ages of Acuna were estimated to be 50–200 Ma from 3He, 21Ne and 38Ar abundances and by utilizing the diagrams of production rates vs. the 4He/21Ne ratio based on the Signer-Nier model. The low exposure age of Acuna may indicate a history different from that of other IIIAB irons whose exposure ages cluster at ∼670 Ma. Otherwise, Acuna may be one of the samples with the low production rate, which can not be estimated from the diagrams of the Signer-Nier model.
Junichi Matsuda - One of the best experts on this subject based on the ideXlab platform.
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noble gas content and isotope abundances in phases of the saint aubin ungr iron meteorite
Meteoritics & Planetary Science, 2008Co-Authors: Chikako Nishimura, Junichi Matsuda, G KuratAbstract:We analyzed the noble gas isotopes in the Fe-Ni metal and inclusions of the Saint-Aubin iron meteorite, utilizing the stepwise heating technique to separate the various components of noble gases. The light noble gases in all samples are mostly cosmogenic, with some admixture from the terrestrial atmosphere. Total abundances of noble gases in metal are one of the lowest found so far in iron meteorites and the 4He/21Ne ratio is as high as 503, suggesting that the Saint-Aubin iron meteorite was derived from a very large meteoroid in space. The exposure ages obtained from cosmogenic 3He were 916 Ma. Saint-Aubin is very peculiar because it contains very large chromite crystals, whichlike the metalcontain only cosmogenic and atmospheric noble gases. The noble gases in all the samples do not reveal any primordial components. The only exception is the 1000 °C fraction of Schreibersite which contained about 5% of the Xe-HL component. The Xe-Q and the El Taco Xe components were not found and only the Xe-HL is present in this fraction. Some presolar diamond, the only carrier for the HL component known today, must have been available during growth of the Schreibersite. However, it is also possible that this excess is due to the addition of cosmogenic and fission components. In this case, all the primordial components are masked (or lost) by the later events such as cosmic-ray irradiation, heating, and radioactive decay.
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noble gases in metal and Schreibersite of the acuna iiiab iron meteorite
Meteoritics & Planetary Science, 1996Co-Authors: Junichi Matsuda, Keisuke Nagao, G KuratAbstract:— We measured abundances and isotopic compositions of noble gases in metal and Schreibersite of the Acuna (IIIAB) iron meteorite. The concentrations of noble gases in Acuna metal are very low compared to those reported so far for other iron meteorites. The isotopic ratios of He, Ne and Ar indicate that they are mostly of cosmogenic origin. Cosmogenic components are even present in Kr and Xe, which could not have been produced from Fe, Ni and P and are probably due to the spallation of trace elements of higher masses. The high 4He/21Ne ratio of 420 in Acuna metal indicates that the samples were at a deep position within a very large meteoroid. The exposure ages of Acuna were estimated to be 50–200 Ma from 3He, 21Ne and 38Ar abundances and by utilizing the diagrams of production rates vs. the 4He/21Ne ratio based on the Signer-Nier model. The low exposure age of Acuna may indicate a history different from that of other IIIAB irons whose exposure ages cluster at ∼670 Ma. Otherwise, Acuna may be one of the samples with the low production rate, which can not be estimated from the diagrams of the Signer-Nier model.
Tasnim Munshi - One of the best experts on this subject based on the ideXlab platform.
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hydrothermal modification of the sikhote alin iron meteorite under low ph geothermal environments a plausibly prebiotic route to activated phosphorus on the early earth
Geochimica et Cosmochimica Acta, 2013Co-Authors: David E Bryant, Matthew A. Pasek, David Greenfield, Richard Walshaw, C L Smith, Barry Herschy, Benjamin R G Johnson, Richard Telford, Ian J Scowen, Tasnim MunshiAbstract:Abstract The Sikhote-Alin (SA) meteorite is an example of a type IIAB octahedrite iron meteorite with ca. 0.5 wt% phosphorus (P) content principally in the form of the siderophilic mineral Schreibersite (Fe,Ni)3P. Meteoritic in-fall to the early Earth would have added significantly to the inventory of such siderophilic P. Subsequent anaerobic corrosion in the presence of a suitable electrolyte would produce P in a form different to that normally found within endogenous geochemistry which could then be released into the environment. One environment of specific interest includes the low pH conditions found in fumaroles or volcanically heated geothermal waters in which anodic oxidation of Fe metal to ferrous (Fe2+) and ferric (Fe3+) would be coupled with cathodic reduction of a suitable electron acceptor. In the absence of aerobic dioxygen (Eo = +1.229 V), the proton would provide an effective final electron acceptor, being converted to dihydrogen gas (Eo = 0 V). Here we explore the hydrothermal modification of sectioned samples of the Sikhote-Alin meteorite in which siderophilic P-phases are exposed. We report on both, (i) simulated volcanic conditions using low pH distilled water and (ii) geothermally heated sub-glacial fluids from the northern Kverkfjoll volcanic region of the Icelandic Vatnajokull glacier. A combination of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements using the scanning Kelvin probe (SKP) method reveals that Schreibersite inclusions are significantly less susceptible to anodic oxidation than their surrounding Fe–Ni matrix, being some 550 mV nobler than matrix material. This results in preferential corrosion of the matrix at the matrix-inclusion boundary as confirmed using topological mapping via infinite focus microscopy and chemical mapping through Raman spectroscopy. The significance of these observations from a chemical perspective is that electrochemically noble inclusions such as Schreibersite are likely to have been released into the geological environment through an undermining corrosion of the surrounding matrix, thus affording localised sources of available water-soluble, chemically reactive P in the form of H-phosphite [ H 2 PO 3 - , Pi(III) as determined by 31P NMR spectroscopy]. This compound has been shown to have considerable prebiotic chemical potential as a source of condensed P-oxyacids. Here we demonstrate that Pi(III) resulting from the hydrothermal modification of Sikhote-Alin by sub-glacial geothermal fluids can be readily dehydrated into the condensed P-oxyacid pyrophosphite [ H 2 P 2 O 5 2 - , PPi(III)] by dry-heating under mild (85 °C) conditions. The potential significance of this latter condensed P-compound for prebiotic chemistry is discussed in the light of its modified chemical properties compared to pyrophosphate [ H 2 P 2 O 7 2 - , PPi(V)].
V A Semionkin - One of the best experts on this subject based on the ideXlab platform.
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an analysis of fe and ni distribution in m1 m2 and m3 sites of iron nickel phosphides extracted from sikhote alin meteorite using mossbauer spectroscopy with a high velocity resolution
Journal of Molecular Structure, 2011Co-Authors: M I Oshtrakh, V I Grokhovsky, Yu M Larionov, V A SemionkinAbstract:Abstract Study of two iron–nickel phosphides crystals (rhabdite and Schreibersite) extracted from Sikhote-Alin (IIAB) iron meteorite was performed using Mossbauer spectroscopy with a high velocity resolution at various temperatures. On the basis of Mossbauer data the temperature dependences of magnetic hyperfine fields for Fe atoms in the crystallographically non-equivalent M1, M2 and M3 sites of rhabdite were shown as well as Fe and Ni occupancies of these sites were evaluated for both phosphides.
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study of iron meteorite sikhote alin and extracted iron nickel phosphides using mossbauer spectroscopy with high velocity resolution
Hyperfine Interactions, 2008Co-Authors: M I Oshtrakh, V I Grokhovsky, Yu M Larionov, V A SemionkinAbstract:Comparative study of Schreibersite and rhabdite extracted from Sikhote–Alin (IIAB) iron meteorite using Mossbauer spectroscopy, X-ray diffraction and magnetic measurements was carried out. Mossbauer spectra of bulk meteorite sample and extracted phosphides were recorded in 4,096 channels and then presented in 1,024 channels. Differences of the unit cell structure, the Fe, Ni and Co content, the room temperature Mossbauer spectra and Curie temperature for rhabdite and Schreibersite were found.