Soda Fe-Mn Pegmatite Phosphates

Fisher, D. Jerome

doi:10.1126/science.121.3139.312

Cited by 5 publications

(4 citation statements)

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“…The existence of primary alluaudites, first alluded to Fisher (1958) in his presidential address to the Mineralogical Society of America, was confirmed by Fransolet (1975Fransolet ( , 1977, who noted sharp contacts between alluaudite and ferrisicklerite [Li 1-x (Fe 3? ,Mn 2?…”

Section: Introductionmentioning

confidence: 94%

Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates

Hatert

Ottolini

Schmid‐Beurmann³

2010

Contrib Mineral Petrol

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In order to assess the stability of the primary alluaudite ? triphylite assemblage, we performed hydrothermal experiments between 400 and 800°C, starting from the LiNa 2 Mn x Fe 3-x 2? Fe 3? (PO 4 ) 4 compositions (x = 1.054, 1.502, 1.745) that represent the ideal compositions of the alluaudite ? triphylite assemblages from the Kibingo (Rwanda), Hagendorf-Su ¨d (Germany), and Buranga (Rwanda) pegmatites, respectively. The pressure was maintained at 1 kbar, and the oxygen fugacity was controlled by the Ni-NiO buffer. The results of these experiments show that the alluaudite ? triphylite assemblage crystallizes at 400 and 500°C, while the association alluaudite ? triphylite ? maric ´ite appears at 600 and 700°C. The limit between these two domains, at ca. 550°C, corresponds to the maximum temperature that can be reached by the alluaudite ? triphylite assemblages in granitic pegmatites, because maric ´ite has never been observed in such geological environments. At 800°C, the formation of the X-phase ? triphylite assemblage indicates a strong reduction of the bulk composition, according to the reaction 0.5LiM 2? PO 4 (triphylite) ? 3Na 2 M 2 2? Fe 3? (PO 4 ) 3 (alluaudite) ? 1.5H 2 O = 4.5NaM 2? PO 4 (maric ´ite) ? Li 0.5 Na 1.5 M 5 2?(PO 4 ) 4 (X-phase) ? H 3 PO 4 ? 0.75O 2 (M 2? = Fe 2? , Mn). Secondary ion mass spectrometry (SIMS) was used at our knowledge for the first time to measure Li in all the Li-bearing phosphates. A specific methodological procedure was developed with the ion microprobe to get accurate Li 2 O data over a wide concentration range spanning from few ppm Li up to *11 wt%. Li 2 O. Our SIMS analyses of the synthesized phosphates indicate that the Li contents of alluaudites, maric ´ites, and X-phase increase progressively with temperature, while the Li content of triphylite-type phosphates decreases due to the Li ? Na substitution. The Na-exchange equilibrium between triphylite-type phosphates and alluaudite is correlated with the temperature according to the equation: ln(x Na Tri /x Na All ) = -7.0(7) 10 3 / T ? 5.4(9). This equation can be used to estimate the crystallization temperature of triphylite-alluaudite assemblages independently of the oxygen fugacity.

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Section: Introductionmentioning

confidence: 94%

Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates

Hatert

Ottolini

Schmid‐Beurmann³

2010

Contrib Mineral Petrol

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“…Previous work [3,4] on this subject had been carried out prior to the first crystallographic studies. As an extension of the present X-ray study and in order to improve our model of the arrojadite structure, further single-crystal measurements using neutron radiation were performed [16].…”

Section: Introductionmentioning

confidence: 99%

“…Investigations of the physical and chemical properties of arrojadite performed during the last half century include chemical analyses, phase analysis by X-ray powder diffraction (XRD) [2], investigations of the thermal behavior [3,4], preparation of synthetic Fe-arrojadite [5], and Mössbauer-spectroscopic studies [6]. In addition, new deposits and new members of the dickinsonite-arrojadite mineral series (e. g., sigismundite from Italy [7]) were discovered.…”

Section: Introductionmentioning

confidence: 99%

The Transition Metal-rich Orthophosphate Arrojadite with Special Structural Features

Kallfaß

Hoch

Schier

et al. 2010

Zeitschrift Für Naturforschung B

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The crystal structure of the transition metal-rich orthophosphate mineral arrojadite was reexamined, and the disorder phenomena were analyzed applying modern X-ray single-crystal diffraction and refinement methods on samples from Nickel Plate (USA) and Hagendorf (Germany). As a new feature of the arrojadite structure, two different types of channels oriented along [010] are described. The occupancy of the atomic positions inside these channels have been elucidated.

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“…Hydrothermal phosphates have been extensively studied in multiple settings on Earth [216][217][218][219], and it is known that different minerals form under different conditions, including at different temperatures [218] (Figure 9) and depending on the pH, chemistry, and oxidation state of the reacting fluids [217,219]. This type of extremely valuable information about past hydrothermal environments may therefore be available for Mars if hydrothermal phosphates can be identified on Mars (e.g., [58]) or in returned samples.…”

Section: Hydrothermal Phosphates As Temperature Indicatorsmentioning

confidence: 99%

Phosphates on Mars and Their Importance as Igneous, Aqueous, and Astrobiological Indicators

Hausrath,

Adcock,

Berger

et al. 2024

Minerals

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This paper reviews the phosphate phases in meteorites and those measured by landed spacecraft, what they reveal about past igneous and aqueous conditions on Mars, and important implications for potential prebiotic chemistry, past habitability, and potential biosignatures that could be detected in samples returned from Mars. A review of the 378 martian meteorites as of 2023 indicate that of the two most common phosphate minerals in Mars meteorites, merrillite and apatites, the apatite composition is largely F- and Cl-rich, with shergottites containing more OH. The phosphate concentrations examined across multiple missions show a relatively narrow range of phosphate, with higher concentrations observed in the Mount Sharp Group in Gale crater and Wishstone at Gusev crater and lower concentrations observed at Jezero crater floor and Jezero fan. Possible secondary phosphates detected on Mars, including Fe phosphates at Jezero crater and Gusev crater and Ca- and Al-bearing secondary phosphates, temperatures of formation of secondary phases and their dissolution rates and solubilities are reviewed and summarized. Despite this wealth of information about phosphates on Mars, due to their fine scale and relatively low concentrations, Mars Sample Return is needed to better understand phosphate and its implications for the igneous, aqueous, and astrobiological history of Mars.

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Soda Fe-Mn Pegmatite Phosphates

Cited by 5 publications

References 0 publications

Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates

Experimental investigation of the alluaudite + triphylite assemblage, and development of the Na-in-triphylite geothermometer: applications to natural pegmatite phosphates

The Transition Metal-rich Orthophosphate Arrojadite with Special Structural Features

Phosphates on Mars and Their Importance as Igneous, Aqueous, and Astrobiological Indicators

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