Organophosphorus radicals in natural apatites Ca2(PO4)3(F, OH)

Gilinskaya, L. G.; Zanin, Yu. N.; Knubovets, R. G.; Korneva, T. A.; Fadeeva, V. P.

doi:10.1007/bf00745608

Cited by 6 publications

(5 citation statements)

References 9 publications

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“…High uranium concentrations in phosphatic sediments are not necessarily indicative of anoxic conditions because of the efficient redox cycling of this element (Jarvis et al, 1994;Trappe, 1998). Similarly to uranium, thorium in seawater present as Th 4+ may enter the apatite structure by replacing Ca 2+ (Altschuler, 1980;Gilinskaya et al, 1993). It is noteworthy to underline that part of thorium in the bulk phosphatic sediment might be associated with clay minerals (Altschuler, 1980).…”

Section: Evolution Of Redox Conditions Within the Depositional Enviro...mentioning

confidence: 99%

Post-phosphogenesis processes and the natural beneficiation of phosphates: Geochemical evidence from the Moroccan High Atlas phosphate-rich sediments

et al. 2023

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Section: Evolution Of Redox Conditions Within the Depositional Enviro...mentioning

confidence: 99%

Post-phosphogenesis processes and the natural beneficiation of phosphates: Geochemical evidence from the Moroccan High Atlas phosphate-rich sediments

et al. 2023

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“…In addition to the correlation with REE and Sr, apatite also has good correlations with U and Ba; however, the interpretation is more complex. The substitution of U 4+ in Ca 2+ sites [60,61] accounts for the U anomaly in the phosphorite facies, although a distinct relationship with TOC exists for concentrations of much lower magnitude, due to the chelation of U with organic matter. The solid solution between Ba 2+ and Ca 2+ in the structure of fluorapatite [62] may account for its high EF in the granular phosphorite facies, but the Ba concentration in the intraclastic phosphorites are much lower, without any apparent cause.…”

Section: Trace Elementsmentioning

confidence: 99%

Significance and Distribution of Apatite in the Doig Phosphate Zone

Silva¹,

Bustin²

2020

Preprint

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The Doig Phosphate Zone (DPZ) is a phosphate-bearing marine unit located at the base of the Doig Formation, in the Triassic section of the Western Canada Sedimentary Basin. The DPZ has a maximum thickness of 90 m and extends across northeastern British Columbia and western central Alberta. In this study we characterize the significance and interpret the origin of apatite in the DPZ, through mineralogical and geochemical analyses, thin section study and field emission-scanning electron microscopy. The occurrence of apatite in the DPZ is not evenly distributed, but restricted to discrete 10 to 20 cm thick beds, located near the base of the DPZ. Phosphorites are of two types: grainstones composed primarily of unconformity-bounded coated grains, and intraclastic phosphorites composed of detrital silt-sized grains and apatite coated grains in a cryptocrystalline phosphatic matrix. The phosphorite beds are records of stratigraphic condensation due to low detrital input during transgression. The erosionally-truncated phosphatic coated grains and intraclasts are interpreted to be a result of various phases of phosphatization, exhumation, erosion reworking, winnowing and redeposition in alternating quiescence and storms or bottom currents. The abundance of pyrite and chalcophile trace elements, as well as the low concentration of proxy elements for organic matter productivity and preservation, are further evidences of stratigraphic condensation, with sulfidic pore water development and extensive organic recycling promoted by biological activity during the long exposure times. The phosphorites were formed under oxygenated water conditions, as suggested by the depletion in Ce and presence of a diverse benthic fauna.

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“…The relationship between Zr and Hf and quartz is likely due to the association of high specific gravity detrital zircon with the relatively coarser sand and silt-rich facies, since Hf can occupy the Zr-sites In addition to the correlation with REE and Sr, apatite also has strong positive correlations with U and Ba; however, the interpretation is more complex. The substitution of U 4+ in Ca 2+ sites [63,64] accounts for the U anomaly in the phosphorite facies, although a distinct relationship with TOC is observed for concentrations of much lower magnitude, due to the chelation of U with organic matter. The solid solution between Ba 2+ and Ca 2+ in the structure of fluorapatite [65] may account for its high Figure 17.…”

Section: Trace Elementsmentioning

confidence: 99%

“…In addition to the correlation with REE and Sr, apatite also has strong positive correlations with U and Ba; however, the interpretation is more complex. The substitution of U 4+ in Ca 2+ sites [63,64] accounts for the U anomaly in the phosphorite facies, although a distinct relationship with TOC is observed for concentrations of much lower magnitude, due to the chelation of U with organic matter. The solid solution between Ba 2+ and Ca 2+ in the structure of fluorapatite [65] may account for its high EF in the granular phosphorite facies, but the average Ba concentration in the intraclastic phosphorites is much lower, without any apparent cause.…”

Section: Trace Elementsmentioning

confidence: 99%

Significance and Distribution of Apatite in the Triassic Doig Phosphate Zone, Western Canada Sedimentary Basin

Silva

Bustin

2020

Minerals

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The Doig Phosphate Zone (DPZ) is a phosphate-bearing marine unit located at the base of the Doig Formation, in the Triassic section of the Western Canada Sedimentary Basin. The DPZ has a maximum thickness of 90 m and extends across northeastern British Columbia and west-central Alberta. In this study, we characterize the significance and interpret the origin of apatite in the DPZ through mineralogical and geochemical analyses, thin section study, and field emission scanning electron microscopy. The occurrence of apatite in the DPZ is not evenly distributed but restricted to discrete 10 to 20 cm thick beds, located near the base of the DPZ. Phosphorites are of two types: grainstones composed primarily of unconformity-bounded coated grains, and intraclastic phosphorites composed of detrital silt-sized grains and apatite coated grains in a cryptocrystalline phosphatic matrix. The phosphorite beds are records of stratigraphic condensation due to low detrital input during transgression. The erosionally truncated phosphatic coated grains and intraclasts are interpreted to be a result of various phases of phosphatization, exhumation, erosion, reworking, winnowing, and redeposition in alternating quiescence and storms or bottom currents. The abundance of pyrite and chalcophile trace elements, as well as the low concentration of proxy elements for organic matter productivity and preservation, are further evidence of stratigraphic condensation, with sulfidic pore water development and extensive organic recycling promoted by biological activity during the long exposure times. The phosphorites were formed under oxygenated water conditions, as suggested by the depletion in Ce and the presence of a diverse benthic fauna.

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Organophosphorus radicals in natural apatites Ca2(PO4)3(F, OH)

Cited by 6 publications

References 9 publications

Post-phosphogenesis processes and the natural beneficiation of phosphates: Geochemical evidence from the Moroccan High Atlas phosphate-rich sediments

Post-phosphogenesis processes and the natural beneficiation of phosphates: Geochemical evidence from the Moroccan High Atlas phosphate-rich sediments

Significance and Distribution of Apatite in the Doig Phosphate Zone

Significance and Distribution of Apatite in the Triassic Doig Phosphate Zone, Western Canada Sedimentary Basin

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