Marbles containing high-pressure mineral assemblage was found from the Sanandaj-Sirjan metamorphic belt in the Nahavand area in western Iran.  The high-pressure marbles occur as small bodies or lenses within pelitic schist layers and show compositional banding of carbonate- and silicate- rich bands.  Textural analysis revealed two metamorphic stages.  The early stage is testified by relicts of ...

marbles containing high-pressure mineral assemblage was found from the sanandaj-sirjan metamorphic belt in the nahavand area in western iran.  the high-pressure marbles occur as small bodies or lenses within pelitic schist layers and show compositional banding of carbonate- and silicate- rich bands.  textural analysis revealed two metamorphic stages.  the early stage is testified by relicts of ...

Chloroperoxidase and horseradish peroxidase use NaClOz as both the oxidant and the halogen donor for the peroxidative chlorination of monochlorodimedone. Previous studies have shown that both horseradish peroxidase and chloroperoxidase can catalyze iodination reactions with hydrogen peroxide as the oxidant; however, only chloroperoxidase catalyzes chlorination reactions under these conditions. ...

Horseradish peroxidase and chlorite, NaC102, are able to catalyze chlorination of monochlorodimedone to form dichlorodimedone. Catalytic amounts of horseradish peroxidase act to disproportionate chlorite forming chlorine dioxide and chloride ion. The chlorine dioxide thus formed is responsible for the chlorination of monochlorodimedone. It was previously thought (Chiang, R., Rand-Meir, T., Maki...

A compilation of Fe-bearing chlorite analyses is used: (1) to investigate the Alfree di-trioctahedral (AFDT) substitution 2Fe +□ = 3(Mg,Fe) in chlorite; and (2) to estimate the composition of a ferri-sudoite end-member (Si3Al)[(Fe ,Mg)2Fe 3+ 2 □Al]O10(OH)8 within the chlorite solid-solution domain. According to our observations, up to two Fe cations might be allocated in the M2-M3 chlorite site...

The Nahal Yael basin is underlain chiefly by schist, amphibolite, and granite. Thin (generally < 1 m thick), grussy colluvium which covered the lower portions of granitic hillslopes in the late Pleistocene has now been stripped completely, causing marked contrasts in outcrop morphologies, even where there is no contrast of fracture density or petrologic characteristics. Formerly mantled slopes ...

Chlorite dismutases are prokaryotic heme b oxidoreductases that convert chlorite to chloride and dioxygen. It has been postulated that during turnover hypochlorite is formed transiently, which might be responsible for the observed irreversible inactivation of these iron proteins. The only charged distal residue in the heme cavity is a conserved and mobile arginine, but its role in catalysis and...

Acidified sodium chlorite cleaves isodityrosine and solubilizes covalently bound hydroxyproline-rich material from cell walls. This has been taken as evidence that isodityrosine acts as a cross-link holding the hydroxyproline-rich glycoprotein extensin in the cell wall. However, acidified chlorite was found to cleave peptide bonds in salt-soluble extensin and in bovine serum albumin (BSA). This...

This study presents a new geochemical, petrological, and geochronological U–Pb dataset from Ediacaran metabasites of the Canigó Cap de Creus massifs, Eastern Pyrenees. The rocks are composed calcic amphibole + plagioclase chlorite epidote ± quartz plus titanite apatite ilmenite biotite rutile as accessory phases show relict igneous textures. Peak pressure-temperature determinations share common...

RésuméUn profil d’altération développé sur chloritoschistes de la zone Bengbis (Sud Cameroun) a été choisi pour quantifier l’intensité l’altération et comprendre le comportement des terres rares. Les valeurs l’indice mafique combinées aux diagrammes ternaires du système Al – Fe Mg Ca Na K montrent que l’hydrolyse feldspaths est proportionnelle à celle minéraux mafiques (pertes en Mg), bien plag...