The heme enzyme chlorite dismutase (Cld) catalyzes the degradation of chlorite to chloride and dioxygen. Although structure and steady-state kinetics of Clds have been elucidated, many questions remain (e.g., the mechanism of chlorite cleavage and the pH dependence of the reaction). Here, we present high-resolution X-ray crystal structures of a dimeric Cld at pH 6.5 and 8.5, its fluoride and is...

Chlorite dismutase (Cld) is a heme b-dependent, O-O bond forming enzyme that transforms toxic chlorite (ClO(2)(-)) into innocuous chloride and molecular oxygen. The mechanism and specificity of the reaction with chlorite and alternate oxidants were investigated. Chlorite is the sole source of dioxygen as determined by oxygen-18 labeling studies. Based on ion chromatography and mass spectrometry...

A chloritoid schist from the Medvednica Mts. (Croatia, Zagorje-Mid-Transdanubian zone) is part of metasedimentary succession a Palaeozoic-Mesozoic Metamorphic Complex. The studied samples show mineral association chloritoid, chlorite, quartz and white mica. P-T pseudosection, combined with modal chemical isopleths, classical thermobarometric calculations yield peak metamorphic conditions 0.8 – ...

Semi-pelitic rocks ranging in grade from the prehnite–pumpellyite to the greenschist facies from southeastern Otago, New Zealand, have been investigated in order to evaluate the reactions leading to formation and breakdown of stilpnomelane. Detrital grains of mica and chlorite along with fine-grained authigenic illite and chlorite occur in lower-grade rocks with compactional fabric parallel to ...

Rock mass deformation is a time related process, especially for soft rock. Its usually has certain timeliness. Moreover, the of surrounding rock typically asymmetric. Therefore, it great significance to reasonably describe time-dependent mechanical properties and behaviors practical engineering, when actual engineering symmetric structure. Taking chlorite schist section at west end diversion tu...

Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high elect...

Abstract The slab–mantle interface in subduction zones is one of the geological boundaries with most significant chemical potential gradients, which leads to fluid-mediated metasomatic reactions and transport. As subducting sediment basaltic crust often contain silica various forms, Si-metasomatism mantle rocks thought occur along zone interface. However, growing evidence from geochemistry alte...

The Nabeba high-grade iron deposit (Republic of the Congo) is hosted by banded formation (BIF) in Ivindo Basement Complex, which lies northwestern part Congo Craton. BIF intercalated with chlorite-sericite-quartz schist and comprises two facies (oxide a carbonate-oxide). In this study, whole-rock LA-ICP-MS magnetite geochemistry was reported. Magnetite samples from both had fairly similar trace...

Soursat Metamorphic Complex (SMC) in west of Takab city is one of the polyphase metamorphic terrenes in northern Sanandaj-Sirjan metamorphic belt of Iran. The SMC composed mainly of metasedimentary rocks associated with granitic intrusions. Based on metamorphic rocks, two metamorphic phases could be separate in the complex. M1 is representative of regional metamorphisms which varies from greens...