Chemical substitutions, paragenetic relations, and physical conditions of formation of högbomite in the Sittampundi layered anorthosite complex, South India
-
Pulak Sengupta
,
Uttam K. Bhui
Abstract
Layered anorthosite, chromiferous pyroxenite, and spatially associated mafic and felsic rocks of the 2.9 Ga Sittampundi layered complex (SLC), South India, underwent high-grade metamorphism at ca. 2.5 Ga and were subjected to amphibolite-facies metamorphism accompanied by intrusion of granitoid plutons during late-Neoproterozoic tectonothermal activity (0.72-0.45 Ga). During the latter event, anorthosite developed millimeter- to centimeter-thick compositional layers rich in clinopyroxene+amphibole+clinozoisite+chlorite±chromite and corundum+spinel+chlorite. Tiny grains of högbomite replaced only the grains of corundum and spinel and are in textural equilibrium with chlorite. The studied högbomite contains appreciable TiO2 (>4.4 wt%) but insignificant NiO and ZnO. Cr2O3 content reaches up to 0.35 wt% only in chromite-bearing samples. Systematic partitioning of Fe and Mg between högbomite and associated Fe-Mg minerals demonstrate attainment of chemical equilibrium among these phases. Integrating textural relations and algebraic analyses of the phase compositions, several reactions were constructed involving the associated oxide phases (spinel, corundum, högbomite), calcite, and silicates (amphibole, chlorite, anorthite, clinozoisite). Interpretation of the reaction reveals that (1) Mg2+ and Ti4+ were mobile for more than 2 cm during the formation of högbomite and chlorite, and (2) chloritization of amphibole in the clinopyroxene+amphibole-bearing layers released Ti that was transported to the spinel+corundum-bearing layers to develop högbomite. Stability fields of some critical mineral assemblages in P-XCO₂ and T-XCO₂ space combined with geothermobarometry in the associated rocks tightly constrain the growth of högbomite in the presence of aqueous fluids (XCO₂ < 0.15) to the P-T range of 7 ± 1 kbar, 650 ± 50 °C. These aqueous fluids, presumably derived from the Pan-African granitoid batholiths, chloritized amphibole grains, and transported the released Ti4+ to the spinel+corundum-bearing layers to develop högbomite. Topological relations in isothermal-isobaric fugacity diagrams (log fO₂-log fS₂ and log fO₂-log fH₂O) in the system FeO-Al2O3- TiO2-O2-S2-H2O-CO2 (+MgO, Cr2O3) indicate that the stability and compositional characteristics of natural högbomite are strongly influenced by fO₂, fS₂, fH₂O, and concentrations of other soluble species (Ti, Mg, Cr, etc.) in the metamorphic fluids
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Review Paper. Microbe-clay mineral interactions
- Chemical substitutions, paragenetic relations, and physical conditions of formation of högbomite in the Sittampundi layered anorthosite complex, South India
- Miguelromeroite, the Mn analogue of sainfeldite, and redefinition of villyaellenite as an ordered intermediate in the sainfeldite-miguelromeroite series
- Mechanism and kinetics of a mineral transformation under hydrothermal conditions: Calaverite to metallic gold
- A statistical reassessment of the evidence for the racemic distribution of quartz enantiomorphs
- On the crystal structure and crystal chemistry of pollucite, (Cs,Na)16Al16Si32O96·nH2O: A natural microporous material of interest in nuclear technology
- The effect of fluid inclusion size on determination of homogenization temperature and density of liquid-rich aqueous inclusions
- Effect of SiO2, total FeO, Fe3+/Fe2+, and alkali elements in basaltic glasses on mid-infrared
- Influence of cation size on the low-temperature heat capacity of alkaline earth metasilicate glasses
- The high-pressure–high-temperature behavior of bassanite
- Geochemistry of reversible hydratable tephra from the Trans Mexican Volcanic Belt
- Physical contradictions and remedies using simple polythermal equations of state
- Thermodynamic and crystallographic properties of kornelite [Fe2(SO4)3·~7.75H2O] and paracoquimbite [Fe2(SO4)3·9H2O]
- Humidity-induced phase transitions of ferric sulfate minerals studied by in situ and ex situ X-ray diffraction
- In situ Raman spectroscopy of MgSiO3 enstatite up to 1550 K
- Optical spectroscopic study of tetrahedrally coordinated Co2+ in natural spinel and staurolite at different temperatures and pressures
- New insights into smectite illitization: A zoned K-bentonite revisited
- The hydrothermal conversion of kaolinite to kalsilite: Influence of time, temperature, and pH
- Sideronatrite, Na2Fe(SO4)2(OH)·3H2O: Crystal structure of the orthorhombic polytype and OD character analysis
- Anharmonic OH vibrations in brucite: Small pressure-induced redshift in the range 0–22 GPa
- Structural properties of biologically controlled hydrozincite: An HRTEM and NMR spectroscopic study
- Mechanism of wollastonite carbonation deduced from micro- to nanometer length scale observations
- Letter. Crystal structure of argentopyrite, AgFe2S3, and its relationship with cubanite
- Letter. Magnetite-free, yellow lizardite serpentinization of olivine websterite, Canyon Mountain complex, N.E. Oregon
- Letter. The influence of atomic size and charge of dissolved species on the diffusivity and viscosity of silicate melts
- Letter. Si-Al distribution in high-pressure CaAl4Si2O11 phase: A 29Si and 27Al NMR study
Articles in the same Issue
- Review Paper. Microbe-clay mineral interactions
- Chemical substitutions, paragenetic relations, and physical conditions of formation of högbomite in the Sittampundi layered anorthosite complex, South India
- Miguelromeroite, the Mn analogue of sainfeldite, and redefinition of villyaellenite as an ordered intermediate in the sainfeldite-miguelromeroite series
- Mechanism and kinetics of a mineral transformation under hydrothermal conditions: Calaverite to metallic gold
- A statistical reassessment of the evidence for the racemic distribution of quartz enantiomorphs
- On the crystal structure and crystal chemistry of pollucite, (Cs,Na)16Al16Si32O96·nH2O: A natural microporous material of interest in nuclear technology
- The effect of fluid inclusion size on determination of homogenization temperature and density of liquid-rich aqueous inclusions
- Effect of SiO2, total FeO, Fe3+/Fe2+, and alkali elements in basaltic glasses on mid-infrared
- Influence of cation size on the low-temperature heat capacity of alkaline earth metasilicate glasses
- The high-pressure–high-temperature behavior of bassanite
- Geochemistry of reversible hydratable tephra from the Trans Mexican Volcanic Belt
- Physical contradictions and remedies using simple polythermal equations of state
- Thermodynamic and crystallographic properties of kornelite [Fe2(SO4)3·~7.75H2O] and paracoquimbite [Fe2(SO4)3·9H2O]
- Humidity-induced phase transitions of ferric sulfate minerals studied by in situ and ex situ X-ray diffraction
- In situ Raman spectroscopy of MgSiO3 enstatite up to 1550 K
- Optical spectroscopic study of tetrahedrally coordinated Co2+ in natural spinel and staurolite at different temperatures and pressures
- New insights into smectite illitization: A zoned K-bentonite revisited
- The hydrothermal conversion of kaolinite to kalsilite: Influence of time, temperature, and pH
- Sideronatrite, Na2Fe(SO4)2(OH)·3H2O: Crystal structure of the orthorhombic polytype and OD character analysis
- Anharmonic OH vibrations in brucite: Small pressure-induced redshift in the range 0–22 GPa
- Structural properties of biologically controlled hydrozincite: An HRTEM and NMR spectroscopic study
- Mechanism of wollastonite carbonation deduced from micro- to nanometer length scale observations
- Letter. Crystal structure of argentopyrite, AgFe2S3, and its relationship with cubanite
- Letter. Magnetite-free, yellow lizardite serpentinization of olivine websterite, Canyon Mountain complex, N.E. Oregon
- Letter. The influence of atomic size and charge of dissolved species on the diffusivity and viscosity of silicate melts
- Letter. Si-Al distribution in high-pressure CaAl4Si2O11 phase: A 29Si and 27Al NMR study
