Illumination of vein quartz textures in a porphyry copper ore deposit using scanned cathodoluminescence: Grasberg Igneous Complex, Irian Jaya, Indonesia
Abstract
Vein quartz from the Grasberg Igneous Complex in Irian Jaya, Indonesia, displays a wide range of features when observed using scanned cathodoluminescence imaging on the electron microscope. Examination of seventeen samples revealed concentric growth zoning, quartz-filled microfractures, dark luminescence near sulfides, changes in crystal size and orientation from vein edges to vein centers, turbid growth zoning, and the truncation of concentric growth zoning. Individual features observed along two large photomosaic traverses from vein margins to vein centers coupled with trace element analyses from the electron microprobe allow determination of a detailed history of fracture infilling. The two traverses indicate a simple, two-stage history of crystal growth into an open fracture followed by mechanical closing of the fracture with resulting microfractures. Electron microprobe trace-element analyses show that the Fe content of quartz reaches values of up to 4900 ppm in dark-luminescent regions near sulfide crystals and decreases smoothly to ~200 ppm along traverses away from the sulfides. The solution to the diffusion equation coupled with existing experimental data about Fe diffusion in SiO2 indicate the duration of the diffusion was perhaps on the order of thousands of years.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Growth of megaspherulites in a rhyolitic vitrophyre
- Electron microscope study of the reaction olivine + H2O + TiO2 → titanian clinohumite + Titanian chondrodite synthesized at 8 GPa, 1300 K
- In situ discovery of shock-induced graphite-diamond phase transition in gneisses from the Ries Crater, Germany
- Evaluation of shear moduli and other properties of silicates with the spinel structure from IR spectroscopy
- Thermodynamics of the amphiboles: Anthophyllite-ferroanthophyllite and the ortho-clino phase loop
- Illumination of vein quartz textures in a porphyry copper ore deposit using scanned cathodoluminescence: Grasberg Igneous Complex, Irian Jaya, Indonesia
- Rare earth elements in synthetic zircon: Part 1. Synthesis, and rare earth element and phosphorus doping
- Rare-earth elements in synthetic zircon: Part 2. A single-crystal X-ray study of xenotime substitution
- Single-crystal in situ high-temperature structural investigation on strontium feldspar
- Evidence of heterovalent europium in zoned Llallagua apatite using wavelength dispersive XANES
- Characterization of manganese oxide mineralogy in rock varnish and dendrites using X-ray absorption spectroscopy
- Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study
- Mössbauer and XAS study of a green rust mineral; the partial substitution of Fe2+ by Mg2+
- Potential host phase of aluminum and potassium in the Earth’s lower mantle
- Hardystonite from Franklin Furnace: A natural modulated melilite
- Molecular dynamics simulations of seismic discontinuities and phase transitions of MgSiO3 from 4 to 6-coordinated silicate via a novel 5-coordinated phase
- Ab initio study of MgSiO3 low-clinoenstatite at high pressure
Articles in the same Issue
- Growth of megaspherulites in a rhyolitic vitrophyre
- Electron microscope study of the reaction olivine + H2O + TiO2 → titanian clinohumite + Titanian chondrodite synthesized at 8 GPa, 1300 K
- In situ discovery of shock-induced graphite-diamond phase transition in gneisses from the Ries Crater, Germany
- Evaluation of shear moduli and other properties of silicates with the spinel structure from IR spectroscopy
- Thermodynamics of the amphiboles: Anthophyllite-ferroanthophyllite and the ortho-clino phase loop
- Illumination of vein quartz textures in a porphyry copper ore deposit using scanned cathodoluminescence: Grasberg Igneous Complex, Irian Jaya, Indonesia
- Rare earth elements in synthetic zircon: Part 1. Synthesis, and rare earth element and phosphorus doping
- Rare-earth elements in synthetic zircon: Part 2. A single-crystal X-ray study of xenotime substitution
- Single-crystal in situ high-temperature structural investigation on strontium feldspar
- Evidence of heterovalent europium in zoned Llallagua apatite using wavelength dispersive XANES
- Characterization of manganese oxide mineralogy in rock varnish and dendrites using X-ray absorption spectroscopy
- Oxidation state and coordination of Fe in minerals: An Fe K-XANES spectroscopic study
- Mössbauer and XAS study of a green rust mineral; the partial substitution of Fe2+ by Mg2+
- Potential host phase of aluminum and potassium in the Earth’s lower mantle
- Hardystonite from Franklin Furnace: A natural modulated melilite
- Molecular dynamics simulations of seismic discontinuities and phase transitions of MgSiO3 from 4 to 6-coordinated silicate via a novel 5-coordinated phase
- Ab initio study of MgSiO3 low-clinoenstatite at high pressure
