Pressure-temperature paths from garnet-zoning: Evidence for multiple episodes of thrust burial in the hinterland of the Sevier orogenic belt
-
Thomas D. Hoisch
,
Michael L. Wells
Abstract
Garnets are present in two horizons of the schist of Stevens Spring from the Basin Creek area of the Grouse Creek Mountains in northwest Utah. The two horizons possess different bulk compositions, which resulted in garnet growth by different reactions along the same pressure-temperature (P-T) path. Garnet in the upper horizon grew from the breakdown of chlorite at upper greenschistfacies conditions and garnet in the lower horizon grew from the breakdown of staurolite at upper amphibolite-facies conditions. From the upper horizon, five garnets from three samples were analyzed. All display growth zoning, ragged morphologies associated with secondary rim consumption, and yield garnet-biotite geothermometry temperatures of ~460-490 °C. From the lower horizon, one garnet from each of two samples was analyzed. These also display growth zoning, but differ from garnet in the upper horizon in that they are dominantly idioblastic and yield garnet-biotite geothermometry temperatures of ~635 °C. Garnet-biotite geothermometry calculated for every point along detailed compositional traverses across the garnets revealed localized reequilibration along rims, cracks and inclusions in both generations of garnet. Garnets from the upper horizon display prograde reequilibration and the garnets from the lower horizon display retrograde reequilibration. Numerical simulations of garnet growth using the Gibbs method with Duhem’s theorem were carried out to determine P-T paths. The P-T path defined by the modeling of five garnets from the upper horizon is an isothermal pressure increase of ~1.7 kbar. The P-T path defined by the modeling of two garnets from the lower horizon has a steep P-T trajectory (dP/dT = 32 bars/°C) and a total pressure change of ~0.9 kbar. Both paths are indicative of thrust burial; however, the two paths cannot be reconciled as products of a single thrust episode. These data are interpreted to indicate two different episodes of thrust burial during the Sevier Orogeny, separated by ~150 °C of heating and partial exhumation.
© 2015 by Walter de Gruyter Berlin/Boston
Artikel in diesem Heft
- Study on adsorption of submicrometer gold on kaolinite by quantum chemistry calculations
- Image distortion in scanning probe microscopy
- Multiple length scale growth spirals on metamorphic graphite {001} surfaces studied by atomic force microscopy
- 29Si MAS NMR study of diopside–Ca-Tschermak clinopyroxenes: Detecting both tetrahedral and octahedral Al substitution
- Electron paramagnetic resonance spectroscopic study of synthetic fluorapatite: Part I. Local structural environment and substitution mechanism of Gd3+ at the Ca2 site
- Electron paramagnetic resonance spectroscopic study of synthetic fluorapatite: Part II. Gd3+ at the Ca1 site, with a neighboring Ca2 vacancy
- Determination of the H3BO3 concentration in fluid and melt inclusions in granite pegmatites by laser Raman microprobe spectroscopy
- Analysis of natural H2O + CO2 + NaCl fluid inclusions in the hydrothermal diamond anvil cell
- Thermodynamics of the amphiboles: Ca-Mg-Fe2+ quadrilateral
- Phase boundary between rutile-type and CaCl2-type germanium dioxide determined by in situ X-ray observations
- The nature, formation, and stability of end-member illite: A hypothesis
- Determination of melanterite-rozenite and chalcanthite-bonattite equilibria by humidity measurements at 0.1 MPa
- Pressure-temperature paths from garnet-zoning: Evidence for multiple episodes of thrust burial in the hinterland of the Sevier orogenic belt
- Mineralogical and Mössbauer spectroscopic study of a diopside occurring in the marbles of Andranondambo, southern Madagascar
- Correlations of octahedral cations with OH–, O2–, Cl–, and F– in biotite from volcanic rocks and xenoliths
- H positions in leucophoenicite, Mn7Si3O12(OH)2: A close relative of the hydrous B phases
- Ominelite, (Fe,Mg)Al3BSiO9 (Fe2+ analogue of grandidierite), a new mineral from porphyritic granite in Japan
- Closure in crystal size distributions (CSD), verification of CSD calculations, and the significance of CSD fans
- Icosahedral domain structure of framboidal pyrite
Artikel in diesem Heft
- Study on adsorption of submicrometer gold on kaolinite by quantum chemistry calculations
- Image distortion in scanning probe microscopy
- Multiple length scale growth spirals on metamorphic graphite {001} surfaces studied by atomic force microscopy
- 29Si MAS NMR study of diopside–Ca-Tschermak clinopyroxenes: Detecting both tetrahedral and octahedral Al substitution
- Electron paramagnetic resonance spectroscopic study of synthetic fluorapatite: Part I. Local structural environment and substitution mechanism of Gd3+ at the Ca2 site
- Electron paramagnetic resonance spectroscopic study of synthetic fluorapatite: Part II. Gd3+ at the Ca1 site, with a neighboring Ca2 vacancy
- Determination of the H3BO3 concentration in fluid and melt inclusions in granite pegmatites by laser Raman microprobe spectroscopy
- Analysis of natural H2O + CO2 + NaCl fluid inclusions in the hydrothermal diamond anvil cell
- Thermodynamics of the amphiboles: Ca-Mg-Fe2+ quadrilateral
- Phase boundary between rutile-type and CaCl2-type germanium dioxide determined by in situ X-ray observations
- The nature, formation, and stability of end-member illite: A hypothesis
- Determination of melanterite-rozenite and chalcanthite-bonattite equilibria by humidity measurements at 0.1 MPa
- Pressure-temperature paths from garnet-zoning: Evidence for multiple episodes of thrust burial in the hinterland of the Sevier orogenic belt
- Mineralogical and Mössbauer spectroscopic study of a diopside occurring in the marbles of Andranondambo, southern Madagascar
- Correlations of octahedral cations with OH–, O2–, Cl–, and F– in biotite from volcanic rocks and xenoliths
- H positions in leucophoenicite, Mn7Si3O12(OH)2: A close relative of the hydrous B phases
- Ominelite, (Fe,Mg)Al3BSiO9 (Fe2+ analogue of grandidierite), a new mineral from porphyritic granite in Japan
- Closure in crystal size distributions (CSD), verification of CSD calculations, and the significance of CSD fans
- Icosahedral domain structure of framboidal pyrite
