The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Moonsup Cho - One of the best experts on this subject based on the ideXlab platform.
-
zeolite to Prehnite pumpellyite facies metamorphism in the toa baja drill hole puerto rico
Geophysical Research Letters, 1991Co-Authors: Moonsup ChoAbstract:Secondary mineral assemblages in Eocene volcanic and volcaniclastic rocks of the Toa Baja drill hole progressively change as a function of depth. Four metamorphic zones are delineated with increasing depth: Caclinoptilolite→heulandite→laumontite→Prehnite–purnpellyite zone. The deepest belongs to the Prehnite-pumpellyite facies, whereas the three zones at shallower depths (<2350 m) belong to the zeolite facies. Ca-clinoptilolite and heulandite exhibit continuous solid solution with varying Si/Al (2.9–5.2) and Ca/(Ca+Na+K) ratios (0.45–0.89). Pumpellyites are characterized by extensive variation in the Fe/(Fe+Al+Mg) ratio (0.29–0.74) and extreme Fe-enrichment in the laumontite zone. Temperatures estimated from mineral assemblages and fades transitions suggest that the North Coast Basin, Puerto Rico, has been subject to a metamorphic field gradient of ∼50 to 70°C/km.
-
Zeolite to Prehnite‐pumpellyite facies metamorphism in the Toa Baja Drill Hole, Puerto Rico
Geophysical Research Letters, 1991Co-Authors: Moonsup ChoAbstract:Secondary mineral assemblages in Eocene volcanic and volcaniclastic rocks of the Toa Baja drill hole progressively change as a function of depth. Four metamorphic zones are delineated with increasing depth: Caclinoptilolite→heulandite→laumontite→Prehnite–purnpellyite zone. The deepest belongs to the Prehnite-pumpellyite facies, whereas the three zones at shallower depths (
R. E. Beiersdorfer - One of the best experts on this subject based on the ideXlab platform.
-
Prehnite pumpellyite to greenschist facies transition smartville complex near auburn california
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.
-
Prehnite–pumpellyite to greenschist facies transition, Smartville Complex, near Auburn, California
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.
R. K. Springer - One of the best experts on this subject based on the ideXlab platform.
-
Prehnite pumpellyite to greenschist facies transition smartville complex near auburn california
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.
-
Prehnite–pumpellyite to greenschist facies transition, Smartville Complex, near Auburn, California
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.
Edward D. Ghent - One of the best experts on this subject based on the ideXlab platform.
-
Low-pressure metamorphism of the mafic volcanic rocks of the Rossland Group, southeastern British Columbia
Canadian Journal of Earth Sciences, 1996Co-Authors: Wayne Powell, Edward D. GhentAbstract:Mafic volcanic rocks of the Rossland Group have been metamorphosed in the subgreenschist to lower amphibolite facies. Subgreenschist-facies regional metamorphic rocks are subdivided into Prehnite–pumpeilyite zone and Prehnite–epidote zone. Fluid inclusions in two subgreenschist-facies veins yielded mean homogenization temperatures of 139 and 151 °C. Assuming a reasonable maximum temperature limit of 275 °C for the subgreenschist fades, the fluid-inclusion isochores indicate a pressure
-
fluid mineral equilibria in Prehnite pumpellyite to greenschist facies metabasites near flin flon manitoba canada implications for petrogenetic grids
Journal of Metamorphic Geology, 1994Co-Authors: S. Digel, Edward D. GhentAbstract:A sequence of regional metamorphic isograds indicating a range from Prehnite-pumpellyite to lower amphibolite facies was mapped in metabasites near Flin Flon, Manitoba. The lowest grade rocks contain Prehnite + pumpellyite and are cut by younger brittle faults containing epidote + chlorite + calcite. Isobaric temperature-XCO2 and pressure-temperature (constant XCO2) diagrams were calculated to quantify the effects of CO2 in the metamorphic fluid on the stability of Prehnite-pumpellyite facies minerals in metabasites containing excess quartz and chlorite. Prehnite and, to a lesser extent, pumpellyite are stable only in fluids with Xco2 0.002, epidote + chlorite + calcite assemblages are stable. Our calculated phase relations are consistent with regional metamorphism in the Flin Flon area in the presence of an H2O-rich fluid and a more CO2-rich fluid in the later fault zones. We believe that the potential effects of small amounts of CO2 in the metamorphic fluid should be assessed when considering the pressure-temperature implications of mineral assemblages in low-grade metabasites.
-
Fluid‐mineral equilibria in Prehnite‐pumpellyite to greenschist facies metabasites near Flin Flon, Manitoba, Canada: implications for petrogenetic grids
Journal of Metamorphic Geology, 1994Co-Authors: S. Digel, Edward D. GhentAbstract:A sequence of regional metamorphic isograds indicating a range from Prehnite-pumpellyite to lower amphibolite facies was mapped in metabasites near Flin Flon, Manitoba. The lowest grade rocks contain Prehnite + pumpellyite and are cut by younger brittle faults containing epidote + chlorite + calcite. Isobaric temperature-XCO2 and pressure-temperature (constant XCO2) diagrams were calculated to quantify the effects of CO2 in the metamorphic fluid on the stability of Prehnite-pumpellyite facies minerals in metabasites containing excess quartz and chlorite. Prehnite and, to a lesser extent, pumpellyite are stable only in fluids with Xco2 0.002, epidote + chlorite + calcite assemblages are stable. Our calculated phase relations are consistent with regional metamorphism in the Flin Flon area in the presence of an H2O-rich fluid and a more CO2-rich fluid in the later fault zones. We believe that the potential effects of small amounts of CO2 in the metamorphic fluid should be assessed when considering the pressure-temperature implications of mineral assemblages in low-grade metabasites.
Howard W. Day - One of the best experts on this subject based on the ideXlab platform.
-
Prehnite pumpellyite to greenschist facies transition smartville complex near auburn california
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.
-
Prehnite–pumpellyite to greenschist facies transition, Smartville Complex, near Auburn, California
Journal of Metamorphic Geology, 1992Co-Authors: R. K. Springer, Howard W. Day, R. E. BeiersdorferAbstract:The Smartville Complex is a late Jurassic, rifted volcanic arc in the northern Sierra Nevada, California. Near Auburn, California, it consists of a lower volcanic unit, dominated by basaltic flows, and an upper volcanic unit of andesitic volcaniclastic rocks, both of which have been intruded by dykes and irregular bodies of diabase. These rocks contain relict igneous minerals, and the metamorphic minerals albite, chlorite, quartz, pumpellyite, Prehnite, epidote, amphibole, titanite, garnet, biotite, K-feldspar, white mica, calcite, and sulphide and oxide minerals. Prehnite–pumpellyite (PrP), Prehnite–actinolite (PrA), and greenschist (GS) zones have been identified. The pumpellyite-out isograd separates the PrP and PrA zones, and the Prehnite-out isograd separates the PrA and GS zones. The minerals Ab + Qtz + Mt + Tn are common to most assemblages in all three zones. The MgO/(MgO + FeO) ratio of the effective bulk composition has an important and systematic effect on the observed mineral assemblages in the PrP zone. Prehnite-bearing assemblages contain the additional minerals, Pmp + Amp + Ep + Chl in MgO-rich rocks, and either Pmp + Ep + Chl or Amp + Ep + Chl in less magnesian rocks. Subcalcic to calcic amphibole is common in the PrP zone. The mineral assemblage Prh + Act + Ep + Chl, without Pmp, characterizes the PrA zone, and the mineral assemblage Act + Ep + Chl, without Prh or Pmp, characterizes the GS zone. The disappearance of pumpellyite and Prehnite occurred by continuous reactions. The sequence of mineral assemblages was produced by burial metamorphism at P–T conditions of 300° 50°C at approximately 2.5 ± 0.5 kbar. During metamorphism, the composition of the fluid phase was nearly 100% H2O and the oxygen fugacity was between the hematite–magnetite and quartz–fayalite–magnetite buffers.