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Four generations of accessory-phase growth in low-pressure migmatites from SW New Hampshire

  • Joseph M. Pyle EMAIL logo and Frank S. Spear
Published/Copyright: March 31, 2015
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American Mineralogist
From the journal American Mineralogist Volume 88 Issue 2-3

Abstract

Mineral compositions and reaction textures found in migmatitic gneisses from near Gilsum, New Hampshire, constrain both peak metamorphic pressure (P) and temperature (T) conditions and the PT path. Large K-feldspar porphyroblasts indicate isobaric heating of the samples at P < 4 kb (Spear et al. 1999), and relict cordierite + garnet assemblages record the occurrence of biotite vapor-absent melting; garnet-biotite thermometry yields peak temperatures of 740 ℃ at 3.5 kbar. During melt crystallization, low-Ti biotite + sillimanite replaced cordierite, and production of muscovite indicates P > 4 kb on the cooling path. Four generations of monazite have been identified, three of which have been linked to specific whole-rock reactions. Monazite (4) (the last generation) was produced with xenotime ± apatite during melt crystallization and consumption of garnet and cordierite. Monazite (3) grew in a xenotime-absent mineral assemblage as garnet + muscovite reacted to form sillimanite + biotite. Monazite (2) grew in a xenotime-bearing ± garnet + biotite + chlorite assemblage, as xenotime and chlorite were consumed during garnet production. Monazite (1) has not been linked to a specific reaction; it may be detrital, record an earlier metamorphic event, or represent disequilibrium overgrowths of xenotime. YAG-monazite, YAG-xenotime, and monazite-xenotime thermometry for monazite generations (2)-(4) yield temperatures consistent with major-phase thermometers.

Received: 2002-3-11
Accepted: 2002-10-1
Published Online: 2015-3-31
Published in Print: 2003-2-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Structure, metal-insulator transitions, and magnetic properties of FeO at high pressures
  2. The high-temperature behavior of defect hydrogen species in quartz: Implications for hydrogen isotope studies
  3. Thermal stability and vibrational spectra of the sheet borate tuzlaite, NaCa[B5O8(OH)2]·3H2O
  4. Hydrogen-bonded water in laumontite I: X-ray powder diffraction study of water site occupancy and structural changes in laumontite during room-temperature isothermal hydration/dehydration
  5. In-situ determination of mineral solubilities in fluids using a hydrothermal diamond-anvil cell and SR-XRF: Solubility of AgCl in water
  6. Pressure-induced phase transition in malayaite, CaSnOSiO4
  7. Equation of state of stishovite to lower mantle pressures
  8. Chemical transfer during redox exchanges between H2 and Fe-bearing silicate melts
  9. Trace-element partitioning between alkali feldspar and peralkalic quartz trachyte to rhyolite magma. Part I: Systematics of trace-element partitioning
  10. Trace-element partitioning between alkali feldspar and peralkalic quartz trachyte to rhyolite magma. Part II: Empirical equations for calculating trace-element partition coefficients of large-ion lithophile, high field-strength, and rare-earth elements
  11. Four generations of accessory-phase growth in low-pressure migmatites from SW New Hampshire
  12. Mineralogy, chemistry, and formation of oxidized biotite in the weathering profile of granitic rocks
  13. Experimental study of zircon coarsening in quartzite ±H2O at 1.0 GPa and 1000 ℃, with implications for geochronological studies of high-grade metamorphism
  14. Biotite dissolution processes and mechanisms in the laboratory and in nature: Early stage weathering environment and vermiculitization
  15. Fe2+ -Mg partitioning between garnet, magnesiowüstite, and (Mg,Fe)2SiO4 phases of the transition zone
  16. Interlayer structure and dynamics of Cl-bearing hydrotalcite: far infrared spectroscopy and molecular dynamics modeling
  17. Si-Al disorder and solid solutions in analcime, chabazite, and wairakite
  18. Cafetite, Ca[Ti2O5](H2O): Crystal structure and revision of chemical formula
  19. Order-disorder approach to calcioaravaipaite, [PbCa2Al(F,OH)9]: The crystal structure of the triclinic MDO polytype
  20. Ab initio investigation of the structures of NaOH hydrates and their Na+ and OH– coordination polyhedra
  21. Another step toward understanding the true nature of sartorite: Determination and refinement of a ninefold superstructure
  22. Letter. Ultrapotassic clinopyroxene from the Kumdy-Kol microdiamond mine, Kokchetav Complex, Kazakhstan: Occurrence, composition and crystal-chemical characterization
  23. Letter. Determination of planetary basalt parentage: A simple technique using the electron microprobe
https://doi.org/10.2138/am-2003-2-311

Articles in the same Issue

  1. Structure, metal-insulator transitions, and magnetic properties of FeO at high pressures
  2. The high-temperature behavior of defect hydrogen species in quartz: Implications for hydrogen isotope studies
  3. Thermal stability and vibrational spectra of the sheet borate tuzlaite, NaCa[B5O8(OH)2]·3H2O
  4. Hydrogen-bonded water in laumontite I: X-ray powder diffraction study of water site occupancy and structural changes in laumontite during room-temperature isothermal hydration/dehydration
  5. In-situ determination of mineral solubilities in fluids using a hydrothermal diamond-anvil cell and SR-XRF: Solubility of AgCl in water
  6. Pressure-induced phase transition in malayaite, CaSnOSiO4
  7. Equation of state of stishovite to lower mantle pressures
  8. Chemical transfer during redox exchanges between H2 and Fe-bearing silicate melts
  9. Trace-element partitioning between alkali feldspar and peralkalic quartz trachyte to rhyolite magma. Part I: Systematics of trace-element partitioning
  10. Trace-element partitioning between alkali feldspar and peralkalic quartz trachyte to rhyolite magma. Part II: Empirical equations for calculating trace-element partition coefficients of large-ion lithophile, high field-strength, and rare-earth elements
  11. Four generations of accessory-phase growth in low-pressure migmatites from SW New Hampshire
  12. Mineralogy, chemistry, and formation of oxidized biotite in the weathering profile of granitic rocks
  13. Experimental study of zircon coarsening in quartzite ±H2O at 1.0 GPa and 1000 ℃, with implications for geochronological studies of high-grade metamorphism
  14. Biotite dissolution processes and mechanisms in the laboratory and in nature: Early stage weathering environment and vermiculitization
  15. Fe2+ -Mg partitioning between garnet, magnesiowüstite, and (Mg,Fe)2SiO4 phases of the transition zone
  16. Interlayer structure and dynamics of Cl-bearing hydrotalcite: far infrared spectroscopy and molecular dynamics modeling
  17. Si-Al disorder and solid solutions in analcime, chabazite, and wairakite
  18. Cafetite, Ca[Ti2O5](H2O): Crystal structure and revision of chemical formula
  19. Order-disorder approach to calcioaravaipaite, [PbCa2Al(F,OH)9]: The crystal structure of the triclinic MDO polytype
  20. Ab initio investigation of the structures of NaOH hydrates and their Na+ and OH– coordination polyhedra
  21. Another step toward understanding the true nature of sartorite: Determination and refinement of a ninefold superstructure
  22. Letter. Ultrapotassic clinopyroxene from the Kumdy-Kol microdiamond mine, Kokchetav Complex, Kazakhstan: Occurrence, composition and crystal-chemical characterization
  23. Letter. Determination of planetary basalt parentage: A simple technique using the electron microprobe
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