@article{fdi:010070830,
  title = {{T}he cordierite-orthoamphibole rocks of the variscan dome of gavarnie-gedre-heas : the gedrite of {G}{\`e}dre ({H}autes {P}yr{\'e}n{\'e}es, {F}rance)},
  author = {{D}riouch, {Y}. and {D}ebat, {P}. and {G}anne, {J}{\'e}r{\^o}me and {B}eziat, {D}. and {K}riegsman, {L}. {M}. and {M}artignole, {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he low-{P}/high-{T} {V}ariscan metamorphic dome of {G}avarnie-{G}edre-{H}eas, {C}entral {P}yrenees, harbors a small (1 m(3)) but special cordierite and orthoamphibole-bearing enclave embedded within an anatectic granite. {C}ompared to other cordierite-orthoamphibole occurrences described in the literature, the enclave shows singular characteristics: (1) its mineral composition is unique with cordierite ({C}rd)+gedrite ({G}ed) + biotitess ({B}t) +staurolite ({S}t) + garnet ({G}rt) + spinel ({S}pl) + corundum ({C}rn) + ilmenite ({I}lm) and sulfides ({S}ulf), but lacking quartz ({Q}tz), plagioclase ({P}l), and aluminosilicate minerals; and (2) its chemical composition, with low {S}i{O}2, high {A}l2{O}3, {K}2{O}, and {T}i{O}2 and high {F}e2{O}3{T}/{M}g{O}. {T}he {C}rd-{O}am-bearing rocks also occur as layers in stromatic migmatites that show a mineral composition ({B}t+{C}rd+{G}ed+{P}l+{Q}tz+{I}lm+{G}rt 6 {S}t) and a chemical composition more akin to other described occurrences. {T}he cordierite-orthoamphibole enclave records a succession of metamorphic reactions: (1) local {C}rd-{O}am growth at the expense of {B}t with release of {K}2{O}; (2) development of coronas of {C}rd 6 {I}lm 6 {G}rt around {S}t; (3) isochemical breakdown of {S}t to {C}rd+{S}pl+{C}rn. {I}n the {G}ed-bearing layers in interlayered migmatites, the formation of the {C}rd-{O}am assemblage involves the consumption of {B}t, {P}l, and {Q}tz. {M}ass balance calculations show that in the enclave most reactions took place in an open system with addition of {S}i and release of {K}2{O}. {P}seudosections indicate a clockwise {P}-{T} path, with high-temperature conditions (700-730 degrees {C}) at decreasing pressure (from 5.6 to 3 kbar). {T}his fits the {P}-{T} path of other metamorphic domes of the {V}ariscan {C}entral {P}yrenees.},
  keywords = {cordierite-orthoamphibole assemblage ; gedrite ; {G}{\`e}dre ; {P}yrenees ; metamorphic reactions ; mass-balance ; pseudosection ; protolith ; {FRANCE} ; {PYRENEES}},
  booktitle = {},
  journal = {{C}anadian {M}ineralogist},
  volume = {55},
  numero = {2},
  pages = {245--281},
  ISSN = {0008-4476},
  year = {2017},
  DOI = {10.3749/canmin.1600032},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070830},
}