TY - JOUR
T1 - Closed-sytem geochemical recycling of crustal materials in alpine-type peridotite
AU - Morishita, Tomoaki
AU - Arai, Shoji
AU - Gervilla, Fernando
AU - Green, David H.
PY - 2003/1/15
Y1 - 2003/1/15
N2 - We examined aluminous mafic rock (with or without corundum or sapphirine) alternating with peridotite from the Ronda peridotite massif, southern Spain. On the basis of petrographic characteristics, these mafic rocks show a decompression history from high pressure (P > 1.5 GPa), but on the basis of their geochemical characteristics, they are crystal accumulates of plagioclase, clinopyroxene, and olivine formed within the lower crust (P < 1 GPa). A complex evolution history, including higher-pressure recrystallization after initial formation as cumulate gabbros at lower-pressure conditions, is proposed. The aluminous mafic rocks and their peridotite hosts are inferred to be recycled crustal materials now observed as centimeter-scale layered components in alpine-type peridotite. The rocks retained their original cumulate compositions; that is, their compositions were not affected by melting and metasomatic modifications during subduction, intense deformation within the upper mantle, and upwelling to the surface.
AB - We examined aluminous mafic rock (with or without corundum or sapphirine) alternating with peridotite from the Ronda peridotite massif, southern Spain. On the basis of petrographic characteristics, these mafic rocks show a decompression history from high pressure (P > 1.5 GPa), but on the basis of their geochemical characteristics, they are crystal accumulates of plagioclase, clinopyroxene, and olivine formed within the lower crust (P < 1 GPa). A complex evolution history, including higher-pressure recrystallization after initial formation as cumulate gabbros at lower-pressure conditions, is proposed. The aluminous mafic rocks and their peridotite hosts are inferred to be recycled crustal materials now observed as centimeter-scale layered components in alpine-type peridotite. The rocks retained their original cumulate compositions; that is, their compositions were not affected by melting and metasomatic modifications during subduction, intense deformation within the upper mantle, and upwelling to the surface.
UR - http://www.scopus.com/inward/record.url?scp=0037438931&partnerID=8YFLogxK
U2 - 10.1016/S0016-7037(02)01079-7
DO - 10.1016/S0016-7037(02)01079-7
M3 - Article
SN - 0016-7037
VL - 67
SP - 303
EP - 310
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
IS - 2
ER -