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High‐pressure/low‐temperature metamorphism in northern Hubei Province, central China
Author(s) -
ZHOU G.,
LIU Y. J.,
EIDE E. A.,
LIOU J. G.,
ERNST W. G.
Publication year - 1993
Publication title -
journal of metamorphic geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.639
H-Index - 114
eISSN - 1525-1314
pISSN - 0263-4929
DOI - 10.1111/j.1525-1314.1993.tb00172.x
Subject(s) - greenschist , blueschist , metamorphism , geology , metamorphic rock , metamorphic facies , geochemistry , eclogite , craton , shear zone , amphibole , epidote , subduction , petrology , facies , geomorphology , seismology , paleontology , chlorite , quartz , structural basin , tectonics
The Qinling–Dabie accretionary fold belt in east‐central China represents the E–W trending suture zone between the Sino‐Korean and Yangtze cratons. A portion of the accretionary complex exposed in northern Hubei Province contains a high‐pressure/low‐temperature metamorphic sequence progressively metamorphosed from the blueschist through greenschist to epidote–amphibolite/eclogite facies. The ‘Hongan metamorphic belt’can be divided into three metamorphic zones, based on progressive changes in mineral assemblages: Zone I, in the south, is characterized by transitional blueschist–greenschist facies; Zone II is characterized by greenschist facies; Zone III, in the northernmost portion of the belt, is characterized by eclogite and epidote–amphibolite facies sequences. Changes in amphibole compositions from south to north as well as the appearance of increasingly higher pressure mineral assemblages toward the north document differences in metamorphic P–T conditions during formation of this belt. Preliminary P–T estimates for Zone I metamorphism are 5–7 kbar, 350–450°C; estimates for Zone III eclogites are 10–22 kbar, 500 ± 50°C. The petrographic, chemical and structural characteristics of this metamorphic belt indicate its evolution in a northward‐dipping subduction zone and subsequent uplift prior to and during the final collision between the Sino‐Korean and Yangtze cratons.