Geological and Geochemical Evidence for Discriminating Anatectic and Subsolidus Migmatites in the Dabieshan Complex,Northeastern Hubei Province  

作　　者：王江海 邓尚贤 张丽彦 常向阳 

出　　处：《Chinese Journal Of Geochemistry》1997年第2期112-122,共11页中国地球化学学报

摘　　要：Based on the geological and geochemical information about migmatites, the followinglines of evidence have been proposed for discriminating the anatectic leucosome in the DabieshanComplex: (1) its width is larger than that derived from the subsolidus genesis, cutting acrossregional foliation, thus giving rise to complicated folds and wider selvages; (2) it is composedof melanic and accessory minerals in addition to quartz and feldspars; (3) the significant difference in anorthites of plagioclase between paleosome and leucosome; (4) temperature and pressure (P/T) conditions revealed by the mineral compositions and assemblages are over those forthe onset of anatexis; and (5) it is enriched in the major elements (e. g. AiZO3, FeZO3 andTiO2) and immobile and incompatible elements (e. g. LREE, Th, Hf and Zr). Finally, bycombining the geological and geochemical features with the statistical data for the spatial distribution of minerals and mass-balance in the migmatites, it is concluded that anatexis is the cardinal mechanism of migmatization in the Dabieshan Complex.Based on the geological and geochemical information about migmatites, the followinglines of evidence have been proposed for discriminating the anatectic leucosome in the DabieshanComplex: (1) its width is larger than that derived from the subsolidus genesis, cutting acrossregional foliation, thus giving rise to complicated folds and wider selvages; (2) it is composedof melanic and accessory minerals in addition to quartz and feldspars; (3) the significant difference in anorthites of plagioclase between paleosome and leucosome; (4) temperature and pressure (P/T) conditions revealed by the mineral compositions and assemblages are over those forthe onset of anatexis; and (5) it is enriched in the major elements (e. g. AiZO3, FeZO3 andTiO2) and immobile and incompatible elements (e. g. LREE, Th, Hf and Zr). Finally, bycombining the geological and geochemical features with the statistical data for the spatial distribution of minerals and mass-balance in the migmatites, it is concluded that anatexis is the cardinal mechanism of migmatization in the Dabieshan Complex.

关 键 词：地质学 地球化学 深源混合岩 大别山 湖北 

分 类 号：P588.36[天文地球—岩石学]