Eclogites and their country gneisses: Studies on inclusions in the accessory minerals of country gneisses

Thermobaric structure of a traverse across western Dabieshan: implications for collision tectonics between the Sino‐Korean and Yangtze cratons

“…Jadeite in clinopyroxene generally varies with the chemical compositions of the protolith. The jadeite range in clinopyroxene from the western Dabieshan eclogites is about 35–50 mol%, whilst that from an orthogneiss in Zone III is up to 60 mol% (Liu et al ., 1998a). Even if using the most Jd‐rich clinopyroxene in each sample (Jamtveit, 1987), the upper pressure limit gives 18–20 kbar.…”

Deformation features of garnet-bearing granites from Huwan, western Dabie Mountains

“…Current research has not reached consensus on many problems, such as the petrogenesis, age of formation, tectonic setting and geodynamic significance of the foliated granites and their relationship with the UHP metamorphic unit. This hampers our understanding of the formation and structural evolution of the principal rock units in the Dabie-Sulu orogenic belt.There are several theories about the origin of these foliated garnet granites: (1) their protoliths were Jinningian granites that experienced UHP metamorphism along with eclogites during continental subduction [8][9][10][11] , subsequent to intrusion and crystallization into previously regionally metamorphosed country rocks [3] ; (2) their protoliths were feldspathic rocks in the Dabie regional metamorphic complex that did not undergo UHP metamorphism, but were emplaced by mixing or remelting in the middle and lower crust during exhumation of UHP metamorphic rocks [12,13] ; and (3) their protoliths were products of partial melting during exhumation of retrograde UHP rocks and were deformed later [2,[5][6][7][14][15][16][17] . These theories might explain existing chronological data from the foliated garnet granites as…”

“…There are several theories about the origin of these foliated garnet granites: (1) their protoliths were Jinningian granites that experienced UHP metamorphism along with eclogites during continental subduction [8][9][10][11] , subsequent to intrusion and crystallization into previously regionally metamorphosed country rocks [3] ; (2) their protoliths were feldspathic rocks in the Dabie regional metamorphic complex that did not undergo UHP metamorphism, but were emplaced by mixing or remelting in the middle and lower crust during exhumation of UHP metamorphic rocks [12,13] ; and (3) their protoliths were products of partial melting during exhumation of retrograde UHP rocks and were deformed later [2,[5][6][7][14][15][16][17] . These theories might explain existing chronological data from the foliated garnet granites as follows: (1) a zircon U-Pb upper intercept age of 773-727 Ma could represent the intrusion and crystallization ages of the protoliths, while lower intercept ages of 231-219 Ma could be peak metamorphic age of Indosinian UHP rocks, indicating that the foliated garnet granites underwent UHP metamorphism [8,18 -21] or at least fluid infiltration [3] ; or alternatively, (2) a zircon U-Pb concordant age of 234-227 Ma could be the magmatic intrusion age [22,23] , whereas the zircon age of 773-727 Ma represents an inherited zircon age.…”