دگرگوني هيدروترمال رگه اي گابروهاي افيوليتي جندق(شمال شرق استان اصفهان)

Geology Department, The University of Isfahan

Jandaq ophiolite suites are covered by metamorphic rocks that are marbles and schists. This old ophiolitic association has passed different phases of serpentinization and metamorphism. In this rock association, gabbroic dikes cross cut the serpentinized mantle peridotites. Joints and cracks of brittle gabbroic dikes are filled by veins that are light in color. These veins are formed after metamorphism and serpentinization. These coarse grain rocks are free from deformation and foliation, and are formed by calcite, prehnite, epidote, clinopyroxene and chlorite. The most important mineralogical characteristic of these veins is existence and considerable amount of calcite, that is the evidence of high f C02 in minerals bearing fluid. Vein enclosing gabbros, are metamorphosed in amphibolite facies (2.7 to 9 kbar pressure and 630 to 750 of C temperature), and then pass through a retrograde metamorphism in green schist facies.