Study of Metamorphic Reaction in Gharabagh PhlogopiteMica Ore

Category Petrology
Group GSI.IR
Location 21th symposium on geosciences
Holding Date 21 May 2008

      The studied area is located in west Azarbayjan province at northwest terminal part of Uroomiyeh Lake. Field observation results indicate that the contact metamorphic complexes have been occurred by gabbroic penetration into the sequence of shale and dolomite (Barut formation). These rock series include hornfels, forstrite- marble and skarn (e.g. clinopyroxene skarn, clinopyroxene-spinel skarn and garnet-clinozoisite skarn).
   In the marble and skarn of this area, in accordance with mineral assemblages and sequence of mineral paragenesis, they are principally formed at three different phases:
   A) Dry mineral paragenesis which as first phase are formed under high temperature conditions, typically include fassaite, forsterite, and spinel.
   B) Hydrous mineral paragenesis
   Occur in second phase at low temperature conditions under hydrous flows. During this phase, dry mineral assemblages (high temperature) are changed to hydrous minerals (low temperature) as phlogopite, calcite and apatite.
   C) Alteration paragenesis as a function of CO2-rich solutions are formed in brecciated zone and along with the both former mineral phases changed to other minerals such as clinozoisite, serpentine, Mg- chlorite and clay minerals by retrograde metamorphism.
   The presence of two dry and hydrous mineral phases indicate of two different magma generations, in which, dry minerals are formed by basic gabbroic magma ,where as hydrous minerals by acidic intrusions.