Writers : Mehrabi, Behzad; Masoudi, Fariborz ; Mahmudi, Shahryar
Refference : The 21st Symposium on Geoscience;Tehran
Publishing Year : 1381

Abstract :

Andalusite is one of the Al2SiO5 polymorphs, formed in high temperature and low pressure metamorphism. Recent studies show that andalusite may be formed directly from magma crystallization. In Deh Salm metamorphic complex, in the contact of granitoids and metamorphic rocks, magmatic andalusite has been formed as a result of metasomatism. Changes in K/Na ratio from metamorphic rocks toward the granite mass confirm the occurrence of metasomatism in Deh Salm metamorphic complex. The main conditions for magamatic andalusite crystallization are; less than 2kb pressure, 550˚C temperature and presence of acidic granitics fluids. Granite sheets at Deh Salm metamorphic complex contain magmatic andalusite which reveals the characteristic P_T_f condition of formation. Collision zones may create a condition for magma generation which in favorable circumstances and presence of low pH magmatic fluid, magmatic analusite can crystallized directly from magma.

Subject List : Metamorphism