Petrology of aluminosilicate-bearing migmatites of Simin area, Hamadan

Category Petrology
Group GSI.IR
Location The 25 Symposium of Geosciences
Author S.R-Jafari-A.Sepahi-F.Aliani-S.Mani kashani
Holding Date 01 July 2007
 

Petrology of aluminosilicate-bearing migmatites of Simin area, Hamadan

 

Abstract :

 

In the eastern part of metamorphic aureole of  the Alvand plutonic complex and adjacent to granitoids, there is band of migmatites which  have stromatic, petygmatic, schlieren, shoolen, sureitic and nebulitic structures. In the eastern part of the area, near the migmatites, cordierite hornfelses have been extended. The existence of compositional layering, degree of partial melting and decompression have been important  in the formation migmatites of the area. Protolith of the migmatites, are mostly pelitic and mineralogical zones in the area consist of aluminosilicate and sillimanite – feldspar zone. In some localities layers of cordierite-bearing migmatites occur within the other migmatitic rocks. The extention of mesosome in this rocks is more than leucosome and melanosom is very little. The concentration of andalusite, sillimanite and kyanite in mesosome is more visible. Partial melting has been so quick that most of the rocks in the And stability area and before the complere change of andalusite to sillimanite they are partialy melted and migmatized.

 

tags: QAZVIN