, S Karimi,
Volume 10, Issue 2 (2-2010)
Abstract
Abstra
The metapelites of North of Golpayegan show that these rocks can be divided into four categories based on mineral assemblages: chloritoid- garnet- biotite- schist, garnet- biotite- muscovite- schist, staurolite bearing garnet- biotite- muscovite schist and Kyanite bearing staurolite- biotite- muscovite- schist.
The appearance of chloritoid in chloritoid- garnet- biotite schists shows green schist facies. Garnets in garnet- biotite- muscovite schists shows 3 stage of growth and syn-tectonic formation.
The appearance of staurolite in staurolite bearing garnet- biotite- muscovite schists signifies the beginning of amphibolite facies. The absence of zoning in the staurolite contained in these schists suggests the formation and growth of this mineral in a prograde metamorphism.
The thermodynamic study of these rocks shows that North of Golpayegan's metapelites were formed within a temperature range of 480 – 560oC and a pressure range of 1.6 – 4.1 kbar. These results are consistent with the minerals' paragenetic evidence and show that effect of metamorphism on North of Golpayegan's pelitic sediments is to lower amphibolite facies (Epidote amphibolite).
