THE OCCURRENCE AND ORIGIN OF ATOLL GARNET IN HORNBLENDE SCHISTS FROM THE CONTACT AUREOLE OF THE MASHHAD GRANITE, NE IRAN

Document Type: Research Note

Author

Faculty of Earth Sciences, Damghan University of Basic Sciences Cheshmeh-Ali Road Damghan, I. R. of Iran

Abstract

The formation of atoll garnet in hornblende schists from the contact aureole of Mashhad granite,
NE Iran, is discussed using textural and chemical data. These data suggest the possibility of incipient
replacement of pre-existing idioblastic garnet from the core. In addition, the presence of chlorite and calcite in
the core of atoll garnet reveal the retrograde nature of atoll formation.

Keywords