Writers : Allah Yari, S.; Qasemi, H.
Refference : 28th Symposium on Geosciences and the 14th Symposium on Geological Society of Iran
Publishing Year : 1389

Abstract :

Cenozoic alkaline magmatic belt of Abbas abad is located in Northeast side of Central Iran structural zone. The volcanic and volcano – sedimentary rocks of this belt, are composed of an alternation of basic – intermediate volcanic rocks and related pyroclastics which associated with interbedded sedimentary layers specially nummulitic limestones belongs to middle-upper eocene. These volcanic rocks have a lithological range include olivine basalt, trachybasalt, basaltic trachyandesite and trachyandesite. Petrographic evidences such as, appearance and disappearance of some minerals and disequilibrium textures in association with geochemical trends in variation diagrams indicate that continuous fractional changes have been done in them. These alkaline rocks show typical characteristics of arc settings such as enrichment in LREE and LILE and depletion in HREE and HFSE (eg. Nb, Ta, Ti). Parental magma s of the volcanic rocks of this belt, generated from medium partial melting (14 – 16 percentages) of a garnet lherzolitic mantle in 80 to 100 km depths.

Subject List : volcanic rocks