Investigation of Geological and Mineralogical Properties of AftarMine Zeolites, Semnan

Peyravi, S; Zahiri, R; Moradi Harsini, K; Shayesteh Azimian, H

doi:10.22071/gsj.2015.42739

Investigation of Geological and Mineralogical Properties of AftarMine Zeolites, Semnan

Document Type : Original Research Paper

Authors

S Peyravi ¹

R Zahiri ²

K Moradi Harsini ²

H Shayesteh Azimian ³

¹ M.Sc. Student, Faculty of Earth Sciences, Damghan University, Damghan, Iran

² Assistant Professor, Faculty of Earth Sciences, Damghan University, Damghan, Iran

³ M.Sc. Student, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

10.22071/gsj.2015.42739

Abstract

The Eocene-Oligocene zeolitic tuff sequences in the Aftarregion is located at northwestern side of the Aftar village in 32 km northwestwards of the SemnanCity. The studies of mineralogy and geology performed based on the results of the X-Ray data (XRD), chemical analysis (XRF), and the thin sections of taken samples showed 3 important units related to the process of the Aftar zeolites formation including green to brown marl, green tuffs, and Zeolite layer. Most of the known zeolite minerals in the area are clinoptilolite and heulandite and paragenesis minerals in tuffy and marly layers arecalcite, orthoclase, plagioclase, quartz, clay minerals, biotite and volcanic glass.Based on the geological and mineralogical evidences the formation of zeolite derived from the acidic magma of the volcanic eruptions in a shallow sea environment with high pH.The evidences show that increasing the pH in the tuff sedimentation environment, accommodated suitable conditions for conversion of the volcanic glass into the zeolites.

Keywords

Aftar

Zeolite

Volcanic Glass

Clinoptilolite

Heulandite