J Ghalamghash; S. Houshmand Manavi; M. Vousoughi Abedini
Abstract
Oshnavieh Plutonic Complex (OPC), hosted within the northernmost part of the Sanandaj- Sirjan zone, allows distinguishing three suites including diorite, granite and alkalisyenite-alkaligranite (AS-AG). Dioritic rocks formed from partial melting of enriched lithospheric mantle sources on base of minerlogical ...
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Oshnavieh Plutonic Complex (OPC), hosted within the northernmost part of the Sanandaj- Sirjan zone, allows distinguishing three suites including diorite, granite and alkalisyenite-alkaligranite (AS-AG). Dioritic rocks formed from partial melting of enriched lithospheric mantle sources on base of minerlogical and geochemistry. The granite suite is S type that formed from partial melting of metapelitic-greywacke source. The peraluminous A-type granite of AS-AG suite are generated by partial melting of quartzo-feldspatic source at high temperatures. According to the negative Nb, Ta and Ti anomaly in spider diagrams, and tectonic discrimination diagram of Rb-(Y+Nb), the diorite suite formed in active continental margin (VAG) environment. According to the diorite’s formed environment and simultaneously formed granite in 100 M.a., OPC seems to have formed by northeastward subduction of Neo-tethyan oceanic crust under the Iranian continental crust. Following intrusion and setting of mafic magma into the crust, partial melting of pelitic-greywacke, resulted from heating by intrusion of the mafic magma, produced the granitic magma. After 20 Ma the AS-AG suite formed from melting of quartzo-feldspatic rocks of lower crust, probably by heating of mafic magma and/or in relaxation period of subduction and emplaced in the continental volcanic arc.
samad alipour; R. Nikrouz
Abstract
Shahrestan mining district is the largest extensive granitic stone province in Iran. There are 25 active mines in this area. The study of rose diagrams with statistical joint systems at this ornamental stone mining district carried out in order to reduce expenses with low waste disposal of mining extraction. ...
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Shahrestan mining district is the largest extensive granitic stone province in Iran. There are 25 active mines in this area. The study of rose diagrams with statistical joint systems at this ornamental stone mining district carried out in order to reduce expenses with low waste disposal of mining extraction. The most types of intrusive rocks are syenite, monzonite, gabbro and granite cropped out in the region. Alkali syenite is the main rock type in spite of varying color and texture. Diversity of apparent color and rock composition associated with variety of color in low distances, existence of joints, faults and thrusts around formations and rocks of moderately being metamorphosed, are the source of major problems in the region from the exploration till the excavation stages. The study results indicate that the main folding trend is extended in a northwest-southeast direction. Therefore the direction of quarries in central part must be developed in a north-south direction and in the northwest part in northwest–southeast direction while in the east of Shahrestan quarries must be created in a northeast – southwest trend.
