فهرست مقالات Petrogenesis

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  1 - Geochemical evolution and petrogenesis of the eocene Kashmar granitoid rocks, NE Iran: implications for fractional crystallization and crustal contamination processes
  Rahim Dabiri Mohsen Akbari-Mogaddam Mitra Ghaffari
  Kashmar granitoids of Taknar zone, in north part of Lut block, intruded into volcanic rocks and consist of granites, granodiorites, monzodiorite and gabbrodiorites. They are composed of mainly plagioclase, alkali-feldspar, quartz, amphibole, biotite and pyroxene mineral چکیده کامل

  Kashmar granitoids of Taknar zone, in north part of Lut block, intruded into volcanic rocks and consist of granites, granodiorites, monzodiorite and gabbrodiorites. They are composed of mainly plagioclase, alkali-feldspar, quartz, amphibole, biotite and pyroxene minerals. Harker diagram variation, including negative correlations CaO, MgO, FeO, TiO2 and V and positive correlations K2O, Rb, Ba, and Th, with increasing SiO2 and chondrite-normalized REE patterns, suggest that fractional crystallization of gabbrodioritic rocks could have played a significant role in the formation of granites. Their chondrite-normalized REE patterns are characterized by LREE enrichment and show slight negative Eu anomalies. Chondrite-normalized REE modelling indicates that the magma of Kashmar gabbrodiorites were generated with 3–5% of partial melting of a a spinel-lherzolite source. Melting of parental magma located at ~53 km. پرونده مقاله
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  2 - Petrogenesis of volcanic rocks from Razei region in Northwest Ardabil, Iran
  Yousef Vasigh
  The Razei region in the northwest of Ardabil is considered a part of West Alborz-Azerbaijan. Rocks in this area were created by Eocene volcanic activities. These rocks range from andesite to olivine basalt. The common texture of these rocks is Porphyritic with microlith چکیده کامل

  The Razei region in the northwest of Ardabil is considered a part of West Alborz-Azerbaijan. Rocks in this area were created by Eocene volcanic activities. These rocks range from andesite to olivine basalt. The common texture of these rocks is Porphyritic with microlithic matrix. The phenocrysts of these rocks are often clinopyroxene, plagioclase, and olivine. The texture is made of microlithic plagioclase and fine crystals of pyroxene. The studied rocks have clear desire to alkali basalts in terms of chemical nomenclature. Disequilibrium factors between liquid and crystal show the processes of magmatic evolution in an open thermodynamic system. The mixed climate in this region has probably contributed the most to changing the chemical composition of these rocks. In the spider diagrams, enrichments often include some LIL elements and depletions usually include some HFS elements. Enrichment of LILE is probably accompanied with the contamination of the basic magma with materials from continental lithosphere. The volcanic rocks in Razei have mainly geochemical characteristics of back arc basin, and the magmas that created the rocks in this region have an origin of lithospheric mantle. پرونده مقاله