List of Articles سنگ&#172

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  1 - Investigation of source region properties of alkaline basic rocks in the base of Shemshak Formation in the eastern Alborz zone
  Habibollah Ghasemi
  The alkaline basic rocks in the base of Shemshak Formation scattered mainly as intrusive and occasionally as extrusive, in some areas of the eastern Alborz zone. Their petrological compositions range from olivine gabbro to monzonite in intrusives and are olivine bas More

  The alkaline basic rocks in the base of Shemshak Formation scattered mainly as intrusive and occasionally as extrusive, in some areas of the eastern Alborz zone. Their petrological compositions range from olivine gabbro to monzonite in intrusives and are olivine basalt in extrusives. Intracontinental settings of these rocks have been confirmed in various tectonomagmatic diagrams. Geochemical and petrogenetical investigations show the magma forming of these rocks, originated from 10-15 percentages partial melting of an enriched subcontinental lithospheric mantle source with garnet-lherzolitic composition. This alkaline magma has been formed at 25-30 kbar pressures in 90-100 km depths and contaminated by continental rocks in small amounts, during rising and emplacement. Manuscript profile
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  2 - Origin and tectonic environtment of Tertiary volcanic rocks of Damash area in Guilan province(North of Iran)
  Mohammad Hosein Mokhtari
  Tertiary volcanic rocks of Damash area have outcraps about 70km for from east of Roudbar in Guilan province. From geochemical Point of view negative anomaly of P, Ba,Zr ,Ti ,Ta ,Nb and positive anomaly of K,Th,Pb,Rb indicate crustal contamination. The ratios of (T More

  Tertiary volcanic rocks of Damash area have outcraps about 70km for from east of Roudbar in Guilan province. From geochemical Point of view negative anomaly of P, Ba,Zr ,Ti ,Ta ,Nb and positive anomaly of K,Th,Pb,Rb indicate crustal contamination. The ratios of (Tb/Yb)N,Nb/Yb,Zr/Yb,Zr/Y,Zr/Nb,Y/Nb show that the MORB-like depleted mantle source with Spinel Facies. Study of the rang of incompatible elements pattern and compare with the crustal data range and incompatible elements ratios show that the volcanic rocks have been concerned to intra-continental rift magmatism wich are contaminated with continental crust. As a result of the crustal contamination, the original geochemical properties of the volcanic rocks were changed untruthly subduction zones geochemical features. Manuscript profile
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  3 - The study of geochemistry and mineralogy of the adakitic rocks in Monavvar village, North of Tabriz, NW of Iran
  Mahdieh Fazelihagh Nasir Amel Ahmad Jahangiry
  The study area is located 35 kilometers northwest of Tabriz. Based on stratigraphic evidences, age of volcanic rocks in Monavvar area is Mio-Pliocene and Plio – Quaternary. According to geological structure, it is part of the western Alborz – Azerbaijan zone. Most of th More

  The study area is located 35 kilometers northwest of Tabriz. Based on stratigraphic evidences, age of volcanic rocks in Monavvar area is Mio-Pliocene and Plio – Quaternary. According to geological structure, it is part of the western Alborz – Azerbaijan zone. Most of the volcanic rocks are dacite, rhyodacite, andesite, basaltic andesite and trachyandesite. In the spider diagrams these rocks show enrichment of HREE and HFSE elements over LREE and LILE, depletion and negative anomalies for Ti, Nb and Ta (TNT) and Ba/Nb, Ba/Ta. These properties indicate that their formation could occur in the continental arcs and post collisional arcs. High levels of SiO2 equal to 55 to 66 %wt, low levels of MgO, Y, Yb and Sr/Y and La/Yb represent the formation of high silica adakitic magma in the region. According to this evidence and REE distribution patterns, formation of magma was probably from asthenospheric mantle garnet – lherzolite source. Manuscript profile
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  4 - Late Cretaceous Island-arc subduction magmatism in northern edge of central Iran, SW Sabzevar
  Elham Mirzakazemi Habibollah Ghasemi Fardin Mousivand Wilyam Griffin
  A thick sequence of Late Cretaceous volcano-sedimentary rocks crops out on the northern margin of Central Iran, in the southwest of the Sabzevar. The igneous rocks include extrusions (trachy-andesite, dacite and rhyolite) and shallow depth intrusions (gabbro, gabbrodior More

  A thick sequence of Late Cretaceous volcano-sedimentary rocks crops out on the northern margin of Central Iran, in the southwest of the Sabzevar. The igneous rocks include extrusions (trachy-andesite, dacite and rhyolite) and shallow depth intrusions (gabbro, gabbrodiorite, diorite and granite). These igneous rocks have geochemical signatures of magmatic rocks of island-arc subduction zones and plot within field in different tectonic setting discrimination diagrams. The parental magma of these rocks has island arc tholeiitic nature and was produced via partial melting of a depleted spinel lherzolite mantle source during closing of the Sabzevar Neo-Tethyan oceanic basin in the Late Cretaceous. This depleted mantle source was affected by the metasomatic fluids released from dehydration of the Neo-Tethys subducted oceanic slab. Manuscript profile
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  5 - Lithostratigraphy and Sedimentary Environment of the Jahrum Formation in two Anticlines of Jahrum and Tudej
  رضا  صادقی محمد حسین  خواجوئی مریم  جوکار
  Abstract In this study two stratigraphic sections named Tang-e Ab as type section and Tang-e Nimbashi analyzed in order to study lithostratigraphy and microfacies of Jahrum Formation in Fars province. Both sections, Tang-e Ab in northern flank of Jahrum Anticline (Ea More

  Abstract In this study two stratigraphic sections named Tang-e Ab as type section and Tang-e Nimbashi analyzed in order to study lithostratigraphy and microfacies of Jahrum Formation in Fars province. Both sections, Tang-e Ab in northern flank of Jahrum Anticline (East of Jahrom) and Tang-e Nimbashi in northern flank of Tudej Anticline (West of Estahban) located in Interior Fars Sub-Zone at Zagros folded belt. Tang-e Ab section included 450 meters of conglomerate, limestone, nodular marly limestone, dolomitic limestone and dolostone with thin, medium, thick and very thick bedding and Tang-e Nimbashi section included 562 meters of limestone, marly Limestone, nodular marly limestone, dolomitic limestone and dolostone with very thin, thin, medium, thick and very thick bedding. The result of field and laboratory observations is determination of 10 lithostratigraphic unit and 10 microfacies class in Tang-e Ab and 7 lithostratigraphic unit and 11 microfacies class in Tang-e Nimbashi, in both Sections 3 sub-environments included: open marine, lagoon and peritidal and sedimentary settings corresponded on a carbonate platform of homoclinal ramp. Manuscript profile