Gh. Tajbakhsh; M. H. Emami; H. Moine Vaziri; N. Rashidnejad Omran
Abstract
Nepheline syenite intrusive of Kaleybar is located in South and West of the Kaleybar city in eastern Azarbayjan province. This zoned intrusive complex is formed by penetration of two separated silica undersaturated and saturatated magmatic phases with Oligocene-Miocene ages. Undersaturated rocks are ...
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Nepheline syenite intrusive of Kaleybar is located in South and West of the Kaleybar city in eastern Azarbayjan province. This zoned intrusive complex is formed by penetration of two separated silica undersaturated and saturatated magmatic phases with Oligocene-Miocene ages. Undersaturated rocks are composed of alkali pyroxenite, mela alkali-gabbro to nepheline gabbro-diorte, nepheline syenite and nepheline sodalite syenite dikes. Silica saturated rocks is consist of a quartz monzonitic stock, which has penetrated in the center of nepheline syenite intrusive and related quartz syenite - micro syenite dikes. Undersaturated phase has potassic alkaline affinity and nepheline syenites are miaskitic Malignite. In contrast, silica saturated rocks belong to high-K calc-alkaline to shoshonitic magma. Field observation, petrographical and geochemical studies, indicates that undersaturated rocks are comagmatic and crystal fractionation, accumulation and low density minerals floatation processes play significant role in their magmatic evolution. High enrichment of rare elements especially LREE and LILE compare to variable depletion of HREE and HFSE are infer a basanitic parental magma generated from a previously subduction-metasomatised lithospheric mantle source. Silica saturated magma of Kaleybar was probably resulted form the lower crust Partial melting and geochemical similarities resulted from partial melting of lower crust and its geochemical similarities with undersaturated parts is due to magma mixing and contamination. Repeatedly injection of alkaline and calc-alkaline magmas could be occurred in a post collision setting after Eocene in Azerbaijan region.
