نتایج جستجو برای: eocene alkaline rocks
تعداد نتایج: 68026 فیلتر نتایج به سال:
Rasht Abad Cu±Au deposit is a part of the Tarom-Hashtjin metallogenic belt in the western Alborz-Azerbaijan zone. The exposed units in the area include volcanic, sub-volcanic calc-alkaline to shoshonitic rocks with Upper Eocene age and belongs to magmatic arcs setting. The most important alterations related to mineralization include low temperature silicification and sericitic alterations. Mine...
In The northern part of Kerman Volcanic Belt, southwest of Rafsanjan (Deh-Zahir area), a series of diabasic intrusives have intruded into the Eocene andesitic lava flows and pyroclastic rocks. These plutons occur as irregular shaped bodies (up to 8 m in diameter) and dikes (up to 4 m in thicknesses). They show ophitic, sub-ophitic, and porphyritic textures and their major minerals include plagi...
Study area is located in Kerman Province and NE Baft city near to Rabor town. This section is in the structural division of Iran classified as Urumieh-Dokhtar magmatic belt which in Kerman area is called- Dahaj-Sarduieh belt that extended parallel to Urumieh-Dokhtar magmatic belt. These rocks comprise of andesite, andesite-basalt, dacite and rarely basalt and trachy-andesite with Eocene age tha...
"Jake_M," the first rock analyzed by the Alpha Particle X-ray Spectrometer instrument on the Curiosity rover, differs substantially in chemical composition from other known martian igneous rocks: It is alkaline (>15% normative nepheline) and relatively fractionated. Jake_M is compositionally similar to terrestrial mugearites, a rock type typically found at ocean islands and continental rifts. B...
Using a recent compilation of African alkaline igneous rocks and carbonatites, we show that nearly 90% (28 of 32 occurrences) of nepheline syenite gneisses and deformed carbonatites are concentrated within known or inferred Proterozoic suture zones. Given the wellestablished intracontinental rift setting for these rocks and the likely continental collisional setting for their subsequent deforma...
Jalambadan mineralization is located in northwest of Sabzevar, Khorasan Razavi Province, and in the southwestern Quchan-Sabzevar magmatic arc. Geology of the area consists of Eocene andesitic to trachyandesitic volcanic rocks, which are intruded by monzodioritic to dioritic subvolcanic units. Mineralization occurs in intrusive rocks and surrounded volcanic units as disseminated. Pyrite is the m...
Discussions continue about whether Middle Eocene magmatism in the Eastern Pontides is associated with collision or subduction. This paper presents new whole-rock geochemistry, Sr-Nd isotopic and 40Ar-39Ar age data for volcanic rocks from Bayburt area of (NE Turkey) to investigate their sources evolutionary history. The 40Ar–39Ar ages reveal that these erupted between 44.6 ± 0.1 Ma 43.5 Ma, with...
the tajroud vein system is located 190 km southwest of mashhad, and in the southern part of the sabzevar zone. the vein host rocks consist of eocene intermediate to silicic volcanic rocks. the mineralization occurs as open space filling, taking place as veins, veinlets and hydrothermal breccias. based on field geology and textural evidence, three main stages of mineralization were identified. s...
Upper Eocene shoshonitic rocks have very good exposures in the Qaleh-Khargooshi area. These rocks have a wide range of SiO2 content (absarokite to toscanite) and belong to fifth phase of Eocene volcanism in this area. Clinopyroxene is present in all members of shoshonitic group as phenocryst, but they have altered in toscanites. The study of clinopyroxenes composition shows that this mineral h...
The Pliocene calc-alkaline volcanic rocks are exposed in two areas in southeast and northwest of Isfahan and consist of andesites and dacites. Based on geochemical data and multi- elements pattern, these rocks are medium to high calc-alkaline suite and they show LILE and LREE enriched normalized multi-element patterns, and negative Nb and Ti. Condrite-normalized REE patterns display a steep dec...
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