scholarly journals Geology and petrography of the volcanic rocks in the Yakhab area, central Iran

2022 ◽  
pp. 100016
Author(s):  
Kaveh Pazand ◽  
Asghar Ghasemi Bersiani ◽  
Hassan Mohammadnezhad
Keyword(s):  
Volcanic Rocks ◽  
Central Iran

A new perspective on Cenozoic calc-alkaline and shoshonitic volcanic rocks, eastern Saveh (central Iran)

2020 ◽  
pp. 1-28
Author(s):  
Fatemeh Nouri ◽  
Hossein Azizi ◽  
Yoshihiro Asahara ◽  
Robert J. Stern
Keyword(s):  
Volcanic Rocks ◽  
Central Iran ◽  
Calc Alkaline ◽  
New Perspective

scholarly journals Petrology, Geochemistry and Thermobarometery of Abraq-Harmak Volcanic rocks, west of Lut block, Central Iran

2019 ◽  
Vol 10 (3) ◽  
pp. 45-64
Author(s):  
habib biabangard ◽  
Ali Ahmadi ◽  
Shahnaz Rimaz
Keyword(s):  
Volcanic Rocks ◽  
Central Iran ◽  
Lut Block

scholarly journals Zeolites filling cavities and amigdales of basic volcanic rocks in NW of Davazdah-Emam mountain, north Central Iran

2018 ◽  
Vol 26 (3) ◽  
pp. 597-610
Author(s):  
sahar Koohfar ◽  
Amirali Tabbakh Shabani ◽  
kamalodin Bazargani-Guilani ◽  
Morteza Delavari Kooshan ◽  
◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Central Iran ◽  
North Central ◽  
Basic Volcanic

scholarly journals Study of the mineralization potential of the intrusives around Valis (Tarom-Iran)

2015 ◽  
Vol 18 (2) ◽  
pp. 123-129 ◽  
Author(s):  
Mojtaba Bahajroy ◽  
Saeed Taki
Keyword(s):  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Central Iran ◽  
Lava Flows ◽  
Magmatic Activity ◽  
Petrographic Composition ◽  
Molar Ratios ◽  
Exposed Rock ◽  
Metallogenic Zone ◽  
Northwestern Iran

<p>The study area is located in northwestern Iran in the central Iran zone, specifically the western Alborz sub-zone south of the Tarom-Hashtjin metallogenic zone. The exposed rock units in this area generally include Eocene volcanic rocks (lava flows and pyroclasts belonging to the Karaj formation) and Oligocene granitoid intrusive bodies. The intrusive bodies in the area have a petrographic composition of granite, syenite and monzonite and are mostly metaluminous. The dual characteristics of these intrusives (for example, the behavior of elements such as Rb, P, Ga/Al, Y/Nb, K/Na, and FeO/Fe2O3, the Rb/Nb ratios, the A/CNK molar ratios and the ACF and A/CNK-Fe2O3+FeO diagrams), some of which are consistent with the I nature and others with the S and A natures, show that the rocks are among hybrid granitoids and, in terms of the tectonic setting, lie within the WPG range. According to the Rb/Sr, Zr/Hf, K/Rb ratios, the granite melts that form the aforementioned bodies are not extremely evolved and have not undergone post magmatic activity, which would lead to mineralization. The Sm/Eu and Rb/Ba ratios and the behavior of Rb, Ba and Sr within the aforementioned granitoids show that the rocks are similar to average granitoids unrelated to Li, Be, Sn, W and Ta deposits; they fall within the range of barren granitoids but are partially fertile in Cu.</p><p> </p><p><strong>Resumen</strong></p><p>El área de este estudio está localizada en el noroeste de la zona central de Irán, específicamente en el oeste de la subzona de Alborz y al sur de la zona metalogénica de Tarom-Hashtjin. Las unidades de roca expuesta en esta área se clasifican generalmente como rocas volcánicas del Eoceno (flujos de lava y piroclastos pertenecientes a la formación Karaj) y como cuerpos granitoides intrusivos del Oligoceno. Los cuerpos intrusivos en el  área tienen una composición petrográfica de granito, sienita y monzonita mayormente metaluminosa. Las  características duales de estas intrusiones (por ejemplo, el comportamiento de de elementos como Rb, P, Ga/ Al, Y/Nb, K/Na, y Feo/Fe2O3, los índice de Rb/Nb, la proporción molar de los A/CNK y los diagramas ACF y A/CNK-Fe2O3+FeO), algunas de las cuales son consistentes con la índole I y otras con las índoles S y A, muestran que las rocas son granitoides híbridos y, en términos de orden tectónico, subyacen en la cadena WPG. De acuerdo con los índices Rb/Sr, Zr/Hf, K/Rb, los granitos fundieron la forma de los cuerpos sin desarrollarse completamente y sin registrar actividad magmática posterior, lo que llevó a la mineralización. Los índices Sm/Eu y Rb/Ba y el comportamiento del Rb, Ba y Sr al interior de los granitoides mencionados muestran que las rocas son similares al promedio de los granitoides no relacionados con los depósitos de Li, Be, Sn, W y Ta; estos incluyen en el rango de granitoides estériles, pero son parcialemente fértiles en Cu.</p><p><strong><br /></strong></p>

scholarly journals Characteristics of fluid inclusions in the Cenozoic volcanic-hosted Kushk-e-Bahram Manto-type Cu deposit of central Iran

Geologos ◽  
2020 ◽  
Vol 26 (2) ◽  
pp. 127-137
Author(s):  
Marjan Jebeli ◽  
Peyman Afzal ◽  
Mohsen Pourkermani ◽  
Alireza Jafarirad
Keyword(s):  
Volcanic Rocks ◽  
Central Iran ◽  
Fluid Density ◽  
Two Phase ◽  
Ore Formation ◽  
Magmatic Arc ◽  
Density Values ◽  
Phase Liquid ◽  
Homogenization Temperatures ◽  
Volcanic Belts

AbstractThe Kushk-e-Bahram Manto-type Cu deposit is located in central Iran, within Eocene to Oligo–Miocene volcanic strata which occur in the central part of the Uremia-Dokhtar Magmatic Arc (UDMA). Propylitization, silicification, argillization and carbonatization are the main types of alteration to have affected the pyroclastic and volcanic rocks. There are high amounts of oxide minerals, including malachite, azurite, hematite, magnetite and goethite. Three types of primary FIs have been determined in the Kushk-e-Bahram deposit, namely; I: two-phase liquid-rich FIs (L+V), II: mono-phase liquid FIs, III: two-phase vapour-rich FIs which have been identified based on petrographical studies. Based on FI studies of co-existing quartz and calcite, homogenization temperatures (Th) must have been between 67 and 228°C, with an average of 158°C. Moreover, salinity is between 14.0–30.3 wt% NaCl, equivalent to a 19.6% average. Fluid density values vary from 0.8 to 1.1 gr/cm3. Based on FI data and related diagrams, the depth of their trapping was estimated to be <200 m and ore formation occurred at pressures of <50 bars. Consequently, mineralogy, host rock and FIs characteristics in the Kushk-e-Bahram deposit are similar to the Manto-type Cu deposits in Mesozoic-Cenozoic volcanic belts of Iran and South America.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

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