Petrological Journal

Geochemistry and tectonomagmatic setting of theGharuchah-Sofla intrusions (South Mahabad)‎

Abdolnaser Fazlnia; Amir Pahnaei

Volume 9, Issue 2 , September 2018, , Pages 39-58

https://doi.org/10.22108/ijp.2018.101948.1013

Abstract

The Gharuchah-Sofla intrusion from south Mahabad (southeast of West Azerbaijan) consist mostly of granodiorite and tonalite, interspersed with small bodies of quartz diorite, monzogranite, ... Read More The Gharuchah-Sofla intrusion from south Mahabad (southeast of West Azerbaijan) consist mostly of granodiorite and tonalite, interspersed with small bodies of quartz diorite, monzogranite, syenogranite, and alkali feldspar granite. Microgranular mafic enclaves, which are mainly gabbroic diorite, diorite, and quartz diorite in composition, occur as elliptical or circular throughout the intrusion. Samples with gabbroic diorite, diorite, and quartz diorite, in composition consist primarily of plagioclase, clinopyroxene, hornblende, biotite, opaque minerals, and small amount of quartz. Similar mineralogy with the occurrence of K-feldspar and only small amount of clinopyroxene, are found in tonalites, granodiorites and monzogranites. The enclaves are also characterized by the presence of clinopyroxene, biotite, opaque minerals, and small amount of quartz and alkali-feldspar. There are minor minerals such as prismatic apatite and titanite in several samples. The samples show I-type, metaluminus and calc-alkaline characteristics. The Gharuchah-Sofla dioritic gabbro-granitic intrusions are poor in high field strength elements (HFSE) such as Nb, Ta, Hf, and Zr along with P and rich in Sr, K, Rb, and somewhat Ba. Based on the element ratios of (La/Yb)n and (La/Sm)n, levels of light rare Earth elements in the samples from the main mass are more than those of the enclaves; a demonstration of the enrichment of these elements in the main mass. The intrusions resulted from the partial melting of a metasomatized mantle wedge of supra subduction zone typical of subduction-related magmas. These rocks were evolved in an active continental volcanic arc with respect to the Laramide orogeny and the Neotethys subduction under the Sanandaj-Sirjan zone at the post Cretaceous. Magmatic ages of the intrusions are post Cretaceous during the Laramide orogeny. Deep subduction-related faults and fractional crystallization in the crustal chambers helped to petrological evolve the intrusions.

Tectonomagmatic setting of the Siahbaz A-type granitoids and mafic intrusions (Northwest of Khoy

Abdolnaser Fazlnia

Volume 8, Issue 30 , September 2017, , Pages 31-54

https://doi.org/10.22108/ijp.2017.81971

Abstract

The Siahbaz granite-gabbro-appinite outcrops from the Northwest Khoy is related to one of the complex of the Late Ordovician-Early Permian. The complex is located on the north Sanandaj-Sirjan ... Read More

Geochemistry and tectonomagmatic setting of the Kharaju gabbroic intrusions (South Azarshahr, East Azerbaijan province)

Abdolnaser Fazlnia

Volume 7, Issue 28 , February 2017, , Pages 127-144

https://doi.org/10.22108/ijp.2016.21240

Abstract

Kharaju mafic intrusions (south Azarshahr; East Azarbaijan) are gabbro in composition. The rocks with Eocene age intruded the northwest part of Urumieh -Dokhtar magmatic belt with a ... Read More

Penetrative conditions and tectonomagmatic setting of the Takht granitic batholith, Sirjan

Abdolnaser Fazlnia; Susan Jamei; Amin Jafari

Volume 5, Issue 17 , April 2014, , Pages 33-50

Abstract

The Takht granitic batholith of Sirjan contains gabbro-diorite to alkali-feldspar granite in composition. The batholith was emplaced in the south of the Urmia-Dokhtar magmatic belt ... Read More

Petrography, Geochemistry and Tectonomagmatic setting of the southwestern Salmas lamprophyres and related rocks

Abdolnaser Fazlnia; Fahimeh Kouzekoulani

Volume 3, Issue 12 , March 2013, , Pages 69-88

Abstract

The Quaternary lamprophyres and related rocks from southwestern Salmas are laid on the old floodplain deposits in the border of Sanandaj-Sirjan and Urmia-Doukhtar zones. These rocks ... Read More The Quaternary lamprophyres and related rocks from southwestern Salmas are laid on the old floodplain deposits in the border of Sanandaj-Sirjan and Urmia-Doukhtar zones. These rocks are all alkaline and include mostly camptonitic lamprophyres, contaminated Lamprophyres, basalt andesi-basalt and trachy-andesite. The rocks have been cropped out as prismatic and scoria structures with porphyritic and glomeroporphyritic textures. Lamprophyres are mostly composed of major minerals of augite, diopside, biotite, amphibole and tiny plagioclase in the matrix. Other rock types have augite, diopside and plagioclase as major phases. The presence of plagioclase and quartz xenocrystals with rounded margins, normative changes and variation in minor and trace elements content as well as their ratios are indicative of contamination with continental crust. Enrichment of LREE relative to HREE, the lack of Eu anomaly and the occurrence of Ta- and Nb-negative anomalies are important characteristics of all of the studied rocks. High ratios of Lan/Ybn, Lan/Smn and Smn/Ybn, the presence of spinel, augite and diopside and alkaline nature of all samples, indicate a melting process about 1 percent of a mantle with spinel lherzolite composition. The processes likely occurred following the Neotethys subduction beneath Central Iran ended. Slab break off in the remnants of the Neotethys oceanic crust occurred in location of the collision zone of Arabian-Eurasian plates. Arabian oblique tectonic pressure to the Eurasian plate and increasing activity of right-lateral strike-slip faults, which resulted of remnant slab break off the Neotethys, caused to decrease lithostatic pressure. As a consequence, the decompression melting occurred. The occurrence of these processes successively led to the rocks show tectonically within plate characteristic along with interacting of subduction elements. The mantle melts were erupted along these fault systems.

Geochemical modelling of controlling phases on abundances of major and trace elements in the migmatitic amphibolites, Seghalaton, Neyriz, Iran

Abdolnaser Fazlnia

Volume 3, Issue 9 , June 2012, , Pages 71-86

Abstract

Arc-related regional metamorphic process at c. 147 Ma caused a Barrovian-type metamorphism on the Qori old amphibolites crop outed in the southeast of the Sanandaj-Sirjan zone. As a ... Read More

Geochemical and petrological reconstruction of the Talle-Pahlevani mafic-ultramafic intrusions Shahre-Babak, Iran

Abdolnaser Fazlnia

Volume 2, Issue 5 , June 2011, , Pages 93-112

Abstract

The Talle-Pahlevani mafic-ultramafic intrusions located in northwest and south of leuco-quartz dioritic and anorthositic batholiths developed in the southwestern Sanandaj-Sirjan zone ... Read More The Talle-Pahlevani mafic-ultramafic intrusions located in northwest and south of leuco-quartz dioritic and anorthositic batholiths developed in the southwestern Sanandaj-Sirjan zone (173 Ma). These intrusions consist primarily of gabbro in association with veins and lenses of anorthosite, trectolite, clinopyroxenite, and wehrlite which show gradual and sometimes sharp boundaries with the gabbro. In the gradual boundaries, the gabbro are mineralogically transformed into anorthosites and wehrlites. On the other hand, in the sharp boundaries, the mineral assemblages in two sides are different. There is no clear deformation in the Talle-Pahlevani mafic-ultramafic intrusions. Hence, the changes in mineral compositions are the result of crystallization processes in the magma chamber. The chemical changes, especially for REE, from anorthosite and wehrlite veins and lenses toward gabbro in the gradual boundaries are continuous. The changes are presumably resulted from different crystallization processes in the different parts of the intrusions that cause crystallization of anorthosite, clinopyroxenite, and wehrlite cumulates in the intrusions. Rocks of the sharp boundaries show sudden chemical changes, but the changes exhibit the same patterns of increasing and decreasing of the elements, especially for REE. Therefore, it is possible that all parts of the intrusions were formed from the same parental magma. Parts with unequilibrium crystallization in the form of cumulus and sub-solidification, underwent fractures, and were interspersed throughout the magma chamber due to late injection pulses or mechanical movements. The geological and age data show that the intrusions generated from an Al2O3, Sr-, and FeO-enriched and K- and Nb-depleted tholeiitic basaltic magma likely partial melting 5-30 wt. % of the spinel-peridotite mantle within an incipient rift system. Then, the magma was crystallized in lower crust (relatively high P.) magma chamber.

Geochemical modeling of partial melting on the Tall-e-Pahlevani migmatitic xenoliths, Shahr-e-Babak

Abdolnaser Fazlnia

Volume 1, Issue 1 , June 2010, , Pages 11-26

Abstract

Falling down of pieces of garnet-biotite-kyanite schists from the Qori metamorphic complex (southern part of Sanandaj-Sirjan zone, northeast Neyriz) into the Tall-e-Pahlevani intrusion, ... Read More

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Author = Fazlnia, Abdolnaser

Geochemistry and tectonomagmatic setting of theGharuchah-Sofla intrusions (South Mahabad)‎

Abstract

Tectonomagmatic setting of the Siahbaz A-type granitoids and mafic intrusions (Northwest of Khoy

Abstract

Geochemistry and tectonomagmatic setting of the Kharaju gabbroic intrusions (South Azarshahr, East Azerbaijan province)

Abstract

Penetrative conditions and tectonomagmatic setting of the Takht granitic batholith, Sirjan

Abstract

Petrography, Geochemistry and Tectonomagmatic setting of the southwestern Salmas lamprophyres and related rocks

Abstract

Geochemical modelling of controlling phases on abundances of major and trace elements in the migmatitic amphibolites, Seghalaton, Neyriz, Iran

Abstract

Geochemical and petrological reconstruction of the Talle-Pahlevani mafic-ultramafic intrusions Shahre-Babak, Iran

Abstract

Geochemical modeling of partial melting on the Tall-e-Pahlevani migmatitic xenoliths, Shahr-e-Babak

Abstract