Petrology of Intrusive Bodies of Azizabad-Tinamo Area in the South of Songour, Iran

Siavash Gholizadeh,Mohammad-Ali Arian,Abdollah Yazdi,Mahammad-Reza Jafari

doi:10.4236/ojg.2016.612111

Siavash Gholizadeh, Mohammad-Ali Arian + Show 2 more

Open Access

https://doi.org/10.4236/ojg.2016.612111

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Abstract

In terms of structural divisions of the Iran’s earth crust, the studied area is considered as a part of the Sanandaj-Sirjan structural zone and Zagros Thrust. In this area, there are two gabbroic-dioritic and syenitic igneous intrusive bodies. The host rocks of these intrusive bodies are upper Cretaceous limestones and formed by contactmetamorphism at the contact zone between hornfels rocks and skarn. Field and geochemical datasets represent that all various rocks within these intrusive bodies have been originated from the same magma. The process of fractional crystallization and probably a small amount of contamination and assimilation has also played a role in the evolution of parent magma. Generally, these magmas are sub-alkaline and lie in themagmatic range of tholeiitic and calc-alkaline series. Samples investigated are metaluminous and peralkaline.

Highlights

The studied area is located in the 1:100,000-scale geological map of Songour and the west of Iran (Figure 1).The some parts of the stratigraphic units in the studied area belong to SanandajSirjan structural zone and other parts are related to Zagros Thrust Zone, which marked by the large fractures and multiple thrusts, and resulted to structural complexity of the area (Figure 2)
In terms of structural divisions of the Iran’s earth crust, the studied area is considered as a part of the Sanandaj-Sirjan structural zone and Zagros Thrust
According to petrographic and mineralogical studies of thin sections of rocks collected from the studied area, the intrusive igneous rocks in the region from basic to acidic terms include gabbro, gabbro-diorite, diorite, quartz-bearing syenodiorite, syenite, quartz-bearing syenite and granite, which gabbroic and syenitic rocks contain the largest volume in the area studied

Summary

Introduction

The studied area is located in the 1:100,000-scale geological map of Songour and the west of Iran (Figure 1). The some parts of the stratigraphic units in the studied area belong to SanandajSirjan structural zone and other parts are related to Zagros Thrust Zone, which marked by the large fractures and multiple thrusts, and resulted to structural complexity of the area (Figure 2) This area, by the following of geological events in the area, was under the influence of different deformation phases whether orogenic or epeirogenic, the emplacement of intrusive bodies, metemorphism, and other geological events. Given that the Sanandaj-Sirjan zone having NW-SE trending is parallel to the Zagros Thrust Faults, and by considering that this zone has severely affected by these faults activities in during different geological periods after the Cretaceous, as a result, in the area investigated the severe effects of tectonic activities could be well observed due to the proximity to the Main Zagros Fault Among these features, it can be referred to thrust nappes, the presence of thrust faults with Quaternary age, regional metamorphism and intrusion of gabbroic to syenitic bodied and a small amount of granite. This study aims to determine the formation mechanism of gabbros, syenites and granites, discover the genetic relationship among the intrusive bodies of the region, and determine the change and frequency of major and trace elements in the rocks of the region

Geological and Tectonic Setting

Petrology

G-77 G-55 G-76 G-80 G-57 G-75 G-73 G-40 G-70 G-80

G-59 G-83 G-90 G-48 G-91 G-89 G-42 G-63

Findings

Conclusion