Non-Diapiric Salt Domes in the West Zanjan, Central Iran

Sina Alizadeh

doi:10.4236/ojg.2017.72009

Abstract

The salt domes of the west Zanjan (Central Iran) are the most important structures in the study area. They have been formed by the uplifting and erosion together under low humidity and dry and warm climate condition. The salt rocks with near to 200 meters thickness are related to lower member of the Upper Red Formation (Early Miocene) that deposited in the inverted back arc basin. They have been formed in the Central Iran basin after the Arabian-Eurasian convergence. Based on filed works and preparation of geologic map, salt domes have been cropped out during regional uplifting and erosion along hinge zone of a longitudinal anticline. Also, there is no evidence for salt diapirism and so, they are different from some salt diapirs in the southwestern margin of Zanjan that is investigated by other researchers.

Highlights

The Miocene gypsiferous rocks are named Upper Red Formation by the National Iranian Oil Company geologists [1]
The salt rocks with near to 200 meters thickness are related to lower member of the Upper Red Formation (Early Miocene) that deposited in the inverted back arc basin
There is no evidence for salt diapirism and so, they are different from some salt diapirs in the southwestern margin of Zanjan that is investigated by other researchers

Summary

Introduction

The Miocene gypsiferous rocks are named Upper Red Formation by the National Iranian Oil Company geologists [1]. Near Qom city, is about 3000 m and comprises alternations of red fine-grained sandstones, compact gypsum, conglomerate and marly sandstones. The Upper Red Formation overlies the Qom Formation but, in some parts of NW and Central Iran, the contact comprises thick salt and gypsum [1]. The Miocene Upper Red Formation in the study area was deposited in a Marine regression condition (firstly) and fluvial system under dry and warm climatic condition (later) [1]. Salt domes or positive topographical features which have been formed by evaporate minerals (mainly halite) are the index structures in Upper Red Formation [2].

Methods

Results

Conclusion