Geophysical researches for identification of hidden faults in the western region of Banesh, Fars, Iran

Abdolmajid Asadi,Raheleh Farhang

doi:10.18468/estcien.2018v8n3.p61-69

Abstract

Possessing seismic information on active faults is required for earthquake risk estimation. In earthquake prone areas such as Zagros Mountains in which active basement faults are covered by Phanerozoic sedimentary cover, we can use geophysical data such as special resistivity and employ Schlumberger array as an inexpensive and quick method to identify blind faults with high accuracy. For this purpose, 30 vertical electric soundings and 10 profiles were implemented on Banesh Plain in Fars Province of Iran. Using data from geoelectric sections combined with qualitative data, we determined blind faults and sub fractures. The results show two faults zones along east-southwest and northwest-southeast lines and some sub faults and fractures along the Zagros flow.

Highlights

Using geophysical methods in identification of some of ground’s physical features such as electric, elastic and magnetic characteristics of rocks and minerals, earth gravity and such characteristics are of great importance
We use the geoelectric method with Schlumberger array in order to confirm tectonic and geological evidence based on the existence proofs of blind faults in the area
Banesh village in Beyza District, situated on northwest of Shiraz is located on active fold belt tectonic unit of Zagros which is covered by sediments related to Phanerozoic era and has hidden many of geological structures including faults

Summary

INTRODUCTION

Using geophysical methods in identification of some of ground’s physical features such as electric, elastic and magnetic characteristics of rocks and minerals, earth gravity and such characteristics are of great importance. 61-69, Sept./Dec. 2018 mination of anisotropy in different directions This method is best in distinguishing underground layers in terms of their special resistivity and thickness and because of flexibility, high speed, light and portable equipment, low costs of field operations, being economical and ability to directly and qualitatively interpret data, it is one of the strongest discovery methods (Ako and Olorunfemi, 1989). Deep changes of special resistivity and existing layers are investigated using formations in which the distance between some or all electrodes increase symmetrically. Reviewing side changes of special resistivity resulting from geoelectric measurements via profiling method, we can determine underground irregularities and their range or extent underground. Investigating deep or vertical changes of special resistivity resulting from measurements by sounding method can be practically used in hydrological studies and underground waters. Geophysical data and aerial magnetic maps are consistent with this subject (Shahsavari, 2003)

DISCUSSION

CONCLUSION