Assessment of Vertical Magnetic Gradient Data of Tuzla Fault Using Boundary Analysis and 3-D Inversion Techniques

Emre Timur

doi:10.4236/jpee.2017.512006

Abstract

The magnetic prospection is one of the most useful methods to determine buried geological structures such as shallow fracture zones. The investigation of vertical and horizontal gradient and total magnetic field variations over geological structures, which have been used for many years, may reveal their locations, geometries and physical characteristics. In this study, a proposed iterative 3-D rectangular prismatic model inversion algorithm was modified to interpret vertical magnetic gradient data defining the boundaries and the physical parameters of the anomalous structure. Vertical magnetic gradient measurements were carried out at the Tuzla fault, an active fault system located along NE-SW direction in Izmir (Turkey). Boundary analysis studies were applied to data in order to obtain boundaries of the structures, afterwards the inversion process was carried out considering these geometries. As a result, location, direction and other physical and geometrical features of the fault are achieved.

Highlights

Gradient or total magnetic field measurements are acquired from the ground, in the air or on the ocean, covering a large range of scales and for a wide variety of purposes
Boundary analysis studies were applied to data in order to obtain boundaries of the structures, afterwards the inversion process was carried out considering these geometries
This study aims to perform a detailed scale investigation focusing on the Tuzla Fault for better understanding of the region’s tectonics

Summary

Introduction

Gradient or total magnetic field measurements are acquired from the ground, in the air or on the ocean, covering a large range of scales and for a wide variety of purposes. In study areas where formations carrying a magnetic signature dip at a significant angle, a magnetic survey can be used to map surface geology very precisely [14]. For both regional and detailed explorations, magnetic measurements are important for understanding the tectonic setting. Structural terrane boundaries, such as faults, are commonly recognized by the contrast in magnetic fabric across the line of contact [13]. The study of tectonic structures is an important economic application of magnetic surveys, especially in hydrocarbon and geothermal explorations and geotechnical investigations. It is commonly possible to estimate the depth to basement and, under favorable circumstances, quantitatively map basement structures, such as faults and horst blocks [12]

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Conclusion