Manyetize Olmuş Jeolojik Yapıların Model Parametrelerinin Belirlenebilmesi için Gelişmiş Lokal Dalga Sayısı Tekniğinin Toplam Alan Manyetik Anomalilere Uygulanması

Abstract

In this study, enhanced local wave number (ELWN) technique is presented to compute some model parameters of isolated and magnetized geological structures such as horizontal position (exact origin), depth and source geometry using the total field magnetic anomalies (TMAs). The technique uses analytical signal amplitude (ASA) and first- and second-degree horizontal and vertical derivatives of observed TMAs, and then simply computes the model parameters without requiring a priori knowledge about the nature of the causative magnetized body. Additionally, inclination and declination angles of both magnetization and ambient field have no effects on the results. In the ELWN technique source geometry, viz., structural index (contact/fault, dyke, horizontal cylinder and sphere) is determined using the depth and exact origin computed previously. Hypothetic simulations performed using TMAs due to some simple shaped geological models have showed the ability of the technique. Moreover, an actual magnetic data taken over the Kesikköprü iron deposit (Central Turkey), one of the largest iron reserve in Turkey,has been also analysed. A depth of 21.39 m has been computed for the magnetized geological source which includes the mafic rocks rich in magnetic properties, and the iron ore body. The structural indices obtained have indicated a dike-like or an intermediate form between a dike and a horizontal cylinder body for the magnetized source. These findings are compatible with those of a recently published study. Hence, the use of ELWN technique is proposed for rapid and reliable model parameter estimations from TMAs as an alternative or supportive experiment to the inverse modelling studies.