تبدیل فوریه

Identification of deep ore deposits is one of important subjects in exploration field. Discrimination of dispersed mineralization zones and blind mineralization area is an important challenge in exploration of mineral deposits. Geochemical Zonality method and alteration models are traditional method that utilized for exploration of deep ore deposits specially Cu porphyry and Au veiny deposits. In this study, the anomaly thresholds have been determined using the fractal method for calculating the Zonality indexes in Tanurcheh area and then 4 important Zonality indexes have been used. In addition to these traditional methods, suitable information in this field can be achieved using interpretation of geochemical data in frequency domain. The situation of deep deposits and dispersed zones can be surveyed using interpretation of frequency anomaly in frequency coefficients of elements method. In this study, the potential of deep mineralization in one part of Kashmar Au and Cu mineralization area has been surveyed by frequency coefficients of elements method and obtained results have been compared to Zonality method and information of deep exploratory boreholes. The results of frequency coefficients method have properly been confirmed using the results of deep drillings unlike Zonality method.

Determining the position of potential field anomalies is one of the objectives of data processing, which is done using various methods such as normalized full gradient. The normalized full gradient method used in the interpretation of geophysical data is a semi - quantitative and semi - automatic method, which incorporates Fourier transform for the elimination of the problems associated with the application of the downward continuation filter through an anomalous source. The results will be reliable if the number of harmonics in the Fourier series is used correctly. The enhanced normalized full gradient method analyzes the two curves: the energy ratio curve of the reconstructed anomalies and the depth curve, along with variation in the number of harmonics, and provides a suitable solution for selecting the number of optimal harmonics. This method was applied on synthetic models and satisfactory results were obtained. The enhanced normalized full gradient method has also been used to determine the position of the anomalous body of Jalalabad deposit. The result of this study shows that using the enhanced normalized full gradient method it is possible to determine the number of optimal harmonics and the position of anomalous bodies from potential field anomalies.