M Shademan; A.R Arab-Amiri; H Kheyrollahi; D Rajabi
Abstract
Frequency Domain Electromagnetic surveys are being used for various applications like mineral and water exploration, environmental hazards and buried human-made materials because of its resolution and fast acquisition for low depth targets. Resistivity and its depth for each frequency could be calculated ...
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Frequency Domain Electromagnetic surveys are being used for various applications like mineral and water exploration, environmental hazards and buried human-made materials because of its resolution and fast acquisition for low depth targets. Resistivity and its depth for each frequency could be calculated in a simpler approach and shorter time than Iterative Inversion Method, Called Straight or Fast Inversion Methods, by assuming earth as a homogeneous half space. Barika’s Anomaly situated in Alut Geology 1:100,000 sheets in west Azerbaijan is studied in order to prospect gold_ lead mineralization which has been detected in systematic geochemical and litho-geochemical surveys. In this paper we studied different Fast Inversion algorithms for synthetic data then applied the best method for real data. Resistivity distribution for each frequency produced and appropriate interpretation according to geology acquired. The results showed that there is a good correlation between low resistivity and shear zones. Also geology map can be modified with higher frequency resistivity.
E Eshaghi; A Kamkar-Rouhani; A Arab-Amiri
Abstract
Every geophysical method has its own advantages and disadvantages. The integration of the results obtained from surveys using various geophysical methods causes the weaknesses of a particular geophysical method to be covered by the other geophysical methods. For this, different exploration, engineering, ...
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Every geophysical method has its own advantages and disadvantages. The integration of the results obtained from surveys using various geophysical methods causes the weaknesses of a particular geophysical method to be covered by the other geophysical methods. For this, different exploration, engineering, environmental and other investigations using various geophysical methods usually provide more reliable results. In this research work, it is attempted to integrate the results of electrical resistivity tomography (ERT) and ground-penetrating radar (GPR)surveys in order to examine the advantages and weaknesses of each of the two methods, and finally, to present more accurate and more reliable interpretation as a result of this integration. The ERT method that is, in fact, one of optimal resistivity survey methods, renders acceptable results in complex geology areas. The GPR method as a high resolution non-destructive geophysical method, which is based on transmission of electromagnetic waves in the ground and recording the reflected waves from the interfaces of the subsurface layers, is used for shallow subsurface investigations. In this research work, a water qanat was selected as a suitable target for detection by these two geophysical methods, and the, ERT and GPR surveys were carried out in an area enclosing the target. The results obtained from processing, modeling and interpretation of the acquired data indicated that the GPR method, compared to the ERT method, had higher resolution than the ERT method. However, the ERT method, compared to the GPR method, had higher depth of penetration. The results of both methods were mainly in good agreement with each other in depicting features such as subsurface cavities, variation of the grain sizes of the subsurface sediments and water percolation from the qanat to its surroundings. Furthermore, following the integration of the results of these two methods, it was found that the accuracy and reliability of the interpretation were considerably enhanced.
F Doulati Ardejani; M Pishdadian; A.R Arab-Amiri; R Kakaei; M Mohammado Khorasani
Abstract
In the aim of petroleum exploration at Qum area, gravity and magnetic measurements incorporating 2059 measuring stations have been conducted in order to detect likely buried oil traps, any volcanic intrusive, faults and subsurface folding related to the Qum formation. Bouguer and total magnetic anomaly ...
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In the aim of petroleum exploration at Qum area, gravity and magnetic measurements incorporating 2059 measuring stations have been conducted in order to detect likely buried oil traps, any volcanic intrusive, faults and subsurface folding related to the Qum formation. Bouguer and total magnetic anomaly maps were produced when the required corrections were made on the gravity and magnet data. The fractal method incorporating intensity-area model was used to produce residual gravity and magnetic maps. These maps were compared with those maps produced by trend surface analytical method and then interpreted. The results obtained by the interpretation show that although the presence of an anticline which was determined using gravity method is important for petroleum exploration; however, the magnetic intensity is very high on a part of this anomaly. Furthermore, it is probably affected by the surrounding faults. The results obtained in this study can be effectively used to decide doing further exploration works in the study are.
