جستجوی مقالات مرتبط با کلیدواژه « magnetic » در نشریات گروه « مهندسی معدن »

This study presents a comprehensive geophysical investigation of the Sabalan geothermal area in Iran, utilizing magnetic, gravity, and magnetotelluric (MT) data. These data have been inverted to a depth of 5000 meters. Magnetic data inversion accurately identified faults or fractures. Gravity data inversion produced a density model distinguishing intrusive masses, reservoirs, and cover units. MT data inversion utilized apparent resistivity and phase data for both TM and TE modes. The resulting models were compared with geological cross-sections to assess their accuracy and consistency. The integration of geophysical models yielded a comprehensive geological conceptual model for the Sabalan region. Heat sources, hydrothermal reservoirs, and potential geothermal fluid pathways were identified, demonstrating the effectiveness of geophysical methods in subsurface mapping. Consistency with newer Sabalan models based on drilling and geological data increased confidence in findings.

Because of the limitations of manipulating single geophysical data sets to interpret subsurface anomalies for many cases, it is required to combine geophysical data to decrease the ambiguity and non-uniqueness of the interpretation. Integration interpretation of two different geophysical data sets is one of the most common ways to integrate geophysical data and in this paper, we want to utilize the combination of gravity and magnetic data for the Golgohar mine in Iran. This mining case is located in the Sanandaj-Sirjan zone in the province of Kerman. Gravity and magnetic data are interpreted using a MATLAB code written based on the damped weighted minimum length solution for which the model weighting is the product of the multiplying of compactness and depth weighting constraints. At first, the inversion algorithm is applied to the synthetic case to investigate its reliability for practical application on real data. Reconstructed models from the noise-contaminated synthetic data are suggestive of the productivity of the inversion algorithm. Ultimately, the algorithm is applied for the interpretation of the real data and the inversion results of both data sets show a high correlation between the magnetite anomaly position horizontally and vertically. The results represent an anomaly with the depth ranging approximately from 25 to 130 m with the horizontal extension of about 120 m from 280 to 400 m relative to the start of the interesting profile.

Potential field geophysical measurements were conducted in the west of Kifl region in central Iraq to image a plausible oil-trapping reservoir. Ground-based magnetometry and gravimetry surveys were conducted to investigate this region by covering an area of 16  24 km by designing a regular grid spacing of 250 m. After preprocessing potential field data, different filters were utilized to separate the residuals from the regional anomalies. The complicated tectonic setting of the studied area was imaged by recognition of the fault system through simulation of the magnetic and gravity anomalies, which facilitates the configuration display of the oil-trapping mechanism. The geometry of a fault system was derived from parametric inversion of gravity data. The magnetic anomalies were extended with the trends of NS, NW, and NE and reached a maximum value of 55 nT. However, the gravity anomalies appeared with the same extensions and values ranging from -3.3 to 1.5 mGal. The intense magnetic susceptibility amount of the reservoir rocks is arising from chemical processes and iron-oxide ion replacements, accompanied by the migration and accumulation of hydrocarbon. Incorporating the results from the Euler’s depth estimation, parametric data modeling along with logging data assisted simultaneous modeling of the magnetic and gravity data. The 2D geological model of the subsurface layers at the Kifl area presents a graben-horst fault system within a thick sequence of sediment. Geological characteristics extracted from geophysical data modeling provided insightful information on the nature and essence of the hydrocarbon reservoirs in the Kifl area. It has formed through tectonic deformation and tension over the Arabian plate during the Permian – Paleocene cycle. Hence, it can be concluded that the aforementioned fault system has divided the hydrocarbon reservoirs.