Determination of the boundaries of anomaly potential field with analytical signal filter and its orthogonal derivative in Qeshm Island SE Iran

Abstract

Abstract The analytical signal method and its derivatives can be explicitly calculated and assessed for analyzing and estimating the boundary of geological structures, such as faults or dikes, from potential field anomalies. Gravity field of the east of Qeshm Island and its north coast from Sarkhoun to Litadan in SE Iran has been measured in one-kilometer regular network. The regional anomaly effects are deducted from the Bouguer anomaly, where it can get the residual anomalies which is the considered dataset used in this study. The Bouguer range is 297 to 330 milligals (mGal) applying filters and modeling. It was revealed that there are five negative anomalies caused by salt penetration in the region. Regional anomalies expectedly have a low spatial frequency and long wavelengths, while the residual anomalies associated with shallow sub-surface potentials have high spatial frequencies and short-wave wavelengths. Two different fault trends were observed comparing the artificial model using MATLAB coding, the real one, and the filtered residual anomaly map of the Qeshm region. Also, another fault trend is suggested in the east height of Oman, which is a possible place of salt penetration. Due to the limited dimensions (120 * 100 km) and the information obtained from the existing drillings, the depth of the anomaly resources can be examined up to 8 km. Due to the gravitational condition between the two domes of Qeshm saline and the bridge located in the Hara saline area, it is suggested to be considered as an area for further oil exploration routines.