Abstract:

As indicators of certain significant geological structural elements, linear anomalies are important in interpreting gravity and magnetic anomalies. Lineaments are usually mapped by using improved data. Numerous algorithms have been developed to automatize this process. This paper presents an integrated study of the Adapazari basin by taking into consideration a set of gravity data and surface geology. Subsurface geological modeling is performed by Hough transform (HT) based on gradient calculations as an image enhancement technique and an interpretation of the gravity values including boundary analysis algorithms. Application of the gravity method to structural geology helps shedding light on the local changes in the gravity gradient zones caused by density differences pertaining to crustal structure and composition. Anomalies occurring in gradient zones are commonly expressed as potential-field lineaments. The methods proposed to detect these discontinuities and boundaries corresponding to differences are tested on synthetic data as the initial stage and the results obtained are satisfactory. As the second stage, they are applied to the gravity anomaly map of the Adapazari basin and possible lineaments are automatically obtained. In addition to provide supportive data, sediment thickness in the region is computed by using 3DINVER matlab program. Automatic analysis results are compared to the major and minor faults depicted in the geological map of the study area. The results demonstrate that automatic lineament detection depicts more fault traces than visual interpretation. By combining the lineaments obtained with geological and supportive data, we try to introduce a new approach to tectonic development for the study area. These examples demonstrate that in detecting the geological features defined as major and minor faults, the Hough algorithm can be used for qualitative interpretation of gravity anomaly maps.

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