ANALYSIS OF THE GEOMAGNETIC FIELD AND THE BOUGUER ANOMALIES IN CYPRUS AND THEIR RELATION TO THE ISLAND’S GEOLOGY

Abstract

The well-preserved Troodos ophiolite complex comprises the dominant element of the geology of Cyprus. Aeromagnetic data from a 1969 survey and a Bouguer anomaly map of Cyprus were processed to interpret the magnetic and gravity anomalies associated with the ophiolite rocks. The magnetic and gravity data were inverted by means of a terracing technique that defines separate domains of uniform distribution of the physical property causing the aeromagnetic and gravity fields respectively. Maximum values of the horizontal gradient were used to locate the edges of the sources causing the anomalous potential fields. A complex attribute analysis is used to extract parameters of the buried structures that give rise to the anomalous magnetic field. In this study, source parameters such as local depth, strike, dip and susceptibility contrasts are obtained from the complex attributes assuming the sloping contact model. A 3-D model was used to simulate the structure causing the negative gravity anomaly at the highest point of Troodos, Olympos, which is believed to be due to a serpentinite MASS. A number of magnetic anomalies were modeled showing that they were caused by the ophiolitic rocks. Here just one of the models is selected and presented; it shows the continuation of the Troodos ophiolites under the Mesaoria sediments in central-east Cyprus. The results and interpretation of this study are generally in very good agreement with the existing geological models. They verify the knowledge about existing tectonic structures in the area of interest. They also show that the potential fields can be used as stand alone interpretative tools to help in the determination and understanding of the general geology and tectonics of an area.