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Magnetotellurics, Beattie magnetic anomaly, Southern Cape Conductive Belt, Namaqua Natal Mobile Belt; 23. - 26. October 2007
DDC:
550 - Earth sciences
Abstract:
The Beattie Magnetic Anomaly (BMA) and the Southern Cape Conductive Belt (SCCB), which are two of the Earth´s largest geophysical anomalies, extend across the southern African continent for more than 1000 km in an eastwesterly direction. Based on their spatial correlation and previous electrical and magnetometer array measurements it is believed that both anomalies have a common crustal source represented by 50 km wide sliver of serpentinized palaeo-oceanic crust. New two-dimensional (2D) electrical conductivity models along profile MT1 from Prince Albert to Fraserburg and profile MT4 centered on Jansenville outline a narrow (2 km wide) zone of high electrical conductivity in the upper to middle crust below the centre of the Beattie Magnetic Anomaly. With 2D modeling studies of aeromagnetic data we are able to show that simple models which can explain the magnetic signature of the BMA, include an approximately 50-100 km wide magnetic body. These modeling studies indicate that the magnetic model and its interpretation are not consistent with a narrow conductivity anomaly, implying that a common source for the two anomalies is unlikely.
