HR: 1340h
AN: T33B-1366    [Abstracts]
TI: Re - interpretation of magnetic signatures from parts of Colombian and Rancheria basins, Caribbean Sea, north of Colombia
AU: * Sharma, K
EM: kksharma25@hotmail.com
AF: University fo Madras, Prof. KK Sharma, Professor, Department of Applied Goelogy,University of Madras, Gunidy Campus, Chennai 600 025. INDIA, CHENNAI,INDIA, 600025 India
AU: Mallick, K
AF: National Geophysical Research Institute, Dr. K. Mallick, Emeritus Scientist, NGRI, Uppal Road, Hyderabad 500 007, INDIA, HYDERABAD,INDIA, 500007 India
AB: Boundaries of Caribbean are major structural features of earth's surface. Structural features within these boundaries are of great importance in understanding the tectonic history of Caribbean regions. An attempt has been made to re interpret the magnetic signatures with a new technique for better understanding of the area. The paper presents a new technique based on the finite element analysis approach for separating regional and residual components of a magnetic field response. The method is discussed and its efficacy is brought out with the help of field data. The proposed technique is employed to computer the regional and residual components of magnetic anomaly for the area from parts of Colombian and Rancheria basins, Caribbean sea, north of Colombia. The paper discusses the behaviour of residual anomaly map. Given below are some of the observations. Images bring out structural features more clearly than contour maps. Magnitude of the anomalies obtained using this method is greater than obtained using other methods. Northern part of Colombian basin shows EW trend where as the southern part NE - SW trend. Deep basin represents images and contours extending firmly in EW direction where as the marginal anomalies trend roughly parallel to coastline. Contact between ocean and continent \can be drawn. Structure in the extended direction of Beata Ridge is seen in the new map. Possible extension of Cuiza fault (or may be some other structure) extending in the west is seen in the new map. It is shown that these maps prepared using the new technique help in identifying and demarcating structures in the area and hence in better understanding of offshore tectonics and onshore tectonics.
DE: 8110 Continental tectonics--general (0905)
DE: 5109 Magnetic and electrical properties
DE: 5440 Magnetic fields and magnetism
DE: 1714 Geomagnetism and paleomagnetism
DE: 1517 Magnetic anomaly modeling
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting