DECIPHERING GRAVITY SIGNATURES FOR MAPPING PROTEROZOIC SUTURES IN ETHIOPIA: IMPLICATIONS FOR TECTONIC EVOLUTION (Invited Presentation)

Ethiopia, positioned at the convergence of the East African Rift System and the boundary of the Afro-Arabian tectonic plate, represents a dynamic geological environment believed to be marked by suture zones. Suture zones, where tectonic plates meet and merge, are significant geological features offering insights into the region’s dynamic past and development. Accurate identification and mapping of these zones are crucial for understanding local tectonic activities, resource distribution, and seismic risks. Gravity data, sensitive to variations in subsurface density, proves invaluable for delineating these complex structures. When a suture zone is deeply buried and lacks surface indications, making geological mapping challenging, geophysical methods become essential. In this study, airborne gravity data were utilized to pinpoint the location of Proterozoic suture zones. Analysis of Bouguer anomalies, combined with the distinctive 'type gravity anomaly' characteristic of collisional sutures that occur globally, alongside edge detection using tilt angle of directional horizontal gradient of the residual aero gravity grid, is used in identifying a Proterozoic suture zone trending approximately N-S. Employing half width anomaly method and power spectrum analysis, the depth of the proposed suture zone was estimated between 22 and 33 kilometers. This proposed suture zone likely reflects an arc-continent collision during the East African orogeny and the amalgamation of West and East Gondwana.