NEW ENHANCEMENT TECHNIQUES FOR AZIMUTHAL ANALYSIS OF LINEAMENTS FOR DETECTING TECTONIC TRENDS IN AND AROUND THE AFRO-ARABIAN SHIELD

The weighted moving average technique is used to analyse lineament azi muths counted by number and length. The technique enhances peak/noise ratio. The quality of distribution is measured by the chi(2)-test and the degree of correlation between lineament number and length. Moreove r, segmenting lineaments improves the enhancement and makes the counti ng only by number. Lineament distributions in the four study areas in and around the Afro-Arabian Shield are very similar and can be regarde d as a fingerprint. Tentatively, 24 trends are correlated from one are a to the other but with varying shape and amplitude. Among these are t he Red Sea, Aqaba, Najd, Aden, Meridonial and Trans-Red Sea tectonic t rends. A pattern of lineaments disposed about the N-S is traced in all areas, but in Abha, to the south it deviates 7 degrees to the west. I t is related mostly to an old tectonic trend. The deviation might be d ue to the effect of the rotation of the Arabian Plate counter-clockwis e with respect to fixed Africa.