1. Kyushu University, Earth Resources Engineering Department, Hakozaki 6‐10‐1, Fukuoka 812‐8581, Japan; and Nuclear Materials Authority of Egypt, Airborne Geophysics Department, Kattamiya Road, Maddi, P.O. Box 530, Cairo, Egypt.
2. Southern Illinois University at Carbondale, Department of Geology MS 4234, Carbondale, Illinois 62901‐4342.