A Geologic Curiosity in NW Saudi Arabia: the Jabal Rayah Ring Structure
D. Janjou, R. Wyns, Mohammed A. Halawani, and Abdullah Memesh
During geologic mapping program for 1:250,000-scale Tabuk Geoscience Map by a DMMR/BRGM joint team, a curious and singular ring structure was discovered and mapped in detail at a scale of 1:20,000. Field analyses show, that with this ring morphology, are associated structures such as tectonized Lower Paleozoic rocks with subhorizontal thrusts and squeezed thicknesses, star folds within the structure, but no indications of “shatter cones” or impact glass. The context shows that there is no other such circular structure in the region. Following presentation of their observations, the authors discuss the various explanations of the structure’s origin (such as salt doming, or pluton trace), and present the hypothesis of an astrobleme as the most likely explanation. The age of this ring is unknown, although it is between Devonian and Quaternary, but the fresh aspect of the structure and the general geologic history of this area, suggest that the structure is Cenozoic in age.
Janjou, D., Wyns, R., Halawani, M.A., Memesh, A, 2004, A geologic curiosity in NW Saudi Arabia: the Jabal Rayah ring structure: Saudi Geological Survey Data-File Report SGS-DF-2004-3, 8 p, 6 figs., 1 plate.