Structural setting of Jabal Abu Ghurrah Area, Wadi Fatima, west-Central Saudi Arabia

Abstract EN

Detailed field mapping and structural study of J.

Abu Ghurrah area indicate that the uppermost Precambrian sediments and voleanics of the Fatima Formation were deformed by NNW-SSE tangential compression.

The styles of deformation include flexural-slip folding forming a large, ENE to NE plunging, overturned syncline and low-angle thrusting in a hinterland dipping duplex.

The floor thrust of the duplex is a ddcollement between the 150 meters thick andesite sill and the underlying limestone beds of the middle Fatima member.

The roof thrust of the duplex has the largest displacement among the mapped thrusts.

The duplex was formed by continued shortening of the area as the thick andesite sill of the middle Fatima member acted as a rigid and brittle beam that resisted folding and failed by low-angle thrusting.

Layer-parallel shortening by minor folding and thrusting is also common in the area and represents an early phase of deformation.