What type of structure produced by a pair of reverse faults?

Answer 1

I know of no structure caused by pairs of reverse faults. Pairs of normal faults can cause "horsts" and "graben". However in horizontal stress fields where the maximum principle stress is parallel to the Earth's surface and the minimum principle stress is normal to the Earth's surface only one one fault surface/plane usually develops (which may be imbricated) as the shortening and thickening usually build away from the source of compression. Also as the crust thickens the principal stress will not remain normal to Earth's surface for long.

Reverse faults at very high strains therefore merge into napes or subduction zones.

Answer 2

A pair of reverse faults can create a structure called a horst and graben system. In this system, the raised blocks (horsts) are separated by the lowered blocks (grabens) along the fault lines. This structure is typically seen in regions undergoing compressional tectonic forces.