This geology consists of normal faults which separate grabens from horsts. This is a type of block faulting known as grabens and horsts. Multiple sets of horsts and grabens created sudden drowning and shallowing events. These mountains corresponds to horsts and domes separated by basins, including grabens. The crystalline basement is usually uncovered on the South flank of the horsts. Many protruding horsts show many layers of flood basalts. The horsts form two rows of mountains. Horsts and grabens are very well documented throughout this region. The uplifted blocks are block mountains or horsts. These hills are horsts located along the Tornquist Zone. Graben often occur side-by-side with horsts. Higher blocks are called "horsts" and troughs are called "grabens". Adjacent raised blocks (horsts) and down-dropped blocks (grabens) can form high escarpments. Horsts may have either symmetrical or asymmetrical cross-sections. While the blocks remaining up or uplifted produce mountains or ranges, also known as horsts.