GEOMETRIC AND KINEMATIC MODELING OF THE RAMPART RANGE FAULT, COLORADO SPRINGS, COLORADO
Geometric modeling involved unfolding beds in each fault-bounded block by flexural slip unfolding, followed by piecing together the blocks from the east (footwall) to the west (hanging wall of the Rampart Range fault zone). In the retrodeformed section, beds unfold into an irregular triangle zone. Part of the Jurassic and Cretaceous section below the Dakota Sandstone is missing in the retrodeformed section. The approximate location of the splay faults on the undeformed section were identified by locating the ends of beds in each block; all splay faults dip gently west on the undeformed section.
Kinematic forward modeling using trishear reproduced a similar overall geometry to the published cross-section. Although splay faults were not generated by the trishear modeling, they could be explained as accommodation of the thickening of mechanically strong units (such as the Dakota Sandstone, the Lyons Formation, and the Fountain Formation) in the hinge of the trishear zone.