Figure 17: Active faults of Figure 15 overlain on the gravity data of Figure 4, a proxy for viewing rift basin shape. MHSF: Mineral Hot Springs fault (revised), NRC: Northern Rock Creek, RCFZ: Rock Creek fault zone, SCFZ: Sangre de Cristo fault zone, SLFZ: San Luis Creek fault zone, VGFZ: Villa Grove fault zone, and VGTF: Villa Grove town fault. Model for A-A′ is shown in Figure 16.