Figure 1: Geology of the northern San Luis Valley area from published sources (see text). Modifications and additions to these mapped Quaternary (active) faults and general surficial geology are presented in this study (Figure 15). Underlay of shaded-relief terrain is a graphically smoothed, NW-illuminated hillshade derived from the LiDAR data (Figure 3). MHSF: Mineral Hot Springs fault, SCFZ: Sangre de Cristo fault zone, and VGFZ: Villa Grove fault zone. Boxes locate example Areas 1–4. Inset shows the location of the study area within the San Luis Basin and Rio Grande rift (basins are shaded). SJVF: San Juan volcanic field.