Fig. 6. ( a ) Folded and extruded Jurassic and marine synrift strata on the hanging wall of the Chintoraste Fault along the Loa River in the Domeyko Cordillera, evidencing the tectonic inversion of this structure, which is interpreted as a major basin-bounding fault; see Figure 3 for location

Figure 9. Geological map of the Calama Basin west of Calama city, in the eastern sector of the San Salvador–Loa Valley (location is shown by box in Fig. 4 ). Mapped relations are based on field work and our satellite image analysis. Dashed-line faults (thick black lines) are inferred based

Figure 7. Zones of faults and associated folds in the study region. Table 6 describes the physical properties, sense of offset, and age of offset of each fault system. The geology of the rock units underlying the river bed alluvium is shown for comparison to Figures 2 and 4 . R.—river; S

Miocene–Pliocene basin. Both the limestone-dominated facies (pale yellow, brick pattern) and marginal conglomeratic facies (yellow, gravel pattern) are potential aquifers. R.—river; Ch—Chintoraste hills; O—Ojos de Opache region; H—Calama Hill; L—Llalqui area; T—Talabre area. (B) Early and middle Miocene

and thin lines are piezometric contours; gray numbers and lines are land surface contours. Heavy black lines are faults. Elevations are in meters above sea level. A single italicized gray number notes the elevation of the bed of the Loa River north of the region with piezometric data. Solid piezometric

Figure 18. (A) River locations, major faults, and the positions of two schematic geohydrology cross sections (black lines). The reach of the Loa River that probably recharges in part the Calama Valley aquifers is highlighted blue, and river elevations of 2660 m, 2760 m, and 2865 m are noted