Chapter 6.6, Page 2 of 4

Hydrogeologic Units

The San Juan Basin contains numerous aquifers throughout its stratigraphic sequence. Sandstones typically provide the aquifer resources, whereas shales of varying thickness act as confining layers. Significant aquifers in Colorado include the Quaternary alluvium, Tertiary Animas Formation, Cretaceous Mesaverde Group and Dakota Sandstone, and sandstones of the Jurassic Morrison Formation (Table 6.6-1).

Table 6.6-1 Hydrogeologic Units of the San Juan Basin
(Click image to zoom 20KB)

Chapter 6.6, Page 2 of 4