| In Tertiary time, the Batain nappes were unconformably overlain by carbonate and elastic rocks. |
| The shallow soils are derived from fluvial gravel overlain by multiple ash deposits and aeolian dust. |
| These mid-Palaeozoic formations are unconformably overlain by the Carboniferous-Permian Pillahuinco Group. |
| Little has been published about the stratigraphic age of this group, which is abruptly overlain by these limestones. |
| These units are conformably overlain by fluvial and lacustrine volcaniclastic deposits, tuffs and hyaloclastites. |
| The shallow soils are derived from fluvial gravel overlain by multiple Holocene volcanic ash deposits and aeolian dust. |
