The sedimentary beds that form the basin are of Paleozoic, Mesozoic and Paleogene age.

The central plateau consists of ancient crystalline rocks with granites overlain by non-fossiliferous sandstones and conglomerates of Paleozoic age.

Sedimentary deposits of early and middle Paleozoic age include:

The massif is composed of crystalline basement (metamorphic and igneous rocks) with Proterozoic to early Paleozoic ages.

These rocks are of either Proterozoic or Late Paleozoic age.

The ore is massive and disseminated sulfides in hornblende schist of Precambrian or Paleozoic age.

The rocks of the region are essentially little disturbed, flat-lying sedimentary layers of the Paleozoic age.

Erosion has exposed carbonate bedrock of Late Paleozoic age.

To the southeast and southwest, they are covered by sedimentary rocks of Paleozoic age.

Dunbar was a worldwide expert on the evolution of fusulines during the Pennyslvannian and Permian periods of the late Paleozoic age.