The Arcos-Pains-Doresópolis Karstic Province is located along the southwestern border of the Sao Francisco Craton-CSF, which is drained by tributaries of the upper São Francisco river valley. The karst is developed on limestones and dolomites of Bambuí Group (Upper Proterozoic). This stratigraphical unit also includes phyllites and is installed over Archean granites and gneisses. The Precambrian deformation includes thrust and strike-slip faults, as well as folds affecting the rocks of Bambuí Group in some areas.

Morphologically, it is a typical humid tropical karst characterized by towers and a great variety of dolines, formed in many different ways (collapse, solution and subsidence) and situated on plateaus and hilly compartments. More than 60 mapped caverns are organized into three altitudinal subterranean levels corresponding to stages of baselevel lowering, which constituted the responses of the Sao Francisco river entrenchment to the Cenozoic uplift pulses. This evolution is analyzed in basis of the terrace system installed at borders of a 100 meters high karstic canyon.

Morphotectonic studies involving interpretation of aerial photographs, geomorphological mapping and field survey of neotectonic structures, including statistical analysis of its relations with karstic features (dolines and caves) show:

• the area was updomed several times resulting from NW-SE to W-E compressive stress field;
  
• the main axis of updoming, oriented N-S, constitutes an inheritance of the Upper Proterozoic compressive deformation which Cenozoic reactivation has controlled the formation of several old caverns;
  
• the canyon was formed by down-cutting process into limestones and phyllites;
  
• two N35-40W oriented depressions correspond to Upper Cenozoic grabens generated by the reactivation of a N50W oriented strike-slip shear zone (Crustal Discontinuity of Upper Sao Francisco River-DCARSF, Saadi 1991);
  
• the formation of more recent dolines and caves is predominantly controlled by the neotectonic N35-40W normal faults.

*Supported by PRPQ/UFMG and Fundo Academico/UFMG 1999