Cuddapah Basin

Cuddapah Basin

Cuddapah basin is situated east to the Dharwar craton and west to the eastern ghat mobile belt. It is crescent shape basin with concave towards east. The basin shows different structures in east and west. Western side is mostly undisturbed while eastern part has faults and folds.

Evolution of basin

The basin was open in Paleoproterozoic due to crustal thinning of Ur supercontinent. Extension forces opened up the sub-basin and Papaghani group was deposited.     

                                              

                                                  ↓

Dykes and sills were intruded in Papaghani sub-basin.

Papaghani and Cheiyar were deposited in this sub-basin. Soon, the extension setting was switched to convergent one and Nallamalai sub-basin was opened as back arc basin.

These basins collided and thrust were formed. Nallamalai was the upthrown side. Kurnool group was deposited.

In the east, mobile belt was formed and Cuddapah basin deposition was completed.

Lithology & Stratigraphy

The succession of basin is 6 km thick on an average. It is thicker in the eastern side. Cuddapah basin is mostly consisted of quartzites, shales and slate. Limestone has been reported in lower parts. The succession is mostly unfossiliferous.

Papaghani group is the lowest and have dykes and sills intruded. The Vempalle limestone has stromatolite fossils. This group also have deposits of asbestos and barytes. Baryte deposit is huge and famous.  

Nallamalai group has Lead and Copper deposits. This group is of shallow water origin. This group lies in the eastern part of basin and is highly faulted and folded.

Kurnool group is of lower Vindhyan age. Banganpalle quartzite have diamond containing conglomerates. 
__________________

Equivalent formations

Kaladgi and Pakhal groups are almost of same age as of Cuddapah basin.

Kaladgi group has two formations, lower is Bagalkot and upper is Badami.

Similarly, in Pakhal group lower is Mallampulli formation and upper is Mulung formation. 

__________________

Economic value

Mangampetta is famous for Baryte deposits. 

Asbestos are present in Anantpura and Kurnool districts, papaghani group. These are formed due to interaction of mafic sills with limestone. 

Agnigundala, Nallamalai group have deposits of Cu and Pb in dolomite.

Steatite and Talc are present in Anantpura district.

Diamond containing conglomerates are reported from Benganpalle formation of Kurnool group.