Cauvery Basin is the southern sedimentary basin on the East coast of India. The basin covers an area of 150,000 sq.km comprising onland (25,000 sq.km) and shallow offshore areas (30,000 sq km). In addition, there is about 95,000 sq km of deep-water offshore areas in the Cauvery Basin.

The Cauvery Basin is an intra-cratonic rift basin, divided into a number of sub-parallel horsts and grabens, trending in a general NE-SW direction. The Basin evolved as a composite of rifted garben since late Jurassic and formed a part in the development of the East Coast divergent margin in India. The Jurassic fragmentation of eastern Gondwana land into India, Antarctica and Australia initiated the formation of Mesozoic rift basins on the eastern continental margin of India including Cauvery basin. Numerous down-to basin extensional faulting took place in the basin due to rifting. The initial rifting caused the formation of NE-SW horst-graben features. Subsequent drifting and rotation caused the development of NW-SE cross faults.

Evolution of the Cauvery Basin is understood to have taken place through three distinct stages-

Late Jurassic-Early Cretaceous Rift Stage

• Initiation of rifting began during the Late Jurassic/Early Cretaceous.
• Rift stage sediments (Shivganga and Therani formations) of Upper Gondwana affinity are known from exposures.
• These were deposited in fluvial environments.
• The Kallakudi Limestone, younger to the Shivganga Formation, may represent an episode of basinal deepening and paucity of clastic supply.
• In the subsurface, the Andimadam Formation, overlain by the Sattapadi Shale, appears to mark the peak of this transgressive episode during Cenomanian.

Late Cretaceous
• Initiation of rifting began during the Late Jurassic/Early Cretaceous.
• Rift stage sediments (Shivganga and Therani formations) of Upper Gondwana affinity are known from exposures.
• These were deposited in fluvial environments.
• The Kallakudi Limestone , younger to the Shivganga Formation, may represent an episode of basinal deepening and paucity of clastic supply.
• In the subsurface, the Andimadam Formation, overlain by the Sattapadi Shale, appears to mark the peak of this transgressive episode during Cenomanian.

Post Cretaceous
• Towards the end of the Cretaceous, the basin experienced a phase of upliftment and erosion and a gradual basinward tilt of the shelf.
• The Tertiary sequence was deposited in a general prograding environment with gradual subsidence of the shelf.
• This sequence can be subdivided into two groups, the Nagore and Narimanam. The Nagore Group is well developed in the south, whereas the Narimanam Group attains its full development north of Karaikal High.
• The Kallakudi Limestone , younger to the Shivganga Formation, may represent an episode of basinal deepening and paucity of clastic supply.
By this time, Tertiary deltaic environment appears to have considerably progressed eastwards

The Cauvery Basin contains the following major tectonic elements
• Ariyalur-Pondicherry Depression
• Kumbhkonam-Madnam-Portonovo High
• Tranquebar Depression
• Karaikal High
• Nagapattinam Depression
• Vedarniyam High
• Thanjavur Depression
• Pattukuttai-Manargudi Ridge
• Mandapam Ridge
• Mannar Depression
• Vedarniyam – Tiruchirapally Fault