GSI's commemoration document, published on the occasion of the 150 years anniversary celebration, provides an insight into the formation of the subcontinent, the orogeny, the paleoenvironment and the exotic collection of paleo-flora and fauna.

The details provided for the Eparchaean Unconformity monument indicate that this feature forms the boundary surface between Proterozoic Nagari Quartzites and Archaean granite.

The steep scarp of the ranges shows the Eparchian Unconformity's topographic, structural and denudational features.

[5][9] The sedimentary thickness of the Cudappah basin is of the order of 12 kilometres (7.5 mi), and includes volcanic sequences in the form of sills and dykes.

A prominent Eparchaean Unconformity of the formation resting on the archaean peninsular gneissic complex is noted.