Nilkanth Fm

Uttarakhand, Nilkanth locality in Garhwal region of Lesser Himalaya. Shell Limestone was considered part of Tal Fm by Medlicot, 1864, Middlemiss,1885, Auden,1934 and subsequent workers till 1979 (Shanker et al 1993) when Singh, 1979 recognized a major stratigraphic break between the Upper Tal Quartzite and Shell Limestone and separated Shell Limestone from the Tal Fm and designated Shell Limestone as Nilkanth Fm. [Original Publication: Singh, I.B. 1979. Recognition of a sedimentological break between Quartzite and Limestone Member of the Tal Fm, Lesser Himalaya, India Curr. Sci., 48, 206]

Synonym: Shell Limestone

Sandy limestone. Grey to bluish grey sandy shell limestone, 8 to 20 m in thick and thickness varies at different localities i.e. Dhaulagiri, Ghena, Satengal, Ringalgarh and North of Ringalgarh sections.

The ill-preserved broken lamellibranches, gastropod shells, bryozoa, echinoid spines, ostracod, foraminifers and algae of Upper Cretaceous/Daman age were recorded from Shell Limestone of Tal Fm from the Mussoorie Syncline (Saklani et al 1977) However, Late Cretaceous age was assigned to the Tal Shell Limestone of the Garhwal Syncline on the basis of planktonic foraminifers - Globotruncana, Hetrohelix and Hadbergella and bryozoa - Cenocava nilkanthi (Singh, 1980). Bryozoa - Cenocava nilkanthi, echinoid radiole, hydrozoa - Millepora sp, textuland foraminifers, green algae - Acicularia sp, Neomens sp., Ovuhtes sp

The presence of micro and mega biota and the sandy oolitic limestone with abundant bioclasts of foraminifers and dasycladaceae green algae indicates its deposition in a shallow, high energy marine environment.

See Mathur et al., 2008