This series of maps represent the most detailed geological information published till date. India is covered by 392 numbers of 1 degree x 1 degree quadrangle sheets. Out of which 300 sheets are amenable for data collection and publication. on scale 1cm = 2.5 km.

Till date around 278 Geological Quadrangle maps have been published. Compilation of the maps has been done at a scale 1:250,000 from raw data collected at scale 1:50,000 and 1:25,000.