Stratigraphy of India

The surface of Earth is covered by various physical features like mountains, valleys, plateaus, deserts etc. All these features are made up of rocks over millions of years. During their formation, many geological processes such as weathering, erosion, sedimentation, volcanism, tectonism, marine transgression and regression played an important role. India has a marked diversity in its physical features as it contains the folded Himalayan mountain system, Peninsular plateau, Indo-Gangetic plains, Thar desert, Eastern and Western Ghats as well as Islands of the west and east coasts.
Importantly, these regions are made up of rocks belonging to various geological ages, ranging from Precambrian to Holocene (Present). In short, Indian rock record is rich and diverse and its different regions contain rocks of various geological periods, extending from the Archaean.  
Stratigraphy of India refers to the understanding of the sequential arrangement of its rock record from Archaean to Holocene. Rock record constitutes all type of rocks including igneous, sedimentary and metamoprhpic, occur in an area or in a country. However, the rock record of an area is never complete or continuous as it is usually witnessed by non-depositional or erosional periods in the forms of diastems, unconformities and disconformities. This is the reason that the Archaean and Proterozoic rocks are well developed in Peninsular India, whereas Palaeozoic-Mesozoic rocks are almost fully
preserved in the Himalayan region.