Geophysical Division: The Division makes use of sophisticated instruments to locate the hidden sub-surface mineral resources and also subsurface structures by highly trained Geophysical personnel. Their knowledge is also utilized in ascertaining various rock types in depth for foundation work of engineering projects. The division also engages in studies involving earthquakes mechanism and prediction in the earthquake prone region.

Chemical Division: The Chemical Division plays a very important role in chemical analysis of rock and mineral samples collected by field geologists to ascertain their elemental contents. The Division uses highly sophisticated precision instruments for analysis of samples like Atomic Absorption spectrometer at its laboratory at Shillong. Recently X-Ray Florescence Spectrometer and one Atomic Absorption Spectrometer including Graphite furnace and Hybrid Generator unit (GF-AAS) has been installed.

Drilling Division: After systematic mapping, geophysical and geochemical exploration are over, indicating the possibility of mineral deposit at depth, their presence or absence, extent etc are physically verified by drilling. The quality/quantity and grade of minerals are obtained by analyzing and interpreting the drill cores.

Petrology Division: This Division is concerned with study of rock and minerals in the field and laboratory under microscope and with other instruments for the purpose of identification of different constituents required for proper evaluation of field data, relating to geology, genesis and structure. Gem Testing has been started in Northeastern Region with the establishment of small laboratory at Shillong to render service to interested parties. Gemstones are identified based on standard non destructive methods employing both physical and optical properties followed by their mineralogical identification.

Palaeontology Division: This Division studies fossils - identification of which help in deciphering the condition of deposition, palaeogeography and the age of the rock where they are embedded. This also helps in correlation of rocks exposed in different geographic areas. Palaeontological studies in this region proved that the coal forming plant existed along the Himalayan foot hills of Arunachal some 280 million years ago and an arm of sea invaded part of the area in the same period. The southern part of Meghalaya Plateau was under sea at about 100 million years ago. Existence of large reptiles in this region has been indicated by remains of Dinosaurs in the rocks of this region.

Photogeology and Remote Sensing Division: This Division studies aerial photograph and satellite imagery for delineating geological structure, rock type, drainage pattern etc. and structural aspects for identifying potential mineral bearing areas. Considering the inaccessible nature of this terrain this work is of supreme significance.

Map and Compilation Division: This Division is engaged in catering to the map requirement, toposheet, sale of geological and mineral maps, atlas, maintenance of map stock, dissemination of map information through exhibition, book fair etc. Cartographic requirements, archival and updating of maps database and coordination among various operational units are also dealt by this unit. The division is also involved in preparation of quadrangle geological mineral map and digitization of compiled geological maps on 1:50,000 scale.