Geology of Itanagar Capital Complex, Arunachal Himalaya, with Special Reference to Neotectonics

The geology of Itanagar Capital Complex of Arunachal Pradesh is least known. It constitutes mainly Siwalik sediments and unconsolidated Quaternary deposits. The Siwalik sediments are represented by Dafla, Subansiri and Kimin Formations belonging to the Middle Siwalik. The Quaternary sediments have been classified into four formations, viz , Itanagar Formation, Banderdewa Formation, Sonajuli Formation and Pachin Formation. Structurally, the area is squeezed between the Himalayan Frontal Fault in the south and the Bomdila Thrust in the north, and is traversed by a number of other local thrusts and active faults. Morphological features indicating neotectonic activity suggest that the area is geodynamically active.