The Churachandpur-Mao Fault (CMF), trending NNE-SSW, is morphogenic in nature and can be traced for ~ 300 km. It is defined by straight valleys; most prominent being between Kangpokpi and Maram. The fault takes a north-easterly trend from Maram where the fault zone is characterized by active landslides during the monsoon. At Puni Pfosemai, which represents the hanging wall of the fault, extensional tectonics of local extent is observed. This is designated the Puni Pfosemai Fault that trends NNE-SSW and is about 2.5 km in length. The downthrown block is characterized by single-order streams with steep gradients. In the downstream, the fault scarp facing SE developed in the footwall block is more than 100 m in height. The upper portion of the Barak River is tectonically controlled. The SW flowing Barak River takes an almost 360° turn at Karong to flow NNE, before changing course again towards the northwest near Maram. The immediate hanging wall of the CMF is characterized by a narrow valley with relatively high stream-gradient index and steepness index values. A strath terrace of 11 m height is observed on the hanging wall block of the CMF. The straight river valley and concavity (θ) of 0.64 for the Barak River are indicative of active tectonics.