Basin Analysis of Nihal Nala Section, Krol Formation (A Precambrian-Cambrian Transition Zone) Kumaun Lesser Himalaya

The rocks of the Nainital area are highly deformed, as a result the stratigraphic layout has been a matter of debate for quite long time. However, the detailed work done by various organizations in recent years provided a detailed lithostratigraphy of the area. The Naini massif represents the south-eastern part comprising of five en-echelon basins of the Krol Belt which extends from Solan in Himachal-Pradesh to Nainital in Kumaun. The much tightened and faulted synclinorium is thrust over the Shiwalik along the Main Boundary Thrust (MBT). Nihal Nala is situated towards South-East from the Nainital Township. The Nihal Nala section is located along Nainital-Khurpatal-Haldawani bypass road, which cuts the under-construction bridge along this road. The Krol Formation of the Nainital is best displayed along the Nihal Nala section. Nihal Nala originates from the mountainous area on the back side of the Rajbhawan, forming a gorge like structure (i.e. Nala). In this section, the rocks of Krol Formation are well exposed and are easily measurable. Due to highly unstable condition of the rock formation the area is very prone to landslides. Along this section, measurement of the well exposed Krol Formation and the litholog of the Nihal Nala section was done which tells about the deposition condition of the Krol Formation.