Lower Nawakot Gr
Type Locality and Naming
Katmandu region (Lesser Himalayan succession)
Lithology and Thickness
The Lower Nawakot Group represents probably the oldest rock succession in the Lesser Himalaya of Nepal. " The Kuncha Fm is "a very thick and rather monotonous sequence of alternating blue-green to gray-green phyllites or chlorite schists; gray-green to light gray gritty phyllites; that is more than 3000 m thick (no base exposed). The Fagfog Quartzite Fm shows graded bedding, cross-lamination, and spectacular wave and current ripple marks. … The Dandagaon Phyllites Fm is composed of rather uniform argillaceous to finely quartzitic phyllites of dark blue-green color. … The Nourpul Formation represents an assorted succession, comprising quartzites, phyllites, and calcareous rocks. … The Dhading Dolomite is essentially a microcrystalline and dense dolomite."
Relationships and Distribution
Lower contact
Base of Kuncha Fm is not exposed, even though that formation exposure is over 2 km thick!
Upper contact
The contact of the Dhading Dolomite Fm (uppermost formation of Lower Nawakot Gr) with the overlying Benighat Slates Fm (lowermost formation of the Upper Narakot Gr) is quite abrupt in the Budhi Gandaki section of central Nepal, where the black Benighat slates override the dolomites without any transitional zone. At the base of the Benighat Slates, there is an approximately 50–100 cm thick weathered zone alluding to an erosional unconformity at the top of the Dhading Dolomite Fm (Stöcklin and Bhattarai 1977, pp. 17–18). However, in west Nepal and in other parts of the country, such a sharp disconformity is not observed. In places, the dolomites and slates are interbedded and this formation transitionally passes into the black slates of Benighat.
Regional extent
These rocks cover an extensive area north and west of Kathmandu as well as to the east of the valley.
GeoJSON
Fossils
Age
Depositional setting
Additional Information