Geology and Soil of Dhankuta area eastern Nepal

Abstract

A geological map of 200 sq. km of Dhankuta area is presented. Mapped geological formations recognized include Dhankuta and Mulghat formations of Precambrian- Lower Paleozoic age. The Dhaukuta Formation comprises of garnet- biotite- muscovite- quartz schist and gneiss with conspicuous beds of grey and white quartzite. The Mulghat Formation is differentiable into three members and includes schistose phyllite and actinolite schist with carbonates, garnetiferous phyllite with sills of amphibolite, and phyllite and quartzite. The general strike of the formation is east west and dips northerly in order of 20° to 60°. The east- west trending Tamar fault passes to the south of Dhankuta Bazar. The nature of the soil present in Dhankuta Bazar is non-plastic and is formed by insitu weathering of the parent rock. The deep gullies are prominent feature caused by an intensive erosion and denudation of the soil and the instability of the surface could largely be attributed to this factor. A few stone quarries can be operated around Dhankuta Bazar for the supply of building and dimension stones to minimise the immediate brick problem.