Skip to main content

Lesser Himalaya zone in detail

Short answer

The Lesser Himalaya zone (altitude 1000-3000 m, width 60-80 km) lies between MBT and MCT. Its lithology includes Nawakot Complex (slate, phyllite, quartzite, limestone) and Kathmandu Complex (Bhimphedi Group schist, marble; Phulchauki Group slate, limestone) with granites. Structure is intensely folded and thrust with synclinoria, klippen, and north-dipping units.

Describe the Lesser Himalaya zone in detail (lithology and structure).

Lesser Himalaya (Midland, Mahabharat) zone. Lies between the MBT in the south and the MCT in the north; altitude about 1000-3000 m. Width 60-80 km. Rocks are Precambrian to Palaeozoic (some up to Eocene) low-grade metamorphic and sedimentary rocks, with a few granitic intrusions.

Lithology

  • Nawakot Complex: slate, phyllite, quartzite, limestone, dolomite and metasandstone. Lower Nawakot Group: Kuncha, Fagfog, Dandagaon, Nourpul and Dhading formations; Upper Nawakot Group: Benighat, Malekhu and Robang formations.
  • Kathmandu Complex (nappe): the Bhimphedi Group of schist, quartzite and marble (Raduwa, Bhainsedobhan, Kalitar, Chisapani, Kulekhani and Markhu formations), overlain by the Phulchauki Group of slate, sandstone and limestone (Tistung, Sopyang, Chandragiri, Chitlang and Godavari formations).
  • Granite and gneiss bodies: Palung granite and other granites, and the Ulleri augen gneiss.

Structure: intensely folded, faulted and thrust. There are synclinoria (e.g. the Mahabharat synclinorium of the Kathmandu nappe) with klippen, and anticlinoria, with many thrusts and tectonic windows. The beds mostly dip northward.

Engineering problems: landslides in weathered phyllite and slate, karst and seepage in limestone and dolomite, and shear zones along the thrusts.

✓ Answer checked by Claude Opus 5.5 (high effort)

Related questions

All Engineering Geology I chapter 7 questions →