Carosi, R., Gemignanni, L., Godin, L., Iaccarino, S., Larson, K., Montomoli, C. and Rai, S. 2014.   A geological journey through the deepest gorge on Earth: the Kali Gandaki valley section, central Nepal. In: (Eds.) Chiara Montomoli, Rodolfo Carosi, Rick Law, Sandeep Singh, and Santa Man Rai, Geological field trips in the Himalaya, Karakoram and Tibet, Journal of the Virtual Explorer, Electronic Edition, ISSN 1441-8142, volume 47, paper 9.

A geological journey through the deepest gorge on Earth: the Kali Gandaki valley section, central Nepal

Rodolfo Carosi

Department of Earth Sciences, University of Torino, via Valperga Caluso 35, I-10125, Torino, Italy

L. Gemignanni

Department of Earth Science, Faculty of Earth and Life Sciences Vu University, The Netherlands

L. Godin

Queen´s University, Department of Geological Sciences and Geological Engineering, Kingston, Canada

S. Iaccarino

Department of Earth Sciences, University of Pisa, via S. Maria 53, I-56126, Pisa, Italy

K. P. Larson

Earth and Environmental Sciences, IKBSAS, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada

C. Montomoli

Department of Earth Sciences, University of Pisa, via S. Maria 53, I-56126, Pisa, Italy

Santa Man Rai

Department of Geology, Tribhuvan University, Ghantaghar, Kathmandu, Nepal

Abstract

The Kali Gandaki valley in Central Himalaya is the deepest canyon in the world bounded by the eight thousands Annapurna and Dhaulagiri massifs. It offers an invaluable opportunity to directly observe a cross section of the continental crust involved in the Himalayan orogeny. Moreover the North-South trend of the valley cross cuts the major tectonic units of the Himlayas from the Lesser Himalaya, the Greater Himalayan Sequence (GHS) and the Tibetan Sedimentary Sequence. The valley is easily accessible compared to many other sections throught the belt. We propose a one week itinerary starting from the very-low grade Proterozoic quartzites of the Lesser Himalaya to the South, reaching the Cretaceous sequence of the Tibetan Sedimentary Sequence to the North, crossing all the crystalline unit (GHS) with evidence of repeated partial melting both as the meso- and the nano-scale. The major tectonic faults/shear zones such as the Main Central Thrust and the South Tibetan Detachment are well-observable along the section as well as some other important shear zone within the GHS (i.e. Kalopani shear zone). The section offers also a spectacular view both mesoscopic and large-scale deformation affecting the three main tectonic units with particular emphasis to the km-scale north-verging folds in the Tibetan Sedimentary Sequence.