Some 90 million years ago, the Indian Tectonic plate separated from the African plate, floated in a northeasterly direction and collided with stationary Euro-Asian plate. As the northern edge of the Indian plate slid under the Euro-Asian plate, the top crust of the Indian plate was shaved off and got piled up on the Indian plate forming the Great Himalayan Range. The Tethys sea which was between the two plates, as they converged, got uplifted and the ocean bed with its stratified layers of deposits is now visible in the Zanskar and Suru valley areas of Ladakh. The heat generated by the friction of the two colliding plates created the granite masses of the Ladakh Range and its neighbour, the Pangong Range.
The Tibetan area, at the southern edge of the Asian plate, a relatively flat land before the collision took place, was lifted by the Indian plate squeezing under it, to take its present shape of a high plateau. The suture, or the meeting of the two plates on the surface, is presently in the region of the sources of the Indus and Tsang po (Brahmaputra in India) river systems with the northern bank of these valleys representing the Eurasian plate and, on the southern side, the exposed leading edge of the Indian plate.
Kangju Kangri peak on the Pangong range
The dramatic and violent geological past of the Ladakh region gave rise to a bewildering variety of rocks, physical features and landscape. Geography, however, imposed a degree of uniformity to the area. The Himalayas rose (a process which continues today) till they were blocking the rain bearing monsoon clouds from the Indian Ocean to the south.
The Ladakh area, as a whole, soon became a desert with very low precipitation of barely 10 cms annually on an average, with a mere 30% as summer rainfall and the balance 70% coming as winter snowfall. Though a desert, the high altitudes (most of Ladakh is over 9,000 feet above the mean sea level) meant that it was a cold desert.
Sand dunes near Hunder in the Nubra valley
To add to the unfolding drama, the deep snow of the winter months, water mainly from melting snow in the summer months and the cold wind sweeping across the area constantly sculpt the landscape by eroding the soft upper layers to expose the harder rocks below. The eroded materials are relentlessly carried down the Indus and its tributaries by the turbulent snow fed streams.
Nubra valley near the confluence of Shyok and Nubra rivers
The ‘U’ shaped Nubra valley near the confluence of the Nubra and Shyok rivers indicates extensive glaciation during the earlier ice age. The exposed sides of the presently landlocked brackish water Pangong Lake basin, with stratified layers containing fossilised marine creatures, points to the presence of much larger volumes of water earlier, and fresh water at that, draining possibly into the Shyok valley.
Near the western edge of the Pangong Lake
Alluvial deposits of water bodies inundating that valley formed the famous Lamayuru ‘moon land’ and the present furrowed shapes were sculpted through erosion by water and wind.
‘Moon land’ of the Lamayuru valley