In the era of colossal reptiles and turbulent tectonics, a land mass came hurtling through the Tethys Ocean at glacial speed to collide with another. The Indian Plate’s oceanic crust grinding and slipping beneath the Eurasian Plate, the Indus Suture is formed. Millions of years of this prolonged pulverization of Earth produced intense heat and pressure, causing rock to recrystallize into smoother minerals, reducing friction to ensure continued pulverization. The Earth’s skin writhing and raging, squirming and scrambling to form what is now the world’s highest mountain range, and yet rising still. Ladakh, situated smack-dab on top of the Karakoram fault line and the Indus Suture Zone (the intense convergence of two tectonic masses), is a landscape of magnificent, towering vertical rock formations and high altitude glaciation, which determine the fate of billions. And here I am sipping Seabuckthorn juice on top of that fault-line, contemplating 200 million years of complex geological phenomenon.
Igneous and Ocean
The ground I walk each day consists of former ocean floors with aquatic fossils and even corrals and shells, which are prominent in traditional Ladakhi jewelry. Much of the igneous rock found in Ladakh are basalt, gabbro, and serpentinite – all rock formations which predominantly make up the oceanic lithosphere (ocean crust just above the asthenosphere, Earth’s mantle). Additionally, the heat generated from the ocean floor of the Indian Plate sliding under the Eurasian Plate produces hydrothermal energy which rises to the surface of Ladakh, heating aquifers and creating natural hot springs which are both used as a tourist attraction as well as generating local electricity. Granite and andesite are also frequent igneous rocks found in the region.
Sediment and Sea
Sandstones, limestones, and conglomerates are all results of erosion and deposition in bodies of water, which demonstrate past existence of rivers, lakes, glaciers, and ocean. Since sedimentary rock is our “rock of ages,” so to speak, the sediments of Ladakh can tell us about past environmental conditions, the formations of distinct layers and fossils. As the Indian Plate proceeds to slide under the Eurasion Plate, sediments are continuing to stack and fold upward, forming vertical folded layers. It’s magnificent; I can stare at this formation for hours. Limestone in particular is most often formed from sea organisms with calcitic shells, and can often be found with fossilized seashells. This, in my opinion, is one of the most exciting and fascinating aspects of Ladakh’s geology, that sea rock and the history of the Tethys Ocean can be touched, climbed, and studied on the rooftop of the world.
Heat, Heights, and Everything Gneiss
With all of these minerals and elements churning and changing from the depths of the Earth to the highest altitude, metamorphic rocks are forceful and frequent. Since oceanic crust is much thinner and in closer contact with the intensely hot asthenosphere than continental crust, the collision between the Indian Plate and Eurasian Plate caused a significant uplift of metamorphic rock, as the rising and falling of sedimentary and igneous influenced the metamorphic rock formation in the region. This newly formed and recrystallized rock which rises from the depths are called batholiths, here known as the Trans-Himalayan Ladakh Batholith. South of the Indus Suture are the Himalayan Nappes, complex rock layers consisting of original parts of the Indian continent, Tethys platform and oceanic crust. The continuous stacking and accumulation forces the bottom layers to depths of over 100km during subduction, subjecting these diverse minerals to extreme pressure and heat to form minerals entirely unique to Ladakh, including abundant rubies.
HotSpots and Aftershocks
Ladakh’s hydrothermal reserves, caused by this accumulation of magma close to the surface, produces over 20 hotsprings in the area which have the ability to harness over 20 megawatts of energy. Since the Himalayas are dynamic, with frequent earthquakes, landslides, and fluctuations in amount of glacial melt, access to power is spotty. Additionally, when the Indus River freezes in winter, Ladakh’s hydropower plants begin to fail. These hostsprings and circulation of groundwaters is a new area of potential natural energy that could be a valuable resource in sustainable development in Ladakh. When these natural disasters such as earthquakes and landslides occur, access to power and connectivity is an even greater concern. Geologists have been anticipating an impending earthquake of extreme magnitude, exceeding that of the disastrous earthquake in Nepal in 2015, to hit the northern region of the Himalayas any time, which would severely affect Ladakh in particular. This is one of many reasons why education on Ladakh’s geology and general geo-hazards of the Himalayas is a topic of interest when planning lessons and workshops for students, which has been my main focus in my final months of implementing my education project at the Snow Leopard Conservancy, India Trust’s (SLC-IT) pilot school in Matho village.
It’s not only important for Ladakhi students to care about the rock phenomena all around them, but also for the rest of India and the entire northern hemisphere. The Himalayas, as massive as they are, effect global climate and wind patterns, but also play a crucial role in South Asian monsoons. The entire Tibetan Plateau (upon which Ladakh is situated) is heated through the above-mentioned thermal processes, which drives the circulation required to produce the summer monsoons in the south. With approximately 100,000 square kilometers of glacier ice providing water supply to Ladakh, the resulting moisture and glacial melt feeds into atmospheric processes and rivers which run throughout India to the sea. However, with the Himalayas rising at an average rate of 3.4mm/year, this monsoonal moisture is being increasingly blocked by Himalayan uplift and resulting in more glacial retreat. Climate change is a growing concern not only for regions which rely on glacier melt, but also a concern for the rest of the globe which is indirectly effected by these high altitude geologic processes.
This is a topic I’ve been researching more and more in my final months of my service as an AIF Clinton Fellow at SLC-IT, collaborating with my colleagues to develop a new curriculum devoted to Ladakh’s geology to be incorporated into our monthly environmental workshops at Matho’s government school. Understanding Ladakh’s geology is crucial for a sustainable future in development in tandem with Ladakh’s unique environmental evolution, considering everything between geo-hazards, harnessing available resources, and appreciating the magnificence of Ladakh’s geological processes.
I was staying in a very rural community in a home that had welcomed me in as a stranger at dusk. I was talking about all the wonderful things I had seen on my trek into the village, between yaks, wild ungulates, wooly hares, and eagles. The old man shook his head and smiled, saying that’s not very exciting, that Ladakh isn’t as interesting as outsiders seem to believe. He kept repeating, “All we have is rocks, all we have is rocks, nothing but rocks rocks rocks.” I responded that all those rocks are the most beautiful part about Ladakh’s landscape, to which he just laughed in disbelief. It’s true; rocks are in many respects the foundation for life in Ladakh. Humans and animals alike rely on rocks for so many things, and thus perhaps are taken for granted. Used for communication in the remote hills, for art and expression, for construction, protection, and tools, rocks are pervasively important for understanding Ladakh’s landscape, environment, and cultures.