Field Photos- Jaisalmer: Landscapes, History, Geology, Fossils

Jaisalmer was fun!

I was staying last weekend at the pretty amazing Suryagarh hotel. It is a relatively new hotel, but built in the style of an ancient fort. The interiors are stylishly crafted, with courtyards and sunlight corridors, and absolutely beautiful elegant use of lights in the evenings...the service was impeccable and the food was great too! I sampled quite a variety of cuisines, from the classic Halwai breakfast made in the Rajasthani style, to a lunch inspired by a hodge podge of different styles from Mediterranean to Thai, to another Rajasthani style meat and rice platter dinner. The highlight for me among the myriad dishes was a palate freshener made from basil, sweet melon (Mosumbi), lime and salt. It was liquid citrus basil chutney, served chilled. Simple, yet sublime!

Pune is green and black. Trees and that volcanic beast, the Deccan Basalts, give it those hues. Jaisalmer is buff, off-white, yellow, fawn, brown, rust, red, black. These are the colors of the clays and sandstones and limestones deposited in an immense sea which covered the area from the Jurassic to the early Cenozoic. I got to see only the Jurassic section, and that too only in a hurry.

Suryagarh had organized a long drive in the outback.. I guess that's the word that comes to my mind when facing an immense desert. The Thar stretches in all directions of Jaisalmer and a couple of km off-road you begin to sense the isolation.

An Oasis with the vast Thar behind.

We visited the smallish Khaba fort. The interesting history is at the base of the fort.

These are the ruins of the Paliwal community which is said to have moved to this area from Pali, Rajasthan few hundred years ago. They built a successful sustainable agricultural society, making clever use of the limited amount of available water. Then legend has it, they fell out of favor with some powerful locals and almost overnight abandoned their homes, migrating to several larger towns in Rajasthan.

All around, the Jurassic is inescapable. These are north tilted shales and sandstones. Only a few hundred feet of strata outcrop (on the surface), but there is more than five thousand meters of sediment in the Jaisalmer basin subsurface. Some layers are oil and natural gas reservoirs which ONGC has tapped into.

The shales, sandstones and limestones are fossil rich. I could spot ammonoids, belemnites and clams. In an isolated homestead belonging to a Bhil tribal family, we met this amazing old woman who scours the countryside for fossils and then sells them in the Jaisalmer market. This is her treasure trove!

.. and the Bhil family in their abode. The Bhils occupy a proud place in Rajasthan history, being most well known for the military support they gave to Maharana Pratap is his battles against the Mughal emperor Akbar. They, as most of the tribal societies in India are, quite marginalized, sustaining themselves on small farm plots and as day laborers.

Another type of remains of this ancient Jurassic life are ichnofossils. These are tracks and trails and burrows of worms and other creatures disturbing the sea floor and preserved as impressions and casts and molds. Here is a horizontal burrow system likely made by a polychaete worm like creature. The ichnofossils of the Jaisalmer area and their paleo-ecology have been well studied by paleontologists from Pune. Check out this paper co-authored by my friend P.K Sarkar from Fergusson College, Pune.

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More aspects of the geology and the physical processes prevailing in the Jurassic seas are seen in the building stones.

Here is a shell hash with pebbles, a concentration of coarse shells of molluscs and rock fragments, deposited on a Jurassic beach or in very shallow seas where strong wave action removes the finer clay and mud particles, leaving behind a lag of clean sand. Such coarse sands are of great importance to geologists. They are often quite porous and may end up hosting petroleum. So, the basic processes that control their distribution in ancient seas are studied intensely by sedimentologists.

And this great example of deposition in a Jurassic storm. The coarser pebbly layer contains "intraclasts" which are pieces of hardened sea floor that has been ripped up by storm waves, transported and then re-deposited. I could have stood and photographed the walls of the Suryagarh hotel all day. There is so much sedimentology to be learned, all literally written in stone.

The main source of water for these remote communities are these depressions where scanty rainfall accumulates. These make for a really soothing sight in the midst of the harsher surroundings.

Groundwater is usually found at depths of few hundred feet and is often saline. Aquifers are present in the top sand, as well as the Cenozoic, Cretaceous and Jurassic strata underneath. Back in the early Holocene some 8-10 thousand years ago, Rajasthan and Jaisalmer got a lot more  rain. Groundwater got stored in these deeper strata, but over the past few thousand years, the climate became drier, and these deep aquifers don't get replenished too often. Prolonged reaction of the water with the rock increases the salinity of the water.  But there are at places shallower lenses of fresh water which do get replenished from time to time. This community got lucky and has struck potable water at twenty odd feet. Here I am at one of the wells.

Another place of historical interest we visited was an ancient cemetery. Jaisalmer had trading links with Eurasia from medieval times and scattered through the countryside are tombs for the fallen traveler and important locals.

.. and off course a trip to the desert without sand dunes?.. This is part of the Sam Sand Dune National Park..

Overall, my visit was far too short, there is just a lot of history and geology to see around Jaisalmer. I did not even have the time to visit the world famous Jaisalmer fort, which is a UNESCO heritage site.  

Hey,  I am not really complaining! Who would, if you woke up to a view like this?