Thursday, November 25, 2021

Reverend William Buckland's Pie Crust

I came across this delightful passage in Elsa Panciroli's book, Beasts Before Us: The Untold Story of Mammal Origins and Evolution.

Naturalists exploring southern Scotland in the early nineteenth century came across some intriguing looking footprints impressed in red sandstone in a quarry at Corncockle Muir. The geologist Reverend Henry Duncan described these footprints and send some casts to the Reverend William Buckland who was making a name for himself in the emerging field of geology. The thinking was that these tracks were most likely made by crocodiles and turtles. Reverend Buckland came up with a clever way to test this idea. 

From Elsa Panciroli's book-

'Ist I made a crocodile walk over soft pye-crust [sic]' he wrote in a letter to Duncan, 'and took impressions of his feet...[second] I made tortoises, of three distinct species, travel over pye-crust, and wet sand and soft-clay...' Buckland's wife supplied the pie-crust and Buckland supplied the tortoises. Where the crocodiles came from is unclear, but as Buckland had a penchant for eating them he probably also had access to  live ones. The results : the marks matched the tortoises. He concluded, 'though I cannot identify them with any of the living species.... the form of the footsteps of a modern tortoise corresponds sufficiently well.... so I conceive your wild tortoises of the red sandstone age would move with more activity and speed... than my dull torpid prisoners.'

It was understood much later that these footprints in sand from Permian times (299 -252 million years ago) were made by early Therapsids from which arose the mammalian lineage. 

I am really enjoying this book! 

Monday, November 15, 2021

Char Dham Route Landslide Hazard Maps

The Geological Survey of India has published a report of landslide susceptibility along the Char Dham routes being expanded in Gharwal, Uttarakhand. The Char Dham refers to the four holy sites of pilgrimage in the Uttarakhand Himalaya, namely, Gangotri, Yamunotri, Kedarnath, and Badrinath.

The report is available for download - Uttarakhand 2013 Deluge: Landslide Impact on Char Dham Routes

A series of maps of the routes are published showing landslide hazard zones.An example posted here is of the section between Siri and Gangotri

The report focuses on the damage done to the hill slopes due to the deluge and floods in June 2013 where intense runoff and river erosion  caused massive landslides.  But it also states that road building at places has resulted in the development of new landslide loci. That road building is triggering landslides along these routes is obvious judging by the regular reports of new landslides all across Gharwal. This is a well compiled report, but I despair that the advice of geologists and ecologists on the impact this road expansion is having on this part of the Himalaya is being ignored. 

Instead, the GSI has this reassuring tip for travelers: 

"This Coffee Table book will be of immense use for pilgrims passing through the landslide vulnerable tracts leading to the Char Dhams in Uttarakhand".

 Happy Journey!