Benjamin Franklin And Erasmus Darwin: Musings About Geology and Evolution

I am reading When You Were A Tadpole and I Was A Fish  by Martin Gardner. It is a collection of essays on science and culture. There is a really good one on the complex personality of Isaac Newton, another one on Ann Coulter's rants against evolution and quite a bit of writing on debunking paranormal claims. I haven't yet finished the entire book with some chapters on literature and religion still unread. I am not sure they will hold my interest as there is more critical dissection of literary figures like Chesterton and a long explanation on why he (Mr. Gardner) is not an atheist than I care to read about.

In one of the chapters Mr. Gardner gives a list of anticipations made by famous figures about how the world works which have turned out to be right, although not in all details. The larger point he is making throughout the book is the lack of evidence for clairvoyance. People are making predictions all the time. Most of them turn out to be wrong. We however tend to remember and wonder only at the tiny fraction that turn out to be correct.

He off course does not categorize Benjamin Franklin and Erasmus Darwin as people making loose predictions. They were both far better thinkers than your run of the mill soothsayers and fortune tellers. Their musings were serious attempts to understand natural processes and were not just opportunistic attention grabbing stunts.

This is Benjamin Franklin in a letter to Abbe Soulaive, September 22, 1782:

"Such changes in the superficial parts of the globe seemed to be unlikely to happen if the Earth was solid to the centre. I therefore imagined that the internal parts might be a fluid more dense, and of greater specific gravity than any of the solids we are acquainted with; which therefore swim in or upon that fluid. Thus the surface of the globe would be a shell, capable of being broken and disordered by the violent movements of the fluid on which it rested."

Exhumation Patterns Of Dhauladhar Range Himalayas: Interplay Of Tectonics And Climate

Open access in Current Science:

 New apatite and zircon fission-track ages from the Dalhousie Granite exposed along Dhauladhar Range, Northwest Himalaya extend from 2.9 ±  0.2 to 4.4± 1.0 Ma and 10.4 ±  1.4 to 21.1 ±  2.2 Ma respectively. One-dimensional thermal modelling of the data suggests slow exhumation during Middle to Late Miocene, followed by acceleration during Plio-Pleistocene. The activity along the Panjal Thrust (PT)/Main Central Thrust (MCT) in this region ceased at ~ 15 Ma, while tectonic activity along the Main Boundary Thrust (MBT) started prior to ~ 10 Ma. Tilting of topography due to activation of MBT controls the exhumation pattern of Dalhousie Granite during Middle to Late Miocene. Correlation among structure, topographic pattern and thermochronometric ages indicates interplay between tectonics and erosion controlled  exhumation along the mountain front. The fast exhumation rates since Pliocene are synchronous with intensification of the Asian monsoon and suggest a causal link between erosion and climate variation for evolution of the landscape.

What is heartening to see is that research like this requiring sophisticated geochemical analysis is coming out of regional Universities like Kurukshetra and Ambala.  Ten to fifteen years ago, a paper like this would be most likely published from labs of just a few elite institutions in India, with the analysis being done by a Western collaborator in a U.S. or European University. That is still the case with many research programs, where Indian geologists seek collaboration to access instrumentation not easily available in India, but with more money being available through Science and Technology Ministry grants, the research environment may be slowly changing.

A while ago I had an email exchange with a senior geology faculty where I ventured to ask him if my perception was correct that many really large research projects on Himalayan tectonics involve primarily Western researchers with a solitary India based colleague. He agreed somewhat, but opined that this was not because there is a lack of research funding potentially available to address Himalayan geology, but rather funding towards subjects like climate change, groundwater, Quaternary processes and environmental geology has increased and many researchers today prefer more theoretical and lab based work than difficult high altitude Himalayan fieldwork!

A bit unkind I thought :).. but this paper is a departure from such slack attitudes if they really do exist!

Going Hiking In Pangaean India

I have been thinking unhappy thoughts ever since I came upon this map of Pangaea with today's political boundaries overlaid on it.

Where would I have going hiking in Pangaean India?

1) The Himalayas, crown jewel of hikers arose begining early Cenozoic and reached their bewitching heights in the mid Miocene -Pliocene.

2) The Western Ghats, the poor man's Himalayas, arose in the Cenozoic too after the breakup of India from Madagascar (88 mya) and Seychelles (66 mya). They represent heights reached due to an initial high rift flank, amplified by denudational isostacy and crustal upwarp due to intraplate stresses propagated southwards from the Himalayan collisional zone.

3) The Eastern Ghats, a line of mountains parallel to the east coast of India also arose much later than Pangaea forming during and after the breakup of India with Antarctica about 130 mya.

4) The Vindhyan and Satpura mountains in central India are composed of Proterozoic and late Paleozoic -Mesozoic rocks resp. but much of today's relief also represents topography rejuvenated since mid Cenozoic, ultimately related to stresses from the Himalayan collision.

5) The Aravalli mountains in Rajasthan is a Proterozoic orogenic belt but probably didn't have much topography during Pangaean times.

For most of the time period from Cambrian to Carboniferous the Indian shield was a tectonically stable area. Pangaean India was a place where a vast peneplain had developed over most of the Indian shield in response to long lasting denudation. This cycle of deep weathering and erosion lasting tens to a hundred million years would have stripped and ultimately flattened the Aravalli and south Indian orogenic mountains, exposing mountain roots and lower crustal rocks like granulites and charnokites. The result would have been a subdued topography with a flat horizon as far as the eye can see, occasionally interrupted by gentle rolling hillocks made up of more resistant lithologies like quartzites and charnokites. 

Subsequent episodes of uplift and erosion has destroyed this flat topographic surface from all over the Indian peninsular region but some remnants of this peneplain termed the Gondwana surface can be observed at around 2400 m mantling the granulites of south India around the popular hill stations of Ooty and Kodaikanal in the Nilgiri mountains.  It has been lifted to these heights during Cenozoic uplift of the Western Ghats.

The only places of considerable relief would have been the emerging Permo-Triassic rift basins of the Satpura, Pranhita Godavari and Mahanadi belts in the central and eastern part of  country. A horst graben structure would have resulting in a ridge and flat valley type topography. Not particularly attractive for a challenging hike. Plus it was really swampy and hot in those rift basins.

I wouldn't have liked to live in Pangaean India. I am too spoilt by views like this one, which appeared only in the Miocene.

Photo: Nanda Devi and Namik Glacier in the Kumaon Himalayas, November 2012.

An Ecologist's Passionate Plea To Protect The Western Ghats

In March 2010 the Ministry of Environment and Forest, India,  constituted the Western Ghat Ecology Expert Panel to study and recommend protection for the ecologically sensitive Western Ghat region. The panel was headed by Dr. Madhav Gadgil. It came up with the idea of a  graded approach to protection, essentially sequestering some areas from any mining and other development,  limited development in other areas and so on. Central to their philosophy of protection was that the voice of the local people be heard. All decisions regarding development would be taken only after extensive consultations with the people of the villages being affected by various developmental projects.

The Indian government, both Central and various State bodies did not like this plan. They undertook what is becoming a depressingly familiar route. They constituted another committee termed "High Level Working Group" to relook the original recommendations. Predictably, the new report by this high level group guarantees protection for a much smaller region of the Western Ghats and does not see a role for village level committees to participate in decisions regards protection and development.

Dr. Madhav Gadgil has come out strongly against this new report headed by Dr. K. Kasturirangan and has written an open letter to him in The Hindu:

An excerpt-

India’s cultural landscape harbours many valuable elements of biodiversity. Fully 75 per cent of the population of lion-tailed macaque, a monkey species confined to the Western Ghats, thrives in the cultural landscape of tea gardens. I live in the city of Pune and scattered in my locality are a large number of banyan, peepal and gular trees; trees that belong to genus Ficus, celebrated in modern ecology as a keystone resource that sustains a wide variety of other species. Through the night I hear peacocks calling, and when I get up and go to the terrace I see them dancing.

It is our people, rooted in India’s strong cultural traditions of respect for nature, who have venerated and protected the sacred groves, the Ficus trees, the monkeys and the peafowl.

Apparently, all this is to be snuffed out. It reminds me of Francis Buchanan, an avowed agent of British imperialism, who wrote in 1801 that India’s sacred groves were merely a contrivance to prevent the East India Company from claiming its rightful property.

It would appear that we are now more British than the British and are asserting that a nature-friendly approach in the cultural landscape is merely a contrivance to prevent the rich and powerful of the country and of the globalised world from taking over all lands and waters to exploit and pollute as they wish while pursuing lawless, jobless economic growth. It is astonishing that your report strongly endorses such an approach. Reality is indeed stranger than we can suppose!

And here is another article by Dr. Gadgil and Ligia Noronha on the subversion of the Gadgil report. 

 

Sunday Humor: A Professor's Prayer

Another classic from PHD comics: