Wednesday, September 26, 2012

Trekking Again In The Open Basalt Landscapes

Mid to late 1600's Maharashtra was a time of war between the local Marathas led by Shivaji and the Sultanate of Bijapur and later with the Mughals. On many steep basalt escarpments were forts that the Marathas controlled and used as strategic vantage points for launching guerrilla attacks on the enemy.

There are many important forts near Pune. Two are seen in the interactive Google imagery below.


View Larger Map

Rajgad was the home and capital of Shivaji for quite some time. A ridge which you can trace west of Rajgad meets Torna fort which was the first fort captured by Shivaji as he launched his resistance against the Bijapur Sultanate. And north north east of Rajgad is Sinhagad, site of one of the most famous night battles of 1600's Maharashtra. To give you a geographic mooring, north east of Sinhagad is the city of Pune.

You can zoom in to locate the plateaus on which the forts are built. The Deccan volcanic pile is made up of lava flows of different physical properties. Some flows are softer and weather into gentler slopes. They may be overlain by harder compact flows that form escarpments and mesas. The forts were built on top of thick compact basalt flows.

I went to Rajgad last Saturday for a one day trek. It is about a two hour climb which offers some great views of the valleys and surrounding countryside.

I'm facing south, looking towards the imposing Rajgad, altitude 4324 feet ASL.


On route a classic view of rural India.


Getting closer; looking onwards from a grassy ridge.


Mountain path with the forts ramparts visible through the trees.


The steep climb begins. The last 200 feet or so is an abrupt change in slope as the escarpment starts.


The topmost compact basalt and a rampart.


That's me trying negotiating the final few steps.


Inside!


Perched aquifers form the water supply of the fort. A perched aquifer is a local aquifer which is underlain by a confining impermeable layer and occurs isolated above the regional water table usually on a mountain top. The regional water table is the groundwater table in the surrounding plains and valleys. Along the slopes of the mountains the aquifer will discharge groundwater as springs. 


A spectacular view of the escarpments and the topmost ramparts.


Countryside is still lush after the monsoons. Springs on the mountain slopes usually begin drying out by February to March, some even earlier. So, water management in the valley in the form of small surface reservoirs (in the center) and groundwater recharging structures is really important to sustain agriculture and livelihoods until the rains come back in June.


 Until next time...

Monday, September 24, 2012

The Early History Of Coal Mining In India

India's coal reserves come from the Permian-Early Mesozoic continental rift basins situated in eastern India.

Coalgate is making headline news almost every day in India but Vikram Doctor on his blog On My Plate writes about the many shenanigans of early coal mining:

It was an American who first tried to develop systematic coal mining in India. Suetonius Grant Heatly was born in Newport, Rhode Island, but during the American Revolution his family was loyal to the British, and fled to Britain. Heatly joined the East India Company in 1766, possibly because Lord Cornwallis, the Governor-General of India, had earlier headed the losing British forces in America, and was expected to favour the British loyalists of that conflict. Heatly became Collector of Chotanagpur and Palamu (now part of Jharkhand). And it was while travelling here that he noticed local tribal people burning coal fires, Jha notes that the seams are found exposed on the surface in these areas. This was not far from the Damodar river and Grant, along with another East Indian man, John Sumner, realised that coal could be mined and floated down the river to Calcutta.

Grant and Sumner teamed up to get Company permission to mine coal. Yet their first application, in 1770, was rejected. Jha suggests this was because the Company was unsure of its rights of mineral extraction and, in any case, preferred to use its monopoly position to import minerals from Britain and sell them at high prices in India. Also, they were apprehensive about Indians learning how to use these minerals: “They even feared that once the natives acquired the art of smelting metals and the manner of casting them into cannon shot and shells that they would become masters of the latter.”

There were many early attempts in the late 1700's to early 1800's to mine coal but these ventures were never profitable due to hazardous mining conditions, legal disputes over land rights, poor transport and the better quality of imported English coal.  Then later in the 1800's demand reached a point whereby mining Indian coal became economic again. The East India Company backed English entrepreneurs who leased land from local rulers.  There were Indian businessman too. Among them who made a fortune in coal was Dwarkanath Tagore, grandfather of one of the most famous Indian poet writers Rabindranath Tagore. 

Tirthankar Roy in his book The East India Company describes the precarious balance the Company had to maintain between monopoly and allowing its agents and other merchants to conduct private trade in competition with the Company. Vikram Doctor's article brings out this aspect of  Company business life quite well along with the ruthless opportunism of these early coal entrepreneurs.

Read more here.

Monday, September 17, 2012

Why Is It Hard To Classify Archaeopteryx?

For the last few days I have had noticeable traffic to my blog via the search term " Why is it hard to classify Archaeopteryx?". And all of it from the United Kingdom! Maybe there is a college essay competition going on there on fossils and evolution..?

Coincidentally, I wrote a post more than two years ago on Archaeopteryx in response to a new analysis of Archaeopteryx bone growth which cast doubt on whether Archaeopteryx was an early bird. More recently, Xu et.al using a wider selection of character traits suggested that Archaeopteryx is not a basal bird i.e. it is not an early representative of the lineage of birds but rather may belong to a different now extinct branch of feathered dinosaurs.  So there is genuine uncertainty on how to classify Archaeopteryx.

I'm reproducing the post below with some new additional comments. Image below sourced from  Wikimedia Commons:

How birdlike was Archaeopteryx?

Beak - Yes

Feathers - Yes
Wishbone - Yes

Growth pattern of blood vessels - Not quite there yet


By comparing the structure of the bone of Archaeopteryx  with modern birds and fossil dinosaurs, researchers found out the growth pattern of blood vessels in Archaeopteryx was more like dinosaurs than modern birds. Archaeopteryx individuals seem to have taken a longer time to mature than modern birds do.


Archaeopteryx lived about 150 million years ago and is the earliest bird-like creature to have been found yet.  A younger bird-like fossil -
Ichthyornis dispar - dated about 94 million years ago shows several characteristics of quick growth, giving us an idea of the timing of the various changes in morphology and physiology that were taking place within the Maniraptor dinosaurian clade as they evolved  characteristics that are recognized as bird-like.

By the way this is not some earth shattering find. The basic relationship that  small carnivorous dinosaurs evolved into birds still holds. But the study highlights how difficult categorizing a creature which is a composite of ancestral and derived traits can be.


It doesn't matter in the larger view if Archaeopteryx is classified as a dinosaur or a bird. The value is in demonstrating that evolution of a complex suite of characters takes place in fits and starts, some features evolve earlier than others preserving the historical trajectories that major transitions in evolution have taken.


Go
here for the lighter version.

Additional comments: Recently, South Korea under pressure from creationist groups was mulling excising mentions of Archaeopteryx from science textbooks because the uncertainty regarding its relationship to birds meant according to creationists that the theory of evolution is an inadequate theory to answering questions about the history of life and to the problem of the evolution of birds. Thankfully better sense has prevailed and Archaeopteryx will continue to have a place in South Korean science education.

As evolutionary biologist Ryan Gregory recently pointed out, there are many aspects to evolution. There is evolution as a fact, evolution as a mechanism, and evolution as a path. Archaeopteryx not being a bird does not in any way threaten the factual basis of evolution, nor does it undermine natural selection or random genetic drift as the principle mechanisms of evolution. Its taxonomic status is a specific hypothesis about how two groups of organisms are related, i.e. evolution as a path. This aspect of evolution is concerned with the historical patterns of life, such as, when did a particular lineage originate, how are lineages related, do species originate geologically suddenly and then show almost no morphological change during their lifetime.

Was Archaeopteryx an early bird is a question of historical detail.  That initial assessment could turn out to be wrong. That does not mean that birds did not evolve but instead were spontaneously created as some creationists would insinuate. Rather, it means that our understanding about one particular ancestor descendant relationship is incomplete. It means that we don't yet have enough data to reconstruct with confidence the unfolding of one particular historical pathway of life.

Wednesday, September 12, 2012

Another Good Writer In The Geology Blogosphere

Dana Hunter is good, but we have another writer in the geoblogosphere:

On a corner in the road, at the entrance to the small village of Churchill in the English Cotswold Hills, is a small monument that seems out of place in its sleepy, pastoral surroundings. It is made from a rough-hewn, locally quarried limestone, which succumbs to the gentle Oxfordshire climate by a modest growth of encrustations of lichen and moss. Turning the corner, one sees an impressive gothic church set within a neat low stone wall, with its steeples reaching skywards, in perfect architectural proportions to itself, but oversized relative to the settlement that it serves, as if history had abandoned it, consigned it as a picturesque relic. There must be many stories to be told about this small village. Only one of them is that an inconspicuous child was born here of a blacksmith father in 1769. His name was William Smith; he is known as the ‘Father of English Geology’ and he drew the ‘Map that Changed the World’[1].

That was Prof. Philip Allen who writes Earth-Literally blog. He comments on a meeting he recently attended on the theme of Strata and Time and where the discussions ranged from stratigraphic completeness to cyclicity to sediment budget and fluxes..

 Enjoyable and educational.

Tuesday, September 11, 2012

Existential Awareness In Gorillas

We always knew that great apes were smart and thoughtful creatures, but they continue to surprise in terms of just how human-like they really are. Using some innovative techniques like euthanizing a pet cat and other visual cues, researchers from Tulane University Louisiana have recently taught Quigley a western lowland Gorilla that he - just like every other living creature - will die one day. Quigley, after a few initial panic attacks soon came to terms with his own mortality. 

A report from the reliable Onion.


 
via WEIT

Thursday, September 6, 2012

Multiple Events Caused K-Pg Mass Extinction?

Tobin et.al. have published work on a K-Pg section from Antarctica. From the latest issue of Palaeogeography, Palaeoclimatology, Palaeoecology:

Although abundant evidence now exists for a massive bolide impact coincident with the Cretaceous–Paleogene (K–Pg) mass extinction event (~ 65.5 Ma), the relative importance of this impact as an extinction mechanism is still the subject of debate. On Seymour Island, Antarctic Peninsula, the L√≥pez de Bertodano Formation yields one of the most expanded K–Pg boundary sections known. Using a new chronology from magnetostratigraphy, and isotopic data from carbonate-secreting macrofauna, we present a high-resolution, high-latitude paleotemperature record spanning this time interval. We find two prominent warming events synchronous with the three main phases of Deccan Traps flood volcanism, and the onset of the second is contemporaneous with a local extinction that pre-dates the bolide impact. What has been termed the K–Pg extinction is potentially the sum of multiple, independent events, at least at high latitudes.

I don't have access to the paper so just some general thoughts.

Gerta Keller and colleagues have also challenged the theory that a single meteorite impact caused the mass extinction 65 mya. Except, their theory is that the bolide impact everyone is familiar with, which is the Chicxulub impact event in Yucatan Mexico took place about 300,000 thousand years before the peak Deccan volcanism. They base this on observations made on K-Pg boundary sections in Mexico and Texas and some work in India published in Journal of the Geological Society of India and Earth and Planetary Science Letters which support a link between Deccan volcanism and regional extinctions.

So, was the Chicxulub meteorite impact before the peak Deccan volcanism as Keller and colleagues say or was it 200,000- 300,000 thousand years after Deccan volcanism as this new paper by Tobin et. al. suggests. The famous iridium anomaly observed in many K-Pg boundary sections has been dated to after the main phase of Deccan volcanism indicating that there was a meteorite impact some time after peak volcanism.

Or were there two impacts with the Deccan volcanism sandwiched in between? It does seem that the single bullet theory for the K-Pg mass extinction is under serious threat.

Science Daily summary of Tobin et.al.' s paper

Sunday, September 2, 2012

Borlaug Award For Study Of Groundwater Use In West Bengal

It's good to see the vital role groundwater plays in Indian agriculture gain recognition. Aditi Mukherji with the International Water Management Institute has been awarded the Norman Borlaug award given by the World Food Prize Foundation for her work on access and usage of groundwater in agriculture in West Bengal.

From the Times of India interview with Aditi Mukherji:

West Bengal has one of the best agricultural electricity governance regimes in India. The majority of electricity pumps are metered and farmers pay high electricity bills, which in my opinion is a good thing. It sends the right price signal.

The real constraint was getting an electricity connection. We suggested removal of permits system in all blocks where the groundwater situation is safe. We also suggested rationalization of capital costs of initial electrification, but also recommended that metered tariffs must continue. The government has accepted most of these suggestions. In addition, it is deploying NREGA funds for excavation of ponds. That will help in groundwater recharge.


The prerequisite for a successful policy change in terms of immediate benefit to farmers as well as judicious use of groundwater was already in place in West Bengal. By prerequisite I mean good electricity governance. In the interview Ms. Mukherji mentions that Punjab, Haryana, Andhra Pradesh and Karnataka have 80% of pumps electrified, a high percentage achieved due to past populist policies of handing out free electricity to farmers. The consequence has been rampant over exploitation of groundwater (largely by richer farmers). To avoid over extraction of groundwater,  West Bengal had set up a blanket restrictive permit policy even for areas within the state that had abundant groundwater. This perversely affected poor and marginal farmers in West Bengal who would have benefited from access to groundwater.

She suggests her recommendations could also be extended to the eastern states of Assam and Bihar. Geological conditions there are right for making such a policy work in favor of small farmers. Aquifers are alluvial over large parts. Groundwater is easier to find and is available at shallow depths.