Sunday, June 26, 2011

Natural Gas: Expectations Fulfilled?

Couple of articles on the expectations surrounding natural gas -

Over at the Barrel, John Kingston points to an article by Mriganka Jaipuriyar on the delays and production problems at India's giant natural gas field KG-D6 in the east coast Krishna Godavari basin.

Across the continents, Ian Urbina of the New York Times dives into industry memos and internal emails expressing skepticism about the potential of shale gas in the U.S to remain a vast and profitable source of energy in the future. 

Friday, June 24, 2011

What's Your Favorite Geology Word: Primarrumpf

Honestly.. I don't have a favorite word, but Primarrumpf has stuck in my mind for sometime.

I posted it as a geology quiz a couple of years ago. It's a german word for the oldest preserved planation surface or peneplain on the continent. In the Indian context the Primarrumpf developed during a long period of tectonic stability through the late Paleozoic and Mesozoic, wherein the Precambrian cratonic shield was eroded to a low relief landscape or peneplain. Its often referred to as the Gondwana surface.

A friend who is not a geologist emailed me at that time and told me that she thought Primarrumpf meant a primate's rump..  not too far off since rumpf means body or torso!

so the happy memories :)

This posting is in response to Accretionary Wedge #35 hosted by Georneys.

Monday, June 20, 2011

Paper On Himalayan Mineral Retracted By Geology

I had blogged a while back about a paper in Geology by Dr. Anju Pandey and colleagues on the presence of the mineral majorite from the Ladakh region of the Himalayas. Majorite is a mineral stable under very high pressures and its presence in a rock known as eclogite implied that the Indian plate during its collision with the Asian plate had subducted to great depths perhaps as deep as 200 km  and then been brought up to the surface relatively rapidly by thrust faults and erosional unroofing.

Sigh... turns out Geology has retracted that paper because metamorphic petrologists pointed out that a key photograph in the paper showing majorite has been plagiarized from an older paper published in 1998 from a Norwegian rock sample . The Himalayan sample.. the thin section from which the microphotograph of majorite was supposed to have been taken is missing. Which means, unless the original sample is found or another sample from the field area is taken and the analysis replicated, the results published in the paper by Pandey  are suspect.

Retraction Watch has the details of what went wrong and the article is worth reading. It will give readers an idea of how large collaborative projects spanning continents are put together and culminate in a scientific paper often with different contributors not knowing what is going on with a different component of the study.

Coauthor Mary Leech for example worked with Dr. Pandey on the tectonic implications of the mineral majorite but she did not actually see the sample.  Dr. Pandey only provided photographs of the sample and Mary Leech trusted the photographs in front of her. Shouldn't she have insisted that she take a look at the sample itself? Another co-author Preeti Singh had originally worked on the sample and had not found any evidence of majorite. Did she not look more closely at Dr. Pandey's  new results to figure out how she had missed noticing the mineral earlier? Dr. Pandey looks to be the one most in trouble, but what are the responsibilities of the co-authors?

Isn't making sure that the primary data actually exists before agreeing to be co-author one of them?

Tip: Highly Allochthonous

Tuesday, June 14, 2011

Earliest Examples Of Biomineralization

On Wired Science Brandon Keim summarizes the discovery of phosphatic biomineralization in Neo-Proterozoic protists, published in the June issue of Geology.

The microfossils were preserved in 750 million year old strata of the Fifteenmile Group in Yukon Territory, Canada. This makes it one of the earliest examples in eukaryotes of the ability to precipitate minerals from sea water and use them as structural support or as a protective casing around soft tissue.

In marine organisms, biomineralization has evolved independently many times in different eukaryotic groups. Preserved instances of biomineralization from the Neo-Proterozoic and the earliest Cambrian are of unicellular organisms like protists using mostly phosphatic minerals like apatite. That changed with the evolution of larger complex metazoans by early mid Cambrian times. These creatures preferred calcium carbonate in the form of either aragonite or calcite to build their skeletons.

This might reflect changing sea water chemistry, the increasing saturation of the Cambrian shallow water areas in calcium carbonate and the decreasing availability of phosphorus or it might reflect inherent energy efficiencies in large skeletal construction. Perhaps calcium carbonate molecules are easier to assemble into the larger edifices required than calcium phosphate is..that's just my speculation..

Brandon Keim ends his article quite evocatively:

Of course, predators eventually developed their own biomineralization strategies, as did other algae. Eventually it became ubiquitous in the marine world, to the point where what we now call limestone is simply a composite of microscopic fossil seashells. It’s also the primary ingredient in concrete. Their shells have become our own.

Thursday, June 9, 2011

Will There Be Any Water Left On Earth If ..

...Religious fundamentalists keep drinking from the well of stupidity?

..don't know the original source..I got it via - Pharyngula

A Primer On Homo Sapiens

On BioMed Central Mason Liang and Rasmus Nielsen have an informative Q & A on recent advances in our understanding of the evolutionary origins of Homo sapiens.

Q & A: Who is H. sapiens really and how do we know?

Monday, June 6, 2011

Male Australopithecines Were Not House Husbands

Evolution research is routinely misreported in the Indian media and I had a chuckle when I read this summary published in the Times of India:

Early women worked, men stayed home:

Early species of cavemen who roamed the earth two million years ago did not go to work but stayed at home and looked after the kids, while their females earned bread for the family, says a new research.

Scientists at the University of Oxford arrived at the conclusion by using new techniques to extract information from the fossilized teeth of our ancient human ancestors.  the conclusion scientists reached after studying strontium isotope content of fossilized teeth from two species of ancient hominins from South Africa was not about the daily division of labor between the sexes but about another aspect of their social life.

Different rock types like granites, basalts, dolomites have characteristic strontium isotope signatures. Plants take up strontium from bedrock and derived soil. Animals eat those plants and the strontium ends up in the enamel of their teeth. Analyzing the strontium isotope values of ancient mineralized teeth can help identify the geological substrate on which ancient animals, in this case ancient hominins lived. 

Scientists tested 19 teeth from the Sterkfontein and Swartkrans cave sites in South Africa dating from about 2.4 to 1.7 million years ago from two hominin species, Australopithecus africanus and Paranthropus robustus. These samples were preserved in a dolomite substrate.

The fragmentary body fossil record of these two species hints at a considerable degree of sexual dimorphism i.e. the females were significantly smaller in size than the males. When the the teeth were analyzed scientists found that a large proportion of smaller teeth likely belonging to females show strontium isotope values not reflecting the local landscape i.e. not reflecting the dolomite substrate, suggesting that many females had come into this area from outside the geological terrain where these sampled populations lived. On the other hand,  a large proportion of teeth likely belonging to males reflected local geology.

So, the inferences drawn from the strontium isotope values were (a) in these ancient hominins, females on reaching maturity dispersed away from their natal or family group and joined another group while males remained with their group and did not migrate elsewhere, and (b) male hominins had small home ranges i.e. they stayed most of their lives in a relatively small area.

Many social animals show a pattern of either the females or males leaving their family group on maturity, a behavior that may have evolved to minimize inbreeding. The social pattern of female dispersal inferred in these ancient hominins is similar to that seen in chimpanzees and many modern human societies as well.

Social behavior does not fossilize. Tools made by ancient humans is one way to understand certain aspects of behavior. In this case the scientists linked a physiological mechanism - the uptake through food and localization of strontium in teeth - to social behavior.

I thought it is a smart piece of forensic science.. even though it didn't tell us whether or not those ancient males were house husbands!

Science Daily summary.