As Colourful As It Gets

When I was a kid, the only thing I was good at (and my mum will probably stand testimony to that) was smearing colour all over me and anything around me. As children, everyone of us was fascinated by that chart on the last page of our drawing books which showed us what we could obtain if we mixed the basic colours. (if you don't remember, have a look here : http://www.siliconimaging.com/ARTICLES/CMOS%20PRIMER/image006.gif )

All in all, most of us retain this childish allure for anything that exhibits a multitude of colour. There are very few examples in nature that are as captivating when it comes to this. One among them are minerals. And, as if to prove me right, I was noticing my classmates when our professor was teaching us the reasons behind these wonderfully coloured crystals. All their eyes lit up when a gemstone was shown on the screen and when the professor actually handed out some from his collection, everyone forgot that there was a lecture going on. (believe me the stone hadn't even gone back into the paper packet and most of the class was already half-asleep.)

Now, you find a variety of colours in minerals. Thousands of hues and shades of all possible colours are seen. Over time, a geologist sees so many minerals that nothing amazes him. And there is nothing more omnipresent than the mineral that makes up the sandy beaches that mark our shores - quartz.

Quartz is such a mineral that does not evoke any curiosity. White and transparent - there is hardly anything that is interesting. But, sometimes even this oft forgotten member of the mineral world conjures up something that makes us sit up and notice it. Purple amethysts and yellow citrines (pictured below) serve to remind us not to write anyone off so easily.

Yes, agreed, crystals are pretty but there is a cryptocrystalline variety of quartz that is sometimes as beautiful as the ones above. And, if you need proof, have a look below. Believe it or not, these are just some of the extraordinary range of colours that can be exhibited.

(Photo credit : David Englund; http://www.davidenglundphotography.com/)

(Photo credit : David Englund; http://www.davidenglundphotography.com/)

Known as agate, these beautiful mineral specimens are classically associated with volcanic rocks. They are generally found in nodules or hollow cavities in volcanic rocks formed by volatiles previously present in the lava and it is their monochromatic or coloured bandings that are their most striking features. Now, the burning question is - how do these bands form or more precisely, how are agates formed?

It all begins with a cavity in the rock, preferably in a volcanic rock. Water containing SiO2 (silica - the composition of quartz) percolates through these holes and the mineral starts to crystallize. In the initial stages, the concentration is high and the silica in the solution is in a polymerized state. This is supposed to lead to rapid crystallization in the form of fibrous crystals which nucleate on the wall and grow inwards. This makes the first layer very fine grained. It is followed by a comparatively coarser layer of quartz. However, the solution is an open system with continuous variation in the solute and the solvent due to external sources of water and silica. Thus, when the concentration gets high enough again, the silica crystallizes rapidly and voila! You have your peculiar bandings, all the result of  these periodic changes in the concentration of the silica in the fluid.

And, the vivid colours that make agates so valuable and appealing to the eye are the result of trace impurities in the form of transition metals. Iron, manganese, copper are some of the ions that impart these colours to them. Iron oxides make the bands go red, brown, black or green depending on the various factors like oxidation state etc. Oxides of manganese colour the layers pink, violet or black. There are various combinations of these ions that bring about the other shades that are seen.

Sometimes, however, the concentrations don't vary as time passes and the silica keeps getting depleted as the crystalliztion proceeds inwards. This results in progressively coarser quartz grains towards the centre and we have what we call a geode (they are some impressive freaks of nature - fully formed crystals enclosed in a rock. Do check them out!)

Notice how the layers become coarser towards the centre.
(Photo credit : David Englund; http://www.davidenglundphotography.com/)

But this is not the place to be talking about geodes. For now, focus on the hypnotic beauty of the agates. I'll be back soon with some other stuff...

The List : Krem Liat Prah

What was your first reaction when you read the title? Is this guy talking about a Chinese movie on his list? Or maybe, it was : he has lost it after just five posts. Sadly, I am still sane and this is another awesome addition to The List.

Krem Liat Prah is the largest natural cave in India. It is situated in the Shnongrim Ridge of the Jaintia Hills district in the state of Meghalaya, northeast India. Currently being surveyed in the Abode of the Clouds Expedition, its length is approximately 25 kms and more is being added to that as connecting tunnels are discovered. It is carved out of limestone and contains some spectacular caverns, one of which is called the Aircraft Hangar. (Well, they must have named it that for a reason, no guesses why!)

Krem Liat Prah   (picture courtesy: Hugh Penney; flickr.com)

And that's not it. Liat Prah is not the only cave in the area. There are around 150 other caves, not as large as Liat Prah but equally spectacular.

So, now that you are all in awe and amazed at the beauty and extent of the cave, let's get a little geological insight into it as well. How are these formed? And why here of all places? The reason is simple - I mentioned it before - limestone.

Limestone is a sedimentary rock composed primarily of calcium carbonate. CaCO3 is one mineral which dissolves so easily that I sometimes wonder how it even forms huge massive rock deposits! So, as groundwater makes its way through these rocks, it carves out a path and over a period of time enlarges them enough to create these marvels. And, sure enough, the Jaintia Hills, where these caves are found, are composed of  limestones belonging to the Prang formation of the Sylhet Group. Massive, fossiliferous and grey, these limestones are from the Eocene Period (approximately 48 MYA to 34 MYA) and form a thick succession which is perfect for the formation of an underground network.


Going by the extra ordinary proportions of Krem Liat Prah, it is a surprise it has remained hidden for so long. Not anymore. Its wait in the shadows ends now. Time for some spelunking!

So Where Are The Comments?

First of all, I would like to apologize for the lack of posts. I've been quite busy with - midterms, competitions and above all, journal completion. But don't you worry. I've got a lot of stuff lined up for the next few weeks. I'll put it up soon enough for you to enjoy - that's assuming you enjoy reading my posts.

So, that brings me to my next point. At the start of this blog, my first post had emphasized on the fact that I am doing this to try and create a network of young geologists like us. But I do not see that happening. I mean, if you really do enjoy reading my posts (again, just assuming) I guess Blogger would have told me to get out because the comments section was getting flooded with, well, comments.

I do not ask you to start a conversation everytime I post on the blog. But what I ask of you is that if you really think that this is a good initiative, help me make this better. Help me reach out to the thousands of geologists who never get a chance to speak out. It is only with your feedback that I can improve or else I'll just keep posting whatever I like. And that really doesn't serve any purpose at all.

If you are confused on how you can contribute, here are some pointers - 

YOU COULD

• comment on the post and share it (well, sorry, that was a little obvious).
• send me written articles about something interesting that you found and that you would like to share with us. My email id is right beside the photo of the handsome guy you see to your left.
• suggest a topic on which you would like a post either by mentioning it in a comment or via email.
• if you know me personally, I would like you to let your friends know that I am an awesome guy and that I do not put emails regarding any query into my spam folder.

These are just some of the ways you could help out (feel free to innovate and find out new ways to spread the word).

So, that's all for now. Keep your eyes peeled for the expected posts.

Peace Out.

The List : Balancing Rock of Jabalpur

Let's start off with a weird entry...

Balancing rocks are known worldwide for their gravity defying appearance (and also partly because everyone likes to take a picture with them trying to push it off). Now as the name suggests, they mostly occur as large boulders (some as big as buses) resting on other rocks. The most astonishing part about these features though is that they are naturally occurring. The term however is not technically sound; not all 'balancing' rocks are 'balancing' themselves but are actually firmly attached to the rock below. But who cares right? As long as they don't topple over on you while you are busy capturing what would probably end up as your Facebook profile picture.

Now, some of these are so famous that just a picture of the feature can lead you to naming the place where it has been clicked.

The one in Utah, US, is by far the most popular among these. The total height of ‘Balanced Rock’, as it’s called, is about 39 m, with the balancing rock rising 16.75 m above the base (The big rock on top is the size of three school buses).

Balanced Rock, Utah (photo credits : Jean-Christophe Benoist)

Then, there’s the one situated at Kjeragbolten, Norway. Suspended at a height of 984 metres, it takes a lot of courage to go stand atop that. Have a look and decide for yourself.

Kjeragbolten, Norway

However, what is not known is that we have our own stuntmen in India. In Jabalpur, Madhya Pradesh. Formed as a result of erosion of volcanic rocks, these are said to have survived an earthquake of magnitude 6.5 on the Richter Scale. Given below are some pictures that show how precarious it is. Agreed, it is not as spectacular as some of its more distinguished siblings but hey, it's a wonder of nature too!

                                     

Balancing Rocks at Jabalpur (source : http://www.jabalpurtourismpc.com)

Don't you agree that this is worth a visit? There are many such hidden gems that are waiting to be discovered. But that’s it for The List now. Got to study. As they say, got to maintain the right ‘balance’ in life.

The List

How many of you have heard of the Grand Canyon? If I had asked you to raise your hand if you had heard of it, 99% of the hands would have gone up (The 1% is for those who were probably scratching something or gorging on some snack while reading this). Now, if I mentioned the Yellowstone National Park (last seen in the geologically horrible movie, 2012) or the Meteor Crater in Arizona, less hands would shoot up but it is still quite popular.

But what if I asked you where we find fossilized dinosaur eggs in India? Stumped right? It is mildly amusing and very surprising that we do not have much knowledge of geological sites that exist right in our own backyard. Not that I do not understand the importance and significance of the above mentioned sites. It's just that maybe it's our own fault when we dream of going to these world-famous sites and crib about it when we can't (money issues!) when all we have to do is hop on a bus or a train and tour our own country which has no shortage of similar wonders.

So, for the next few days, I am going to be mentioning some of the sites that I happened to come upon in my quest to find a cheap and fun way to satisfy my geological curiosity. Do tell me about any sites that you would want to have known or that you would have heard of and would like to visit.

Let's begin The List....

Finally, A Park For Geologists!

Amit Vikram (Banaras Hindu University)

Hi everyone.

I thought of sharing something that all of you must know. It's a matter of  great pride and privilege that within the geographical boundaries of our country lies a place called the Salkhan Fossil Park. As part of our 2nd year B.Sc. field work, we paid a visit to this site to study fossil stromatolites.

It's a large area inside the Kaimur Wildlife Sanctuary, Sonbhadra, Uttar Pradesh. The preservation is really exceptional and it is now internationally recognized as one of the best preserved sites to study algal stromatolites. About 1400 million years old, belonging to the Proterozoic Eon, they occur as rings on the rocks telling a story back in time.

And to add to all this, this park is 3 times larger than the Yellowstone National Park! Now, that is something...


Blogger's note:

It does seem an interesting location. The link to the site where its location and accessibility are mentioned is: http://www.easternuptourism.com/Salkhan-Fossils-Park.jsp. 

Spread the word. There's an exclusive park for geologists.

Who's Fault Is It?

In our final year of B.Sc., we had been to Bhuj in the state of Gujarat for our annual field trip. We were supposed to be heading for Malvan in the southern part of Maharashtra. But some crazy circumstances forced us to head north into the dry region (most of us know what I mean by dry region :p) of Kutch. It was unexplored and uncharted territory. Our professors were relying on past experiences and reference materials. It very often happened that we would stumble upon something completely new and start breaking our heads over the mystery of the outcrop. It was during one of these exploratory trips that our professor realized that there was something weird across the road that ran in front of our lodging.

So, one fine morning (half asleep actually), we walked up this small hillock. Once we were at the top, our professor pointed out this feature to us.

Naturally, we were confused. We did notice that long linear mark on the surface. But we had no idea what it could possible be. Lots of options ran through our minds. A dike maybe? Or was it a fault? It could also be some thin rock strata of a different composition. With these thoughts, we started our investigation.

We began with the thin zone marked in red in the pic above. The material within that was definitely fine grained. Extremely fine, to the point that it felt like it was crushed. It was highly jointed, with sets of joints running perpendicular to the length of the zone as well parallel to it. As expected, there was intense venation around it.

We cast our attention to the surrounding area. We noticed a reddish ferruginous sandstone bed on one side. But,no matter where we searched we couldn't find the corresponding outcrop on the other side. This eliminated a lot of our guesses and we had narrowed it down to one option. It was definitely a fault. But we needed proof. And that we got.

Small striations (or as we know them: slickensides) were noticed by someone on the rocks on the supposedly upthrown block. And as a bonus, we got some minor faults at the top of the hill. So, that was it then. Mystery solved.

It was our fault. :P

P.S. The road is called the Bhuj Airport Road and the fault is located right opposite to Navchetna Lodge. So, if you ever feel like, you can surely go. Maybe you'll find a pencil or something which one of us left behind.

Getting Started...

Almost a week back, I started the next two years of my academic life (it is getting boring now!) in IIT Bombay. It took a crazy amount of hard work and mind numbing hours with books I would rather not start naming here. But I made it. I was looking forward to making new friends, getting to know people from different places and backgrounds. Know their story. Try to figure out if I had anything in common with the twenty nine other faces in that classroom. But I did not realize that it would be this hard.

I know it is too early to draw out conclusions and call this a doomed cause. But maybe something could be done to make this transition easier. Something that will make budding geologists recognize the talents of their peers spread all across the country. Why, just the other day, I came to know that there are approximately 500 departments dealing specifically in Earth Sciences. (Whoa!)

Now that is a number that is both amazing and surprising in equal amounts. Amazing because I never knew these many institutions catering to this field even existed in India. And surprising that I hadn't heard about them before. Where are the students of these places? More than that, how are they? Are they brilliant geologists? Expert field or lab researchers? Do they have the same interest as all the students I have encountered till now? Or are they different? If so, how? So many questions...

I am beginning to understand some of the answers to these questions as I sit and look around in my current class in IIT. I see people with the same exact doubts that go through my mind. People making the same sad geology jokes that are starting to get old. (I don't think that's gneiss, we must do something about this schist) I see the same excitement when talk of field work crops up. Maybe we are not so diverse after all. Of course, we all have our own unique capabilites, unique quirks and point of views. But the basic fabric (ah! a geology term finally!) that makes us geologists remains the same.

So, here I am. I think what we, the students of geology, need is a platform. A place to share our experience. Let others know about ourselves. Let out our thoughts and peek into the mind of like-minded individuals. Learn, teach, understand, grow...

P.S.

It will be a momentous task I know. It is not going to easy to get going. But I am sure that with your support, this will seem as easy learning the names in Indian Stratigraphy of the three types of rocks.