Mystery behind Krishna's butter ball - balancing boulder, Mahabalipuram

Balancing boulder, Mahabalipuram,Tamil Nadu. Alamy
 There are many places in world where the nature acts  like a fine artist and produces  a  myriad of  land forms  of different shapes and sizes. Some of them are  odd and unique and they are so impressive and awe-inspiring,  far above our imagination. They are the results of  ' continuous natural  process' involving water, wind and  weathering or otherwise  called geological processes, Such strange land forms are not created over night and they  require  several thousand years to more than a million years. The balancing rock near the historical site of Mahabalipuram is an interesting one.

In the historical town of  Mahabalipuram, close to Chennai in Tamil Nadu, stands  a gigantic boulder that is  6 meters high and 5 meters wide and weighs around 250 tons. What is often referred to here as Krishna's butter ball or Vaan Irai Kal in local parlance is actually a huge  balancing  boulder resting almost near the edge of an  45 degrees inclined plane.  What is special about this giant boulder made of granite? With a small base, it is balancing  precariously and  it has been in the same position for more than 1200 years. Though facing the vagaries of weather and climatic changes through ages, it  has not moved an inch from it original position  on the slope. 

The giant boulder stands in such a way that you must muster enough courage to stand or sit  on the downward side of the slope Because, the huge monolith rock boulder stands on a base of just four feet and it appears at any time it may slip down slope, hurtling  to the bottom. According to the Hindu mythology, when Krishna was stealing butter from the handi and eating it  in small balls, one of them might have fallen here. 

This mysterious geologic feature  has attracted lots of people daily to this spot  In the past Pallava King Narasimhavarman  (630-668 C.E).
Krishna's butter  ball. flat side shaped by weathering.TripAdvisor
too tried to move the boulder from its place, but it ended up in failure. Way back 1000 years ago, the great Chola King Rajarajan (builder of Thanjavur big temple) visited this place and was impressed by the balancing rock. This land form gave him inspiration to
make mud dolls called Thanjavur Thalaiyatti Bommai with half spherical base. Every time you make it fall, it returns to its original position because of smooth spherical base. Since the center of gravity shifts and adjusts so quickly, it never allows the doll to fall. 
Thanjavur doll, it'll never fall. Snapdeal

During the colonial period under the British Crown, Arthur Lawley (12 November 1860 – 14 June 1932)  served as the governor of Madras from March 1906  to November 1911 and on his visit to this place in 1908, he was  surprised about the massive size of the boulder and it gravity-defying position on the edge of the slope. He tried to dislodge the boulder by using seven jumbos. His attempt was just a futile one. 
Krishna's butter ball.

 Mushroom rock formation. Let's learn Geology -

fotrmation of mushroom rock or balancing rock SlideShare

 How is the huge boulder formed in this part of Mahabalipuram? How does it defy the law of gravity? These two  common questions pop up among the curious people which is quite natural. As for the formation of this boulder, it is likely it was caused by wind action - blasting of  sand, small particles of rock or broken pieces on a tall solid rock outcrop. The abrasive action at the bottom of the rock will be more vigorous .This slow and and continuous wind action over a long  period of time  may lead to the formation of a pedestal rock or mushroom rock. Further action over  years may lead to the collapse of the pedestal rock and the solid mass at top will come down and rest on the basement rock. Depending on the angle of gradient, it may move or remain stationary. Such wind erosion is common in desert or semi desert areas and normally such mushroom rocks are found among sedimentary rock formations  consisting of alternating hard and soft layers where the soft layers will get eroded easily leaving the hard layers to weather slowly. The hard layers have better resistance.

Regarding  Vaan Irai Kal at Mahabalipuram,  it is a monolith igneous rock called granite.  To form  and shape such a massive block  of rock in a hard rock terrain, it might take eons - a couple of million years. This particular rock and the surrounding outcrops that form the basement rock complex belong to  the
Mahabalipuram balancing rock or Vaan Irai Kal
Achaean group (shield area) whose geologic age is as old as the earth - roughly 3.5  to 4 billion years and  they have been in existence since the formation of the earth. A good example in Tamil Nadu is the rock fort complex at Tiruchirapally. The Uchchi Pilliyar temple is built on the Achaean rocks made mostly of granite and related rocks. Likewise one could see boulders of  hard rock in different shapes and sizes on the bus route between Villupuram and Tiruvanamalai, Tamil Nadu. They are caused by  normal weathering process - frost and root wedging plus action of wind. The combined  action breaks the massive boulders into smaller ones  that stand precariously.

So, my assumption is this boulder- Krishna Butter ball was formed due to Eolian process - continuous wind erosion coupled with normal weathering process that had acted on it over years far beyond our imagination. Flat face on the boulder is caused by the above processes.

As for its gravity-defying position: 1. The angle of inclination is not good enough to trigger a slide, 2. From the shape of boulder, it is clear, much of the weight is exerted on the base near the edge of the slope that gives stability. 3. The shift of center of gravity is within the safe limit something like a man standing on a slope when his body leaning toward the upper side.
Brimham Moor in North Yorkshire.

 Above image: Many curious rock formations are scattered over 50 acres on Brimham Moor in North Yorkshire, England.This will give you some idea about the action of wind on the boulder.

This balancing rock in the Garden of the Gods in Colorado Springs, Colo. USA.

The Garden of the Gods in Colorado Springs,
Above images: Very old sedimentary rock  called  steam boat rock.
Garden of the Gods is a public park located in Colorado Springs, Colorado, USA. It was designated a National Natural Landmark
 One of them is the Idol Rock precariously balanced on top of a smaller rock. The rocks eroded by water, glaciation and wind, have taken amazing shapes. Many of the formations suggest all manner of things, including elephants, hippos, bears, and mushrooms.
 Above image: Near Yangon in Myanmar (Burma), there is a balancing rock called The Golden Rock (Kyaik-htiyo or Kyaiktiyo), precariously perching  atop a cliff. It is one of the sacred sites for the Buddhists near Yangon, is one of the most sacred sites in Burma.The rock is almost at the edge ready to fall.


 Mushroom rock formation.Let's learn Geology -