The rock on a hill

It is one of the oldest rock formation on Earth and  it is located bang in the centre of a  botanical Garden. Formed millions of years ago, it stands a mute testimony to the events gone by. Over the years, it has become as much an attraction as the garden itself.

Children love to climb it, while lovers search for an isolated spot to sit. A rickety blue board proclaims that thro ck is a geological wonder.

Apart from the board, there is very little information about the rock and people make a beeline to the tower atop the rock to get themselves photographed. They rarely get themselves photographed with the background of the rock.

What people do not relies is that while the garden is a manmade wonder, the rock is a natural wonder and its origin goes back to hundred of million years. The garden, on the other hand, is a little more than 250 years old.

Yes, this rock is the Peninsular Gneiss of Lalbagh of Bangalore.

Peninsular means a mixture of granitic rocks and this type of rock is widely dispersed in the southern plateu of India. The Peninsular Gneiss was first coined by Dr W F Smeeth of the Mysore Geological Department. When the Rock at Lalbagh was dated, it was  declared a national geological monument way back in 1916.
The antiquity of this rock has attracted geologists from all over the world and has given rise to several scientific papers on the evolution of earth.  Geologists from the Mysore Geological Department, Geological Survey of India and scholars have written realms on it. The stone quarry of this Gneiss continues to be source material for research in the various branches of earth science.

Geologist Dr. M.S. Anantha of Mysore says such rocks can help unlock the secret behind the evolution of Earth and also give invaluable information on geological history.

This rock is 2.5 to 3.4 billion years old and this shows that it took shape much before the evolution of man. Such Peninsular Gneissic rocks form the basement of the bedrock in south or peninsular  India.

The Gneiss and Dharwar rock types are classified groups of the Precambrian rocks of India. The precambrian period refers to the time that began with the formation of the Earth around 4500 million years ago and concluded with the Cambrian period about 542 million years ago.

Whew. So this means that the Peninsular Gneiss surfaced during the evolution of the Earth or thereabouts. It is really a natural marvel that we can view above the surface the deepest rock type.

This makes it all the more exciting as generally most of Earth’s bedrock or consolidated rock surface is covered by numerous layers of soil, deposits, vegetation, and gravel. These overlying layers can be as thick as several hundred meters above the bedrock. As a result, it is difficult to access the Earth’s rock surface without extensive drilling. Even then , you cannot see them. Here, you see it free of cost.

When you start climbing the rock, you notice white strips along the rock surface. This indicates the presence of  sedimentary rock called Biolite. Interestingly, Biolite is formed either by living organisms or by their remains or fossil.

Remnants of older rocks are seen in the form of enclaves. Some excellent research information of the geological record of the gneisses is published in the “Geological Monuments of India”, brought out by the Geological Survey of India.

The GSI publication says the Gneiss “is dark grey to black rock called amphibolite containing the minerals plagioclase feldspar and horneblend. Due to interactions with granite fluids, these enclaves have developed a border rich in biotite mica. Later magmatic activity represented by grey poryphiritic granite followed by pink massive granite is also seen at several places. The gneisses and granites have been profusely invaded by still younger veins of coarse grained pegmatite which have cut up the gneisses into several irregular and lenticular shapes”.

The GSI has identified this Gneiss as one of the best exposures of this rock mass, protruding high above the ground as a hillock, dated 2.5 to 3.4 billion years. It has called it the Lalbagh rock.

Generally, such Gneiss is a coarse-grained high grade metamorphic rock formed at high pressures and temperatures in which light and dark mineral constituents are segregated into visible bands.

Kempe Gowda built a tower atop this rock. What have we done. We climb the rock, look around casually and get down, without realising that we are on the cusp of  Earth’s history. We have also littered it in every way that could have been possibly done.

The story of a memorial rock

Almost all Bangaloreans are aware of the National War Memorial  that is coming up at the Indira Gandhi Park in Central Bangalore. The memorial has been a subject matter of  a prolonged dispute between environmentalists on one hand and the Government and military on the other.

The matter even reached the courts and the project for constructing Bangalore’s first national memorial took off only after the Supreme Court okayed the project.

The project includes the installation of a 87-foot high single stone which will be the centerpiece of the memorial. But did you know that the stone is being mined near Bangalore and that the State Government issued the permit for mining such a huge slab near the reservoir of Tippegondanahalli (TG Halli), near Bangalore.

The single rock at the memorial comprises a 750-ton block of granite and the State Government issued necessary permits to mine this stone at a quarry site near the TG Halli reservoir in 2009.

The stone, 87-foot-high, will be a fitting memorial to those bravehearts who fought in the Kargil War.  The rock is being mined from the quarry of a farmer called Munne Gowda and it is called Veeragallu (The Kannada meaning of a brave heart-Veera means brave and Kallu means stone).

The stone from which the Veeragallu is being carved is not found anywhere else in Karnataka but in Koyira village near TG Halli. This type of rock is locally known as Kajjikayalu.

The State Government records itself show that this type of  rock is not found anywhere except here in Karnataka. It also shows that the BDA was permitted to mine the area near the TG Halli reservoir for extracting the stone.

Do you know the cost for quarrying, extracting, transporting and installing the rock at the memorial site. It is Rs.28,408,903. And what are the consequences of transporting a huge boulder of this size.

The Government itself says it would be required to demolish some bridges and buildings to ensure smooth movement of the vehicle carrying such a statue from TG Halli to central Bangalore. The cost?  Your guess is as good as mine.

When completed, the rock will be 75 feet in height and it will weigh about 700 tons. As many as 20 sculptors are giving it finishing touches. The memorial will also have the tallest flag mast in India at 65 metres (around 213 feet). The flag mast will adorn the country's largest national flag measuring 48 x 78 feet.