Ritigala – A Himalaya fragment on Sri Lanka? EarthCache

Note: this text might be too long for paperless geocaching

Some climbing over stones and roots is required near the entrance, then mostly an ancient paved path, partly with steps uphill to target coordinates, ~ 40 minutes one way. The climate can be very humid. Expect to see reptiles, insects and maybe larger animals.

With regards to what the latest Lonely Planet reports, the site is currently not included in the cultural triangle round ticket anymore.

Location

The monastic complex is situated on the lower slope of Ritigala Mountain in the north central plains of Sri Lanka. The entrance can be reached via a 9km long, strongly eroded sand track from the Habarana-Anuradhapura road which might be difficult to use with normal cars during rain season. The ruins are connected by an approximately 2km long ancient path climbing up the mountain. As Ritigala is a strict natural reserve you need to take a guide along to visit the ruins. You can only visit other parts of the mountain with previously obtained permission.

The Myth

Ritigala is mentioned in the Hindu epic Ramayana where the story goes that Hanuman, the warrior monkey-god came to Sri Lanka in search of Lord Rama’s wife, Sita, who had been abducted by Ravana, the king of demons. After Hanuman had found Ravana, he informs Lord Rama of the news. He then led a monkey army across the strait separating South India from Lanka and waged war against Ravana. During that war, Rama’s brother was wounded in battle and Sanjivani, a medicinal herb was required to save his life. Hanuman was send to the Dronagiri mountain in the Himalayas to collect this herb, but he was unable to find it before nightfall. So he brought back a fragment of the Himalayas twisted in his tail, in the hope that the right herb will be amongst the many. However, the mountain fragment slipped and fell while Hanuman was over the battlefield, and it broke into three pieces. These landed in different locations, one of which was Ritigala. Maybe this part of the legend is due to the mountain’s specific microclimate and a vegetation that is distinct from the dry zone flora on the plains surrounding the mountain. The summit itself has a cool and wet micro climate due to almost permanent clouds and mists hanging over the mountain. This enables many plants to thrive that don't grow anywhere else on Sri Lanka.

The Ruins

The oldest inscriptions found in the secluded ruins date from the third and second century BC. They were most likely build by monks. It also appears to be a refuge for King Dutugamunu of Ruhuna (161-136 BC) and for King Jetthatissa (623 AD) in their battles against marauding Dravidian invaders from South India. Ritigala was abandoned following the Chola invasions in the 10th & 11th centuries and was only rediscovered by the British surveyor James Mantell in 1872.

The Granite

The building material of the Ritigala ruins is granite that has been quarried directly from the Ritigala Mountain, the highest mountain on the north central plains. Granite is a common rock on Sri Lanka and an intrusive igneous rock. As the magma doesn't reach the surface it cools more slowly than lava exposed to air, thus there is more time for larger crystals to form. Compared to volcanic lava which cools within seconds or minutes, magma within the Earth often takes years to cool.

Granites originate from relatively small blobs of magma that intrude the Earth's crust and cool there. They are usually very hard, massive and show no internal structures. After softer rock that surrounded the intrusion was eroded away the granite remained as a big mountain in the otherwise relatively flat plains on north central Sri Lanka. Have a look at the landscape from the view point the coordinates lead you to. Can you spot other mountains that seem to have been dropped onto the plains by the monk-god?

The magma that forms granites usually is created at convergent plate boundaries where subduction is taking place. Subduction is the diving of one plate of crust underneath another and into the Earth's mantle. With increasing depth the temperature and pressure increases and the subducted plate begins to heat up and melt, forming magma. Because magma is less dense than the solid rock surrounding it, it will rise through fractures. Dissolved gases under pressure also help to force the magma upwards and cooler rock that gets in contact with the hot melt will start to partially melt as well. The type of rocks that form the subducted plate and the mantle rocks surrounding it will determine the chemical composition of the melt The granites that were used for the base of the great stupas at Anuradhapura or into which the big Buddha figures at Buduruwagala were carved might have a different chemical composition, colour and age than the granite that is Ritigale Mountain.

Granites are usually of light colours because their main minerals are high in silica. These include minerals such as quartz, and orthoclase and plagioclase feldspar. Quartz crystals are usually transparent white while feldspars are pink, milky white or grey. Mica crystals are smaller, have a platy appearance and can be silvery transparent (muscovite) or darkbrown to black (biotite). Other dark minerals common in granites include hornblende and augite. Feldspars determine what colour a granite will have due to their abundance within the rock and variety in appearance. If most feldspar minerals are potassium-rich (alkali minerals, such as orthoclase) the granites may have a colour ranging from milky white to pink to greenish in colour and if they are rich in calcium (plagioclase) light to dark grey. Given the right mineral composition, granites can even be black.

The major mineral constituents that make up a granite have a relatively low melting temperature and high amounts of relatively light elements such as silica, aluminium, calcium and potassium. Granites orginiate from different processes, but all involve the melting and cooling of a body of magma.

Every rock is composed of minerals of different compositions. Each mineral type has a different chemical composition and a different melting temperature. Most elements granites are made of have a lower melting temperature while other ones, such as iron, titanium, magnesium, sodium and calcium have a higher melting temperature. When a volume of rock gets heated up the least heat-resistant minerals will melt first. These partial melts are thus enriched in the chemical components of minerals with lower melting temperatures and can form granites, while the non-melted portion of the rock surrounding the melt remain composed of minerals with higher melting temperatures.

In return, in a volume of cooling magma elements with a high melting temperature will first combine to form crystals. If the cooling happens very slowly these minerals will sink to the bottom of the magma chamber as minerals with a high melting temperature are also generally heavier than the elements that remain in the melt. The remaining magma will become more and more reduced in those elements and enriched in the least heat-resistant elements. A granite can then form from those elements.

There are four types of granites, which all originate from a different source rock or location:

Thus looking at the colour and mineral composition of the Ritigala ruins stones can tell a lot about the history and origin of the granite they were build from. This granite will most likely have a different composition and originate from a different magma than other granites on Sri Lanka.

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