Ever wonder about our own wonders?
The World’s End escarpment between the 3rd and 2nd peneplains. Pix by Dr. Nalaka Ranasinghe
Sri Lankans travel far and wide within the country, taking in picture-postcard like scenery, being entranced by waterfalls splashing down mountain sides, peering deeply down gorges or gazing in amazement at wide vistas of flatland.
But, how many ponder over the passionate love affair, going back aeons, among the elements, particularly earth, water and wind (air).
It is into this very love affair which would sometimes be gentle and at others rough that Dr. Pradeep Nalaka Ranasinghe of the Ruhuna University’s Department of Oceanography and Marine Geology takes a spell-bound audience of the Sri Lanka Natural History Society recently.
Dr. Ranasinghe who has trekked many a mile up hill and down dale has to his credit the first-ever ‘Geotourist Map’ of Sri Lanka which was published by the Geological Survey & Mines Bureau in 2002 when he was working there. It pinpointed 201 Geotourist Locations in the country but has become very scarce now and a revised edition with more sites and new information is set to be published shortly.
Back in time we travel to when the earth was one landmass and how the movement of the tectonic plates (massive, irregularly-shaped slabs of solid rock) which are part of earth’s crust shifted 150 million years ago, creating a northward push of India and Sri Lanka from Antarctica. The India-Sri Lanka landmass, tried to separate, while drifting, but opened up and collided with Eurasia. With the ocean being squeezed out, this is how marine fossils coming from ocean sediments are being found in the Himalayas, according to Dr. Ranasinghe.
Sri Lanka should have moved south – but “luckily” or “unluckily” remained near India, he says, grouping the three major geo-complexes in the country as Wanni, Highland and Vijayan Complexes.
Before taking us on an exciting journey cross-country to geo-beauty spots through slides, Dr. Ranasinghe differentiates the thin line between ‘eco-tourism’ and ‘geo-tourism’ and stresses how abundantly-blessed Sri Lanka is in this regard. Typically, eco-tourism involves the biotic (linked to living organisms) environment, while geo-tourism involves the abiotic (physical than biological) environment.
With ‘eco-tourism’ being “environmentally-responsible travel to natural areas to enjoy and appreciate nature (and accompanying cultural features, both past and present) that promotes conservation, has a low visitor impact and provides for beneficially active socio-economic involvement of local people,” he says that ‘geo-tourism’ is “tourism that sustains or enhances the geographical character of a place – its environment, culture, aesthetics, heritage and the well-being of its residents”.
Many are the Sri Lankans who go to such places as the Grand Canyon National Park in Arizona, the Yosemite National Park in California, the Niagara Falls in New York or the Yellowstone National Park in Wyoming, all in the United States of America, when right here in Sri Lanka, we have a wide variety of wonders.
Sri Lanka has three peneplains, says Dr. Ranasinghe adding that the 1st comprises the coastal lowlands from about 0-270 metres; the 2nd the uplands from about 270-1,060m and the 3rd the highlands from about 1,060-2,240m.
He groups geo-tourism locations as geo-archaeological, geo-morphological, geologically-important and those rich in mineral deposits
Pointing out that geo-archaeological locations are those with archaeological sites and ancient distinctive constructions which have geological aspects, he picks out:
The Gal Viharaya Buddha statue sculptured on migmatitic gneiss rock
Maligawila with its 12.6-metre statue of Lord Buddha carved of crystalline marble belonging to the 6th century AD.
Buduruwagala with its 13.5m statue of Lord Buddha and two Bodhisatva statues including that of Avalokhiteswara, carved on the face of a migmatitic biotite gneiss rock.
Kadurugoda (Kantarodai) with 20 complete small ‘stupas’ made of limestone found in the area, of which the largest is nearly 7m in diameter and the smallest 2m. There are also granite slabs which, however, had been brought from outside and used for the construction of other buildings of the temple complex.
Pahiyangala with archaeological excavations uncovering human relics dating back to 34,000 BP (Before Present). This natural cave is on the face of a 40-metre rock cliff formed by wind erosion along a fold axis of the rock formation.
Mihintale replete with ruins of a large Buddhist monastic complex. This area includes Mihintale hill, Athvehera, Aneikutti ridge and Rajagiri lena hill which are small granitic gneiss ridges formed due to resistance to weathering. Several dagobas, 68 rock shelters, numerous stone pillars, stone sculptures, ponds and stone bases of various buildings dotting the area are of granitic rocks.
Some of the eye-catching geomorphologically-important locations, according to Dr. Ranasinghe are:
Kuragala from the peak of which situated at the southern edge of the second peneplain (Kaltota escarpment) that one gets a panoramic view of all three peneplains. The southern massif including Horton Plains, Idalgashinna and Haputale seen towards the north and the flat terrain of the 1st peneplain visible on other sides.
Dambetenna from Lipton’s Seat, wide vistas within the Western, Sabaragamuwa, Southern, Eastern and Uva Provinces may be enjoyed, while getting a glimpse of the conspicuous changes of the physiography from the 3rd to the 1st peneplain.
Diyaluma Falls the result of a tributary of the Kuda Ganga taking a deep dive 220m over the escarpment separating the 3rd and the 2nd peneplain, this is the third highest waterfall in the country.
Horton Plains is the highest plateau (2,100-2,300m) of Sri Lanka which has the second and third highest peaks of the country — Kirigalpotta-2395m and Totupola-2359m and also the Agrabopath ridge. This plateau has been formed by low dipping rock layers of an overturned anticline fold. Horton Plains is home to the headwaters of the Walawe, the Mahaweli and the Kelani rivers.
Dumbara Hills are the Dumbara Range (Knuckles Range or Knuckles Massif), a mountain range separated from the central highlands. Intense erosion along a weak fracture zone has formed the Mahaweli river valley, separating the Dumbara hills from the Central Highlands.
Madu Ganga is an example of a braided river where 64 small islands have been formed by the deposition of sediment brought by the Magala Oya. Such island-formation is a characteristic of a ‘mature’ river.
Pooneryn is a large dune field formed by wind-blown sand and a superb view of it is from the beach, south of Kalmunai Point.
Next, Dr. Ranasinghe highlights geologically-important locations which clearly give an overall picture of the country’s geology:
Ussangoda – whatever the legends may indicate, a more rational explanation is the exposure of a serpentinite deposit which brings out green and pink on the beach. Over the deposit, there is only sparse vegetation of a few species of grass, due to the high amounts of Ni and Cr in the soil by the weathering of the serpentinite rock. Large parts of the area have a reddish hue due to an iron-rich laterite cap.
Mahapelessa has a hot-water spring, with the water having a temperature of around 44°C. A deep-seated fracture-zone between the Highland and the Vijayan Complexes is thought to be the origin of this spring.
Minihagalkanda – here are found sedimentary sequences of the Miocene periods, containing beds of fossiliferous nodular limestone and sandstone. Unique it is, for there is evidence of tectonic-related erosion.
Tangentenna calcite mine
Namal Uyana has a pink quartzite ridge and even though these ridges are common around the country, the colour makes this formation unique.
Lover’s Leap — a deep fracture situated on a spit at the northern end of the Dutch Bay. Offshore rock exposures with an orthogonal joint system can be seen from the top of the cliff. The Trincomalee canyon which reaches a 1,000m isobath at its deepest end extends from the Trincomalee Bay to the shelf edge. The Mahaweli river sediments flow down the shelf edge through this canyon which aligns with the Highland-Vijayan geological boundary. Extensive weathering along the fracture zones of this weak tectonic boundary could have formed the deep Trincomalee canyon.
Referring to mineral deposits, Dr. Ranasinghe focuses on some of the accessible major mineral deposits.
In Ambalantota, on a pro-grading beach area about 60m wide and about 4km long, can be found an accumulation of garnet sand, believed to have been transported by the Walawe river which falls into the sea here.
Pelmadulla has a large number of alluvial-type gem mines, yielding both precious and semi-precious stones. The mines in a swampy area had formed during the Pleistocene period and are believed to have had now-extinct animals such as hippopotamus, rhinoceros and gaur.
Owala and Kaikawala are the site of large feldspar deposits bearing pegmatite and also containing fluorspar and amazonite. Vein Quartz is mined at Owala.
| Here are our geo-tourist routes | |
| Dr. Ranasinghe shows the way along ‘geo-tourist’ routes.The Geomorphological Routes are –Panama-Vakarai and also Elephant Pass-Kalmunai Point showing off its beach morphology Belihul Oya-Bandarawela boasting the physiography of plains The Mineral Deposit Routes are – Balangoda-Kaltota and Matale-Rattota-Hattota-Amuna The Geotechnical Routes are – Ginigathhena-Maskeliya and Kandy-Randenigala
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| Most eco-tourism here is not eco-tourism | |
| Stressing that Sri Lanka needs to be aware of the potential negative impacts of eco-geotourism, Dr. Ranasinghe points out that most tourism in natural areas today is not eco-tourism.According to him the increase of visitors to ecologically-sensitive areas can lead to significant environmental degradation, while regulations for environmental protection at eco-tourism sites may be vaguely defined, costly to implement, hard to enforce and uncertain in their effectiveness.“Local communities and indigenous cultures can be harmed in numerous ways by an influx of foreign visitors and wealth, with few benefits to local communities. Over-dependence on an industry like eco-tourism which is highly susceptible to fluctuations in climate, currency exchange rates and political and social conditions is risky,” warns Dr. Ranasinghe. |