Exploring Pannila Limestone Cave Complex

Year and Month	10-December-2017
Number of Days	One
Crew	03
Accommodation	N/A
Transport	Motor Bicycles
Activities	Hiking, Nature Exploring, Photography, Sightseeing, Caving,
Weather	Good
Route	Colombo -> Ratnapura -> Pelmadulla -> Kahawatte -> Horahinella -> Manan Dola- Endana Road -> Pannila Road -> Pannila
Tips, Notes and Special remark	Carry enough water Do not try in rainy days Wear leech socks as there are many Beware of slippery rocks Start your journey early morning Carry a powerful torch per person Wear appropriate suite inside of the cave Wearing shoes is better Finish your journey before the evening Do not harm to the limestone Beware of Ma-Ussa plant and thrones Do not disturb bats and nature Ask the directions from local Do not disturb to the villagers Do not litter Leave only footprints
Related Resources	None
Author	Ranshan Fernando
Comments	Discuss this trip report, provide feedback or make suggestions at Lakdasun Forum on the thread Exploring Pannila Limestone Cave Complex

පන්නිල හිරිගල් ගුහා

The Rakwana mountain range, which is located in the margin of the northern side of Sinharaja, a UNESCO world heritage site, is an area having rich bio–diversity. The recent excavations of the alluvial deposits in Sabaragamuwa basin associated with northern side of Sinharaja area revealed that the existance of caves in the vicinity of Pannila mountain. The cave formation is seen within the rocks of crystalline limestons (marble),which is popularly known as ‘Pannila Hunugala’ is of 550 m in length and 350 cm height at its entrance of which 60 cm filled with water, where special cave characteristics are visible. Stalagmite and stalactites of 2.5 m height at the core of the cave was believed to be formed after re-crystallization of pre-existing crystalline limestones- the basement rock – in the Highland Complex of Sri Lanka belongs to the Precambrian age. Speleothem dimensions were used to measure the volume of stalagmite and stalagtites. The action of chemical weathering of crystalline limestone followed by limy solutions makes it secondary features like stalagmite and stalactite.It is postulated from the Geological map of Sri Lanka that the same crystalline limestones bed is extended to the Rakwana Pannila Hunugala’ ,Samanalawewa, Handagiriya caves.

A few are developed entirely in marble but most are not. ‘Pannila Hunugala’ is a part of the basement marble bed in the Highland Complex of Sri Lanka which is belongs to the Precambrian age. It is postulated that the same marble bed is extended to the marble beds located at the Samanalawewa, and Rakwana. The action of chemical weathering occurred in the recent times makes it secondary features like stalagmite and stalactite.

In order to penetrate into the fractures of the limestone rock, the rainwater, acidulated by atmospheric and soil carbon-dioxide (CO2), dissolves it and carries off the calcium carbonate until it finally emerges on the roof of the cave. The drop of water suspended on the roof of the cave is exposed to environmental conditions, such as greater ventilation, alterations in temperature, pH, and CO2 pressure. These environmental conditions create chemical instability through the liberation of the CO2 into the cave and the consequent precipitation of part of the dissolved carbonate. The drop of water hangs on the roof until it reaches the volume and weight necessary to overcome surface tension and fall. Hanging on the roof of the cave and exposed to environmental conditions of the interior’s cave, the surface of the drop develops the first crystals of calcite; these, organizing themselves during the period in which the drop is still in contact with the roof, form an initial crystalline ring which will serve as a base for a future stalactite.

Drop by drop, a hollow tubular stalactite grows in a downward direction. The drop, when it at last falls, carries with it a solution of carbonate which slowly forms a sucession of layers on the floor immediately below, and which becomes a stalagmite. The opposing growth of stalactites and stalagmites might finally result in the union of the two, to form a column. Fig: 03: (A) and (B) show examples of stalactites and stalagmites, respectively, whereas (C) A flowstone illustrates a after column, formed by the union of a stalactite with a stalagmite. Speleothems take various forms, depending on whether the water drips, seeps, condenses, flows, or ponds. Many speleothems are named for their resemblance to man-made or natural objects. Types of speleothems include Dripstone, Stalactites, Soda straws, Helictites , Flowstone, Speleogens.

Source – Research Article

As per my understanding there is a special geographical resource around Ratnapura to Kalthota area. As I know I have visited many Limestone caves and areas around Samanala Wewa such as Sandagiriya, Andiri Lena (Less Limestone) , Hunugal Pond at Kalthota, Waulpane, Samanalawewa also based on a Limestone that is why there is a unstoppable leak. There is some thing on this ground. I believe that there will be more Limestone caves in deep forests of Ratnapura district which are not yet seen by human. Because the underground is mostly based on limestone. This caving reminded my journey to Rotupihilla Caves.

It is a very difficult hike along the stream and we have to face plenty of leech attacks. And we should specially make our eyes on Ma-Ussa plant as it is venomous. When you enter to the cave try to be adjust as per the limestone and find all the entrances and go inside of all of them. You could realize that the water is coming from there and Limestone generates the water too. Some caves are full with some level of water and some are also wet like the springs.