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Emerald Cave

A cache by Struep Send Message to Owner Message this owner
Hidden : 03/01/2011
2.5 out of 5
5 out of 5

Size: Size:   other (other)

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Geocache Description:

Emerald Cave is located in a large bay with a multitude of limestone rocks, also known as a Karst area. This area is part of the Had Chao Mai National Park.

The geologic origin:

The first important geologic event happened 300 million years ago, when South East Asia was still the largest coral reef in history. Obviously formed under the sea, the crescent-shaped reef ran from Bali and Borneo north off Australia and drifted past Thailand, creating incredible pressures that rippled the landscape into giant ridges running North and South.

The consistently humid warm temperatures and the surface water which seeped into the porous subsoil let the lime sediments weather. Funnel-shaped valleys where formed, so-called dolinas and gigantic limestone caves. With progressive erosion the dolinas increased more and more in the depth, while the cave covers often collapsed. Thus originated the tower and cone mattocks which are typical today for many regions of South-East Asia. There are similar bizarr sceneries, for example, in Guilin in China or in the Halong bay in the north of Vietnam.

The fact that the mattock towers are in the water in Had Chao Mai National Park, is the result of an other tectonic movement. The sea scenery originated from a overturning of the Malayan peninsula at which the western part sank and the eastern was lifted however. In the Andamanensee whole lime massifs "drowned" during this tectonic process. Only the peaks of the limestone rocks, overgrown with jungle, rise as islands from the sea.


The mostly from carbonate rocks (in part to sulfate and salt rocks) are mainly built karst rocks by solution and carbonic acid weathering and precipitation of biogenic limestone and sediments were similar with high levels of calcium carbonate (CaCO3). The rocks are carbon dioxide released (see stalactites ). Rain water with a pH below 7 is considered acidic. This is done by absorbing carbon dioxide CO 2. expressed chemically reacts the CO 2 in the air with the water and forms part of carbonic acid (H 2 CO 3). The carbonic acid dissociates now in HCO 3 - and H + and is able to (CaCO 3) to dissolve the lime. By penetrating into the rock, aerated water releases courses and cavities, which can develop over millions of years to enormous response systems. Often form in these cavities by dripping acidic surface water containing dissolved lime stalactites. Breaking the cavities arises, can funnel-shaped depressions ( sink hole ) are formed. Greater lowering of a few square kilometers area will Polje called. They are created by foreign bodies in fine-grained sediments to the bottom of the Polje seal and protect it from further weathering. Flowing water often disappears at the edges of Polje in a sip hole ( Ponor ), underground to and from another place to come to light. On the surface of the rock caused washouts, gullies and ridges, the so-called cart . Landscapes, which are constructed mainly of carbonates are formed as karst landscapes. Great Kart these landscapes are found around the Mediterranean (Balkans, Spain, Italy), as well as in Southeast Asia (Thailand, Burma, Malaysia) and South China, the Greater Antilles and Indoaustralischen archipelago.

West of Ko Muk you will find this cave, named Emerald Cave.

This cave is unique, because you have to cross an 80 meter tunnel to enter it.Look how the rock surface changes when you enter the tunnel. You can clearly see the difference between the beach side and the cave entry. Inside this tunnel you will see a lot of different stalactites which are especially formed. Also the wall of this tunnel has an especially surface. Inside the cave there is a great lagoon and the roof has a big hole, which gives the impression of being inside a vulcano.

The Cave is well worth exploring on a dive trip from Ko Lanta or Trang. The entrance to the Emerald Cave is somewhat hidden at the island's western side. It's located behind a stone hole wich disappears beneath the water surface during high tide. From the rowing boats and swimmers wearing life jackets cross an eighty meter long tunnel before entering a phenominal lagoon.This pool of cristal clear water is surrunded by a white beach and steep in green coverd hills. Note that this direction is the only way in and out.

Atention: New! EarthCache Guideline Updated 10 June, 2019

Your tasks:

1.)Are there any signs of erosion? Which ones?

2.)What difference can you see between the tunnel's rock surface and the cave's rock surface?

3.)What do you think looks this cave in 10.000 years? Please explain your answer based on some of the observations you made during your visit.

4.) Add a photo in front of the  signe of the cave with you or a person object (GPS or thomething else).

Mail me your answers 1.) - 3.), add the foto on  your log. We will contact you, if there is thomething wrong.

Any logs that does not have the required photo will be deleted without notice. No excuses/reasons will be accepted, just simply log this earthcache when you have a photo to include into your log and then email answers. Do not log a find without it.

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