AREA 31: Tan Lac
TL1: Xom Ton
Development:
284 m
Denivelation:
-25m
Water of
a small river disappears in an impenetrable passage. The entrance is
about three meter above a small river. The walls and ceiling of the
cave are completely covered with mud, this means that the cave floods
during rainy season. It consists of relatively easy passages, but a
slippery floor. Many swallow holes in
the floor are present. They give contact with the lower (underlying)
narrow active
cave system. At the end of the cave a 30 m rope gives access to a
‘window’ to the active river, both sides are too
small to pass
TL2: Xom Bo
Development:
104 m
Denivelation:
-34 m
The
entrance is 30 to 40 m higher than the presumed underground river
(level of rice fields). The cave ends in a chamber
with muddy floor and two sinks. A warm moist air blows out of the cave.
TL3: Xom My
Development:
104 m
Denivelation: -34 m
Xom My is a river cave through the mountain with 4 entrances. A river
disappears in the first entrance. A second entrance is a pitch which
gives again access to the river. The third entrance is situated in a
large doline. From the third entrance a series of small steps and
galleries lead to a sump which can be by-passed by fossil passage 10 m
before the sump. A descent leads to a lake in open air: entrance four.
TL4: Bai Vang
Development:
144 m
Denivelation: - 51 m
A vertical shaft of about 40 m gives way to a muddy slope, 10 m lower a
small river is reached; in the two directions ending on a sump.
TL7: Lang No 3
Development:
75 m
Denivelation: -12 m
Approximately 30 m up in sidewall of karst cone (halfway up). Starts
with a climb of 5m, then a horizontal development up to the final pitch
of 6 m. From there on the dry cave develops a few meters more.
TL8: Lang No 4
Development:
40 m
Denivelation: -7 m
The entrance is situated about 15 m above the water level in the
sidewall of a karst cone. After going down for 6 m a horizontal cave
develops. It stops on a muddy siphon.
TL9: Xom Lo
Development:
387 m
Denivelation: -42 m
This fossil cave is a labyrinth of passages 2 m high. The entrance is a
few meters above the base level. Air is blowing into the cave. The cave
could be suitable for adventurous touristic caving trips. A few fossil
concretions are present. Also archived as Lang No 5.
TL12: Hay Hai
Development:
47 m
Denivelation: -47 m
The entrance to this cave is to be found in the backyard of a house in
Hay Hai village. The entrance was opened with spades by the local
people, as the entrance had been closed with soil for safety reasons.
The cave is a fossil vertical shaft, 0.5 m by 1 m, with water in the
rainy season. Halfway, the shaft becomes wider as a shaft from above
joins.
TL15: Xom Nghe 1
Development:
20 m
Denivelation: 0 m
The cave develops in a fault parallel with the karst cone outside wall.
Shortly after the entrance the cave develops in two directions: to the
left it stops on blocks after 8 m; to the right a meander can be
followed for about 12 m before it becomes too narrow; wind blows into
this small passage.
TL16: Xom Nghe 2
Development:
60 m
Denivelation: -29 m
The cave develops in a fault parallel with the karst cone outside wall.
The vertical cave is entered approximately 25 m above the lowest point.
The rope is fixed outside the cave, on the right side. After climbing
down 3 m, the rope is belayed on a spit and an AN. 17 m lower a second
AN allows to reach the bottom, consisting of large blocks.
TL17: Xom Xom 1
Development:
50 m (est.)
Denivelation: -25 m (est.)
The river disappears at several places in sumps. 5 m above the valley
bottom an entrance of a cave is found. The passages are narrow, the
walls are clean. At several places the water disappears into too small
squeezes. But one or a few meters higher up by-passes are found. At
about 25 m depth (app. 50 m from the entrance) no by-passes are found
anymore. The water falls in the a small chamber and the water
disappears into a narrow squeeze.
TL18: Xom Xom 2
Development:
0 m
Denivelation: 0 m
A strong, wet and hot draft could be felt between blocks, but no way to
get in. There is very likely a physical connection to the underground
river we followed in Xom Xom 1.
TL20: Xom Xom 4
Development:
22 m
Denivelation: -22 m
A fossil 22 m shaft (30 m rope, 2 AN).
TL21: Xom Xom 5
Development:
30 m (est.)
Denivelation: -18 m (est.)
Via a squeeze a 9 m pitch is descended. Under a larger block, which is
stabilized with bamboo, a gentle slope leads to a huge block. Below the
block a 6 m unstable pitch is dugged out in the sediment. It is a
former gold mine. Outside the cave remains of equipment to wash the
sediment (to concentrate the heavy metals in the sediment) is found.
Local people told us the mining activity stopped only a few years ago.
TL22: Hang Bung 1
Development:
85 m
Denivelation: -58 m
This cave was used as a gold mine. The entrance is a doline. What
follows is a succession of small pitches that can easily be free
climbed, except the last one that must be equipped with rope (or
bamboo). It ends in a too narrow passage with some draft. The mud in
the squeeze was removed, the width of the passage led us conclude that
only children are able to do so.