VIETNAM
EXPEDITION 2007
- Period: from 20 january
to 10 february
- Area: Cao Bang provnce, northern Vietnam
- Partecipants: Phil Bence, Marc Faverjon, Flo Guillot, Richard Huttler,
Rodolphe Sturm, Michele Varin (ita.), Nam Nguyen Xuan (Vietnam), Marco Zambelli
(ita.)
The first sector, the
main objective of the expedition, have been briefly prospected ten years
ago and it looked very interestin according to the maps and the geological
survey.
Despite the efforts and the long walks we didn't find large cave systems
but just one major cave, so the last week of the expedition we decided to
move to Quang Uyen area, looking for horizontal caves.
> Sector 1: Bao Lac district, Dong Mu polje, Song Gam
river gorges.
Sinkholes:
the Dong Mu polje main sinkhole drains through a large boulder breakdown
at the bottom of a wall; the flow didn't generate a major passage in the
entrance section.
We didn't managed to pass through the breakdown despite several descents
among the boulder choke, up to 50 mts deep and the strong air current.
The Ban Giem sinkhole, which drains a non karstifiable formation area through
a valley, is filled with gravels at the bottom of a 20 m shaft. The passages
are carved in a nice marbled limestone.
In Dong Mu we have explored also a stream cave ended by a sump; the passages
follows the polje border for about 1 km.
Dry caves: local people shown us a big entrance, covered by plants. The
cave is composed by a large ascending passage, interrupted by a boulder
choke. Some climbs and descentslead to a second passage, filled with clay
after 600m.
Resirgences: we explored an important rising cave in the Song Gam River
gorge. It's more than 1 km long, with large passages and smaller lateral
branches: the main passage ends in a deep syphon, the lateral passages are
closed by boulder or gravels chokes. This cave drains an important flow
of the massif and it's probably the main rising of Dong Mu area.
Other smaller caves were explored in the area.
> Sector 2: Quang Uyen district, Cao Bang - Hoa An area.
We have prospected the Quang Uyen district, especially in the northern part.
Many sinkholes - resurgence systems were noticed in Nam Phan - Lang Lai
area: a through cave, 1,5 km long was explored.
The last day a stream system was quickly explored in Ban Nua, close to Hoa
An: it ends on an unexplored shaft in the resurgence branch and continues
with a nice river passage on the sinkhole side.
On the whole we explored more than 7 kms in these nice karst mountains.
