TYLLAP CAVE, 1st (aa -)

Herbert Daniel Gebauer - 06/01/2018

Not only three accessible but also two collapsed cave entrances are known to give access to a two-dimensional maze of joint-guided cave passages, which constitute parts of a subterranean estuary and probably function as an overflow resurgence in wet weather. A north-south running stream cave passage (the probable continuation of –>AA Cave, Tyllab, 2nd) is fed by an inlet from an area in the west of the locally north-south flowing Tyllab and covering approximately three to five square kilometres at elevations between circa 30 m and 273 m asl. In case the terminal sump can be passed or bypassed, or if an hydrographically upper cave entrance is found while reconnoitering the surface, this cave may have a great speleological potential. ETYMOLOGY: No locally known name has been identified for this cave, which was found in the valley of the river (known by the Bengali name Sonai in the adjacent North Sylhet subdivision of Bangladesh) flowing past the village of Tyllab and definitely is not Tyllap River Cave (Boycott, Antony 'Tony' 2002 Mss; Rob Harper 2002 Mss) that drains and carries this river from an upstream insurgence to a downstream resurgence. SITUATION: At an unidentified location in an unspecified setting somewhere upstream and -- according to recorded GPS readings -- about 2 km in a direct line north of Tyllap village (note 1) in the Shella - Ichimati area (note 2). APPROACH: Rob Harper (undated February 2001 Mss) advises to start from an unknown place (perhaps Tyllab Bazar) and to follow path [in an unspecific direction towards an unspecified destination] along right bank of river [note 3] past obvious large resurgence at boulder pile to cave entrance approximately 40 m beyond in cliff face. CAVE DESCRIPTION 2002: Three entrances to a static pool and a four way junction: The left hand side passage leads to another entrance. The right hand side passage continues to chamber via sandy crawl. The passage straight on to a phreatic crawl and ends after 30 m ina sump (Harper, undated February 2001 Mss). CAVE DESCRIPTION 2002: Several entrances give access to some 60 m of walking [and rugby player] sized canal passage (2 to 3 m wide, 3 m high) parallel to cliff face which ends at a small sump at the -downstream- end. A low tributary passage (4 to 5 m wide, 0.8 to 1 m high), heading into the hillside can be followed for 35 m to another sump (Harper 2002.04.31 Mss: megahlay #13). PROSPECTS: Little prospects for further extension without diving (Harper 2002.04.31 Mss: megahlay #13). CAVE LIFE: Noticed on the first day of February 2001 and, perhaps, more or less under water, were not only relatively small fish (note 4) but also relatively large tadpoles (note 5) without comparison for scale (Harper 2002.04.31 Mss: megahlay #13). Tyllap River Cave (Boycott, Antony 'Tony' 2002 Mss; Rob Harper 2002 Mss) that drains and carries this river from an upstream insurgence to a downstream resurgence. SITUATION: At an unidentified location in an unspecified setting somewhere upstream and -- according to recorded GPS readings -- about 2 km in a direct line north of Tyllap village (note 1) in the Shella - Ichimati area (note 2). APPROACH: Rob Harper (undated February 2001 Mss) advises to start from an unknown place (perhaps Tyllab Bazar) and to follow path [in an unspecific direction towards an unspecified destination] along right bank of river [note 3] past obvious large resurgence at boulder pile to cave entrance approximately 40 m beyond in cliff face. CAVE DESCRIPTION 2002: Three entrances to a static pool and a four way junction: The left hand side passage leads to another entrance. The right hand side passage continues to chamber via sandy crawl. The passage straight on to a phreatic crawl and ends after 30 m in Tyllap River Cave (Boycott, Antony 'Tony' 2002 Mss; Rob Harper 2002 Mss) that drains and carries this river from an upstream insurgence to a downstream resurgence. SITUATION: At an unidentified location in an unspecified setting somewhere upstream and -- according to recorded GPS readings -- about 2 km in a direct line north of Tyllap village (note 1) in the Shella - Ichimati area (note 2). APPROACH: Rob Harper (undated February 2001 Mss) advises to start from an unknown place (perhaps Tyllab Bazar) and to follow path [in an unspecific direction towards an unspecified destination] along right bank of river [note 3] past obvious large resurgence at boulder pile to cave entrance approximately 40 m beyond in cliff face. CAVE DESCRIPTION 2002: Three entrances to a static pool and a four way junction: The left hand side passage leads to another entrance. The right hand side passage continues to chamber via sandy crawl. The passage straight on to a phreatic crawl and ends after 30 m ina sump (Harper, undated February 2001 Mss). CAVE DESCRIPTION 2002: Several entrances give access to some 60 m of walking [and rugby player] sized canal passage (2 to 3 m wide, 3 m high) parallel to cliff face which ends at a small sump at the -downstream- end. A low tributary passage (4 to 5 m wide, 0.8 to 1 m high), heading into the hillside can be followed for 35 m to another sump (Harper 2002.04.31 Mss: megahlay #13). PROSPECTS: Little prospects for further extension without diving (Harper 2002.04.31 Mss: megahlay #13). CAVE LIFE: Noticed on the first day of February 2001 and, perhaps, more or less under water, were not only relatively small fish (note 4) but also relatively large tadpoles (note 5) without comparison for scale (Harper 2002.04.31 Mss: megahlay #13).