PHUNCHAWNG PUK

Herbert Daniel Gebauer - 06/01/2018

A somewhat T-shaped cave entrance (5 m wide and high) to a wet rift passage (1 m wide, 4 m high, 60 m long) which reaches a vertical depth of 11.2 m before it becomes too narrow (less than 0.25 m wide) to be penetrable. An additional 5 to 7 m were seen to continue with decreasing width. SITUATION: Situated north of Serkawn in dense bamboo jungle (guide!). Reached by taking the old (western) road from Lunglei to Aizawl (via Serkawn, Haulong, etc). Having passed the BSF (Border Security Force) camp at –>Pukpui take a very bumpy -kacha- (note 1) or unmetalled fair weather road to the left. After about half an hour's serious jolting and severe kicking, park the 4WD-vehicle in full sunshine to continue on foot. Descent some 200 to 250 vertical metres to the left hand side (approximate south-west), through papad dry bamboo jungle and across baking hot jhums to the small but dry stream bed running along the very bottom of the valley. CAVE DESCRIPTION: After heavy rains the cave must functin as a concordant resurgence feeding a 10 m long tributary from the right (north-west) to a stream flowing to the south-west. The cave has a peculiar development in two subsequent phases, indicated by a confusing combination of thick bedded and more or less horizontal strata exposed on the cave walls and thin bedded subvertical strata visible in the cave ceiling. In phase one a thin crack (only a few millimetres to centimetres wide) opened along a fault (dipping towards 230° by -80°) at about right angles to the more or less horizontal strata of the host rock which forms the cave walls. The initial crack was soon filled with sand and silt which was cemented by calcite. The crack, however, opened again and again only to become infilled each time. In phase two, the rhythmic strata --now exposed on the cave ceiling-- were removed, most likely in the cause of a piping failure. CAVE LIFE: Bat guano covering the leaning wall of the rift and noise issuing from beyond the terminal constrictio hint to a population of Chiroptera. A solitary spider with strong tiger striped legs took hide in ceiling cracks: This was too compact to represent a 2nd premature stage Meghalayan Heteropoda. Two different leaches (Hirundinae?) were sort of lethargically restless on the moist cave walls: 8 mm Ø and 3mm high -blob- + 1 mm Ø and 4 cm long -tube.-n as a concordant resurgence feeding a 10 m long tributary from the right (north-west) to a stream flowing to the south-west. The cave has a peculiar development in two subsequent phases, indicated by a confusing combination of thick bedded and more or less horizontal strata exposed on the cave walls and thin bedded subvertical strata visible in the cave ceiling. In phase one a thin crack (only a few millimetres to centimetres wide) opened along a fault (dipping towards 230° by -80°) at about right angles to the more or less horizontal strata of the host rock which forms the cave walls. The initial crack was soon filled with sand and silt which was cemented by calcite. The crack, however, opened again and again only to become infilled each time. In phase two, the rhythmic strata --now exposed on the cave ceiling-- were removed, most likely in the cause of a piping failure. CAVE LIFE: Bat guano covering the leaning wall of the rift and noise issuing from beyond the terminal constrictio hint to a population of Chiroptera. A solitary spider with strong tiger striped legs took hide in ceiling cracks: This was too compact to represent a 2nd premature stage Meghalayan Heteropoda. Two different leaches (Hirundinae?) were sort of lethargically restless on the moist cave walls: 8 mm Ø and 3mm high -blob- + 1 mm Ø and 4 cm long -tube.-