The Caves

Click on each link to view surveys, photos or other information on these caves.  Click here to view related cave statistics.

Sima Pumacocha is named after a lake located about an hour's drive above the village of Laraos.  The lake is perched on granodiorite bedrock and the outlet stream has carved a short, shallow canyon for several hundred metres at the contact with the abutting, vertically-bedded limestones.  This short canyon contains three fossil and one active entrance, all of which are primarily vertical and connect (eventually) into one cave system.   SP1 is the active stream sink which was too wet to explore until 2004, and its 282m entrance shaft may be the deepest shaft in the Andes.  SP1.5 is a dry shaft that connects with SP2, the main cave entrance, just below the first pitch.  SP3 is only a few metres down-canyon from SP2 and is a 120m blocked shaft.  Normally dry, SP3 was being fed a portion of the surface stream in 2004; a similar-sized stream was located at about -550m in the main cave.  Sima Pumacocha ends at a sump that drains into an inaccessible crack at -638m, making it the deepest cave in South America at the time (since surpassed in 2007).  The cave strongly and consistently exhales, and the theory that the cave is being pressurized by an as-yet undetected river cave has given way to the less-dramatic theory that the draught may be internal circulation caused by its own stream.

SP4 is a small horizontal cave located a few hundreds of metres down-valley from the Sima Pumacocha entrances.  It has four entrances and requires a short rope to enter.  During exploration and survey in 2002 a human skull and some bones of unknown antiquity were discovered in a niche.

Qaqa Mach'ay is a -125m deep cave located high on the western edge of the Cerro Huampuna cirque several kilometres south of Sima Pumacocha on the narrow winding road that runs past the San Valentin mine.  At 4930 metres above sea level, it is the highest surveyed cave in the world.  It is visible from the road as an unusual undercut cliff and is thought to be an abandoned glacial sink (the topographical maps show no-longer-present glaciers ringing Cerro Huampuna).  The cave's most notable feature is its enormous entrance doline, fifty to seventy metres deep and fifty metres wide.  From its rim a twenty by twenty metre square passage can be seen.  Once down the entrance pitch there are two routes in Qaqa Mach'ay; Blue Lips Passage consists of three short pitches that essentially follow the left-hand wall of the passage down over boulders and ice to a climbdown into a boulder choke, and Red Face Passage is a modest, descending continuation of the main passage down four pitches, again to a choke.  These two routes were named after the effect the high altitude, combined with cold and the sun, had on the cavers.  There are ice masses within each passage, and about a third of the original exploration was anchored off ice-screws.  The cave draughts slightly.

Two small caves were explored and sketched near the mining settlement of Yauricocha.  Yauricocha 1 is located immediately adjacent to the road just west of the pass summit, and is a single blocked shaft about 20m deep.  Yauricocha 2 is visible as a large open rift from the road between the pass and the mine, and consists of a single chamber. 

The Puna Puyo area includes the notation 'tragadero' on the 1:100,000 scale topo sheet and was visited on foot by the 2002 expedition, with partial exploration and survey occuring in 2004.  A well-established trail on very easy terrain starts at the Chacachancha farmhouses a little way up the road above Tinco, continues up the 'puna' (high treeless valley) and reaches a ridge of limestone after a few kilometres.  A series of closed depressions dotted with cairns (presumably to guide shepherds during periods of 'puyo', or mist) leads up this quiet and pretty valley. Many of the obvious and easily-accessible entrances have been investigated; four were surveyed.  Tragadero Puyo is a large entrance that accepts one of only two small surface streams in the valley (the other sinks in gravel).  It consists of a spacious, mossy and quite beautiful entrance shaft leading to a pair of large chambers.  Unfortunately the water is lost even before leaving daylight and further explorations were through modest overflow passage down several short shafts separated by short sections of tight rift.  The cave draughts slightly; exploration was stopped at -107m when time ran out.  Immediately to the right of the Tragadero Puyo entrance is Pozo Waqtanpi, a pair of holes that lead to a 44m blind shaft.  A few hundred metres to the left and about fifteen metres higher is Cueva Puyo, an unlikely-looking entrance that leads down a series of short ramps and drops and is incompletely explored.  About a kilometre downvalley is La Cueva de la Cuerna, a 47m shaft that leads to a small amount of passage.  All four caves are at the contact between the valley floor an the vertically-bedded limestone ridge, except Cueva Puyo which is about 15m up.  All of the Puna Puyo caves are between 4400 and 4600m above sealevel and are amongst the highest surveyed caves in the world.

Varying degrees of surface reconnaissance was conducted in the areas surrounding each surveyed cave; please contact us for details of checked areas where no caves were found, or areas that continue to hold promise. 

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