Plateau with underground rivers
The exotic Mamo plateau consists mainly of carbonate rock – the Darai limestone formation here is approximately 1,400 m thick. These rocks formed in upper Oligocene – middle Miocene and over the last several millions of years have experienced a rise far above the sea level.
During the uprise rocks were fractured and folded and later water found a way through these layers.
Nowadays there are no rivers crossing Mamo plateau above the ground, although this is one of the wettest places on Earth with approximately 11,500 mm of precipitation per year. All the rivers cross the plateau underground, discharging from the precipice – southern rim of Mamo plateau.
These powerful rivers create giant voids in the limestone. After some while the ceiling of these voids collapses and gets covered with unpermeable rock of siltstone and claystone layer which lies above the limestone here. Underground river then finds a new way through the rock and makes there new voids, which again collapse after some time…
For most part these collapses do not serve as entrances in caves. But in the south-eastern part of Mamo plateau there are few beautiful, giant sinkholes which contain entrances in caves.
Most impressive cave here is Mamo Kananda. Total length of explored passages has reached 54,800 m.
Cave has developed in eight levels – each of them has developed in more pure limestone layers of Darai formation. Three chambers here have giant size, exceeding volume of 1 million m³. For example, at furthest point of cave there is located enormous chamber called: Space Oddity. It is the deepest part of the cave, located 528 m below the entrance. If one day this classic domed chamber will collapse, here will open giant sinkhole.
Another characteristic chamber is Rinse Cycle – phreatic tube which floods daily, after the afternoon storms.
- James J.M. Giant dolines pf the Muller Plateau, Papua New Guinea, Speleogenesis.info. Accessed 25.07.10.
|Coordinates:||5.6100 S 142.3314 E|
|Address:||Australia and Oceania, Papua New Guinea, Southern Highlands Province, south-western part of Muller Plateau, 22 km north-west from Mount Karoma|
One of the most exciting and mysterious lands in the world is Papua New Guinea. This country takes half of the second largest island and numerous other larger and smaller islands. Up to this day Papua New Guinea is poorly investigated and here are expected numerous exciting discoveries of geological, biological and archaeological nature.
Category includes outstanding sinkholes – large natural depressions or holes, which for most part represent collapsed caves.
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