File: D030806.jpg
The following text is an extract from the current draft of my chapter on Tropical Monsoon Karren in Australia for the "Karren Book".
Two types of horizontal solution ripple were described by Jennings (1982, p.23): on underhangs and in the twilight walls of cave entrances there are a sharp-ribbed and deeply recessed symmetrical form; whereas on steep slopes exposed by soil erosion of the pediment grikes there are more rounded and asymmetrical ripples that might have resulted from subsoil solution.
Jennings (1982, p.44-45) describes phototropic karren which are oriented grooves, sticks and spines in the twilight zone of the caves and deep grikes (see photos). These are a type of phytokarst eroded by algae. Individual spikes and grooves are between 2-50mm across, but can be up to 400mm long! The orientation varies according to the direction to the light. Some spikes have cave coral growths on their tips, or along their full length. Jennings (1982, p.45) describes small needles, 10mm high and 1-2 mm thick, on the side of a rather deep pan on top of one tower.
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Giant Grike inside a tower. File: D030806.jpg |
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Giant grike merging with a fissure cave passage. File: D030824.jpg |
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Solution ripples on cave wall - twilight zone. File: D030408.jpg |
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Solution ripples and some photo-tropic spikes. On a cave wall, twilight zone. Stereopair - view cross-eyed. File: D030421.jpg and ..420 |
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Solution ripples and phototropic spikes on cave wall - twilight zone. File: D030414.jpg |
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Photo-tropic spikes, with corraloid growths on the tips. Cave wall in twilight zone. Stereopair - view cross-eyed. File: D030419.jpg and ..418 |
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Photo-tropic spikes on cave wall, twilight zone. Stereopair - view cross-eyed. File: D030786.jpg |
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corraloid deposits on photo-tropic spikes. Cave wall in twilight zone. File: D030797.jpg |
(c) KG. Grimes, 2003