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Crayback stalagmites have mainly been reported from New South Wales, Australia. Here we document a small crayback in the entrance of Painted Cave (Kain Hitam), part of the Niah Caves complex in Sarawak, Borneo. Measuring some 65 cm in length and 18 cm in height, this deposit is elongate in the direction of the dominant wind and thus oriented towards the natural tunnel entrance. It shows the classic humpbacked long profile, made up of small transverse segments or plates, in this case the tail extending towards the entrance. The dark blue-green colour down the centre suggests that cyanobacterial growth follows the track of the wind-deflected roof drip. The dry silty cave sediment provides material for accretion onto the biological mat. This is the only example known from Borneo and one of the very few known from outside of Australia
Crayback stalagmites have mainly been reported from New South Wales, Australia. Here we document a small crayback in the entrance of Painted Cave (Kain Hitam), part of the Niah Caves complex in Sarawak, Borneo. Measuring some 65 cm in length and 18 cm in height, this deposit is elongate in the direction of the dominant wind and thus oriented towards the natural tunnel entrance. It shows the classic humpbacked long profile, made up of small transverse segments or plates, in this case the tail extending towards the entrance. The dark blue-green colour down the centre suggests that cyanobacterial growth follows the track of the wind-deflected roof drip. The dry silty cave sediment provides material for accretion onto the biological mat. This is the only example known from Borneo and one of the very few known from outside of Australia.
The Painted Cave is a subhorizontal relict tunnel passage which runs through a small karst tower, approximately 30m above the surrounding alluvial plain and adjacent to other large karst towers in Niah National Park (Sarawak, Malaysia). Lundberg and McFarlane (2011) described the occurrence, morphology and mode of formation of a crayback stalagmite close to the north entrance of the cave. The presence of numerous other crayback-like stalagmites in three zones of the same cave is reported here. Their elongated humped-back morphology indicates formation influenced by cave wind. The axial orientations of the crayback-like stalagmites are similar in each of the three cave zones, but differ between the zones. Many of the stalagmite features resemble those of crayback stalagmites, suggesting that cyanobacteria may also have played a role in their formation. The Painted Cave has large entrances at both ends. The natural light levels within the cave are sufficient for cyanobacterial growth and cave wind is noticeable. A suite of stalagmite morphologies ranging from forms that are wind influenced but abiotic, to forms that are also moderately to strongly influenced by cyanobacteria is suggested.
There are two significant karst regions in northern Sarawak (Malaysia): Niah and Mulu. Both are famous worldwide for their well developed caves. Here we document the presence of over twenty unusual stalagmites in six cave entrances in these two regions. One of the stalagmites has been previously described as a crayback stalagmite (Lundberg and McFarlane 2011) and they all show indications of biological influence. Our study aimed to establish the locations within the cave entrances where these stalagmites are present and to provide a preliminary overview of the stalagmite forms. The environment, and especially availability and direction of light, was also studied at several sites. Surface scrapings were examined for the presence of cyanobacteria. The morphology of the unusual stalagmites is variable and includes forms that are elongated and craybacklike and others that show features not previously described in craybacks: flat tops, bulbous protuberances, phototropic rims, irregular grooves and ridges and oriented coralloid growth. Several of these features are not found in abiotic stalagmites and suggest biological control. The findings of light surveys confirm that certain features of the stalagmites are phototropically controlled. Filamentous cyanobacteria with calcified sheaths and coccoid cyanobacteria are present. we propose that this diverse group of stalagmite be named “tufaceous stalagmite” of which craybacks are thought to be a subgroup.