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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
Unusual speleothems resembling giant mushrooms occur in Cueva Grande de Santa
Catalina, Cuba. Although these mineral buildups are considered a natural heritage, their
composition and formation mechanism remain poorly understood. Here we characterize
their morphology and mineralogy and present a model for their genesis. We propose that
the mushrooms, which are mainly comprised of calcite and aragonite, formed during four
different phases within an evolving cave environment. The stipe of the mushroom is an
assemblage of three well-known speleothems: a stalagmite surrounded by calcite rafts
that were subsequently encrusted by cave clouds (mammillaries). More peculiar is the
cap of the mushroom, which is morphologically similar to cerebroid stromatolites and
thrombolites of microbial origin occurring in marine environments. Scanning electron
microscopy (SEM) investigations of this last unit revealed the presence of fossilized
extracellular polymeric substances (EPS)—the constituents of biofilms and microbial
mats. These organic microstructures are mineralized with Ca-carbonate, suggesting that
the mushroom cap formed through a microbially-influenced mineralization process. The
existence of cerebroid Ca-carbonate buildups forming in dark caves (i.e., in the absence
of phototrophs) has interesting implications for the study of fossil microbialites preserved
in ancient rocks, which are today considered as one of the earliest evidence for life on
Earth.
Although research has been unable to establish a definite date of discovery for the limestone caves at Wellington, New South Wales, documentary evidence has placed it as 1828. The actual discovery could have been made earlier by soldiers or convicts from the Wellington Settlement, which dated from 1823. Whether the aborigines knew of the cave's existence before 1828 is uncertain, but likely, as in 1830 they referred to them as "Mulwang". A number of very small limestone caves were also discovered about the same time in the nearby Molong area. The Bungonia Caves, in the Marulan district near Goulburn, were first written about a short time later. On all the evidence available at present, the Wellington Caves can be considered to be the first of any size discovered on the mainland of Australia. The Wellington Caves are situated in a low, limestone outcrop about six miles south by road from the present town of Wellington, and approximately 190 miles west-north-west of Sydney. They are at an altitude of 1000 feet, about half a mile from the present bed of the Bell River, a tributary of the Macquarie River. One large cave and several small caves exist in the outcrop, and range in size from simple shafts to passages 200 to 300 feet long. Mining for phosphate has been carried out, resulting in extensive galleries, often unstable, at several levels. Two caves have been lit by electricity for the tourist trades; the Cathedral Cave, 400 feet long, maximum width 100 feet, and up to 50 feet high; and the smaller Gaden Cave. The Cathedral Cave contains what is believed to be the largest stalagmite in the world, "The Altar", which stands on a flat floor, is 100 feet round the base and almost touches the roof about 40 feet above. It appears that the name Cathedral was not applied to the cave until this century. The original names were "The Great Cave", "The Large Cave" or "The Main Cave". The Altar was named by Thomas Mitchell in 1830. See map of cave and Plate. Extensive Pleistocene bone deposits - a veritable mine of bone fragments - were found in 1830, and have been studied by palaeontologists almost continually ever since. These bone deposits introduced to the world the extinct marsupials of Australia, and have a special importance in view of the peculiar features of the living fauna of the continent. The names of many famous explorers and scientists are associated with this history, among the most prominent being Sir Thomas Mitchell and Sir Richard Owen. Anderson (1933) gives a brief outline of why the Wellington Caves fossil bone beds so rapidly attracted world-wide interest. During the 18th and early 19th Century, the great palaeontologist, Baron Georges Cuvier, and others, supposed that the earth had suffered a series of catastrophic changes in prehistoric times. As a result of each of these, the animals living in a certain area were destroyed, the area being repopulated from isolated portions of the earth that had escaped the catastrophe. The Bilical Deluge was believed to have been the most recent. Darwin, during the voyage of the Beagle around the world (1832-37), was struck by the abundance of Pleistocene mammalian fossils in South America, and also by the fact that, while these differed from living forms, and were in part of gigantic dimensions, they were closely related to present-day forms in that continent. Darwin's theory of descent with modification did not reconcile with the ideas of Cuvier and others. As the living mammalian fauna of Australia was even more distinctive than that of South America, it was a matter of importance and excitement to discover the nature of the mammals which had lived in Australia in the late Tertiary and Pleistocene.
Halite has been found in five caves on the Nullarbor Plain, Western Australia. It occurs as stalactites, stalagmites, crusts, or fibres. The climate of the plain is arid to semi-arid, and the halite is derived from wind-blown salts that accumulate in the soil. The halite forms in the caves under conditions of relatively low humidity (about 70%) and high temperature (about 67°F). Its association with older calcite deposits suggests the climate was once wetter or cooler than at present.
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