Extracts from QN News No243
Nullabor Plains Caves by David Lowry
General Meeting Report: May 20 2003
David Lowry began his talk by telling us the Eucla Basin is the geologic
term for the area of tertiary sedimentation that extends over the continental
shelf at the Great Australian Bight; Nullarbor is the name for the
treeless stony plain. Coloured maps showed the elevation of the various
areas, the old Miocene shoreline and limestone plateau.
David first went to this area in 1963, looking for a crater; this
was the site of a cave system and he mapped the surface area for the WA
government. Slides illustrated the stony nature of the plain, coastal
cliffs, relic sea scarp, with glimpses of such things as the old telegraph
station and camel wagons.
There are two types of caves: deep and shallow. Cocklebiddy
Cave is a good example of a deep cave, and a cross-section illustration
showed its features that included a lake that lay in a long tube.
A team with diving equipment later swam a distance of about 8 miles
along this. In the cave were halites, and David’s explanation of the presence
of these was that they were possibly caused by salt water (spray across
the land) seeping through into the caves and crystallising out when the water
evaporated, extruding through cracks into these hair shapes.
The shallow caves had ‘blowholes’ out of which very strong winds
blew. He felt that these blowholes were not caused from rock pools
that had corroded their way downwards, as had been assumed. He decided
they had come up from underneath, in domes that eventually broke through
He noticed that the Cocklebiddy lake level changed during the day
and that this change had a correlation with the air pressure – the rising
pressure of air pushes the lake level down.
In 1966 he found the cave that became known as the Thylacine
Cave, as he found a very well preserved carcase of a thylacine there.
This cave is a typical example of a shallow cave, and it had a huge amount
of skeletal material from animals that presumably had fallen down the hole.
It was a little surprising that there were more remains of carnivores than
of herbivores, but perhaps the carnivores were attracted by the smell of
trapped herbivores. The thylacine was taken to WA Museum and
dated at 4600 years old, but stories from a local Aboriginal source seemed
to suggest to David a much later date for the presence of thylacines (e.g.
about 400 years). The animal was a subspecies that was smaller than
the Tasmanian thylacine and probably a female (from its size).
Life in the caves was sparse. There were bats, crickets
and others that came in to shelter. Two spiders and one centipede
were blind and without pigment, suggesting that they had adapted entirely
to life underground (perhaps not only in these caves, however).
David was working only in the Western Australian stretch; here there
were 20 odd deep caves and a lot of blowhole caves.
EXCURSION REPORT: Jolly’s Lookout to Boombana, BFP, May 18 2002
The seven members who made it to this walk had a most enjoyable day.
Although easily accessible at any time, being a public walking track, the
area has much of natural history to offer, and is rarely, if ever, host
to a concentration of people. To walk it as a Nats group was a huge
bonus. We encountered only two other couples fast-tracking past, so
virtually had it all to ourselves.
We took time to look at the excellent display of the volcanic
origins of Jolly’s Lookout and then went on the 4 kilometre track that heads
out into the forest, staying on the one contour level all the way to Boombana.
It goes through both sclerophyll and rain forests, and we stopped many times
to look at such things as the arrangement of spores on ferns (we passed
eleven species), the smooth trunks of Python wood (Austromyrtus bidwillii),
Logrunners scratching in the litter, and small unidentifiable flowers shed
on the path from somewhere up in the high canopy. Not surprising then
to reach the morning tea spot, about three quarters of the way along, at
about 11.30. Consequently, lunch was a divided affair, partaken partly
here and the rest at Boombana a little later. (Some people called this
part of it ‘munch’.)
After lunch, we did the circuit walk at Boombana, but the
highlight was a view of a male Paradise Riflebird at lunch time.
Having left one car at Boombana, we transported drivers back to
their cars to avoid the walk back along the road, and had afternoon tea
at our place down the range. It was very pleasant indeed, made more
so by the fact that it was all ours for the day and so close to Brisbane.
Stephens, K.M. & Dowling, R.M.: Wetland Plants
of Queensland. A field guide. 160 pp. CSIRO
The book was originally planned ‘as a resource to assist those people involved
in the construction and use of artificial wetlands used for the treatment
of waste water’. However, its value extends beyond that area; it is
an attractively produced work and will be a useful source for naturalists
interested in the flora of wet freshwater areas.
There is a ‘Key to the Genera of Wetland Plants Occurring
in Queensland’. This is clear and well-constructed and leads one mostly
to a genus, in two cases to a family, and, where only one species of a genus
is treated, to that species. In the families Cyperaceae and Poaceae and
the genus Juncus the use is directed to previously published keys.
Otherwise, for each genus mentioned in the main key there follows a key
to ‘species occurring in Queensland wetlands’. These keys contain numerous
species which I should have thought of as being typically plants of other
habitats. Examples of such species are Anagallis arvensis (Scarlet Pimpernel)
and Cardamine hirsuta (Common Bittercress), both common weeds of gardens,
and Hydrocotyle pedicellosa, usually occurring along rainforest tracks.
In the Introduction it is stated: ‘The key will also help you to identify
closely related species’, but since the key headings state ‘species occurring
in Queensland wetlands’ and there is no identifying of the ‘closely related
species’ there is potential here for confusion. Nearly 350 species
are included in the keys.
For ninety species, there is a page each with family name,
scientific name, habit and description, flowering period and notes.
There is a map of Queensland showing distribution of the species and photographs,
sometimes two, of the plant. These illustrations, in the main, provide
useful assistance in making a determination but a few, such as those of Hydrilla
verticiallata and Utricularia stellaris are of doubtful value.
The copy received for review lacked several pages at the end
which included most of the Glossary, References and Index.