CAVES AND GEOLOGICAL CONSERVATION IN NEW SOUTH WALES
ABSTRACT
Eight karst areas; Borenore, Bungonia, Cliefden, Ettrema, Jenolan, Wee Jasper, Wellington and Wombeyan and one pseudokarst area, Coolah Tops, are listed in the register of significant geological and geomorphological sites in NSW maintained by the Geological Society of Australia. Four Areas: Bungonia, Cliefden, Ettrema and Wee Jasper are described in Volumes 1 & 2 of the Geological Heritage of N.S.W.
Except in the case of Coolah Tops the development of caves was not the only reason for the sites significance and in most cases the development of caves was only considered to be of secondary significance. Cave managers need to be aware of the variety of geological phenomena that occur in the areas they administer and the potential that these have for geological education.
INTRODUCTION
Geological conservation is concerned with the identification, investigation, documentation, preservation and management of significant geological and geomorphological sites. These include: fossil and mineral localities, geological structures, stratigraphic type localities and representative landforms. The burden of this work in Australia has fallen on sub-committees of the Geological Society of Australia Inc. in each State and in the Commonwealth Territories.
The Geological Sites and Monuments Sub-Committee of the NSW Division of the Geological Society of Australia maintains a register of significant geological and geomorphological sites in New South Wales, has received grants under the National Estate Programme for identification and documentation of sites and is actively involved in the preservation and management of sites. The Sub-Committee provides information for Local Environment Plans and Plans of Management of National Parks and works in close co-operation with the Australian Heritage Commission, the NSW Heritage Council and the National Parks and Wildlife Service NSW. The Sub-Committee presently has a contractor working on further documentation of sites funded by a National Estate Grant of $20,000.
The work of the Sub-Committee covers all aspects of earth science (except soil reference sites which are the preserve of the Australian Institute of Soil Science) and has necessarily investigated some karst areas, most of which were brought to the Sub-Committee's attention for reasons other than the development of karst features.
The Sub-Committee has been reluctant to become involved in areas of purely "cave" significance as it believes that this is the proper role of the Australian Speleological Federation which has received a National Estate Grant for preparation of the Australian Karst Index.
In order to illustrate their geological significance, six of the karst sites and the one pseudokarst site are described below. I have not discussed Jenolan and Wombeyan which will be very familiar to you, however, it is important to note that these are significant vertebrate fossil localities.
SOME SIGNIFICANT GEOLOGICAL SITES IN NSW WITH KARST OR PSEUDOKARST FEATURES
1. Borenore
Borenore Caves are located west of Orange in central western NSW. The site was nominated as a type locality for vertebrate fossils (associated with cave deposits) and for the presence of highly fossiliferous Silurian limestones. This combination of Palaeozoic invertebrate fossils, Cainozoic vertebrate fossils and significant karst features (e.g. Arch and Verandah Caves) is typical of the karst areas included in the register.
The area is presently being investigated by the Sub-Committee's contractor who will be making a number of recommendations concerning its management. At present Verandah Cave (a significant ingrown meander cave) is not within the reserve boundaries and there are numerous problems with weeds, litter, lack of supervision and legal access to parts of the reserve These problems are currently receiving attention from the NSW Lands Department.
2. Bungonia
Bungonia Caves, northeast of Goulburn, is documented in the Geological Heritage of N.S.W. Vol II. (Stevenson, 1981). The site includes the caves, Bungonia Gorge and its environs. The Gorge, as a large scale karst landform, the fossiliferous Silurian limestones, and the presence of Tertiary leaf fossils were the original reasons for the site's nomination.
Bungonia is managed as a State Recreation Area by a trust appointed under the National Parks and Wildlife Act and is popular with both cavers and tourists. Their activities pose little threat to the geological significance of the area but do present a problem as far as cave and normal park management are concerned. The long term effects of limestone quarrying on the gorge, however, are still unclear. As with most geological sites with tourist potential much more could be done to inform the public about the reasons for the area's significance.
3. Cliefden
Cliefden Caves is an internationally significant Ordovician fossil locality and has been the subject of much palaeontological research. It was for this reason that the site was included in the register. The caves at Cliefden are also considered to be significant containing blue aragonitic stalactites and a profusion of helictites.
Cliefden Caves are located on private property which is managed as a Wildlife Refuge under the National Parks and Wildlife Act. The owner manages the caves in co-operation with Orange Speleological Society and access to the fossil localities is restricted to genuine researchers. As a result of this Cliefden Caves is one of the best managed geological sites in NSW. Despite gating of the cave entrances vandalism, including removal of part of a blue stalactite (probably by commercial mineral collectors), has taken place.
The area is threatened in the long term by dam proposals which would result in inundation of both the caves and the significant fossil localities. Cliefden Caves is documented in the Geological Heritage of N.S.W. Vol I. (Percival, 1979).
4. Ettrema
Ettrema Creek is a tributary of the Shoalhaven River in the ranges west of Nowra. At the Ettrema site limestones of Late Devonian (Frasnian) age are exposed. These are unusual in NSW. A massive sulfide deposit is also found in the area. Minor karst development is reported in the limestone at Ettrema but its age, palaeontology and the mineralisation are the reasons why this is considered to be a significant geological site. Ettrema is documented in the Geological Heritage of N.S.W. Vol II. (Stevenson, 1981).
5. Wee Jasper
The Wee Jasper site covers a large area of land in the valley of the Goodradigbee River, a tributary of the Murrumbidgee that flows into Burrinjuck Dam. The Wee Jasper Caves are included within the sites.
The Devonian rocks exposed are important as sources of invertebrate and fish fossils and it was for this reason that the site was included in the register.
Extensive caves are developed in the limestone but except for Careys Cave, which is managed as a tourist cave there is little cave management. Wee Jasper is documented in the Geological Heritage of N.S.W. Vol II. (Stevenson, 1981).
6. Wellington
Wellington Caves, located 8km south of Wellington, in central western NSW is the only site registered whose significance is based largely on cave sediments and their fossils. Since the discovery of vertebrate fossils in the caves in 1831, Wellington Caves has been a Cainozoic fossil locality of great significance.
Two caves are operated as tourist attractions by Wellington Shire Council but the public do not see the extensive bone deposits which have been at the centre of scientific research for over 150 years.
Significant cave deposits are found in the floors of the caves and in the Phosphate Mine, Big Sink and Bone Cave which are artificial excavations. Loss of exposure by collapse of unstable mine passages and poorly organised research programmes pose the greatest threat to the Wellington Caves site. Much collecting in the past has resulted in collections of fossils without adequate location data and in the production of many unsightly excavations. Wellington Caves are not threatened by amateur or illegal fossil collectors due to the high level of security maintained by the Council's staff. The value of the deposits themselves and their accessibility to researchers could be put in jeopardy if relations between scientists and the Council were to deteriorate of if poor research techniques were to be used. Wellington Caves are currently being investigated by the Sub-Committee's contractor.
7. Coolah Tops
Coolah Tops are part of the Liverpool Ranges, an extensive basalt plateau located in central NSW. The area is significant for the development of caves within Tertiary basalt.
The exact mode of formation of these caves, which contain both carbonate and zeolite spelothems, is unclear but they do not seem to be lava caves in the normal use of the term and may be blister caves.
The caves occur both on freehold land and in State Forests, are poorly known and difficult of access. The number and extent of these caves is not known and only very preliminary research has been carried out into their origin and the mineralogy of their deposits.
For the time being at least there seems to be little threat to the caves but their status will need to be monitored particularly if visitation to the area increases. At least part of the area in which the caves occur is in a National Park proposal.
IMPLICATIONS FOR CAVE MANAGERS
Cave areas often have geological significance apart from that directly related to their caves and other karst features An awareness of these will enable managers of karst areas to better fulfil their important interpretative functions.
The karst areas described above are those whose general geological significance has been identified and in no way relate to their significance as examples of karst. Geological conservationists working in the Sub-Committees of the Geological Society of Australia are not in a position to determine either the significance or representativeness of karst features and these only make up a small subset of the whole range of geological and geomorphological sites with which they are concerned. Since so many karst sites are registered for reasons not directly related to karst is seems likely that the karst areas not registered may very well also have significant geological features that have not been recognised.
As geological conservation is still in its infancy in Australia and work in this field is largely done on a part-time, voluntary basis present knowledge of the geological heritage of Australia is fairly poor. For this reason the NSW Sites and Monuments Sub-Committee works, within the constraints of its limited resources, to make information about geological conservation available to planners and natural resource managers. Cave managers control a significant part of the geological heritage it is the aim of this paper to show them that as well as their caves, the rock in which they have formed can be a significant part of the nation's heritage.
REFERENCES
PERCIVAL, I.S., 1979: The Geological Heritage of New South Wales. Geological Society of Australia Inc, Sydney (unpubl)
STEVENSON, B., 1981: The Geological Heritage of New South Wales Volume II. Geological Society of Australia Inc, Sydney (unpubl).