Chapter 3 KARST RESOURCES AND CAVE ...

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from the mechanical failure of cavities and generally have steeper sides and are more irregular in plan than solution sinkholes. The Arrakis or Fairy Dell sinkhole.
Chapter 3

KARST RESOURCES AND CAVE BIOLOGY bv K. Kiernan and S. Eberhard The World Heritage Area (WHA) contains a diverse range of karst phenomena that contributed significantly to the case for World Heritage status. Important phenomena are revealed by analysts at four levels: karst systems, landforms and landform assemblages, landform contents, and human use of the karsts. Evolution of the karst has been strongly influenced by late Cainozoic environmental change and many features are multiphase phenomena. The karst fauna includes cave obligate invertebrate species known only from the WHA. Caves have served as refuges for some species during periods of cold glacial climate. Several distinctive community types and bioiieographical groups are discernible, and these suggest that the age and composition of the cave fauna have the potential to be related to past climate change and the geomorphic history of the area. Key Words: geomorphology, karst, landt'orms. caves, cave biology, biogeography, refuges, truglobites, evolution, environmental change, world heritage. Tasmania. In Smith. S.J. & Banks. M.R. (Eds). 1993: TASMANIA^ WILDERNESS—WORLD HERITAGE VALUES. Roval Society ot" Tasmania. Hobart: 28-37.

INTRODUCTION

scientirlc knowledge of the WHA has been out of proportion to their areai extent. For example, debate over possible limestone mining at Precipitous Bluff was a major stimulant to the establishment of the National Estate Enquiry and the founding of the Australian Heritage Commission (Kiernan I989gi. Former Prime Minister Malcolm Fraser has claimed that it was the archaeological discoveries in Kutikina. a karst cave, that tipped the balance towards saving the Franklin River from hydro-electric development (R. Williams 1985). The karst contributed significantly to the case for World Heritage status being accorded to the urea. The Australian Government's nomination cited karst values with respect to all of the four possible criteria under which natural heritage siter> may be nominated, and with respect to two of the six possible criteria for nomination of cultural heritage sites.

Karst landscapes result from the higher than average solubility in natural waters of some rock types, notably limestones and dolomites, and the dissolution of these rocks to form underground drainage channels and caverns (Jennings 1985). Karst areas are characterised by a paucity of surface streams and by surface landforms that include various forms of enclosed depressions (sinkholes ordolines). rock outcrops complexly sculpted by solution (karren). and residual hills. Subsurface drainage patterns may bear little or no resemblance to the directions of drainage suggested by the surface topography. Karst terrain can be of high conservation significance for a variety of scientific, economic, recreational, educational and aesthetic reasons. By world standards. Australia contains little e.\posed karst (Jennings 1975). However. Tasmania approaches the world average, and about 120000 ha ore. Sc/c of the World Heritage Area (WHA) may be underlain by carbonate rocks (fig. 3.11 (Kieman 19XSa). Few of these karsts are well known. Nevertheless, important phenomena are revealed by analysis at four levels: karst systems, landforms and landfonn assemblages, landform contents, and human use of the karsts. The contribution of these karsts to issues of resource politics and to

NATURE OF THE KARST SYSTEMS The World Heritage n o m i n a t i o n recognises that processes of karst geomorphological and hydrologicai evolution continue uninterrupted in the WHA. in LI variety of lithological. topographic, biokarstic and climatic (including palaeoclimatic) contexts (natural 28

FIG.3.1 —Approximate extent of potentially karstic iii/tiiferx in the Tasmuntan World Heritage Area and adjacent bursts mentioned in text. Low itqwftrapllit' relief din/ thick covers of Quaternary sediment inin'hit karat topography in some of these ureas. / - He du Golfe: 2- Rocky Bout Harhonr: 3 - Surprise Bay: 4 — Pi/i(iars:5~ Precipitous Bluff: () - \ Falls: 7 - Ida Bay;