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Clastic sedimentary rocks are generally considered non-karstifiable and thus less vulnerable to pathogen contamination than karst aquifers. However, dissolution phenomena have been observed in clastic carbonate conglomerates of the Subalpine Molasse zone of the northern Alps and other regions of Europe, indicating karstification and high vulnerability, which is currently not considered for source protection zoning. Therefore, a research program was established at the Hochgrat site (Austria/Germany), as a demonstration that karst-like characteristics, flow behavior and high vulnerability to microbial contamination are possible in this type of aquifer. The study included geomorphologic mapping, comparative multi-tracer tests with fluorescent dyes and bacteria-sized fluorescent microspheres, and analyses of fecal indicator bacteria (FIB) in spring waters during different seasons. Results demonstrate that (i) flow velocities in carbonate conglomerates are similar as in typical karst aquifers, often exceeding 100 m/h; (ii) microbial contaminants are rapidly transported towards springs; and (iii) the magnitude and seasonal pattern of FIB variability depends on the land use in the spring catchment and its altitude. Different ground water protection strategies than currently applied are consequently required in regions formed by karstified carbonatic clastic rocks, taking into account their high degree of heterogeneity and vulnerability.
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Anomalous behaviour of specific electrical conductivity (SEC) was observed at a karst spring in Slovenia during 26 high-flow events in an 18-month monitoring period. A conceptual model explaining this anomalous SEC variability is presented and reproduced by numerical modelling, and the practical relevance for source protection zoning is discussed. After storm rainfall, discharge increases rapidly, which is typical for karst springs. SEC displays a first maximum during the rising limb of the spring hydrograph, followed by a minimum indicating the arrival of freshly infiltrated water, often confirmed by increased levels of total organic carbon (TOC). The anomalous behaviour starts after this SEC minimum, when SEC rises again and remains elevated during the entire high-flow period, typically 20–40 µS/cm above the baseflow value. This is explained by variable catchment boundaries: When the water level in the aquifer rises, the catchment expands, incorporating zones of groundwater with higher SEC, caused by higher unsaturated zone thickness and subtle lithologic changes. This conceptual model has been checked by numerical investigations. A generalized finite-difference model including high-conductivity cells representing the conduit network (“discrete-continuum approach”) was set up to simulate the observed behaviour of the karst system. The model reproduces the shifting groundwater divide and the nearly simultaneous increase of discharge and SEC during high-flow periods. The observed behaviour is relevant for groundwater source protection zoning, which requires reliable delineation of catchment areas. Anomalous behaviour of SEC can point to variable catchment boundaries that can be checked by tracer tests during different hydrologic conditions.
The historical study of Australian caves and caving areas is fascinating although involving the expenditure of vast amounts of time. Australia's early days are unusually well-documented, but in the case of caves the early history is usually wrapped up in rumour, hearsay and clouded by lack of written record. Most research work means long hours poring over old newspaper files, mine reports, land department records and so on, little of which is catalogued. A small number of exploration journals and scientific studies have extensive material on special cave areas, and of these, the volume by Rev. Julian Edmund Woods, F.G.S., F.R.S.V., F.P.S., etc., and is one of the most interesting. This book gives the ideas and beliefs of 100 years ago concerning the origin, development and bone contents of caves and makes interesting reading in the light of more recent studies of cave origins. Wood's study "Geological Observations in South Australia : Principally in the District South-East of Adelaide" was published in 1862 by Longman, Green, Roberts and Green, London. In a preface dated November 15, 1861, Rev. Woods points out that the book was written while he was serving as a missionary in a 22,000 square mile district, and "without the benefit of reference, museum, library, or scientific men closer than England". Up to the time of writing, almost no scientific or geological work had been done in South Australia and much of the area was completely unexplored. The book, also, contained the first detailed description of caves in the south-east of the state. Father Woods writes about many different types of caves in South Australia, for instance, the "native wells" in the Mt. Gambier/Mt. Shanck area. These are caves, rounded like pipes, and generally leading to water level. Woods points out their likeness to artificial wells. He also writes of sea cliff caves, particularly in the Guichen Bay area, and blow holes caused by the action of the waves on the limestone cliffs. Woods discusses many other types of caves found further inland, particularly bone caves. Father Woods discusses cave origins under two sub-heads: 1. Trap rock caves generally resulting from violent igneous action, and 2. Limestone caves resulting from infiltration of some kind. He is mainly concerned with limestone caves which he sub-divides into (a) crevice caves - caves which have arisen from fissures in the rock and are therefore wedge-shaped crevices, widest at the opening, (b) sea-beach caves, caves which face the seashore and are merely holes that have been worn by the dashing of the sea on the face of the cliff, (c) egress caves, or passages to give egress to subterranean streams, (d) ingress caves, or passages caused by water flowing into the holes of rocks and disappearing underground. These caves would have entrance holes in the ground, opening very wide underneath, and having the appearance of water having entered from above, (e) finally a group of caves which he lists by use as "dens of animals".
Various geomorphologists such as Bögli, Corbel and Lehmann have in recent years demonstrated the interest that certain simple chemical analyses of natural waters can have for the comparison of rates of limestone solution in different in different climatic conditions. They can also have their relevance for the tracing of underground water connections as Oertli (1953) has shown in the example of the Slovenian part of the classical Yugoslavian karst. Since 1957, the writer has therefore been making such analyses of waters from Australian limestone areas. The chief significance of these measurements comes when one caving area is compared with another. M.M. Sweeting (1960) has already commented briefly on observations from Mole Creek, Tasmania, Buchan, Victoria and the Fitzroy Basin, Western Australia, made in 1958-59 by herself and the writer; further discussion will appear in a forthcoming publication of ours on the Limestone Ranges of the Fitzroy Basin. Nevertheless measurements of this kind can have a certain intrinsic interest as it is hoped to show in the following notes on the few observations I made at Yarrangobilly. These observations are set out in tabular and Trombe graph forms; the locations of the collecting points are shown on the map.
The majority of South Australian caves occur in the Tertiary and Quaternary limestones of the coastal areas. Their distribution is discussed here on a geological rather than a geographical basis. The most significant caves are briefly described and illustrated to indicate different types and related developments in the coastal limestones. The most notable feature of the limestones is their soft, porous nature. Caves also occur in South Australia in hard, massively bedded Cambrian and Pre-Cambrian limestones and dolomites. These are not discussed in the present paper. To facilitate recording, South Australia has been divided into six zones as shown in Figure 1, and the caves numbered in order of discovery in each area. In general, both the name and the number of the cave have been given, but unnamed caves are specified by number only. The cave maps have been chosen to give as wide a coverage as possible of the various types, or to illustrate points of particular interest. The arrows on the section lines show the direction of viewing, and the sections are numbered to relate them to the plans. Where a cross-section and longitudinal section intersect, the common line has been drawn to relate the sections. The same scale has been used throughout for ease of comparison.
The clustering areas of bent-winged bats in limestone caves are frequently stained and etched. This staining is very intense, and covers large areas at breeding caves present in Palaeozoic limestones. Erosion of limestone is very conspicuous in these caves. Staining is not intense at breeding caves in Tertiary limestones, but a combination of chemical and mechanical erosion may, in part, account for the depth of dome pits in which the bats cluster. Certain caves that are characterised by extensive guano deposits and by conspicuously eroded and/or stained limestone, but which are currently without large colonies of bats, may represent ancestral breeding caves.
Eight breeding Caves of Miniopterus schreibersi (Kuhl) are described from South Australia, Victoria, New South Wales and Southern Queensland, in terms of their structure, the location of nursery areas at which juveniles are deposited after birth, and their physical environments. Maternity colonies are found at these caves through spring, summer and early autumn. Established colonies range from about 15,000 to 200,000 bats at peak size. These individuals are predominantly adult females and their young. Adult males are conspicuous only at the single South Australian breeding cave. Births occur from approximately the beginning of December to mid-January at all colonies except that in South Australia, where a birth period is evident between mid-October to late-November. Artificial warming, as a consequence of bat activity, appears to be characteristic of these Miniopterus schreibersi breeding caves. It is suggested that this may have functional significance in facilitating adequate development of juveniles, and that the habit could be a reflection of the tropical ancestry of this species.
The caves of the Chillagoe District are well-known by repute, but have not been described in speleological literature to date. The author visited the area in April, 1964, in company with Mr. D. Fitzsimon, of Mareeba. This paper summarises the observations made on that occasion. Chillagoe is an almost deserted town, once the centre of an extensive mining industry, and is situated about 120 miles west of Cairns, North Queensland. Access may be gained either by road or rail from Cairns. It can be seen from Table 1 that the climate is monsoonal, with comparatively heavy summer rains, but with dry weather throughout the remainder of the year. The Silurian Limestone in which the caves occur forms a belt some 40 miles long by four miles wide, extending from Almaden in the south-east to the Walsh River in the north-west. Caves probably occur throughout much of this belt, but known caves are concentrated in the Chillagoe and Mungana areas. Mungana lies approximately ten miles north-west of Chillagoe.
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