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<title>Cambridge Underground 1982: Expo Cave Development</title>
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<center><font size=-1>Cambridge Underground 1982 pp 15-20</font>
<h1>Loser Plateau: Geology and Speleogenesis</h1>

<h2>CAVE DEVELOPMENT IN THE TOTES GEBIRGE, AUSTRIA</h2></center>

<p><font size=-1>Webeditor's note: although this article expounds theories
somewhat at odds with current thinking, it does have the one great advantage
of having been written down and published, something which few of the more
qualified club theorists have been able to achieve. It is thus included on
the site for completeness, but should probably be taken with a pinch of
salt.</font>
<hr>
<p>Locally-hosted copies of extensive archive of geology and cave formation papers:
<ul>
<li><a href="/expofiles/documents/cave_science_articles/structural-geology/">
Structural geology</a>
<li><a href="/expofiles/documents/cave_science_articles/speleogenesis/">
Speleogenesis</a>
<li><a href="/expofiles/documents/cave_science_articles/landscape-evolution-paleoclimate/">
Paleoclimate and landscape</a>
<li><a href="/expofiles/documents/cave_science_articles/">
Other cave science articles</a>
<li><a href="/expofiles/documents/cave_science_articles/german-stuff/">
(papers in German)</a>
</ul>
<h3>INTRODUCTION</h3>

<p>In reading through material related to this discourse I discovered
reference to the writings of Cvijic, who had devoted considerable effort to
the study of the extensive karst region of Jugoslavia, drawing certain
conclusions as to the formation of that area, which I incorporate here as
background to the area of Austria we have visited over the last few years
considering its apparent similarities.

<p>The basis for Cvijic's cycle of erosion requires three factors to be
present: a thick and extensive mass of limestone, accompanied by an
underlying impermeable rock for the initiation of a stream pattern.

<p>"A study of the Totes Gebirge region (the Northern Limestone Alps), shows
that it is composed mainly of Alpine Triassic and Jurassic (limestone),
nonconformably overlain by paralic and largely detrital sediments of late
Cretaceous and early Tertiary age (the Gosau Beds found in small scattered
concentrations). The main elements of the Northern Limestone Alps are massive
carbonate series of the Middle and Upper Triassic which may reach thicknesses
of over one kilometre. Below and between the massive carbonate members are
found thinly bedded series of shales and evaporites." The requirements seem
amply fulfilled.

<p>Cvijic's cycle then has three phases of development; in Youth the upper
impermeable layer is removed by streams which then go underground through
enlarged joints and fissures, the drainage pattern disintegrates, streams
flow down normal valleys only to disappear into solution holes at blind ends.
In Late Maturity the underground streams reach the impermeable underlying
stratum and cavern roofs collapse, the limestone cover is reduced to a few
outliers honeycombed with caves, and is finally removed.

<p>In the area of the Totes Gebirge the Youth phase has been passed with
almost no surface drainage now apparent, although
<b lang=de>Sonnenstrahlh&ouml;hle</b> is an example of the result of a
previous surface stream pattern which once flowed down a well defined valley
into its impressive entrance chamber (partially collapsed). The surface is
now generally composed of highly jointed limestone with no soil to prevent
water from passing directly underground. How far the area has moved into the
Mature stage is the question of greatest interest to the speleologist in the
search for a deep system, a question which will be answered by continued
exploration.

<h3>DETAILED CONSIDERATION</h3>

<p>In the two major systems discovered to date we have encountered the two
forms of cave entrance in the shaft-like solution hole of
<b lang=de>Eislufth&ouml;hle,</b> and the funnel-shaped depression of
<b lang=de>Sonnenstrahlh&ouml;hle</b> (considered likely to be a top entrance
to the <b lang=de>Stellerweg</b> system). In this context their relative
positions on the massif are interesting (see <a href="tmmap.htm">map and
section</a>). Returning to Cvijic's erosion cycle, the
original surface stream pattern formed on an impermeable layer has, in the
case of <b lang=de>Sonnenstrahlh&ouml;hle</b>, followed a well-defined route
towards the edge of the massif where it has met a weak point in the limestone
structure in the form of a slip fault. The angle of the passage in this cave
and <b lang=de>Stellerweg</b> is similar (around 60 degrees from the
horizontal) and conforms to the notion of water eroding along a line of least
resistance, along this fault.

<p>In the case of <b lang=de>Eislufth&ouml;hle</b> the situation is rather
different (refer to <a href="tmmap.htm">map, section</a> and 
<a href="tmelev.htm">surveys</a>). The cave is situated roughly centrally in
a depression surrounded on three sides by steep slopes - a depression of
bare, heavily-jointed limestone. During the ice age this high ground would
have been covered with a permanent ice field. In this situation the erosional
processes would be concentrated under the snow allowing a depression to be
formed, itself enlarged into a more circular plan by the action of ablation
around its edges. As the depression begins to form its development
accelerates as snow becomes more readily captured in it and its permanence
becomes enhanced as its bulk reduces the effects of temperature fall. As
opposed to the tremendous abrading of the valley glaciers, solution becomes
the dominant erosional process as meltwaters flow under the ice searching for
the easiest way down to the water table. Over long periods of time a cave
system is formed draining the plateau.

<p>The position of the water table then begins to affect the formation of the
cave. As long as the water table is beneath the surface, water will percolate
down along the easiest route, defined by the structure of the rock itself.
The actual form of the water table will itself be dependent on the
permeability of the rock - small and irregular joints will form the water
table into a dome shape before the pressure of water is sufficient to produce
lateral movement; conversely, if the joints have been enlarged by solution
(ie. a cave system exists) the water will escape rapidly producing an almost
flat water table.

<p>In <b lang=de>Sonnenstrahlh&ouml;hle</b> there are four levels at which
horizontal cave development has occurred. The entrance series results from
the direct action of the surface water in its original pre-glacial pattern
flowing into the fault and searching for the easiest way down. Down in fact
to the second level of horizontal activity at around 1600 metres, at which
level a large chamber with side phreatic passages has formed. This is the
same level as the horizontal entrance series found in
<b lang=de>Stellerweg</b> (see <a href="tmelev.htm">surveys</a>).

<p>(It should be noted that the angle of the elevation for the 113 survey
does not demonstrate the extent of the horizontal development. For a better
picture see plan of 113, Cambridge Underground 1981.)

<p>The series of shafts that dissect the horizontal route from above and
continuing below, are the later routes formed by water percolating down from
the denuded limestone surface to the much reduced water table below these
abandonded upper phreatic sections. By this stage the surface drainage
pattern has disappeared and the cave has become a collector of water from
numerous sources rather than its original stream route. The horizontal
phreatic tube 'entrance' to Stellerweg is a long-abandoned resurgence.

<p>At 1600 metres, therefore, <b lang=de>Sonnenstrahlh&ouml;hle</b> has
become a collector for waters searching for the water table which, following
the advance of the neighbouring valley glacier, has been greatly lowered. The
cave enters a vertical phase, a large shaft enlarged by spray action, until
it reaches 1500 metres at a very jagged broken floor with an immature stream
outlet and a small meandering phreatic tube opening once more onto an
enormous shaft section - this has no apparent equivalent in
<b lang=de>Stellerweg</b> (perhaps it can be attributed to a localised change
in the character of the rock). The termination of the next vertical section
is, however, directly reflected in <b lang=de>Stellerweg</b> at 1400 metres.
There is considerable horizontal development in <b lang=de>Stellerweg</b> at
this level which has not been explored as yet, but suggests the possibility
of a link with <b lang=de>Sonnenstrahlh&ouml;hle</b> because of the abandoned
phreatic development evident there also and an apparent continuation of that
section, unfortunately blocked by boulders at present. The complex phreatic
entrance series to 115 is also located at this level. This is obviously the
level of the water table following the first major invasion of ice in this
area. The large, now abandoned, phreatic cave passages developed during a
period of stability during and after the retreat of the ice, emerging as
tubes of varying sizes from the valley sides. These holes are, however, now
perched several hundred metres up the sheer slopes. Following a further
advance of the ice which brought about a further severe reduction of the
valley floor and thus the water table, in Stellerweg and 115 we find a
further phreatic level developed extensively at 1200 metres, at which a
tortuous streamway meanders at a gentle incline before descending in a
further series of pitches.

<p>It is interesting to make a comparison between these closely related
caves, and it is also interesting to note (see map, section and surveys) the
apparent direct relationship of the development of
<b lang=de>Eislufth&ouml;hle</b> to the features of the caves at the edge of
the massif some two kilometres away to the north. It is clear that
<b lang=de>Eislufth&ouml;hle</b> has a level of horizontal, if not distinctly
phreatic, development at around 1400 metres - the same as in
<b lang=de>Stellerweg</b> and <b lang=de>Sonnenstrahlh&ouml;hle</b>. If these
levels defining stages of development of the caves correspond directly, the
resultant very flat water table suggests a veritable network of caves sending
water rushing away to the edges of the limestone. Further the level of the
sump in <b lang=de>Eislufth&ouml;hle</b> compares with the phreatic level
around 1200 metres in <b lang=de>Stellerweg</b>.

<h3>CONCLUSIONS</h3>

<p>The indications are that, considering its close proximity and similarity
of development to <b lang=de>Stellerweg, Sonnenstrahlh&ouml;hle</b> should
continue to a depth approaching that of <b lang=de>Stellerweg</b> and may
well join it. The doubts raised are whether the next section, the first in
fact in the cave, of wet and awkward streamway will lead to the head of a
shaft, as has already happened in <b lang=de>Stellerweg</b>. Clearly the
streamway does not end immediately as it did not back up in its constricted
passage in flood conditions, and there was still a strong draught at this
level. With progress down to this point being relatively straightforward, a
further visit seems imperative.

<p>The question of Eislufth&ouml;hle is an interesting one. Depending on the
point of view, two different conclusions may be drawn: if the cave ends at
1150 metres, the water table is domed and there will be no hope of deeper
caves in that area. If the development of the cave is directly related to the
falls in the water-table as seen in <b lang=de>Stellerweg</b> then the water
table is very flat and further depth should be possible, the sump therefore
being a perched one. Reference to the other major discoveries in the area and
the levels at which they terminate (see surveys) suggests, tantalisingly,
that it is only a question of finding a way through an apparent end, no
matter how obscure (as demonstrated on two occasions in
<b lang=de>Sonnenstrahlh&ouml;hle</b>). Other routes in
<b lang=de>Eislufth&ouml;hle</b> have never been pushed to a conclusion, but
will anyone ever go back?

<p>Any comment on the state of <b lang=de>Stellerweg</b> may seem obvious,
however it would seem likely that a further 200 metres should be added to its
depth (down to the neighbouring lake level of 712 metres). The extent of the
phreatic development threatens to be vast, the hillside quite honeycombed
with cave passage (as predicted in Cvijic's erosion cycle). If the water
table is flat, there should be passages heading away into the mountain,
carrying the waters from the plateau.

<p>Finally, the intriguing question of cave draughts often raised its head in
discussion in Austria. Almost all the caves that we have explored in the area
have had powerful draughts emanating from the entrance;
<b lang=de>Sonnenstrahlh&ouml;hle</b>, however, had a distinct inward draught
at the entrance, reverting to outward at around the 1600 metre level. In
winter, the cave apparently sends clouds of snow billowing up from the
entrance as the relatively warm cave air rises (as substantiated by our local
contact on a ski trip). It would be expected that the other entrances draught
inwards in winter as the air is drawn up through the cave system. The obvious
conclusion is that <b lang=de>Sonnenstrahlh&ouml;hle</b>
is the top entrance to the whole system. If this is the case and
<b lang=de>Sonnenstrahlh&ouml;hle</b> can be connected to the
<b lang=de>Stellerweg</b> system, there is the possibility of
achieving a 1000 metre cave - unless fears of the cave joining
<b lang=de>Nagelstegh&ouml;hle</b> prove justified.

<h4>REFERENCES</h4>

<p>Studies in Physical Geography, ed. K.J. Gregory, Dawson Publishing<br />
Periglacial Processes and Environments, A.L. Washburn, Arnold<br />
The Geology of Western Europe, M.G. Rutten, Elsevier<br />
Jurassic Environments, A. Hallam, Cambridge Earth Science Series<br />
Geomorphology and Climate, ed. E. Derbyshire, John Wiley and Sons<br />
Weathering, Geomorphology, Text 2, C.D. Ollier<br />
Structural Geomorphology, J. Tricart<br />
Geomorphology, B.W. Sparks, Longman

<p>For detailed surveys see Cambridge Underground from 1978 onwards, which
will give more details of the caves mentioned above as well as other smaller
discoveries.

<p align=right>Tony Malcolm

<hr />
Link to <a href="https://en.wikipedia.org/wiki/Eastern_Alps">Wikipedia: Eastern Alps Geology</a>.
<br />
Link to <a href="geolog2.htm">Anonymous Geological Outline (2015?)</a>.
<br />
Link to <a href="years/1987/geolog.htm">Jared's Geological Guide (1988)</a>.
<br />
Link to <a href="years/1981/cavdev.htm">Tony Malcolm's Geological Guide (1982)</a>.
<br />
Link to <a href="https://onrappel.blogspot.com/2018/05/dachstein-massif-geology-intro.html">Excellent long article on Dachsteinkalk</a>
<hr />



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