Glasenbachklamm
The Glasenbachklamm is a gorge of the Klausbach in Glasenbach , a district of the municipality of Elsbethen , south of the city of Salzburg in Austria . It is a popular hiking area for residents of the city and the surrounding area. The Glasenbach Gorge is known for fossil finds such as the ichthyosaur , which is exhibited in the House of Nature . Another special feature are the 200 million year old rock formations from the Jurassic period exposed by the mountain stream. This allows the history of origin of the Alps can be viewed in detail from the former seabed to today's mountains.
Geographical location
Coordinates: 47 ° 46 ′ 3 ″ N , 13 ° 5 ′ 44 ″ E
The Glasenbachklamm is located in the northern foothills of the Alps in the Osterhorn group . The valley of the gorge runs about three kilometers from east to west .
The Glasenbachklamm is located about 500 meters south of the city limits of Salzburg. The Klausbach is a right tributary of the Salzach , which has its origin at about 650 meters above sea level from the now silted up Egelsee. The Klausbach drains parts of the Osterhorn group, such as Gaisberg , Schwarzerberg and Mühlstein . The Glasenbachklamm ends about two kilometers upstream above the mouth. The entrance to the Glasenbachklamm is about 450 meters above sea level, the end at about 650 meters above sea level in the hamlet of Höhenwald Gfalls.
General
The stream that flows through the Glasenbachklamm is called Klausbach and was therefore not the name of the gorge - besides, the Glasbach is the stream to the north, near Glas . Instead, Glasenbach originally referred to a small group of hamlets between the ancient place Glas ( glasa ) with its Roman settlement remains and the Klausbach. Aigen - Glas (today the municipality of Salzburg City) and Elsbethen - Glasenbach both originally belonged to Elsbethen and are now largely overgrown.
The name Klausbach can be traced back to the fact that the stream flowing through the gorge was formerly provided with Klausen because of the wood drift . Until the opening of the Giselabahn in 1871 (section between Salzburg and Hallein ), at least 12,000 fathoms (= 46,680 solid cubic meters ) of wood had been lifted each year. This wood was needed to fire the boiler in the salt works in Hallein. Around 1880, however, wood drifting was discontinued because the new railway connection to the saltworks meant that wood firing had been discontinued and switched to coal firing. This was the reason for the Mayr-Melnhof'sche forest administration, which owned numerous properties at the time, to create a mule track along the Klausbach through the Glasenbachklamm in 1882.
The Klausbach has its origin at around 650 meters above sea level and overcomes an altitude difference of around 150 meters to its confluence with the Salzach. There are numerous ditches on the south side of the Glasenbachklamm, while the north side forms a steep slope. Only a few channels flow into the Klausbach from the north. From the south, the largest tributary is the Lettenbach .
The gorge was created by the eroding deepening of the stream after the end of the Ice Age from 12,000 years ago. The design process is ongoing.
business
The Klausbach was a magnet for businesses that needed water power to drive their machines. As a result, the stream was used by several companies, and this resulted in particular difficulties because the water had to be divided fairly between the users.
The first known company in Klausbach was a ball mill , which was built in 1770, but was torn away again in 1798 by a flood. The later operations in the Glasenbach industrial district were no longer located directly on the Klausbach, but instead obtained the water from a works sewer derived from the Klausbach, which was also known as the Pulvermühlbach. This works canal was approx. 1200 m long, branched off from the Klausbach at the exit of the Glasenbachklamm and flowed back into the stream shortly before the Klausbach joins the Salzach. From 1800 it is known that the water power of the works canal was used by two mills (Höllmühle and Glasenbachmühle), a blacksmith and armory, a sawmill and two powder mills . In 1830, the powder makers Löhner and Sinder each operated two powder rammers on the works channel, which were expanded to a total of six rammers by 1883. The first timber drift then took place in 1860, as a lumberjack was allowed to drive sawn timber , but not round timber (also called bloche), from the Höhenwald to below the Höllmühle. But he had to answer for possible damage to the Glasenbach Bridge, Salzburg-Halleiner Straße and the bridge at the confluence of the Klausbach into the Salzach.
The economic use of the Klausbach and its side canal was discontinued around 1954. The reasons for this were, on the one hand, the destruction of the weir , which had backed up the water of the Klausbach, due to flooding and, on the other hand, the electrification of the sawmill, which at that time was the last company still using the works canal (the operation in the powder-making house was already closed in 1918 ).
geology
Formation of the rocks
The Glasenbachklamm clearly offers a multitude of rocks from the individual epochs of the earth's history . These rocks originate mainly from the Jurassic and Cretaceous but also from the Pleistocene (Ice Age). The exogenous forces that formed this gorge are at work to this day.
But not only the time of 213 million years, but also the sedimentation had an influence since the beginning of the formation of the rocks. Because the deposits did not take place in today's area of Salzburg, but in a warm, tropical sea, far to the south - around the geographical latitude of today's North Africa . The fossil flora and fauna of the rock layers in the gorge point to these conditions. Although the global average temperature at the time of the Mesozoic era , when the rocks were deposited in the Glasenbach Gorge, was significantly higher than it is today, the tropical climatic area by no means reached as far as the current latitudes of the gorge (approx. 47.5 ° N ) . Concrete facts for an area of origin far to the south provide primarily plate tectonic and palaeomagnetic considerations.
The first considerations about a southern area of origin began when Alfred Wegener claimed in 1912 that the continents are not rigid, immobile land masses, but rather drift like ice floes on a viscous subsoil in the upper part of the earth's mantle. It later emerged that not only could the continents change their position, but their documents could also approach and move away from each other. Today this speed is about 3–15 cm per year, during the Cretaceous the movements may have been as much as 25 cm per year. This theory put forward by Harry Hammond Hess became known as the "theory of plate tectonics". It is based on that of Alfred Wegener and the undercurrent theory of the Austrian geologist Otto Ampferer .
There is further evidence that the Glasenbachklamm sediments were deposited further south through their paleomagnetism. The magnetizable minerals in the sediment or in the liquid magma behave like magnets and adjust themselves depending on the direction of the prevailing magnetic field . The solidification of the sediments or the solidification of the magma "freezes" the inclination of the magnetized minerals. Since these materials retain their inclination, conclusions can be drawn from the results of the inclination measurement about their area of origin.
Paleogeography
| era | system | step | series | rock |
|---|---|---|---|---|
| Cenozoic | Neogene | Moraine , Nagelfluh | ||
| Paleogene | not open-minded | |||
| Mesozoic | chalk | Gosau conglomerate | ||
| law | Upper Jurassic | Radiolarite | ||
| Middle Jurassic | Pelagic Limes as Dogger | |||
| Lower Jurassic | Toarcium | Red tuber limestone , tuber breccia | ||
| Pliensbachium | Adneter marl series | |||
| Sinemurium | Scheibelberg Limestone | |||
| Triad | Only in blocks within the Lower Jurassic layers |
The majority of the rocks formed at different times in different regions and under different climatic conditions. In the Glasenbachklamm it is not so easy to reconcile the chronological succession of the rock formation from back then with the spatial coexistence of the current location. The oldest exposed rocks come from the oldest period of the Mesozoic, the Triassic.
Triad
In the Triassic period , approx. 240 million years ago , an extremely shallow shallow sea spread out in the northern part of the deposit area in which the Limestone Alps were formed. It was around 25 ° to 30 ° north latitude, which corresponds to the current locations of Las Palmas , Cairo and Kuwait . Conditions similar to those in this former shallow sea prevail today in the Gulf of Mexico . In the mud flats of this shallow sea, dolomite , the so-called main dolomite , formed from deposited limestone layers . Towards the end of the Triassic period, the shallow water area fell and with it the water temperature, which ultimately led to the reefs dying off .
law
In Jura lower temperatures prevailed as in the Triassic, but still much warmer than today. As a result, not only did the sedimentation conditions change compared to the Triassic, but there was also an increasing number of soil unrest, which led to sedimentation interruptions. Furthermore, the tectonic unrest led to sediment discharges. When these lubricants disintegrated, breccia formed (see tuber breccia ). In the Glasenbachklamm these rocks reach a height of up to 15 m.
chalk
The transition from the Jurassic to the Cretaceous 145 million years ago mostly passed without any rock-like changes. In the Higher Lower Cretaceous the first bulges and folds occurred in the course of the first great Alpid mountain formation phase , which occurred in the Middle Cretaceous about 120 million years ago and reached its climax 88 million years ago. With the beginning of the Upper Cretaceous , the Gosau deposits began to form. From a tectonic point of view, the time of the Gosau deposits was characterized by severe ground unrest, which is expressed in the appearance of powerful conglomerates . With each phase of the unfolding of the Alps, there was increased erosion. Torrents transported the rubble into the shallow seas and built up mighty gravel bodies that exist today as a conglomerate.
Tertiary
In the Glasenbachklamm no deposits are known with certainty from the Tertiary . Thus, a period of 63 million years is not rock-proof.
quaternary
The Quaternary is 1.64 million years ago the youngest section of the Earth's history. The Cenozoic began 1.64 million years ago with the Ice Age (Pleistocene). The most recent segment of the New Earth Era, the Holocene , began with the melting of the great glacial masses. The formation of the Kerbtal of the Klausbach can be traced back to the Ice Age with its alternating cold and warm periods, which began 2.6 million years ago. In the main valleys of the Alps, deepened by the glacier masses, the side streams poured up mighty alluvial cones. At the foot of the steep trough walls, heaps of rubble formed, which eroded over time, also in the formerly longer valley of the Klausbach.
flora
The Glasenbachklamm is not only a popular hiking destination for the people of Salzburg and the surrounding area from a geological point of view, but also because of the variety of plants that grow in the gorge. Because of its geological and biological peculiarities, this area was declared a "Protected Part of the Landscape" in 1987. The deeply cut valley with a poorly developed valley floor offers different ecological conditions for the plants than for those in the surrounding area. In contrast to the slopes above, the gorge contains a variety of deciduous trees . The common beech ( Fagus sylvatica ) actually only penetrates deeper gorges to a subordinate extent, here mainly sycamore maple ( Acer pseudoplatanus ), Norway maple ( Acer platanoides ), ash ( Fraxinus excelsior ), gray alder ( Alnus incana ) and sycamore elm ( Ulmus ) thrive glabra ). This tree population is also largely shaped by the given climatic factors. The east-west location lets little sunshine into the gorge, which promotes shade plants. The high humidity , which is caused by the shade and the evaporation of the Klausbach, leads to a cool local climate even on hot days.
In the flatter areas of the lower slope, nutrients and humus accumulate with the surface water . This creates lush floodplain vegetation with bushes and a large number of ferns , especially the thorny shield fern ( Polystichum aculeatum ), the forest lady fern ( Athyrium filix-femina ) and the otherwise rare but abundant deer tongue ( Phyllitis scolopendrium ). The most common representative of the shrubs is the red honeysuckle ( Lonicera xylosteum ). Epiphytes such as ivy ( Hedera helix ) and tall perennials such as the forest goat's beard ( Aruncus dioicus ), the spiked St. Christopher's weed ( Actaea spicata ), the yellow blooming wolf monkshood ( Aconitum vulparia ) can also be found in this area. A good supply of nutrients with consistently high moisture is also important for the great nettle ( Urtica dioica ), the ground elder ( Aegopodium podagraria ) and the great balsam ( Impatiens noli-tangere ).
The numerous types of moss that thrive on the bark of trees, on rocks and also on the forest floor are particularly lush . The brown striped fern ( Asplenium trichomanes ) can be found on the path walls and stones along the stream, in addition to the mosses .
The humid canyon forest also provides a habitat for a wide variety of mushroom species . The limited timber management, a sometimes high tree age, the large number of dead wood , the near-natural to natural tree species composition and an extraordinarily humid, cool canyon forest climate are preferred by wood-dwelling fungus species.
The damp rock walls and the stones lying on the ground are covered with different colored crust lichen that requires little light. There are also occasional light brownish green spots on the bark of trees, these are epiphytic crustal lichens that develop their storage cells directly in the bark.
fauna
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In addition to the great variety of flora, the Glasenbachklamm is a retreat and ecologically diverse habitat for a remarkable fauna. Insects (such as stone flies , mayflies , caddis flies , black flies ), the larvae of which can be found in the stream, form the food base for birds and fish.
The cleanliness of the water is crucial for the occurrence of the brown trout ( Salmo trutta ). The Koppe ( Cottus gobio ) also lives in the brook.
Various beetles, butterflies ( aurora butterflies , lemon butterflies ), snails or the moisture-loving fire salamander ( Salamandra salamandra ) are also very numerous in the gorge.
Mammals in the Glasenbachklamm area include badgers ( Meles meles ), foxes ( Vulpes vulpes ), pine marten ( Martes martes ) and Alpine shrew ( Sorex alpinus ).
The dipper ( Cinclus cinclus ) and the gray wagtail ( Motacilla cinerea ) prefer the habitat of a mountain stream. Song thrush , blue tit , cabbage tit , fir tit , crested tit and marsh tit , robin , nuthatch , chaffinch and others also live in the Glasenbach gorge .
Fossils
The remains of an ichthyosaurus were described for the first time as early as 1897 . Later excavations from 1960 to 1978 produced a number of other teeth, vertebrae and ribs, which are now exhibited in the Haus der Natur in Salzburg.
The marls of the Glasenbachklamm lead to a rich and well-preserved spore flora from the Triassic.
Discharges into younger strata are evident from the fact that ammonites were found both in the lying (lower strata) and in the hanging wall (upper strata) . Furthermore, a number of specimens of ammonites ( Echioceras raricostatum ) from the Lias were found below the dinosaur site, which are now kept in the House of Nature.
The relatively high plankton productivity in seawater and the lack of oxygen on the seabed also caused the high nutrient content of the Scheibelberg strata.
Many fossils can still be recovered today, mostly after the winter snow melts or after a landslide in the gorge. The gravel slopes exposed by this bring a large number of fossils to light. In 2002 a huge landslide (200 m wide and 100 m long) uncovered a large number of fossils near the dinosaur site, such as B. ammonites, mussels and snails.
Hiking trail and display boards
The entrance is in Glasenbach, a little south of the city of Salzburg. The Glasenbachklamm can easily be reached from the city with the trolleybus line 7 . After about ten minutes of walking you will reach the entrance of the Glasenbachklamm and thus also the first of several information boards in the canyon. After about 3 km you will reach the end of the gorge. From there you can either go to Gasthaus Ramsau or continue in the direction of Gaisberg .
| No. | Name of the display board | Description of the job | image |
|---|---|---|---|
| 1 | The Gosau conglomerate | At this point a rock can be seen that is widespread throughout the northern edge of the Alps , the conglomerate . The conglomerate was formed by the continental drift of the North African plate more than 80 million years ago ( Upper Cretaceous ). This rock is found relatively often in the Glasenbachklamm, mainly on the orographic left side of the Klausbach. | |
| 2 | The radiolarite | From this point you can see the radiolarite built up in layers one on top of the other . This rock was formed from dead, so-called radiolarians , around 150 million years ago . With a few exceptions, the radiolarite in the Glasenbachklamm can only be seen on the orographically right side of the Klausbach. | |
| 3 | Red and gray marls | At this point of the Glasenbachklamm you can see red and gray marls . They form a rock wall about 20 meters high from which a small waterfall falls. Marls formed from fine deposited mud about 160 million years ago. This is also where the Lettenbach flows into the Klausbach. | |
| 4th | Red tuber limestone and marl | These rocks are located in the immediate vicinity of the red and gray marls and can hardly be distinguished from one another. | |
| 5 | The tuber breccia | This location is further inside the Glasenbachklamm than the previously mentioned ones. Here you can see the breccia , which, like the conglomerate, consists of cemented rocks. The rock is located along the hiking trail and in large boulders in the river bed of the Klausbach. This breccia was formed around 180 million years ago ( Lower Jurassic Period ). | |
| 6th | Introduction | A little further on from position 5, one encounters an approximately two meter thick breccia inlet line in the red tuberous limestone. | |
| 7th | Introductions | After a slight bend in the path, two approximately one meter thick introductions of red tuber breccias in a layer of Scheiblberg layers follow. | |
| 8th | Red tuber lime and gray chert tuber lime | From this point of view you can clearly see a layer of red tuber lime on top of a layer of gray chert tuber lime. The Red Knollenkalk created by alternating deposition of lime mud in the sea, the gray Hornsteinknollenkalk consists of silica and was used in the Stone Age as a tool. These rocks were formed about 200 million years ago (Lower Jurassic Period). | |
| 9 | Dinosaur discovery site | At this point in the Glasenbach Gorge, the first fossils were found around 125 years ago . Even today, many fossils can be recovered at this point, mainly because in 2004 a huge landslide uprooted the entire earth and uncovered new fossils. Excavations for fossils were carried out here as early as 1896 . Today excavations of any kind in the Glasenbachklamm are forbidden, as the area has been declared a "Protected Part of the Landscape". | |
| 10 | Folded layers of lime | This part of the Glasenbachklamm is one of the most spectacular. Here you can see plates lying on top of each other, which have been pressed into the most bizarre formations over the course of millions of years. | |
| 11 | The Nagelfluh | At the end of the Glasenbachklamm you can still see mighty rock walls and boulders from Nagelfluh . The Nagelfluh was created in the Ice Age when the rivers transported sedimentary rocks from the Alps to the north. This rock is therefore the youngest in the Glasenbachklamm. |
literature
- Gottfried Tichy, Judith Herbst: Glasenbachklamm. Natural history and geological guide . Published by: ÖNB & OeAV, 1997, ISBN 3-901866-00-0
- Robert Karl: “Elsbethen. A place through the ages ”. Published by: Elsbethen Municipality, 1994
Individual evidence
- ↑ Gottfried Tichy, Judith Herbst: Glasenbachklamm. Natural history and geological guide p. 17
- ↑ Robert Karl: “Elsbethen. A place through the ages ”p. 14
Web links
- www.Alpintouren.at - description of the hike with some data
