For many millennia and millennia the river Rhummel deepened the gorge on its way to the sea. Where the rock was more permeable, it flowed in a cave underground. When the cave became clogged, she cut her way above it. Over time, the roof of the cave collapsed in some places. This is how the natural bridge in the gorge of the Rhummel river could somehow have been created.
And because a natural rock bridge is a subspecies of a rock window (natural arch in English), we will talk about such a geomorphological formation.
Natural arch is a geological formation, a naturally formed opening, completely surrounded by rock. It is created by various forms of erosion (especially selective erosion - less resistant part of the rock is eroded), but exceptionally it can also be created in another way, for example by a lava flow.
Natural arches can form in all types of rocks, especially in sandstones and limestones. But they are also common in volcanic rocks and can also be found in rhyolite, quartz or granite.
In terms of location, they are found in mountains, but also in deserts and in large numbers on sea cliffs.
Depending on the shape, size, origin and surroundings, rock windows can also be called natural bridges, gates or tunnels.
If the opening in the rock extends to its foot, we speak of a natural gate.
If a stream of water flows through the arch, or it was created by a stream of water, or the surface can be crossed to the opposite side of the terrain obstacle, we can talk about a natural bridge.
If the length of the hole in the rock is greater than the height and width, such an arch can also be called a natural tunnel.
According to the dimensions, natural arches can be large from tens of centimeters to the largest in China, USA and Chad with a span or height of more than 100 meters.
Natural Arch and Bridge Society (NABS) is a non-profit society dedicated to the study, evaluation and protection of natural arches, and defines a natural arch as follows:
1. It must be in the rock. A formation made of compacted soil, ice, or organic matter (eg, a tree trunk, unless it has turned to rock as a fossil) may exhibit all the other attributes of the definition, but it is still not a natural arch.
2. It must be exposed rock. So the arch is surrounded by air. It can be partially embedded in soil or water, but must not be completely enclosed.
3. An opening through a rock must conform to the mathematical or topological definition of an opening. In a non-mathematical sense, the hole must go completely through the rock.
4. The arch must been created by natural, selective removal of rock. Typically, this removal is the result of erosion processes, e.g. by the action of water.
5. The rock framing that is around the arch must still be relatively intact. Fractures and cracks may be present. There may even be some slippage, as long as it is evident that this has occurred after the arch has been formed. Of course, there can be no air gaps in the rock (frame).
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In Algeria, very many natural arches are located in Tassili National Park and Ahaggar National Park. Both Tassili National Park and Ahaggar National Park are in the Sahara Desert in the southeastern part of Algeria. Tassili National Park is near the town of Djanet and Ahaggar National Park is near the city of Tamanrasset.
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From this point, on the coordinates, we can see this beautiful natural bridge directly below the famous Sidi M'Cid bridge. Access on foot is easy, there is a small view point. Parking directly at the coordinates can be a problem, the easiest way is to come by taxi.
To confirm the log, please visit this place and answer the following questions. You can write the log immediately after sending answers to my profile. I will contact you if something goes don't right.
1) In which rock was this window formed (limestone or sandstone)?
2) Estimate the height of the arch. For comparison, the Sidi M'Cid Bridge is 175 m high.
3) Attach a photo of yourself with an arch to your log. Or a photo of the arch with your GPS device with the coordinates, so that your visit is clearly identified.
***** Happy earth geocaching :) *****
There is a small gift for FTF finder at V0 coordinates. Lean a little over.
FTF: Rosee&Wrecje