Dellen
Encyclopedia
Dellen is a lake system in the province
Provinces of Sweden
The provinces of Sweden, landskap, are historical, geographical and cultural regions. Sweden has 25 provinces and they have no administrative function, but remain historical legacies and the means of cultural identification....

 of Hälsingland
Hälsingland
' is a historical province or landskap in central Sweden. It borders to Gästrikland, Dalarna, Härjedalen, Medelpad and to the Gulf of Bothnia...

, Sweden. It consists of two lakes, Northern Dellen and Southern Dellen, appreciated among fly-fishermen for their distinct population of brown trout
Brown trout
The brown trout and the sea trout are fish of the same species....

.

Southern Dellen has a surface area of 52 km² and a water volume of 1,226 million m³.
Northern Dellen has an area of 82 km² and a water volume of 1,489 million m³.

The two lakes are only united by a short channel, and it is therefore disputed whether they should be counted as one or two lakes. If counted together, it would have a total area of 130 km², making it the 18th largest Swedish lake.

The vaguely circular lake system was formed by an impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 89.0 ± 2.7 million years ago, placing the impact in the Upper Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

. The resulting impact crater measures about 19 kilometres in diameter. It has resulted in the area containing the rock Dellenite (a rock intermediate in composition between Rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...

 and Dacite
Dacite
Dacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...

), which has become the provincial rock.

Asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 7704 Dellen
7704 Dellen
- External links :*...

was named after it.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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