Dellen is a lake system in the

province A province is an administrative division within a country or sovereign state, state. The term derives from the ancient Roman , which was the major territorial and administrative unit of the Roman Empire, Roman Empire's territorial possessions ou ...

Hälsingland Hälsingland (), sometimes referred to by the Latin name Helsingia, is a historical Provinces of Sweden, province or ''landskap'' in central Sweden. It borders Gästrikland, Dalarna, Härjedalen, Medelpad and the Gulf of Bothnia. It is part of ...

, Sweden. It consists of two lakes, ''Northern Dellen'' and ''Southern Dellen'', appreciated among fly-fishermen for their population of

brown trout The brown trout (''Salmo trutta'') is a species of salmonid ray-finned fish and the most widely distributed species of the genus ''Salmo'', endemic to most of Europe, West Asia and parts of North Africa, and has been widely introduced globally ...

. 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 separated by a short channel, and it is therefore disputed whether they should be counted as one or two lakes. The two lakes together have a total area of 130 km², which would be the 18th largest Swedish lake. The vaguely circular lake system was formed by an

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

89 million years ago, placing the impact in the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

. The resulting impact crater measures about 19 kilometers in diameter. It has resulted in the area containing the rock Dellenite (a rock intermediate in composition between

Rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

and

Dacite Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. ...

), which has become the provincial rock.

Asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

7704 Dellen was named after it. An installation of the

Sweden Solar System The Sweden Solar System is the world's largest permanent Solar System model, scale model of the Solar System. The Sun is represented by the Avicii Arena in Stockholm, the List of largest spherical buildings, largest hemispherical building in the ...

representing

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...

and

Charon In Greek mythology, Charon or Kharon ( ; ) is a psychopomp, the ferryman of the Greek underworld. He carries the souls of those who have been given funeral rites across the rivers Acheron and Styx, which separate the worlds of the living and ...

lies near the southern lake; the pillars holding the model objects are made of dellenite.

References

External links

Dellen Information and map
Dellenbygden.nu; in Swedish only {{Impact cratering on Earth Impact craters of Sweden Cretaceous impact craters Hälsingland Lakes of Gävleborg County Landforms of Gävleborg County Impact crater lakes