Dellen is a lake system in the

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

Hälsingland Hälsingland (), sometimes referred to as Helsingia in English, is a historical province or ''landskap'' in central Sweden. It borders Gästrikland, Dalarna, Härjedalen, Medelpad and the Gulf of Bothnia. It is part of the land of Norrland. Ad ...

, 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 European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...

. 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 circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

89 million years ago, placing the impact in the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger 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 ''creta'', the ...

. 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, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

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 of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

7704 Dellen 77 may refer to: * 77 (number) * one of the years 77 BC, AD 77, 1977, 2077 Music * 77 (band), a Spanish hard rock band * ''77'' (Matt Kennon album) * '' Talking Heads: 77'', debut album by Talking Heads * ''77'' (Nude Beach album), an album by t ...

was named after it. An installation of the

Sweden Solar System The Sweden Solar System is the world's largest permanent scale model of the Solar System. The Sun is represented by the Avicii Arena in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockhol ...

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 S ...

and

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

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