The Hummeln structure was confirmed, in 2015, as an impact crater in Småland province, Sweden.[1] It is a 1.2 kilometres (0.75 mi) wide depression within Lake Hummeln and is estimated to have formed between 470 and 443 Ma ago, during the Ordovician.

Hummeln structure
Hummeln structure is located in Sweden
Hummeln structure
Location of the crater in Sweden
Impact crater/structure
ConfidenceConfirmed
Diameter1.2 km (0.75 mi)
Age443-470 Ma
Ordovician
ExposedYes
DrilledNo
Bolide typeChondrite
Ordovician meteor event?
Location
Coordinates57°22′N 16°15′E / 57.367°N 16.250°E / 57.367; 16.250
CountrySweden
ProvinceSmåland

Description edit

The depression was first described in 1826 but was considered to be the result of volcanism or tectonics.[2] In the 1960s, mapping of the lake topography gave the first hints of an impact event. More conclusive evidence was found recently when scientists from Lund University, while trying to get to nearby Siljan crater, found shocked quartz around the lake.[3] Further investigation led to more details such as breccia that firmly established the structure's impact nature.

It has also been suggested that this structure, the nearby Granby crater, and other coeval small craters in Baltoscandia may be connected to the Ordovician meteor event of 470 Ma.[2]

See also edit

References edit

  1. ^ "Hummeln". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2016-05-25.
  2. ^ a b L. Ferrière, C. Alwmark, S. Holm-Alwmark, J. Ormö, H. Leroux, and E. Sturkell (2015). The Hummeln Structure (Sweden) – Impact Origin Confirmed And Its Link To The L-Chondrite Parent Body Break-Up Event, 46th Lunar and Planetary Science Conference
  3. ^ Daniel Kelly (2015). Space Rock Created Sweden’s Hummeln Lake, Lake Scientist, Mar 2015.