Lumparn (fi. ''Lumpari'') is a large

bay A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a Gulf (geography), gulf, sea, sound (geography), sound, or bight (geogra ...

devoid of islands in the main island of

Åland Åland ( fi, Ahvenanmaa: ; ; ) is an Federacy, autonomous and Demilitarized zone, demilitarised region of Finland since 1920 by a decision of the League of Nations. It is the smallest region of Finland by area and population, with a size of 1 ...

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

, bordered by Sund to the north, Lumparland to the east,

Lemland Lemland is a municipality of Åland, an autonomous territory of Finland. The municipality has a population of () and covers an area of of which is water. The population density is . The municipality is unilingually Swedish. The Lemström chan ...

to the south and

Jomala Jomala is a municipality of Åland, an autonomous territory of Finland. In terms of population, it is the next largest after Mariehamn, the capital of Åland. The municipality has a population of () and covers an area of of which is water. The ...

to the west.

Description

Most of the bay fills a nine kilometer wide

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 ...

. The crater is estimated to be about 1000 million years old (

Proterozoic The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided ...

). The depression was originally believed to be a

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...

. Extraterrestrial origin was first proposed in 1979, but not until 1993 was the impact structure finally confirmed. Long

shatter cones Shatter cones are rare geological features that are only known to form in the bedrock beneath meteorite impact craters or underground nuclear explosions. They are evidence that the rock has been subjected to a shock with pressures in the ra ...

have been discovered in the southwestern part of the bay. The crater is filled with sediments, between

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

sediments and crushed

rapakivi granite Rapakivi granite is a hornblende-biotite granite containing large round crystals of orthoclase each with a rim of oligoclase (a variety of plagioclase). The name has come to be used most frequently as a textural term where it implies plagioclase r ...

bedrock In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface mater ...

there is a layer of

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

(

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

)

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

s. This makes Lumparn one of the few places in Finland where

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s have been found. The bay has also previously been referred to as ''Lumpari'' in some

Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...

documents, though the

Research Institute for the Languages of Finland The Institute for the Languages of Finland,, from which the shortened name ''Kotus'' is derived, smn, Päikkieennâm kielâi tutkâmkuávdáš, se, Ruovttueatnan gielaid guovddáš, sms, Dommjânnmlaž ǩiõli kõõskõs, rom, Finnosko tšimbe ...

does not list ''Lumpari'' as in current usage.Svenska Ortnamn i Finland
, The Research Institute for the Languages of Finland, see "Lumparn"

Gallery

References

External links

Lumparn impact structure
(archived link) *