Neugrund breccia is a type of
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wales ...
consisting of
gneiss
Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures a ...
ic
breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix.
The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...
and
amphibolite originating from the
Neugrund crater
Neugrund is a meteorite crater in Estonia. It is in diameter and was previously estimated to have been formed in the Ordovician around 470 Ma, with later research revealing a possible Cambrian origin (around 535 Ma). The crater is at the bottom ...
. Neugrund breccia is different from
Ordovician
The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya.
T ...
breccia, which is found in a similar region but was formed millions of years later after a
different meteor strike.
Neugrund breccia formed during the
cementation of
meteor
A meteoroid () is a small rocky or metallic body in outer space.
Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than this are classified as mi ...
fragments. Glacial action distributed
erratics of breccia throughout an area of over 10,000 km
2 surrounding the impact site.
Boulders of Neugrund breccia can be found in north-western
Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...
and are especially concentrated around the island of
Osmussaar
Osmussaar ( sv, Odensholm, german: Odinsholm) is an Estonian island situated in the mouth of the Gulf of Finland in the Baltic Sea, 7.5 km off the Estonian mainland. Administratively the island is part of Lääne-Nigula Parish in Lään ...
.
The largest known Neugrund breccia formation is Skarvan. It is located near the west coast of Osmussaar.
File:Skarvan, Osmussaar.jpg, Skarvan
File:Rahn Estonia KLO1000558.jpg
File:Osmussaar30.jpg
File:Bretsa Osmussaar.JPG
File:Gneissbretša 1, Osmussaar.jpg
References
{{Reflist
Breccias