Nördlinger Ries
Encyclopedia
The Nördlinger Ries is a large circular depression in western Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, located north of the Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....
in the district of Donau-Ries
Donau-Ries
Donau-Ries is a district in Bavaria, Germany. It is bounded by the districts of Ansbach, Weißenburg-Gunzenhausen, Eichstätt, Neuburg-Schrobenhausen, Aichach-Friedberg, Augsburg and Dillingen, and by the state of Baden-Württemberg .-History:From Palaeolithic times on the Nördlinger Ries was a very...
. The city of Nördlingen
Nördlingen
Nördlingen is a town in the Donau-Ries district, in Bavaria, Germany, with a population of 20,000. It is located in the middle of a complex meteorite crater, called the Nördlinger Ries. The town was also the place of two battles during the Thirty Years' War...
is located about 6 kilometres (3.7 mi) southwest of the centre of the depression.
The word "Ries" is not a German word; it is believed that the term is derived from Raetia
Raetia
Raetia was a province of the Roman Empire, named after the Rhaetian people. It was bounded on the west by the country of the Helvetii, on the east by Noricum, on the north by Vindelicia, on the west by Cisalpine Gaul and on south by Venetia et Histria...
, since the tribe of Raetians lived in the area in pre-Roman
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
times.
Ries impact crater
The depression is interpreted as a meteorMETEOR
METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
formed about 14.3 million–14.5 million years ago in the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
. The crater is most commonly referred to simply as the Ries or Ries crater. The original crater rim had an estimated diameter of 24 kilometres (14.9 mi). The present floor of the depression is about 100 to 150 m (328.1 to 492.1 ft) below the eroded remains of the rim.
It was originally assumed that the Ries was of volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
origin. In 1960 Eugene Shoemaker and a colleague showed that the depression was caused by meteorite impact. The key evidence was the presence of coesite
Coesite
Coesite[p] is a form of silicon dioxide SiO2 that is formed when very high pressure , and moderately high temperature , are applied to quartz. Coesite was first synthesized by Loring Coes, Jr., a chemist at the Norton Company, in 1953. In 1960, coesite was found by Edward C. T...
(shocked quartz
Shocked quartz
Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure , the crystalline structure of quartz will be deformed along planes inside the crystal...
), which, in natural unmetamorphosed
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...
rocks can only be formed by the shock pressures
Shock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...
associated with meteorite impact. The coesite was found in the building stone (suevite) of the Nördlingen
Nördlingen
Nördlingen is a town in the Donau-Ries district, in Bavaria, Germany, with a population of 20,000. It is located in the middle of a complex meteorite crater, called the Nördlinger Ries. The town was also the place of two battles during the Thirty Years' War...
town church, constructed from locally derived stone. The suevite
Suevite
Suevite is a rock consisting partly of melted material, typically forming a breccia containing glass and crystal or lithic fragments, formed during an impact event...
was formed from mesozoic sediments.
Another impact crater, the much smaller (3.8 km diameter) Steinheim crater
Steinheim crater
The Steinheim crater is a meteorite crater in Steinheim am Albuch, Heidenheim County, Baden-Württemberg, Germany. The crater is located at the northeastern end of the Swabian Alb near the much larger Nördlinger Ries crater and was most probably formed simultaneously with it by the oblique, ENE...
, is located about 42 km (26.1 mi) west-southwest from the centre of Ries. The two craters are believed to have formed nearly simultaneously by the impact of a binary asteroid
Binary asteroid
A binary asteroid is a system of two asteroids orbiting their common center of mass, in analogy with binary stars. 243 Ida was the first binary asteroid to be identified when the Galileo spacecraft did a flyby in 1993...
.
Recent computer modeling of the impact event indicates that the impactors probably had diameters of about 1.5 kilometres (4,921.3 ft) (Ries) and 150 metres (492.1 ft) (Steinheim), had a pre-impact separation of some tens of kilometers, and impacted the target area at an angle around 30 to 50 degrees from the surface in a west-southwest to east-northeast direction. The impact velocity is thought to have been about 20 km/s. The resulting explosion had the power of 1.8 million Hiroshima bombs
Little Boy
"Little Boy" was the codename of the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393rd Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon...
, an energy of roughly 2.4x10^21 joules.
The Ries crater impact event is believed to be the source of moldavite
Moldavite
Moldavite is an olive-green or dull greenish vitreous substance possibly formed by a meteorite impact. It is one kind of tektite. It was named by A. Dufrnoy for the town of Moldauthein in Bohemia , where it occurs...
tektite
Tektite
Tektites are natural glass rocks up to a few centimeters in size, which most scientists argue were formed by the impact of large meteorites on Earth's surface. Tektites are typically black or olive-green, and their shape varies from rounded to irregular.Tektites are among the "driest" rocks, with...
s found in Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
and Moravia
Moravia
Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...
(Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....
). The tektite melt originated from a sand-rich surface layer and was ejected to distances up to 450 km (279.6 mi) downrange of the crater.
Stone buildings in Nördlingen contain millions of tiny diamonds, all less than 0.2 mm (0.0078740157480315 in) across. The impact that caused the Nördlinger Ries crater created an estimated 72000 tonnes (79,366.4 ST) of them when it impacted a local graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
deposit. Stone from this area was quarried and used to build the local buildings.