The Nördlinger Ries Crater
The Nördlinger Ries Crater is situated in the
south of Germany in the Bavaria state and the
centre is about 6km northeast of Nördlinger
city as can be seen in the image to the right.
Nördlinger
City
Nördlinger Ries Crater
outline
The impact was of a 1.5km diameter asteroid
travelling at about 72,000 km/h which
happened about 14.3 – 14.5 million years ago.
The asteroid penetrated 1km into earth’s
crust. It is a complex crater and the outer ring
has a 25km diameter and the inner crater is
12km in diameter. The impact energy is
thought to be roughly equal to the energy of
1.8 million Hiroshima bombs which is 2.4×1021
joules
History and Information
An aerial photograph showing the scale of the
structure and how it looks from above.
For over 100 years, until 1960 when Eugene
Shoemaker showed that the formation was
caused by a meteorite impact, it was assumed
that the Ries depression was caused by
volcanic activity. There are six pieces of
evidence that can be found to prove that a
formation was created by an impact and not
by a volcanic event and there are as follows:
 Shatter cones – these are cone shaped
structures found in the rock beneath
impact craters, the apex (point) of the
cone is at the top. A pressure of 2 – 30
Giga Pascals is needed to create these.
Only meteorite impacts and underground
nuclear explosions can create these
features.
 Multiple planar deformation features –
microscopic features in grains of silicate
materials such as quartz or feldspar that
are caused by a shock wave from the
impact. They are narrow planes of glassy
material in
This image shows part of the southern rim of the
crater, sloping down to the flat basin on the right hand
side.
parallel sets that have distinct orientation
with respect to the crystal structure of the
grain.
 High pressure mineral polymorphs – the
high pressures caused by impacts can form
high pressure polymorphs of various
minerals such as quartz, titanium dioxide
and carbon. Quartz can become either
coesite or stishovite and carbon can
become diamond.
 Morphometric structures – size, shape and
morphology of the structure.
 Pseudotachylytes
and
breccias
Pseudotachylytes are fine grained glassy
fault rocks that are made up of a very fine
grained matrix that occur in veins. Breccia
is rock that is made of fragments of
minerals or rock held together by a fine
grained
matrix.
They
contain
contamination of extraterrestrial material
such as iridium and osmium anomalies
 Impact melt sheets, dikes and melt
breccias – A dike is a sheet of rock that has
formed in a crack in pre-existing rock. In
impacts molten rock caused by the event
goes into cracks in pre-existing rock and
crystallizes. Melt breccias is similar to
breccia apart from the matrix that holds
the fragments together. In melt breccia the
cementing breccia is made from
crystallized impact melt.
Two types of titanium dioxide high pressure
polymorphs were found at the Nördlinger Ries
Interesting fact
The two major rock
formations that make up part
of the ejecta of the crater,
the suevite and Bunte breccia
were used as training ground
for some of the Apollo
astronauts.
This image shows some of the impact
breccia at the Nördlinger Ries crater; it is
from just outside of the crater’s inner ring.
For a sense of scale the hammer in the
image is 35cm long
crater. Shocked quartz was also found at the
Nördlinger Ries crater, shocked quartz is only
found at impact sites and not volcanic
formations therefore when it was discovered
at Nördlinger Ries by Eugene Shoemaker it
was proof that this was the result of an
impact not volcanic activity. There is impact
breccia at the site composed of granite and
gneiss along with shatter cones.
Computer simulations indicate that the
meteor would have been about 1.5 km in
diameter and hit the surface at an angle of 30
– 50 degrees and came in from a westsouthwest to east-northeast direction. The
area that it hit was composed of about 500 –
800m thick sedimentary rock with granite and
gneiss underneath.
There is another crater 42 km west-southwest
from the Nördlinger Ries crater called the
Steinheim crater which is the same age and it
is likely that they were created at the same
time by a binary asteroid. The Steinheim
crater is much smaller and was created by an
object approximately ten times smaller than
the one that created Nördlinger Ries.
Formation
The crater is a complex crater as can be seen
in the diagram below which shows a cross
sectional view of the crater. It has a central
uplift in the middle of a shallow, flat crater
floor which is surrounded by the inner ring,
megablock zone and the outer crater rim.
Central uplifts are made of one or more rings
with a peak in the middle and they are
composed of rock that has been brought up
from great depth. The inner crater basin has
been filled in with deposits of suevite, then
after the impact lake deposits filled the crater
in further. The inner ring is made up of shock
metamorphosed material that has been
overturned and upturned by the impact.
Megablocks are large blocks of rock that were
displaced when the crater formed. It is still
not known for certain how megablocks are
formed but there are two leading theories.
The first is that during the crater excavation
stage they were thrown out and deposited at
the same time as the ejecta blanket. The
other theory is that during the modification
stage they slumped inwards.
Complex crater formation can be broken
down into stages. The first of these is contact
with the surface and compression of the rock.
A supersonic shock wave is created at the
point of contact which goes through the
impactor and the surface it has
hit. This shockwave compresses
the impactor and the target and
as a result the target undergoes
shock related changes such as
transforming the quartz mineral in
the rock into shocked quartz and
it melts the impactor. Next
excavation takes places as the
crater grows and material is
ejected out, in the Nördlinger Ries
impact about 150 km3 of rock was
An image depicting complex crater
formation.
thrown out and it fell in the area surrounding
the crater up to 40 km away. Near the crater
the debris was up to 200m thick. The crater
that is created is unstable so modification
takes place, during this stage the walls of the
crater collapse under gravity and the rim
collapses inwards and the centre is uplifted.
The central uplift is a result of material
attempting to return to a state of gravitational
equilibrium. This process is shown in the
image above.
This is a cross sectional diagram of the crater showing the structure of
the crater and where different types of rock can be found.
Museum
In the city of Nördlinger
there is a museum about
the crater called the Ries
Crater Museum. It has
numerous
exhibits
on
meteorites, rocks and fossils
but the main exhibition is
about the Nördlinger Ries
crater and its formation. The
museums location, opening
times and admission fees
are as follows:
At the museum there is a piece of Moon rock that
weighs 165g that was brought back in the Apollo 16
mission. It is from the Descartes region of the southern
lunar highlands.
Address
Ries
Crater
Museum,
Eugene - Shoemaker - Platz
1, 86720 Nördlingen
Opening times
Tuesday to Sunday - 10 am
to 12 am, 1.30 pm to 4.30
pm
Monday - closed; public
holiday
regulations
on
request
Admission Prices
Adults € 4
School student € 1.50
There is also an exhibition about the origin of the
Chicxulub crater in Mexico in the Yucatan Peninsula and
the extinction of the dinosaurs at the museum. As part
of the exhibition there is a short film.
University Students € 2
Disabled € 2.30
Senior € 3
Family ticket € 8.50
Group Adults € 3 each
Class / student group € 1
each
Interesting fact
Many buildings in the town of
Nördlinger are made out of
stone quarried from the crater.
The stone contains millions of
tiny diamonds smaller than 0.2
mm in size, so many buildings in
Nördlinger have diamonds in
their stone.