
The European Cenozoic Rift System (ECRIS) is a long system of
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-graben ...
s formed in the
foreland of the
Alps
The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia.
...
as the
lithosphere
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time ...
responded to the effects of the
Alpine and
Pyrenean orogenies. The system began to form during the Late
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...
and parts (particularly the Upper and Lower
Rhine Grabens) remain seismically active today and are responsible for most of the larger earthquakes in Europe, north of the Alps.
Extent
The ECRIS consists of a series of rifts and associated transfer faults extending from the
Mediterranean
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...
to the
North Sea
The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...
.
Limagne Graben
This north-south trending rift structure formed in the middle Eocene creating a lake that is now the
Limagne plain. The main phase of subsidence continued until the Late
Oligocene
The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...
. The
graben
In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults.
Etymology
''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...
is controlled by faults on its western side and is filled with
Cenozoic
The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...
sediments up to 2 km thick.
Bresse Graben
The Bresse Graben lies to the east of the Limagne Graben. Rifting started during the Eocene,
pausing from the Late Oligocene to Middle
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
before resuming in the Late Miocene. The eastern margin of the basin was overridden by
thrust fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks.
Thrust geometry and nomenclature
Reverse faults
A thrust fault is a type of reverse fault that has a dip of 45 degrees or less.
I ...
s from the
Jura Mountains
The Jura Mountains ( ) are a sub-alpine mountain range a short distance north of the Western Alps and mainly demarcate a long part of the French–Swiss border. While the Jura range proper (" folded Jura", ) is located in France and Switzerla ...
, the leading edge of the Alpine
thin-skinned deformation.
Upper Rhine Graben
The Upper Rhine Graben extends from the northern edge of the Jura mountains in the south up to the
triple junction where the ECRIS branches. Rifting initiated here in the Oligocene but the northern and southern parts of the graben show distinct post-Oligocene histories. In the
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
the southern part of the graben became uplifted, while the northern part continued to subside into the
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...
. Currently the Upper Rhine Graben is thought to be experiencing
dextral strike-slip
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
reactivation.
Lower Rhine Graben
The Lower Rhine Graben or Lower Rhine Embayment, trends NW-SE and continues offshore into structures within the southern
North Sea
The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...
.
To the southeast the dominant faults are SW-dipping, while to the northwest they become NE-dipping, in both cases giving it a
half-graben geometry. Rifting initiated during the Oligocene and continues to the present day.
Hessian Grabens
The Hessian grabens lie north of the Upper Rhine Graben and follow the same trend. There are two main rift structures, the Wetterau and Leine grabens. They were active during the Oligocene but are inactive now.
Eger Graben
The easternmost part of the system, the Eger Graben shows two distinct phases of extension at the end of the Eocene and during the early Miocene. The first phase was oblique to the rift axis and led to the formation of en-echelon W-E trending fault sets. The second was orthogonal to the rift axis, leading to overprinting of the early W-E faults by later SW-NE trending faults.
Origin
The rift system is thought to have formed in response to compression of the lithosphere in front of the zones of collision that formed the Alps and Pyrenees. The initial rift propagated northwards as the collision along the Alps intensified and the western part of France moved to the west.
Volcanism
The development of the ECRIS was accompanied (and in some cases preceded) by
volcanic
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often fo ...
activity over large parts of the rift system that persisted into the
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...
. The largest volcanic centres were located to the southwest of the Limagne and Bresse Grabens, the
Massif Central, at the rift triple junction at the northern end of the Upper Rhine Graben, the
Vogelsberg Mountains and around the Eger Graben.
The last recorded volcanic activity was a
phreatomagmatic eruption
Phreatomagmatic eruptions are volcanic eruptions resulting from interaction between magma and water. They differ from exclusively magmatic eruptions and phreatic eruptions. Unlike phreatic eruptions, the products of phreatomagmatic eruptions cont ...
in the
Chaîne des Puys about 6,000 years ago.
Seismicity
Most seismic activity within the ECRIS is confined to the Upper and Lower Rhine Grabens.
The
1356 Basel earthquake, which had an
epicenter
The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates.
Determination
The primary purpose of a ...
within the Upper Rhine Graben is the most damaging historical seismic event known from central Europe.
Mediterranean-Mjosa Zone
The term ''Mediterranean-Mjosa Zone'' (Mittelmeer-Mjösen-Zone) was coined by the German geologist
Hans Stille
Hans Wilhelm Stille (8 October 1876 – 26 December 1966) was an influential Germany, German geologist working primarily on tectonics and the collation of tectonic events during the Phanerozoic. Stille adhered to the contracting Earth hypothesis ...
in about 1930 to describe 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-graben ...
in the continental
Crust crossing
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
from the
Mediterranean Sea
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...
via
Marseille
Marseille (; ; see #Name, below) is a city in southern France, the Prefectures in France, prefecture of the Departments of France, department of Bouches-du-Rhône and of the Provence-Alpes-Côte d'Azur Regions of France, region. Situated in the ...
, the
Rhine rift as far as
Mjøsa
Mjøsa is the largest lake in Norway and the fourth deepest in Norway and Europe. It is located in the southern part of Norway, about north of the city of Oslo. Its main tributary is the river Gudbrandsdalslågen flowing in from the north; the ...
in the south of
Norway
Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...
, a total length of 2000 km.
The rift is composed of the following sections: ''Valley of
Rhône
The Rhône ( , ; Occitan language, Occitan: ''Ròse''; Franco-Provençal, Arpitan: ''Rôno'') is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and Southeastern France before dischargi ...
'' in
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
and its northern continuation the ''
Bresse
Bresse () is a former French province. It is located in the regions of Auvergne-Rhône-Alpes and Bourgogne-Franche-Comté of eastern France. The geographical term ''Bresse'' has two meanings: ''Bresse bourguignonne'' (or ''louhannaise''), whic ...
Rift'', the ''
Rhine Rift Valley'' and the ''
Mainz Basin''. Here the rift system splits up into a north-eastern and a north-western branch. Part of the north-western branch is the ''
Lower Rhine Bay'' and the ''Lower Rhine Rift'' as a central
Netherlands
, Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...
rift system. The north-eastern branch continues with the ''
Wetterau
The Wetterau (, ) is a fertile undulating tract, watered by the Wetter (river), Wetter, a tributary of the Nidda (river), Nidda River, in the western German state of Hesse, between the hilly province Oberhessen and the north-western Taunus mounta ...
'', the ''Giessen Basin'', the ''Amöneburg Basin'', the ''
Upper Hessian Ridge'' near ''
Neustadt'', the ''
West Hesse Depression'', the ''Leine Rift'', part of the
Salt dome
A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered us ...
region in northern Germany, the ''
Kattegat
The Kattegat (; ; ) is a sea area bounded by the peninsula of Jutland in the west, the Danish straits islands of Denmark and the Baltic Sea to the south and the Swedish provinces of Bohuslän, Västergötland, Halland and Scania in Swede ...
'', the ''
Oslo Rift'' and eventually ''
Mjøsa
Mjøsa is the largest lake in Norway and the fourth deepest in Norway and Europe. It is located in the southern part of Norway, about north of the city of Oslo. Its main tributary is the river Gudbrandsdalslågen flowing in from the north; the ...
'' with
Lillehammer
Lillehammer () is a municipality in Innlandet county, Norway. It is located in the traditional district of Gudbrandsdal. The administrative centre of the municipality is the town of Lillehammer. Some of the more notable villages in the munici ...
at its northern end.
In the area surrounding the Mediterranean-Mjosa Zone there was some volcanism, e.g. ''
Kaiserstuhl'' or ''Hoher Habichtswald'' west of
Kassel
Kassel (; in Germany, spelled Cassel until 1926) is a city on the Fulda River in North Hesse, northern Hesse, in Central Germany (geography), central Germany. It is the administrative seat of the Regierungsbezirk Kassel (region), Kassel and the d ...
, which primarily consist of
Basalt
Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...
.
References
External links
''Morphologisches Leitbild Niederrhein'', Merkblatt 41, LUA NRW Essen, 2003, Abschnitt 2.2(PDF-Datei; 1,83 MB)
{{Geology of Europe
Rifts and grabens
Geology of Europe
Cenozoic rifts and grabens