The European Cenozoic Rift System (ECRIS) is a long system of rifts formed in the foreland of the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

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 (geology), crust and the portion of the upper mantle (geology), mantle that behaves elastically on time sca ...

responded to the effects of the

Alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

and Pyrenean orogenies. The system began to form during the Late

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

and parts (particularly the Upper and Lower

Rhine Graben The Upper Rhine Plain, Rhine Rift Valley or Upper Rhine Graben (German: ''Oberrheinische Tiefebene'', ''Oberrheinisches Tiefland'' or ''Oberrheingraben'', French: ''Vallée du Rhin'') is a major rift, about and on average , between Basel in the so ...

s) 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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

to the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

Limagne Graben

This north-south trending rift structure formed in the middle Eocene creating a lake that is now the

Limagne The Limagne () is large plain in the Auvergne region of France in the valley of the Allier river, on the edge of the Massif Central. It lies entirely within the ''département'' of Puy-de-Dôme. The term is sometimes used to include this, and t ...

plain. The main phase of subsidence continued until the Late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

. The

graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...

is controlled by faults on its western side and is filled with

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...

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 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 means "less recen ...

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. If ...

s from the

Jura Mountains The Jura Mountains ( , , , ; french: Massif du Jura; german: Juragebirge; it, Massiccio del Giura, rm, Montagnas da Jura) are a sub-alpine mountain range a short distance north of the Western Alps and mainly demarcate a long part of the Frenc ...

, the leading edge of the Alpine

thin-skinned deformation Thin-skinned deformation is a style of deformation in plate tectonics at a convergent boundary which occurs with shallow thrust faults that only involves cover rocks (typically sedimentary rocks), and not deeper basement rocks. The thin-skinned s ...

Upper Rhine Graben

The Upper Rhine Graben extends from the northern edge of the Jura mountains in the south up to the

triple junction A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can b ...

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

the southern part of the graben became uplifted, while the northern part continued to subside into the

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 ...

. Currently the Upper Rhine Graben is thought to be experiencing

dextral Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...

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

. 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 A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults. Rift and fault structure A rift is a region where the lithosphere ...

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 a rupture 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 found where tectonic plates a ...

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). It follows the Neogene Period and spans from 2.58 million years ...

. The largest volcanic centres were located to the southwest of the Limagne and Bresse Grabens, the

Massif Central The (; oc, Massís Central, ; literally ''"Central Massif"'') is a highland region in south-central France, consisting of mountains and plateaus. It covers about 15% of mainland France. Subject to volcanism that has subsided in the last 10,00 ...

, 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 in the

Chaîne des Puys The Chaîne des Puys () is a north-south oriented chain of cinder cones, lava domes, and maars in the Massif Central of France. The chain is about 40 km (25 mi) long, and the identified volcanic features, which constitute a volcanic fie ...

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 The 1356 Basel earthquake is the most significant seismological event to have occurred in Central Europe in recorded history and had a moment magnitude in the range of 6.0–7.1.epicenter 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 in about 1930 to describe a rift in the continental Crust crossing

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

via

Marseille Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern Franc ...

, the Rhine rift as far as

Mjøsa Mjøsa is Norway's largest lake, as well as one of the deepest lakes in Norway and in Europe. It is the fourth-deepest lake in Norway. It is located in the southern part of Norway, about north of the city of Oslo. Its main tributary is the rive ...

in the south of

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

, a total length of 2000 km. The rift is composed of the following sections: ''Valley of

Rhône The Rhône ( , ; wae, Rotten ; frp, Rôno ; oc, Ròse ) is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea. At Ar ...

'' in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

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 The Mainz Basin (german: Mainzer Becken) or Rhine-Main BasinElkins, T H (1972). ''Germany'' (3rd ed.). London: Chatto & Windus, 1972, p. 218. . is the name given to a Cenozoic marine basin that covered the area of the present-day region of Rhenish ...

''. 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 The Lower Rhine Bay (german: Niederrheinische Bucht), sometimes called the Lower Rhine Bight,Luttig, G.W. (ed.), ''General Geology of the Federal Republic of Germany'', Nagel u. Obermiller, 1980, pp. 29 and 44. is a lowland plain in the German sta ...

'' and the ''Lower Rhine Rift'' as a central

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

rift system. The north-eastern branch continues with the '' Wetterau'', the ''Giessen Basin'', the ''Amöneburg Basin'', the ''

Upper Hessian Ridge The Upper Hessian Ridge (german: Oberhessische Schwelle) or Upper Hesse Ridge is a hill chain in the West Hesse Highlands in North Hesse, North and Middle Hesse, which lies on the Rhine-Weser watershed and links the montane Central Upland ranges of ...

'' near '' Neustadt'', the ''

West Hesse Depression The West Hesse Depression (german: Westhessische Senke) is part of the West Hesse Highlands and Lowlands region in the north of the German state of Hesse. Like the East Hesse Depression, it is a series of separate depressions that form a natural c ...

'', 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 using ...

region in northern Germany, the '' Kattegat'', the '' Oslo Rift'' and eventually ''

'' 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 municip ...

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 northern Hesse, Germany. It is the administrative seat of the Regierungsbezirk Kassel and the district of the same name and had 201,048 inhabitants in December 2020 ...

, 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