Paris Basin (geology)
Encyclopedia
The Paris Basin is one of the major geological regions of France
having developed since the Triassic
on a basement formed by the Variscan orogeny
.
to Poitiers
and from Caen
to the brink of the middle Rhine Valley, east of Saarbrücken
.
and the Seuil de Bourgogne (Threshold of Burgundy) differential erosion of the strata has left low scarps with the dip slopes towards the centre. The varying nature of the clays, limestones and chalk gives rise to the characteristics of the regions such as Champagne Humide (Damp Champagne), Champagne Pouilleuse (poor Champagne), the Pays de Caux
and the Pays de Bray
.
basin
of sedimentary rock
s. It overlies geological strata
disturbed by the Variscan orogeny and forms a broad shallow bowl in which successive marine deposits from throughout periods from the Triassic
to the Pliocene
were laid down: their extent generally diminishing with time.
To the west, the strata folded by the Variscan, rise from below it in the hills of Brittany
and in and east the Ardennes
, Hunsrück
and Vosges
. To the south, it borders on the Massif Central
and the Morvan
. To the north, its strata link into those of the bed of the English Channel
and south-eastern England
. Other boundaries lie on ridges in less old rocks and scarps such as the Côte d'Or
(on an Alpine
fault line) and the Hills of Artois
which overlie the margin of London-Brabant Massif.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
having developed since the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
on a basement formed by the Variscan orogeny
Variscan orogeny
The Variscan orogeny is a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica and Gondwana to form the supercontinent of Pangaea.-Naming:...
.
Extent
The region usually regarded as the Paris Basin is rather smaller than the area formed by the geological structure. The former occupies the centre of the northern half of the country, excluding Eastern France. The latter extends from the hills just south of CalaisCalais
Calais is a town in Northern France in the department of Pas-de-Calais, of which it is a sub-prefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's capital is its third-largest city of Arras....
to Poitiers
Poitiers
Poitiers is a city on the Clain river in west central France. It is a commune and the capital of the Vienne department and of the Poitou-Charentes region. The centre is picturesque and its streets are interesting for predominant remains of historical architecture, especially from the Romanesque...
and from Caen
Caen
Caen is a commune in northwestern France. It is the prefecture of the Calvados department and the capital of the Basse-Normandie region. It is located inland from the English Channel....
to the brink of the middle Rhine Valley, east of Saarbrücken
Saarbrücken
Saarbrücken is the capital of the state of Saarland in Germany. The city is situated at the heart of a metropolitan area that borders on the west on Dillingen and to the north-east on Neunkirchen, where most of the people of the Saarland live....
.
Geography
The countryside is one of plains and plateaux of limited altitude. In the south-east and east the plain of ChampagneChampagne (province)
The Champagne wine region is a historic province within the Champagne administrative province in the northeast of France. The area is best known for the production of the sparkling white wine that bears the region's name...
and the Seuil de Bourgogne (Threshold of Burgundy) differential erosion of the strata has left low scarps with the dip slopes towards the centre. The varying nature of the clays, limestones and chalk gives rise to the characteristics of the regions such as Champagne Humide (Damp Champagne), Champagne Pouilleuse (poor Champagne), the Pays de Caux
Pays de Caux
The Pays de Caux is an area in Normandy occupying the greater part of the French département of Seine Maritime in Haute-Normandie. It is a chalk plateau to the north of the Seine Estuary and extending to the cliffs on the English Channel coast - its coastline is known as the Côte d'Albâtre...
and the Pays de Bray
Pays de Bray
The Pays de Bray is a small natural region of France situated to the north-east of Rouen, straddling the French départements of the Seine-Maritime and Oise...
.
Structure
The Paris Basin is a geologicalGeology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
basin
Sedimentary basin
The term sedimentary basin is used to refer to any geographical feature exhibiting subsidence and consequent infilling by sedimentation. As the sediments are buried, they are subjected to increasing pressure and begin the process of lithification...
of sedimentary rock
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
s. It overlies geological strata
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
disturbed by the Variscan orogeny and forms a broad shallow bowl in which successive marine deposits from throughout periods from the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
to the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
were laid down: their extent generally diminishing with time.
To the west, the strata folded by the Variscan, rise from below it in the hills of Brittany
Brittany
Brittany is a cultural and administrative region in the north-west of France. Previously a kingdom and then a duchy, Brittany was united to the Kingdom of France in 1532 as a province. Brittany has also been referred to as Less, Lesser or Little Britain...
and in and east the Ardennes
Ardennes
The Ardennes is a region of extensive forests, rolling hills and ridges formed within the Givetian Ardennes mountain range, primarily in Belgium and Luxembourg, but stretching into France , and geologically into the Eifel...
, Hunsrück
Hunsrück
The Hunsrück is a low mountain range in Rhineland-Palatinate, Germany. It is bounded by the river valleys of the Moselle , the Nahe , and the Rhine . The Hunsrück is continued by the Taunus mountains on the eastern side of the Rhine. In the north behind the Moselle it is continued by the Eifel...
and Vosges
Vosges
Vosges is a French department, named after the local mountain range. It contains the hometown of Joan of Arc, Domrémy.-History:The Vosges department is one of the original 83 departments of France, created on February 9, 1790 during the French Revolution. It was made of territories that had been...
. To the south, it borders on the Massif Central
Massif Central
The Massif Central is an elevated region in south-central France, consisting of mountains and plateaux....
and the Morvan
Morvan
The Morvan is a mountainous massif lying just to the west of the Côte d'Or escarpment in Burgundy, France. It is a northerly extension of the Massif Central and is of Variscan age. It is composed of granites and basalts and formed a promontory extending northwards into the Jurassic sea.-Music:The...
. To the north, its strata link into those of the bed of the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
and south-eastern England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. Other boundaries lie on ridges in less old rocks and scarps such as the Côte d'Or
Côte d'Or (escarpment)
The Côte d'Or is a limestone escarpment in Burgundy, France that lends its name to the department which was formed around it...
(on an Alpine
Alpine orogeny
The Alpine orogeny is an orogenic phase in the Late Mesozoic and Tertiary that formed the mountain ranges of the Alpide belt...
fault line) and the Hills of Artois
Artois
Artois is a former province of northern France. Its territory has an area of around 4000 km² and a population of about one million. Its principal cities are Arras , Saint-Omer, Lens and Béthune.-Location:...
which overlie the margin of London-Brabant Massif.