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Aquitaine Basin AI simulator
(@Aquitaine Basin_simulator)
Hub AI
Aquitaine Basin AI simulator
(@Aquitaine Basin_simulator)
Aquitaine Basin
The Aquitaine Basin is the second largest Mesozoic and Cenozoic sedimentary basin in France after the Paris Basin, occupying a large part of the country's southwestern quadrant. Its surface area covers 66,000 km2 onshore. It formed on Variscan basement which was peneplained during the Permian and then started subsiding in the early Triassic. The basement is covered in the Parentis Basin and in the Subpyrenean Basin—both sub-basins of the main Aquitaine Basin—by 11,000 m of sediment.
The Aquitaine Basin, named after the French region Aquitaine, is roughly funnel-shaped with its opening pointing towards the Atlantic Ocean. Here it meets for 330 km the straight, more or less north–south-trending Atlantic coastline but continues offshore to the continental slope. To the south, it is delimitated for 350 km by the west-northwest–east-southeast trending Pyrenees. In the southeast, the basin reaches the Seuil de Naurouze (also called Seuil du Lauragais) between the Montagne Noire on its northern side and the Mouthoumet range in the south. Just west of Narbonne, the basin is overridden by Pyrenean thrusts. The northeastern boundary of the basin is formed by the arcuate basement outcrops of the Massif Central. Via the 100 km wide Seuil du Poitou in the northeast, the basin is connected to the Paris Basin. In the far north, the basin abuts the east–west-oriented Variscan basement of the Vendée, the southernmost part of the Armorican Massif.
The Aquitaine Basin is a very asymmetric foreland basin. It reaches its deepest part of 11 km just in front of the North Pyrenean Thrust.
The 2,000 m isobath follows more or less the course of the Garonne River and divides the basin into a relatively shallow northern platform, the so-called Aquitaine Plateau, and into a much deeper, tightly folded, southern region. The tabular platform in the north contains only a much reduced sedimentary succession that is gently undulating and occasionally faulted. The folding intensity in the southern region increases steadily towards the south, the structures being further complicated by superimposed salt diapirism.
This somewhat simplified structural subdivision gets complicated by the Parentis Basin which extends out into the Atlantic. The Parentis Basin is situated in the Golfe de Gascogne and also reaches 11 km depth; it is a symmetrical basin oriented east–west and comes ashore near Arcachon. This sub-basin is underlain on its far western side by oceanic crust dated at 100–95 million years BP (Cenomanian). It is bounded by dextral wrench faults (possible transform faults) and probably represents a pull-apart basin.
(Note: Permo-Triassic basins like the Brive Basin and the Grésigne Basin are considered to belong to the basement of the Massif Central.)
Structural and sedimentological investigations of the basin have been carried out in over 70 drilled wells that encountered the Variscan basement sometimes below 6,000 m of sedimentary cover.
The sedimentary evolution in the Aquitaine Basin begins in the Lower Triassic close to the North Pyrenean Thrust. From here, it slowly started spreading farther north.
Aquitaine Basin
The Aquitaine Basin is the second largest Mesozoic and Cenozoic sedimentary basin in France after the Paris Basin, occupying a large part of the country's southwestern quadrant. Its surface area covers 66,000 km2 onshore. It formed on Variscan basement which was peneplained during the Permian and then started subsiding in the early Triassic. The basement is covered in the Parentis Basin and in the Subpyrenean Basin—both sub-basins of the main Aquitaine Basin—by 11,000 m of sediment.
The Aquitaine Basin, named after the French region Aquitaine, is roughly funnel-shaped with its opening pointing towards the Atlantic Ocean. Here it meets for 330 km the straight, more or less north–south-trending Atlantic coastline but continues offshore to the continental slope. To the south, it is delimitated for 350 km by the west-northwest–east-southeast trending Pyrenees. In the southeast, the basin reaches the Seuil de Naurouze (also called Seuil du Lauragais) between the Montagne Noire on its northern side and the Mouthoumet range in the south. Just west of Narbonne, the basin is overridden by Pyrenean thrusts. The northeastern boundary of the basin is formed by the arcuate basement outcrops of the Massif Central. Via the 100 km wide Seuil du Poitou in the northeast, the basin is connected to the Paris Basin. In the far north, the basin abuts the east–west-oriented Variscan basement of the Vendée, the southernmost part of the Armorican Massif.
The Aquitaine Basin is a very asymmetric foreland basin. It reaches its deepest part of 11 km just in front of the North Pyrenean Thrust.
The 2,000 m isobath follows more or less the course of the Garonne River and divides the basin into a relatively shallow northern platform, the so-called Aquitaine Plateau, and into a much deeper, tightly folded, southern region. The tabular platform in the north contains only a much reduced sedimentary succession that is gently undulating and occasionally faulted. The folding intensity in the southern region increases steadily towards the south, the structures being further complicated by superimposed salt diapirism.
This somewhat simplified structural subdivision gets complicated by the Parentis Basin which extends out into the Atlantic. The Parentis Basin is situated in the Golfe de Gascogne and also reaches 11 km depth; it is a symmetrical basin oriented east–west and comes ashore near Arcachon. This sub-basin is underlain on its far western side by oceanic crust dated at 100–95 million years BP (Cenomanian). It is bounded by dextral wrench faults (possible transform faults) and probably represents a pull-apart basin.
(Note: Permo-Triassic basins like the Brive Basin and the Grésigne Basin are considered to belong to the basement of the Massif Central.)
Structural and sedimentological investigations of the basin have been carried out in over 70 drilled wells that encountered the Variscan basement sometimes below 6,000 m of sedimentary cover.
The sedimentary evolution in the Aquitaine Basin begins in the Lower Triassic close to the North Pyrenean Thrust. From here, it slowly started spreading farther north.