Catalan Central Depression
Encyclopedia
Depression (geology)
A depression in geology is a landform sunken or depressed below the surrounding area. Depressions may be formed by various mechanisms.Structural or tectonic related:...
between the Pre-Pyrenees
Pre-Pyrenees
The Pre-Pyrenees are the foothills of the Pyrenees.-Description:As a mountainous system the Pre-Pyrenees are part of the Pyrenees. They run parallel to the main mountain range in a west to east direction...
and the Catalan Pre-Coastal Range
Catalan Pre-Coastal Range
The Catalan Pre-Coastal Range is a system of mountain ranges running parallel to the Mediterranean Sea coast in Catalonia. It is part of the Catalan Mediterranean System. Its main axis runs between the Catalan Transversal Range and the Serra de l'Espina, which connects with the Ports de...
. It widens towards the west, linking with the Ebro Depression
Ebro
The Ebro or Ebre is one of the most important rivers in the Iberian Peninsula. It is the biggest river by discharge volume in Spain.The Ebro flows through the following cities:*Reinosa in Cantabria.*Miranda de Ebro in Castile and León....
, , of which it could be considered an eastern extension. The Catalan Central Depression is about 180 km long with an average width of 50 km.
Description
The Catalan Central Depression consists of a succession of high plateaus between 800 and 1,000 metres in altitude that gradually lose height westwards until the Ebro Depression. There are erodedErosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
river basins limiting these heights wherever the ground is made up of clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
or marlstone. The Pla de Bages
Pla de Bages
Pla de Bages is a Spanish Denominación de Origen for wines, located in the province of Barcelona , and is one of the smallest DOs in Spain, covering only 600 hectares...
and the Conca de Barberà
Conca de Barberà
Conca de Barberà is a comarca in the province of Tarragona, Catalonia, Spain.-Municipalities:*Barberà de la Conca - pop. 434*Blancafort - pop. 412*Conesa - pop. 123*Espluga de Francolí - pop. 3,687*Forès - pop. 60*Llorac - pop. 128...
are examples of these higher regions.
The limits of the Central Depression are different whether considered from the point of view of their origin or their actual relief. Some mountain ranges outside of the depression, like Montserrat
Montserrat (mountain)
Montserrat is a multi-peaked mountain located near the city of Barcelona, in Catalonia, Spain. It is part of the Catalan Pre-Coastal Range. The main peaks are Sant Jeroni , Montgrós and Miranda de les Agulles...
and Sant Llorenç del Munt
Sant Llorenç del Munt
Sant Llorenç del Munt is a largely rocky mountain massif in central Catalonia, Spain. The highest summit, where the Sant Llorenç del Munt Monastery is located, has an altitude of 1,004.2 metres above sea level and is known as La Mola...
, are formed by the same geologic materials that make up the Central Depression, even though geographically they are situated in the Pre-Coastal Range. These materials were piled up over the more ancient rocks of the Catalan Mediterranean System
Catalan Mediterranean System
The Catalan Mediterranean System, also known as Mediterranean System, Transversal Ibero-Pyrenaean System and Catalanid Systemis a wide coastal geographical region in Catalonia...
.
The Central Depression formed in the Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
, when a great gulf, that later became a sea, had its boundaries in the Pyrenees
Pyrenees
The Pyrenees is a range of mountains in southwest Europe that forms a natural border between France and Spain...
and the Catalan-Balearic Massif.
Marine sedimentation
Sedimentation
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...
formed clay, and other limestone materials, like bluish marl where the sedimentation had been part of a quiet and slow process, as well as conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
in the areas of the mouths of ancient rivers coming down from the Pyrenees and the former Catalan-Balearic Massif. Evaporation produced sodium and potassium salts, as well as gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
in certain areas.
Mountain ranges
Some minor mountain ranges are scattered within the Central Depression without a regular pattern. The main ones are:- Serrat Gran de Postius
- Serrat de la Minyona
- Serrat de la Rodoreda
- Serra de Castelltallat
- Serra de Pinós
- Serra de Brufaganya
- Serra de Palomes
- Serra de Rubió
- Serra d'Almenara
- Serra de Sant Miquel
- Punta d'Ossós
- Muntanya de Sant Mamet
- Mont-Roig
- Serra Carbonera
- Serra d'Oliana
- Serra del TallatSerra del TallatSerra del Tallat is a mountain range of the Catalan Central Depression, Catalonia, Spain. It has an altitude of 802 metres above sea level.Thhe highest summit of the Serra del Tallat is the Tossal Gros de Vallbona; it is located between the municipal limits of Espluga de Francolí, Conca de Barberà...
- Serra de Vilobí
- MontmeneuMontmeneuMontmeneu is a mountain of Catalonia, Spain. It is located in the La Granja d'Escarp and Seròs municipal limits, Segrià.It is an isolated hill of the Catalan Central Depression, visible from far away.-External links:* Map Segrià, ICC 1:50.000**...
- Serra de Matalescabres
- Serra de la FatarellaSerra de la FatarellaSerra de la Fatarella is one of the isolated mountain ranges of the Catalan Central Depression located off the southern end of the Catalan Pre-Coastal Range between La Fatarella and Ascó....
- Serra dels PesellsSerra dels PesellsSerra dels Pesells is a mountain chain located near the southern end of the Catalan Pre-Coastal Range between Bot and Arenys de Lledó.The ridge's highest point is 541,3 m. This smooth range runs in a NNE - SSW direction and divides the basins of the Canaletes and Algars rivers...