Geography of Spain: Relief, Formation, and Regional Features
Spain as a Territorial Unit
The Iberian Peninsula consists of the State of Spain (predominant in the peninsula), Portugal, Andorra, and the Gibraltar enclave. In turn, Spain consists of the Spanish territories of the peninsula, the Balearic and Canary Islands, and the autonomous cities of Ceuta and Melilla, located in northern Africa. All these areas account for 504,782 km2, of which 492,494 km2 occupies mainland Spain. Mainland Spain has two types of boundaries: maritime, formed by the Cantabrian Sea, the Mediterranean Sea, and the Atlantic Ocean, and land, formed in the west by the border with Portugal, and in the north by the Pyrenees, which set the French border.
Because of its large size and its peninsular nature, Spain has a huge coastal development. Mainland Spain has 3,904 km of coastline.
Geographical Position as a Singular Fact
Spain has been recognized since ancient times as a singular country. The features that give it this uniqueness are:
Peninsular Character
Spain is a peninsula joined to the European mainland by the isthmus of the Pyrenees. The huge ring of the Hispanic landmass is attached to the European continent by an isthmus, and upon it rests the Pyrenees, accentuating the mainland character of Spain. This isthmus gives the Iberian Peninsula a uniqueness that neither the Italian nor Balkan peninsulas have, and it makes the isolation of the Iberian Peninsula greater.
Geographical Location and Position of the Iberian Peninsula
It has a unique position and situation. Unlike other European peninsulas, the Iberian Peninsula is the only one that lies between two seas, is the southernmost and westernmost peninsula in Europe, and the closest to the African continent. The Peninsula is located in the temperate northern hemisphere. This situation gives the Peninsula the following original features:
- Spain is located in the westernmost part of the Mediterranean, where its waters mingle with the Atlantic Ocean.
- Spain, due to its advanced position toward the south, is the country closest to Africa. Only 14 km separate the African coast from the peninsula by the Strait of Gibraltar.
Setting the Relief
Spain’s geographical uniqueness is determined by the particular characteristics of the mainland relief organization:
a) The compact form, due to the large extent in latitude and longitude of the Peninsula. This gives it a continental character since many points are far inland from the coast.
b) The high average altitude is not the result of the presence of high peaks, but the existence of the Castilian plateau.
c) The provision of peripheral large mountain ranges that are available on or independent of the Castilian Plateau.
Consequences of the Regional Singularity
Spain as a Crossroads
In natural terms, the climatic features of the Peninsula are determined, first, by the influence of depressions and anticyclones from the Atlantic and, therefore, by weather conditions that are generated in the Mediterranean basin. However, one should not forget the influences it receives from the centers of high or low pressure located in the European and African continents. In Spain, there are also species of flora and fauna from Europe and Africa. In northern Spain are groups such as white spruce, beech, and oak; in the south and east of the peninsula grows spontaneously palmetto, a typically African plant (in the center and south is the large domain of oak and cork oak in second place). In human terms, the Hispanic landmass has been since ancient times a place of settlement for people of diverse backgrounds, who have approached from all fronts. Just remember the Phoenician, Carthaginian, Greek, and Roman settlements of the first centuries of our history, or the subsequent invasion of the barbarians from Europe. Later came the Muslim invasion. Acts of a similar nature reinforce Spain’s character as a meeting place. This is demonstrated by migration flows from Africa, Eastern Europe, or Latin America.
Spain’s Geostrategic Position
The status and geographical position of Spain also imply a geostrategic position of the first order to establish relations of any kind with countries on two continents as diverse as Africa and America. Spain is the European country closest to Africa, so it is said that the Strait of Gibraltar, rather than a border, is a bridge between Europe and Africa through Spain. No less important is the position of Spain in its relations with the Americas. Spain controls one of the steps by which the sea flows in the direction of the parallels, through the Straits of Gibraltar and the Suez and Panama Canals. It is now possible to move from Asia to America via the Mediterranean and the Atlantic without having to go around the two continents. The position of the Canary Islands forces the proximity of America to Spain.
General Features of Relief
In an overview of the relief of the Iberian Peninsula, three of its main features can be seen: the high average altitude, the peripheral arrangement of the mountain systems, and how solid and compact the Peninsula is.
- The high average altitude. Spain has an average altitude of 660m above sea level, making it the second most mountainous country in Europe after Switzerland (1300m). The mountainous nature of the Peninsula imposes conditions unfavorable to agriculture, the distribution of the population, means of communication, or the use of rivers and waterways.
- The provision of peripheral relief. Most of the Peninsula’s mountain systems are arranged in relation to the Plateau. Inside (the Central System and Montes de Toledo), around it (mountains of León, Cantabrian and Iberian mountain ranges, Sierra Morena), or independent of it (Betic and Pyrenean). This peripheral provision is responsible for interior peninsular isolation and the limited penetration of the influence of the sea.
- How solid and compact. It is due to the vastness of the Iberian Peninsula in latitude (700km) and length (1,024 km) with respect to the other Mediterranean peninsulas.
As a result of this compact and solid nature, the Peninsula becomes a small continent, whose interior is protected by the mountains outside.
Formation of the Peninsular Relief
The main orogenic phases correspond to the Primary and Tertiary Eras, Hercynian, and Alpine folds. By contrast, the Quaternary and Tertiary Eras correspond with periods of erosion and sedimentation.
Orogenic Phases
About 300 million years ago, at the end of the Primary Era, the Hercynian folding did emerge from the seas that covered the Hesperian Massif Peninsula. At the end of folding in the Carboniferous period, average erosion destroys the new relief, making an extensive peneplain. At the beginning of the Secondary Era, about 200 million years ago, the land surface was organized into two major continental areas: the continents of Laurasia and Gondwana. Between them stood the Tethys Sea. In the Tertiary, Alpine folding pushed the continent of Gondwana against the North Atlantic, thereby compressing the sediments and the sea of Tethys. The Alpine orogeny raised the Betic Cordilleras and the Pyrenees; fractured the edges of the plateau, forming the Cantabrian and Iberian mountain ranges and Sierra Morena; raised the Central System and the Montes de Toledo; created the depressions of the Ebro and Guadalquivir; and finally, tilted the whole west, forcing the new water network to be directed towards the Atlantic Ocean.
Post-Orogenic Evolution: The Quaternary
In the Quaternary Era, glacial and interglacial periods alternated in Spain and Europe.
a) In glacial periods, high mountains were occupied by vast glaciers, whose valleys and languages dragged till and all materials, from stone to sand. The low areas, in turn, were affected by intense erosion of the rivers.
b) In the interglacial stages, which correspond to warmer weather, the ice accumulated during the glaciations melted. As a result, the flow and the erosive force of the rivers increased, deepening their channels and forming large terraces of boulders, or alluvium, sand, and silt.
Lithological and Structural Division
The Siliceous Iberia
This area is made up of those areas where abundant crop materials such as silica and quartz, and the predominant eruptive rocks (granite) and metamorphic rocks (gneiss, quartzite, slate, marble) are found. Siliceous Iberia occupies the western third of the Peninsula: the base of the plateau, the Galician massif, the Central System, the Montes de Toledo, and Sierra Morena. However, siliceous rocks are also present in the Axial Zone of the Pyrenees, the high peaks of Sierra Nevada, and isolated nuclei of the Iberian System.
Structurally, this area is consistent with the massive ancient Iberia. It consists of Paleozoic and Precambrian materials, very worn by senile erosion. The topography is characterized by the appearance of a plateau or plateau checkered by failure, in which the rivers have drawn throats of steep slopes.
The Limestone Iberia
This Iberia is composed of sedimentary formations, the majority of marine origin, deposited during the Secondary Era. Along with the limestone, sometimes as abundant conglomerate, sandstone, and marl. The limestone Iberia draws an inverted Z, starting in the Pyrenees, extending through the Basque Mountains and the eastern part of the Cantabrian Mountains, the Iberian System, and the Betic Cordillera.
Structurally, it corresponds to modern ridges, formed when the Alpine orogeny folded in areas that had received marine sedimentation during the Secondary Era. Young mountain ranges are characterized by great heights. The topography of the area comes from the characteristics of the limestone. It is a hard rock, hence the rivers form deep gorges or ravines; it is a permeable rock, resulting in a typical karst landscape, the most typical forms of which are dolines, sinkholes, caves, poljes, and depths.
The Clay Iberia
This area comprises sedimentary material of continental or marine origin, such as marl, gypsum, and clay, which form the covering of the broad plains of the Castilian plateau.