Landforms Glossary: Definitions & Examples
CERRO WITNESS: Rest of the platform in a tabular relief (set of hard and soft layers arranged horizontally in which erosion has carved a horizontal landscape). With increasing erosion by rivers in the soft layers, hills are formed, and if the plateau is attacked by erosion everywhere, “isolated hills with flat tops” appear. They are quite common in sedimentary basins of the two sub-plateaus and in the depression of the Ebro.
TECTONIC FORM OR STYLE: Set of characters that a tectonic structure may have and the deformation mechanisms that produce it. Tectonic deformations are usually grouped into sets characterized by the predominance of failure or of a certain type of fold; these groups pose a tectonic style. When faults are essential elements in the structure, it is called a Germanic style. In the case of deformations of folding, the most prominent styles are the Saxon (influenced by fracturing of the basement into blocks) and Jurassic (regular juxtaposition of anticlines and synclines, with a straight surface appearing as hills and valleys). If the anticlines are expressed on the surface as valleys and the synclines as mountains, we find relief reversed.
PLATEAU: Flat surface or slightly tilted in one direction, crossed by valleys and located at a certain altitude above sea level. It usually distinguishes the engagement of the valleys, the average height, small accidents that show, etc. On the Peninsula, it is the fundamental unit of relief. This is the old remains of a mass arising in the Hercynian orogeny (Paleozoic) destroyed by erosion and deformed during the Alpine orogeny, which gave rise to the interior mountains (Central System and Montes de Toledo), internal sedimentary basins (northern and southern sub-plateau), and the mountain ridges (Galician Massif, Cantabrian Mountains, Iberian System, and Sierra Morena).
OROGENIC MOVEMENT/OROGENY: Set of geological processes, both external and internal, which cause the formation and folding of mountains. This process is closely linked to plate tectonics. On a global scale, and its importance in the genesis of the massive and current ranges, there are two orogenies: the Hercynian orogeny, which occurred in the late Paleozoic, and the Alpine orogeny during the Cenozoic.
PÁRAMO or GRINDING: Surface more or less significantly high and horizontal, undeveloped land, rocky or stony, and therefore poor in vegetation. They are characteristic of the northern sub-plateau.
COUNTRYSIDE: Low areas north of the central plains, where the disappearance of the overburden limestone has resulted in a smoother relief on soft materials such as loam and clay. It has a large agricultural development.
PENEPLANE: How to stress that tends to occupy large areas and which, through erosion, has a gently undulating surface, with little difference in height between the valleys and watersheds. It consists of ancient and eroded materials. In temperate countries, it is recognized by the regularity of the surfaces; the watersheds are all the same altitude, the valleys have cut back these dating from the Cenozoic peneplain. Its formation is due to the end of the cycle of erosion that is completed with the total destruction of the reliefs with the result of a monotonous and slightly raised relief on the base level. In Spain, they are located in the northwest of the central plains. The Extremadura peneplain is a great extension that has between 300 and 500 m. altitude that consists of a basement crossed by the Guadiana River.
FROG: A term used in the Iberian Peninsula to designate deposits consisting mainly of coarse quartzite cobbles, which extends in glacis motions or covers the foot of the mountains and very specifically in the mountains of the central and western Paleozoic Peninsula. In Extremadura, they are characteristic in the region of Las Villuercas.
RELIEF APALACHENSE: Result of a long evolution: old folded chains are transformed into peneplains by erosion and then rise again and are eroded, so soft materials wear out quickly and leave the hard ones protruding. Some examples in Spain can be seen in the mountains between Asturias and Galicia, and in the Montes de Toledo, in the region of Las Villuercas (Cáceres).
ALPINE RELIEF: The relief of acute ridges and sharp peaks, similar to that of the Alps.
CUESTA RELIEF: This occurs when layers of sediment deposited horizontally, and composed of materials with different resistance to erosion, suffer tilting. The slope is an asymmetrical relief, as the softer side (back) coincides with the resistance level and the sharpest (front) with soft materials.
KARST LANDFORMS: Designates the modeling of any region that evolves through limestone dissolution, since limestone rock is hard but soluble in water. It is characterized by the appearance of narrow gorges, sinkholes, and caves in amesetadas areas, poljes in which the few rivers are lost in sinkholes, and rock fluting (long grooves that sometimes form sinkholes). The origin of the term comes from a region of Slovenia. In Spain, this type of modeling is quite common; “Ciudad Encantada de Cuenca” is an example of karst in a very advanced state of destruction, examples of sinkholes or torques exist in Antequera, Ronda sickles, etc.
SOCKET or SHIELD: Ground of very old rocks formed in the Precambrian or the Paleozoic and that have under the layered sedimentary rocks further training (they support sediment as the base of the building). In the Iberian Peninsula, the socket is formed by the substrate of the Plateau and the northwestern peninsula, the result of the Hercynian orogeny, which later suffered the effects of pressure in the Tertiary orogenic and subsequent erosion and sedimentation.
EROSION: Action and effects primarily by three actors: wind, water, and ice, which will act slowly over the relief items that stand out until the time comes to change its shape. When the same erosive cause acts in different ways due to the rocky nature, we talk about differential erosion.
FOLD: Deformation of the wave-shaped geological layers. Folds arise as a result of tectonic pressure in plastic rocks, which fold instead of breaking. A fold is formed by an anticline-syncline set. The folds may be right, leaning, or lying down, depending on the dip of the axial plane, and have varying degrees of curvature.
ANTICLINE: In the landforms produced by folded orogenies, the crease would be convex upward. A ripple is a layer of variable size and shape, in which the oldest strata are at the core of the fold. The opposite is a syncline. It may be straight, bent, or lying down. An example of this type of relief can be seen in the Pyrenees, where two mountain ranges or anticlines are separated by a depression or syncline.
SYNCLINE: Marine sedimentation basin, long and deep, in which thick layers of sediment are deposited. The weight of these causes the bottom of the geosyncline to sink, causing the rupture of the seafloor. In the end, the sediments are folded, creating a ridge. They correspond to large depressions that carry the name “val”. Sometimes the very deep erosion attacks the anticlines and the synclines are the highest reliefs, then adopting the name of “synclines hung” as in the Campo de Jaca.
FAULT: Fracture line and discontinuity between two rocky blocks, through which they travel, vertically or horizontally. The failures usually coincide with areas of high seismic and volcanic activity. The old beds, made of very rigid materials, do not bend but break. The reliefs are the accidental failure of these ancient massifs characterized by horsts and grabens. The fault scarps are caused by very complex evolution; erosion is also favored by the presence of faults.
GLACIS: How typical of foothills that is rooted in a mountain slope to link to a valley bottom or depression; in this sense, it is a transition with a slight slope, straight or slightly concave profile.
MOTION: Surface erosion and gentle slopes generated by resistant crystalline rocks. May be coated with a detrital film. Morphoclimatic media forms with a long dry season.
SINKHOLES or LENAR: Grooves or cavities that are separated by sharp walls. They are formed on the slopes by escorentería (lapiaz of slope) or cracked plains (lapiaz in table).
DOLINAS or TORQUES: Large cavities formed over years where water stagnates.
BERROCAL: Typical landscape of granite areas, with bowling and other forms of modeling typical of this rock.
CANCHAL: Pedriza. Accumulation of songs at the foot of a peak or on the slopes of a mountain.
CAÑON-THROAT-HOZ-FOZ: Deep and narrow valley, with vertical walls, carved by a stream. They are typical of the karst landscape of limestone, but can also be carved in granite, in this case, by rivers of great erosive power.
GULLIES or BAD-LANDS: A form of erosion by water, in clay or loam soils lacking vegetation. The area is crossed by numerous ravines and the soil is easily washed by rain.
CIRQUE GLACIER: Zone of large accumulation of ice and snow at the top of a glacier.
OR CONTOURS/CONTOURS: Lines on a map joining points of the same height.
DELTA: Sedimentary accumulation deposited by a river at its mouth. Named for its triangular shape (like the Greek letter Delta). The Delta is also subject to marine erosion. The most important in Spain is the Ebro Delta.
DUNES: Accumulations of sand, typical of coastal or desert areas, shaped by wind.
TECTONIC or FAULT GRABEN: Block sunk, limited by faults.
HORST: High block in a faulted landscape.
GELIFRACCIÓN: Rupture of the rocks by the action of the processes of freezing and thawing.
IBÓN: Name given in the Aragonese Pyrenees to glacial lakes, housed, usually in buckets of remarkable depth.
MARSHES: Land located below sea level, which is flooded with the tides, the waters of rivers, or both at once.
MEANDERS: Sinuous curves drawn by a river. They usually occur in the lower reaches of the valley where the river is less steep and therefore has less erosive power.
MORAINE: Warehouse of torn materials transported by a glacier and located on its forehead (frontal moraine) or on its sides (lateral moraines).
RAMBLA: Torrentera. It only carries water when it rains abundantly. They are typical of arid regions. Abundant in the Mediterranean coast.
RIES: Valleys that have been sunk under the sea, typical of the Galician and Cantabrian coast.
TERRAZAS: Fluvial deposits that are staggered on landings on the sides of a river.
VALLEY GLACIER: The valley excavated by the action of a glacier. Often with vertical sides and a flat bottom (U-shaped valley).