Key Geological Terms: Relief, Rocks, and Tectonic Processes

Posted on Mar 26, 2025 in Geology

Geological and Geographical Definitions

Appalachian Relief

A type of folded structure rejuvenated by erosion that highlights hard materials and depresses soft layers (e.g., Montes de Toledo).

Germanic Relief

Relief where the hardness of materials led to fracturing or faulting. Characterized by horsts and grabens (rifts).

Jurassic Relief

A type of folded structure formed by anticlines and synclines.

Saxon Relief (or Fold-Fault Relief)

A mixed relief type involving both folding and fracturing.

Igneous Rock

Rocks formed deep within the Earth by the progressive and slow cooling of magma.

Sedimentary Rock

Rocks typically deposited in horizontal layers, originating from the breakdown of other rocks or minerals.

Rock

Naturally occurring materials found on the Earth’s surface, composed of one or more minerals or resulting from the breakdown of other rocks.

Paleozoic Rock (Siliceous in Spain)

Remnants of the ancient basement complex (Massif), formed during the Primary Era (Hercynian orogeny), eroded during that period, and rejuvenated during the Alpine orogeny (Tertiary Era).

Metamorphic Rock

Rocks that have undergone transformation due to high temperatures and pressures.

Roques

Lava spouts or plugs.

Roque (Canary Islands)

A sharp volcanic rock elevation resulting from differential erosion in volcanic relief.

Rotation

The movement of a celestial body around its own axis. Earth’s rotation takes approximately 24 hours.

Sedimentation

The process by which materials transported by an agent of erosion (like water, wind, or ice) are deposited.

North

Refers to locations situated in the northerly direction.

Syncline

A downward fold in the Earth’s crust caused by tectonic movements, where rock strata converge downwards. It features a hinge and limbs (sides).

Overexploitation

The utilization of environmental resources beyond their capacity for production and regeneration.

Solstice

The time when the sun’s rays fall perpendicularly on one of the tropics (Cancer or Capricorn).

Solifluction

The slow downslope movement of water-saturated soil or regolith, especially in periglacial environments.

Abrasion Platform (or Wave-Cut Platform)

A coastal surface shaped by the erosive action of waves.

Marine Transgression

An event where sea levels rise relative to the land, causing the sea to invade previously exposed land areas.

Terra Rossa

A reddish clay soil type, often found as residue in limestone areas, particularly in Mediterranean climates.

Slope

An inclined surface. In monoclinal structures, softer, erodible layers often form gentler slopes.

Tectonics

Processes involving forces within the Earth capable of producing movement, deformation, or rupture of the crust (including orogeny and epeirogenesis).

River Terrace

Relatively flat surfaces flanking a river valley, representing former floodplain levels, formed by river erosion and sedimentation.

Tombolo

A sandbar or spit connecting an island or rocky outcrop to the mainland or another island.

Revolution (Orbital Motion)

The movement of a celestial body around another star or celestial body. Earth’s revolution around the Sun takes approximately 365.25 days.

Tropics

Imaginary lines of latitude located at approximately 23°26′ North (Tropic of Cancer) and 23°26′ South (Tropic of Capricorn). They mark the northernmost and southernmost latitudes where the sun can be directly overhead (at its zenith).

Morphostructural Units

The shape and internal arrangement of relief features. They result from tectonic movements (uplift, subsidence, displacement) within the Earth and the subsequent actions of erosion and sedimentation, influenced by rock type.

Uvala

(Serbo-Croatian term) Large, complex depressions formed in limestone terrains due to the merging of several sinkholes (karst phenomena).

Wide Valley

A river valley carved into softer rocks, allowing for significant erosion of the valley walls, creating a wider form.

Volcanism

The set of geological phenomena associated with volcanic activity, including eruptions of lava, ash, and gases.

Basement Complex (Zócalo)

A foundation of ancient, rigid crystalline rocks, often covered by younger sedimentary layers. These platforms can be later rejuvenated and fractured by tectonic activity.