Orogenesis and Mountain Building Processes

Practice flashcards focusing on key vocabulary related to orogenesis and mountain building processes.

Orogenesis

The set of processes that forms a mountain belt.

Compressional mountains

Mountains formed through the faulting and folding of large quantities of preexisting sedimentary and crystalline rocks.

Subduction

The process where one tectonic plate moves beneath another plate, typical in oceanic-continental collisions.

Volcanic island arcs

Landforms created where subduction occurs beneath oceanic lithosphere, resulting in volcanic activity.

Continental volcanic arcs

Mountains that form where subduction occurs beneath continental plates.

Accretionary wedge

An accumulation of sedimentary and metamorphic rocks that gets scraped off from the subducting plate.

Andean-type convergent zones

Regions where continental volcanic arcs typically form due to subduction.

Passive continental margin

Areas of continental crust that are not currently active tectonically but may accumulate sediment.

Active continental margin

The coastal area where tectonic plates meet and result in geological activity such as subduction.

Cordilleran-type mountain building

Mountain building associated with Pacific-like ocean basins and rapid rates of subduction.

Terranes

Crustal fragments that can include microcontinents, involved in collisional mountain building.

Microcontinent

A small landmass that can be part of a terrane involved in mountain building processes.

Alpine-type orogenies

Mountain building resulting from the collision of continental plates.

Appalachians

Mountain range created by orogenies over several hundred million years, key in assembling Pangaea.

Basin and Range Mountain Belts

Mountains formed when a continent starts to rift and parts of the ground drop down.

Sedimentary rocks

Rocks formed by the accumulation of sediment, often involved in mountain-building processes.

Crystalline rocks

Igneous or metamorphic rocks that are formed through the cooling of magma or transformation of existing rocks.

Elevational criteria for mountains

Mountains must generally meet specific elevation and slope requirements to be classified as mountains.

Oceanic plate

The dense, tectonic plate that typically subducts beneath a continental plate.

Collision between Indian and Eurasian plates

Responsible for the formation of the Himalayas through Alpine-type mountain building.

Rifting

The process where the Earth's crust breaks apart, often leading to the formation of new basins or mountain ranges.

Orogenesis

The set of processes that forms a mountain belt.

Compressional mountains

Mountains formed through the faulting and folding of large quantities of preexisting sedimentary and crystalline rocks.

Subduction

The process where one tectonic plate moves beneath another plate, typical in oceanic-continental collisions.

Volcanic island arcs

Landforms created where subduction occurs beneath oceanic lithosphere, resulting in volcanic activity.

Continental volcanic arcs

Mountains that form where subduction occurs beneath continental plates.

Accretionary wedge

An accumulation of sedimentary and metamorphic rocks that gets scraped off from the subducting plate.

Andean-type convergent zones

Regions where continental volcanic arcs typically form due to subduction.

Passive continental margin

Areas of continental crust that are not currently active tectonically but may accumulate sediment.

Active continental margin

The coastal area where tectonic plates meet and result in geological activity such as subduction.

Cordilleran-type mountain building

Mountain building associated with Pacific-like ocean basins and rapid rates of subduction.

Terranes

Crustal fragments that can include microcontinents, involved in collisional mountain building.

Microcontinent

A small landmass that can be part of a terrane involved in mountain building processes.

Alpine-type orogenies

Mountain building resulting from the collision of continental plates.

Appalachians

Mountain range created by orogenies over several hundred million years, key in assembling Pangaea.

Basin and Range Mountain Belts

Mountains formed when a continent starts to rift and parts of the ground drop down.

Sedimentary rocks

Rocks formed by the accumulation of sediment, often involved in mountain-building processes.

Crystalline rocks

Igneous or metamorphic rocks that are formed through the cooling of magma or transformation of existing rocks.

Elevational criteria for mountains

Mountains must generally meet specific elevation and slope requirements to be classified as mountains.

Oceanic plate

The dense, tectonic plate that typically subducts beneath a continental plate.

Collision between Indian and Eurasian plates

Responsible for the formation of the Himalayas through Alpine-type mountain building.

Rifting

The process where the Earth's crust breaks apart, often leading to the formation of new basins or mountain ranges.

Primary Causes of Mountain Building

Mountain ranges largely result from plate tectonic processes, including convergent plate interactions (subduction and continental collisions) and episodes of continental rifting or crustal extension.

Fold-and-Thrust Belts

A common type of mountain structure formed by compressional forces, characterized by intensely folded rock layers and multiple thrust faults that shorten and thicken the crust.

Role of Accreted Terranes in Orogenesis

Exotic crustal blocks (terranes), such as island arcs or microcontinents, can be scraped off a subducting plate and added to the overriding continent, contributing significantly to the growth and complexity of mountain belts.