Plate Tectonics & Sedimentary Basins & Geologic Time Scale (GEOL 306) Review

Flashcards providing vocabulary terms and definitions related to Plate Tectonics, Sedimentary Basins, and the Geologic Time Scale, based on the GEOL 306 lecture notes by Dr. Julia Reece.

Divergent Plate Boundary

A plate boundary where two tectonic plates are moving away from each other.

Convergent Plate Boundary

A plate boundary where two tectonic plates are moving toward each other, often resulting in subduction or collision.

Transform Plate Boundary

A plate boundary where two tectonic plates slide horizontally past each other.

Trench

A deep, narrow depression in the ocean floor, typically formed at convergent plate boundaries where one plate subducts beneath another.

Island Arc

A curved chain of volcanic islands formed above a subducting oceanic plate at an oceanic-oceanic convergent boundary.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and the uppermost part of the mantle.

Asthenosphere

The highly viscous, ductile region of the upper mantle below the lithosphere, allowing for plate movement.

Hot Spot

An area in the Earth's mantle where heat rises as a thermal plume, creating volcanoes away from plate boundaries.

Continental Rift Zone

A linear zone where continental lithosphere is being stretched and thinned, representing a young divergent plate boundary.

Plate Tectonics

The theory explaining the Earth's crustal structure and associated phenomena through the interaction and movement of rigid lithospheric plates.

Sedimentary Basins

Regions where sediments accumulate into thick successions of strata, recording tectonic history and depositional conditions.

Geologic Time Scale

A system of chronological dating that relates geological strata to time, organizing Earth's history.

Ridge Push

A gravity-driven force that pushes young, hot plates away from spreading ridges at divergent boundaries.

Slab Pull

A gravity-driven force where old, cold, and dense oceanic plates are pulled down into subduction zones.

Oceanic Crust

The part of Earth's crust that underlies the ocean basins, which is much younger than continental crust, with a mean age of ~60 my and maximum of ~180 my.

Lithos

A Greek word meaning 'rock' or 'stone'.

Tekton

A Greek word meaning 'builder'.

Passive Margins (Continental Terraces)

Formed when oceanic crust develops and continental crust moves away from a rift, characterizing the continental shelf and slope.

Fast-spreading Ridges

Divergent boundaries characterized by a mountain chain along the crest, high heat and magma input, making the ridge buoyant (e.g., East Pacific Rise).

Slow-spreading Ridges

Divergent boundaries that form valleys on the ridge crests with lower heat input (e.g., Mid-Atlantic Ridge).

Basin-and-range Province

A type of topography characterized by parallel mountains and valleys dispersed across a broad uplifted area resulting from early extension.

Ring of Fire

A major tectonic belt around the Pacific Ocean characterized by numerous deep earthquakes and chains of volcanoes due to mostly convergent plate boundaries.

Left Lateral (Sinistral) Strike-Slip Fault

A type of transform fault where the block on the opposite side moves to the left relative to an observer.

Right Lateral (Dextral) Strike-Slip Fault

A type of transform fault where the block on the opposite side moves to the right relative to an observer.

Intracratonic Basins

Broad and shallow regions of subsidence within a continental block (craton), away from plate margins, commonly filled with lacustrine and fluvial sediments.

Rift

A structural valley bounded by extensional (normal) faults, with its axis perpendicular to the direction of stress.

Passive Margin

The continental shelf and slope separating an ocean and continent where no subduction occurs; important areas for accumulation of carbonate and clastic sediments.

Pelagic Sedimentation

Sedimentation in deeper ocean parts consisting of fine-grained biogenic detritus and clays.

Volcanic Arc

A line of volcanoes formed by rising magma where a down-going slab partially melts in a subduction zone.

Backarc Basin

An extensional basin formed if the angle of subduction is steep and the rate of convergence is slower than subduction.

Accretionary Complex/Prism/Wedge

A mass of sediments scraped off the subducting oceanic crust and accumulated at the edge of the overriding plate at a convergent boundary.

Orogenic Belt

A mountain range formed by the collision between two continental plates.

Crustal Loading

The thickening of the crust that results in additional loading, causing a downward flexure of the crust.

Pull-apart Basin

A basin formed as a result of an offset or bend along a strike-slip fault.

Wilson Cycle

A geological process, named after J. Tuzo Wilson, describing the breakup of supercontinents, formation of an ocean, and eventual convergence leading to the closure of the ocean basin.