Plate Tectonics Lecture Notes Flashcards

A set of vocabulary flashcards covering Earth's structure, plate tectonic theory, seafloor spreading, magnetic striping, and the different types of plate boundaries mentioned in the lecture transcript.

Crust

The outermost layer of the Earth, varying in thickness from $6-70\,km$.

Mantle

The layer in between the crust and the core, approximately $2,900\,km$ thick with a temperature between $1000-3700^\circ C$.

Core

The innermost and thickest layer of the Earth ($3,300\,km$), with the highest temperatures ranging from $4400-6000^\circ C$.

Oceanic Crust

A heavy and dense layer beneath deep oceans, $5-8\,km$ thick, composed of basalt and aged less than $200$ million years.

Continental Crust

A lighter rock layer beneath land masses, $35-70\,km$ thick, composed of granite and aged up to $4$ billion years.

Convection currents

The process where heat from the core causes mantle material to become less dense and rise, then cool and sink, dragging or colliding tectonic plates.

Slab-pull force

A force contributing to plate movement where gravity pulls denser oceanic crust deeper into the mantle as it subducts.

Divergent Plate Boundary (Oceanic-oceanic)

A boundary where oceanic plates move away from each other, forming mid-ocean ridges like the Mid-Atlantic Ridge and volcanic islands like Surtsey Island.

Divergent Plate Boundary (Continental-continental)

A boundary where continental plates move apart, creating rift valleys like the East African Rift Valley and volcanoes like Mount Kilimanjaro.

Convergent Plate Boundary (Oceanic-oceanic)

A boundary where two oceanic plates collide, forming oceanic trenches like the Mariana Trench and volcanic islands.

Convergent Plate Boundary (Continental-continental)

A boundary where two continental plates collide and buckle, forming fold mountains like the Himalayas.

Convergent Plate Boundary (Oceanic-continental)

A boundary where an oceanic plate subducts under a continental plate, forming trenches (Peru-Chile Trench), fold mountains (Andes), and volcanoes (Nevado del Ruiz).

Transform Plate Boundary

A boundary where plates slide past each other, creating faults like the San Andreas Fault and causing earthquakes like the 1989 Loma Prieta Earthquake.

Seafloor Spreading

The process where magma rises at mid-ocean ridges, cools to form new oceanic crust, and pushes older crust laterally away from the ridge.

Magnetic Striping

The zebra-like symmetrical pattern of alternating normal and reversed polarity rocks on the seafloor, recorded as iron-rich lava cools.

Earth's Last Magnetic Reversal

The most recent event where Earth's polarity flipped, occurring about $780\,000$ years ago.

Subduction Zone

The area at a convergent boundary where the denser plate sinks beneath another plate into the mantle, forming an oceanic trench.

Fold Mountains

Geological features formed when plates collide and the less dense, buoyant continental plate is uplifted and buckled.