The Wilson Cycle* Flashcards
What is the first stage?
Rifting
What happens in the first stage?
Cycle begins with the formation of a rift or divergent boundary where lithosphere is stretched and tinned, leading to the separation of tectonic plates. Magma rises and fills the gap, creating new oceanic crust. Can develop an ocean basin
What is the second stage?
Seafloor spread
What happens in the second stage?
The seafloor spreads apart along the rift. Magma wells upwards from the mantle forming new oceanic crust at mid-ocean ridges. Processes causes oceanic plates to move away from each other further
What is the third stage?
Subduction
What happens in the thrid stage?
Oceanic lithosphere becomes denser and colder. When it encounters a convergent boundary, where the two plates collide, the denser oceanic plate is forced beneath the less dense continental plate by subduction. This forms a subduction zone with deep ocean trenches, volcanic arcs and seismic activity
What is the fourth stage?
Continental collision
What happens in the fourth stage?
As the oceanic plate subducts, the distance between the continents decreases. The two continental plates will collide, resulting in a collision zone. Collision causes deformation, folding and thrusting. Leads to mountain ranges
What is the fifth stage?
Uplift and erosion
What happens in the fifth stage?
The mountain range undergoes uplift due to compressional forces. Erosion processes gradually wear down the mountain range
What is the sixth stage?
Breakup and rifting
What happens in the sixth stage?
as erosion lowers the mountain range, tensional forces develop within the crust, leading to the formation of new rifts and the initiation of a new Wilson Cycle
