ERS120H5 Lecture Notes - Lecture 3: Bunsen Burner, Triple Junction, Kauai
22 Jan 2016
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Document Summary
As sea-floor spreading progresses, new oceanic lithosphere forms at the mid- ocean ridge axis, for simplicity only the crust is shown. The youngest oceanic curst occurs along the ridge axis (time 2) Some magma freezes into new rock within the crust, whereas some spills out onto the surface of the sea floor the faults break up the crust as it stretches apart. Initial rift forms, but is not necessarily straight. As the rifting progresses, spreading ridges from perpendicular and transform faults form parallel to plate motion. Differential motion of transform faults forms fracture zones. The blue arrows show the rate and direction at which the plate on one side of the boundary is moving with respect to the plate on the other side. The length of the arrow represents the velocity. The red arrows show the velocity of the plates with respect to a fixed point in the mantle.
