GEOL 1001 Lecture : Geology Notes
Document Summary
Continental rifting: splits a land mass into two or more smaller segments along a continental rift. Older positions of oceanic plates are returned to the mantle at these destructive plate margins. Surface expression of the descending plate is an ocean trench. Plates slide past one another and no new lithosphere is created or destroyed. Most join two segments of a mid-ocean ridge along breaks in the oceanic crust known as fracture zones. A few (the san andreas fault and the alpine fault of new. Volcanos can form over them (hawaiian island chain) Volcanic activity at hot-spots well away from plate margins (e. g. hawaii) provides strong support for the plume hypothesis. Researchers agree that convective flow in the mantle is the basic . Formed by solidification of magma or molten (liquid) rock. Therefore, magma forms within the earth through melting. Temperature high enough to promote melting to produce magma occurs in the mantle.
