land forms of plate movement Flashcards
what are the different types of land forms?
ocean ridges rift valleys fold mountains deep sea trenches island arcs vonlcanoes
how is an ocean ridge formed?
when two oceanic plates pull away from each other, gap is filled by basaltic lava which can rise above sea level and create submarine volcanoes
how is a rift valley created?
when two continental plates pull apart, the crust in between two plates drops down to form a valley
how is a deep sea trench created?
when an oceanic plate sub ducts under a continental, forms a very deep part of the ocean
how are island arcs created?
when plates sub duct in the ocean, part of the plate is melted through friction, the magma is less dense so it rises, this creates volcanoes and as the magma solidifies it causes it to pile up until above sea level creating islands
how are young fold mountains created?
when two continental plates meet, one cannot sub duct, they collide forcing sediment upwards, an example is the Himalayas
how are volcanoes formed?
the same way as island arc
