igneous rocks that are dense and dark-colored thet form from magma that is rich in iron and magnesium and poor in silica
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The earth's plates usually move in three different ways resulting in three different types of plate margins/ boundaries: CONVERGENT, DIVERGENT and TRANSFORM plate boundaries.
When plates move towards each other, they collide and this usually either results in the denser of the plates sliding below the other plate or both plates pushing against each other resulting in both plates being pushed upwards to form often times Fold Mountains. This type of earth tectonics causes a CONVERGENT (destructive; because the collision of the plates results in loss of earth surface area) plate boundary to be formed.
Plates can also pull away from each other and in so doing creating space usually in the form of a fissure between the two moving plates. This fissure usually also for molten earth (magma) rising to the surface and closing the opening between the plates. This type of earth tectonic is known to form DIVERGENT (constructive; because it usually results in new land being formed) plate margins.
Plates also slide against each other (side to side) thus not resulting in neither the destruction or creation of new land. This kind of plate margin is known as the TRANSFORM plate boundary.
The diagram below helps to solidify the points made above.
When plates move towards each other, they collide and this usually either results in the denser of the plates sliding below the other plate or both plates pushing against each other resulting in both plates being pushed upwards to form often times Fold Mountains. This type of earth tectonics causes a CONVERGENT (destructive; because the collision of the plates results in loss of earth surface area) plate boundary to be formed.
Plates can also pull away from each other and in so doing creating space usually in the form of a fissure between the two moving plates. This fissure usually also for molten earth (magma) rising to the surface and closing the opening between the plates. This type of earth tectonic is known to form DIVERGENT (constructive; because it usually results in new land being formed) plate margins.
Plates also slide against each other (side to side) thus not resulting in neither the destruction or creation of new land. This kind of plate margin is known as the TRANSFORM plate boundary.
The diagram below helps to solidify the points made above.