46) Iceland a good example of an island arc, formed : 2086399
46) Iceland is a good example of an island arc, formed from an oceanic-oceanic plate collision.
47) The oldest rocks on the seafloor are much younger than the oldest rocks on the continents.
48) Wegener's continental drift hypothesis was weakened because a viable mechanism for moving the continents was lacking.
49) During the geologic past, the magnetic field poles have generally been very close to Earth's rotational poles.
50) In general, rocks of the continental crust are less dense than rocks of the oceanic crust.