New oceanic lithosphere crystallizes from magma injected along the axis of a mid-ocean ridge. we are going to focus on a point located at latitude 45.9°n and longitude 129.9 w along the juan de fuca ridge between the pacific and juan de fuca plates, about 560 km west of portland, oregon (fig. a2.1.1). merican plate reference point 5.9°n 122.9°w pacific s plate /r juan de fuca plate oregon 0 100 200 km north figure a2.1.1