sentences: tectonic plates colliding causes older layers of rock to be located above newer layers of rock
docs: freeboard_deck is upper_deck. cover_plate is covering. bridge is upper_deck. tectonic_plate is stone. colliding is change_of_location. subchain is chain. earth has tectonic_plates metamorphic_rock is rock. crossroads is where_two_roads_intersect_each_other. reef is ridge.