Differing physical forces is the correct answer :)
The flags that were placed by people who landed there
The effects of living next to/by a volcano can be very deadly. If the volcano were to erupt, lava would burn down everything and you would be left homeless and the city (if there was one would be destroyed. You would also have lots of ash. Might not have a lot of time to prepare to leave. <span />
Answer:
When rocks deform by plastic deformation they can bend and fold. The process of folding occurs when rock is compressed, as it is along colliding plate boundaries. Upturned folds are called anticlines and down turned folds are called synclines.