At plate boundaries, tectonic plates are pushed away from each other when magma rises to the surface, creating new crust.

It would create a divergent boundary

Argon, carbon-14, and carbon-12

Master planned communities outside of chicago. note: population density means people living in an area per square mile. chicago, an urban and highly populated area has a much more higher density than a desert, amish community, settlement, or nomadic region.