Sandstones and gravels make the only aquifers; no other rocks are useful.

The greater part of the sand from most beaches comes from ____. 

Deep rocks behave as _____ material under stress rather than breaking. 

A(n) _________ aquifer is completely filled with water under pressure and is separated from the surface by an aquitard.  

The most important concentration of earthquakes in the world is the Mediterranean-Himalayan Belt.

An area with many sinkholes and caves is said to have ___ topography. 

When a well is pumped, water flows into the well bore to replace the pumped water. This results in deformation of the water table around the well. What is this deformed area called?  

A(n) ___ stream flows in a network of rivulets (subchannels) around numerous sandbars. 

A stream can increase its length by _____. 

Uniformitarianism reflects the belief among geologists that the Earth remains uniform and unchanging through time.