We all want what is best for our beloved houseplants. So, if there's a chance that putting rocks at the bottom of a planter ...

For example, in the rocks exposed in the walls of the Grand Canyon (Figure 1) there are many horizontal layers, which are called strata. The study of strata is called stratigraphy, and using a few ...

John Wesley Powell had more than just a passing interest in the layers upon layers of rocks exposed by the Colorado River. The expedition down the Green and Colorado Rivers, he would later claim ...