WHAT IS STRATIGRAPHY?
	How many of you have ever made a birthday cake or saw someone else make one?  Well, how you make a cake is very similar to something archaeologists (and geologists) call stratigraphy. The steps in making a cake are simple.  First, one cake layer is laid down.  This is followed by a coating of icing.  The second layer of cake is laid on top of the first layer.  And finally, the entire cake is iced.  If you think about it, the first layer of cake would be the oldest since it was laid down first. The next most recent layer would be the icing, followed by the next layer of cake.  The top coat of icing would be the youngest or most recent layer. When an archaeologist digs into the earth, they are actually digging through "layers", or strata (one layer is called a  stratum), of history.  Generally, the deeper you get, the older or farther back in time you go.  The top layers are usually younger or more recent.  Archaeologists use these strata to help them figure out how old something is in comparison to something else.  For example, if Layer A is located entirely under Layer B, than Layer A must be older than Layer B, because Layer A must have been put down first.
			Keep in mind that although it may take only a few hours to make a cake, the time it takes to make one stratum can take anywhere from days to literally thousands of years! Can you think of ways in which layers of earth may be laid down? Try this game to see if you can piece together the history of the site by putting the layers and the events that took place on those layers in order from oldest to most recent.  There may be more than one right answer.  You may want to work with a friend or a group of friends to see if you can unravel the mystery of this site!
	This archaeologist digs into the earth at the Reed Farmstead site, carefully peeling back layers, or strata, of time to expose evidence of past human activity.