" Slate Bugs "
When Mariposa County was underwater millions of years ago
shale was formed from layers and layers of mud.
In between those layers one can find history today by carefully
opening each layer like turning pages in a book to reveal a story
about times gone by as mollusks, bugs, leaves and other
things that were caught between the layers of mud are preserved
by leaving behind an impression in the mud / shale.
In the center of this photo is the outline of such a bug that was about
an inch long.