There are several different rock types that can be found in our survey areas. Here is a pictorial overview to help you classify them on fossilfinder.org.
Basalt
Volcanic, Igneous

Sandstone
Sedimentary
Sandstone boulders are sand coloured and come in various shapes and sizes. They can be anglular but don’t have sharp straight breakage planes.
There are several different types to look out for:
Fine Grained
Coarse Grained
Fossil Rich
They can also be ‘bioturbated’: during their formation animals burrowed and modified the structure.