Stratigraphy is important to understand events that happened over time
and over a large area, However, to interpret these events you require
slices of rocks through time commonly referred to as or cores.
Ships can core rock layers from the ocean bottom. Cores would be taken
at intervals that can help us correlate and interpret how the rocks were
In the figure of cores, each core represents a slice of the Earth. In
"A," the green shells are the oldest and the blue seastars are
the youngest. You can see that as you go from cores A to D the fauna
adds snails to the region. A stratigrapher would determine what
caused this sequence of events. Stratigraphers also look at the rocks,
the fossils, and other evidence to make these conclusions.
Ship taking a core