Your goal is to study the smooth, parallel layers of rock to learn how the land built up over geologic time.
(light brown) Next, fossil-rich sedimentary rocks were precipitated.
These rocks are tilted due to deposition on the non-horizontal surfaces of primitive rocks.
Geologists establish the age of rocks in two ways: numerical dating and relative dating.
Numerical dating determines the actual ages of rocks through the study of radioactive decay.
The secondary rocks were thought to include interlayered basalts, which Werner thought formed by combustion of buried coal layers.