Before his theory, it was commonly held that Earth was only a few thousand years old.
It is believed that Hutton’s theory helped prompt others to question whether ideas about Earth’s age were correct.
Later, Charles Lyell developed the law of superposition, which says that the lowest layers of soils are the oldest.
William Smith developed a similar theory called the principle of faunal succession.
Stratigraphers believe that each of those bands represents a period.
They believe those bands contain information about the past.
These are slices of Earth composed of numerous strata.
Among the principal subdisciplines of historical geology is stratigraphy, the study of rock layers, which are called strata or, in the singular form, a stratum.Stratigraphy is the study of rock layers (strata) deposited in the earth.It is one of the most challenging of geologic subdisciplines, comparable to an exacting form of detective work, yet it is also one of the most important branches of study in the geologic sciences.Earth’s history, quite literally, is written on the strata of its rocks, and from observing these layers, geologists have been able to form an idea of the various phases in that long history.Naturally, information is more readily discernible about the more recent phases, though even in studying these phases, it is possible to be misled by gaps in the rock record, known as unconformities.