Brongniart was the first to use fossils to date rock strata., which states that geologic events are caused by natural processes, many of which are operating in our own time.
This law was independently discovered by William Smith (1769-1839), a British engineer, while working on excavations for canals in England (Winchester, 2002 p.
131) and by Georges Cuvier (1769-1832), a French anatomist, and Alexandre Brongniart (1770-1847), a French naturalist and geologist, during their work on the deposits of the Paris Basin.
Examples include fractures, faults, and igneous intrusions.
Igneous intrusions are sometimes referred to as a seperate principle, the Hutton’s theory of uniformatarianism and the principles of stratigraphy would be fully developed and made popular by another Scottish geologist Charles Lyell (1797-1875) with his classic three volume work, first published from 1830 to 1833, entitled The science of stratigraphy changed humans’ view of the world from one, which was static to one that was dynamic and changing.
Steno formalized the laws of superposition, original horizontality, original continuity and inclusions in his publication entitled states that any inclusion is older than the rock that contains it.
Steno's idea that fossils are older than the rock in which they are found hints at this principle, but Hutton is most often given credit for this principle.states that fossil organisms succeed one another in a definite, irreversible, and determinable order.
The sedimentary layers with the simplest fossils are assumed to be older even if the sedimentary layer is found on top of a sedimentary layer that has fossils that are more complex and therefore assumed to be younger.
Fossils that are in violation of the law of superposition where the older fossil occurs above a younger fossil are said to be stratigraphically disordered.
The method of reading the order is called stratigraphy (layers of rock are called strata).
Relative dating does not provide actual numerical dates for the rocks.
Many of these organisms have left their remains as fossils in sedimentary rocks.