Relative dating uses the principles or laws of stratigraphy to order sequences of rock strata.
Relative dating not only determines which layers are older or younger, but also gives insight into the paleoenvironments that formed the particular sequence of rock.
After brief stints in Paris and Montpelier, he moved to Florence, Italy in 1665.
His studies in anatomy attracted the attention of the Grand Duke of Tuscany, Ferdinand II, who was also a patron of the sciences.
Three of these are known as Steno's principles, and a fourth observation, on crystals, is known as Steno's Law.
The quotes given here are from the English translation of 1916.
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.
Now imagine that you come upon a formation like this: What do you think of it? How can you make any conclusions about rock layers that make such a crazy arrangement?
Steno's anatomical studies focused at first on the muscular system and the nature of muscle contraction -- for example, he used geometry to show that a contracting muscle changes its shape but not its volume.
However, in October 1666, two fishermen caught a huge shark near the town of Livorno, and Duke Ferdinand ordered its head to be sent to Steno.
Today we apply this principle across the Grand Canyon—even across oceans to link continents that once were adjoined. in the plane of the [crystal] axis both the number and the length of the sides are changed in various ways without changing the angles."The other principles are often called Steno's Laws, but this one stands alone at the foundation of crystallography.
"If a body or discontinuity cuts across a stratum, it must have formed after that stratum."This principle is essential in studying all kinds of rocks, not just sedimentary ones. It explains just what it is about mineral crystals that make them distinct and identifiable even when their overall shapes may differ—the angles between their faces.