Four laws or principles are involved with the study of stratigraphy. They are _____.
Original Horizontality- all sedimentary rocks are originally deposited horizontally. [ Sedimentary rocks that are no longer horizontal have been tilted from their original position.
"Strata either perpendicular to the horizon or inclined to the horizon were at one time parallel to the horizon." Steno, 1669
Lateral Continuity- sedimentary rocks are laterally continuous over large
areas. A useful way for Wisconsinites to consider this law is to think of snowfalls. As snow falls, it is not limited to the intersection of Main and Division streets, nor UWSP campus, but falls over a larger area such as Central Wisconsin. Sediments also "rain" down in a simialr fashion such that sedimentary layers are laterally continuous over an area similar to, or greater than, Central Wisconsin.
"Material forming any stratum were continuous over the surface of the Earth unless some other solid bodies stood in the way." Steno, 1669
Law of Inclusions- this law states that rock fragments (in another rock) must be older than the rock containing the fragments. Refer to Inclusions.
Law of Faunal Succession- This law was developed by William "Strata" Smith who recognized that fossil groups were succeeded by other fossil groups through time. This allowed geologists to develop a fossil stratigraphy and provided a means to correlate rocks throughout the world. ]
There are no new answers.