The table below summarises key features: Gastrioceras listeri is a particularly good example of a ZONE fossil.
Although the types of trash in each pit is quite variable, each layer has a distinctive kind of trash that distinguishes it from other layers in the pits.
What would the geologist be able to deduce about the world we live in, based on what was left in the strata?
Stratigraphy started to become a formal science due to the work of a man who published under the name Nicolaus Steno in the 17th century.
Prior to the late 17th century, geologic time was thought to be the same as historical time.
Archbishop James Ussher of Armagh, Ireland, 1654, added up generations from the Old Testament and determined that Earth formed on October 23, 4004 BCE.
These ages have been derived from relative dating and absolute dating (radiometric dating) of rock layers and fossils.