Relative age dating concepts
his document discusses the way radiometric dating and stratigraphic principles are used to establish the conventional geological time scale.It is not about the theory behind radiometric dating methods, it is about their , and it therefore assumes the reader has some familiarity with the technique already (refer to "Other Sources" for more information).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.Principles of Stratigraphy Stratigraphy is the study of strata (sedimentary layers) in the Earth's crust.Stratigraphic Superposition - Because of Earth's gravity, deposition of sediment will occur depositing older layers first followed by successively younger layers.Thus, in a sequence of layers that have not been overturned by a later deformational event, the oldest layers will be on the bottom.
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. Stratigraphy = the study of strata (layers) in the Earth's crust.Geochronologists do not claim that radiometric dating is foolproof (no scientific method is), but it does work reliably for most samples.It is these highly consistent and reliable samples, rather than the tricky ones, that have to be falsified for "young Earth" theories to have any scientific plausibility, not to mention the need to falsify huge amounts of evidence from other techniques.From the beginning of this course, we have stated that the Earth is about 4.6 billion years old.
How do we know this and how do we know the ages of other events in Earth history? To better understand these concepts, let's look at an archeological example: Imagine we are a group of archeologists studying two different trash pits recently discovered.