What methods are used in relative dating
These strata are often most visible in canyons or gorges which are good sites to find and identify fossils.
Understanding the geologic history of an area and the different strata is important to interpreting and understanding archaeological findings.
In areas in which scientists have tree rings sequences that reach back thousands of years, they can examine the patterns of rings in the wood and determine when the wood was cut down.
This works better in temperate areas that have more distinct growing seasons (and this rings) and relatively long-lived tree species to provide a baseline.
There are two basic approaches: relative age dating, and absolute age dating.
Here is an easy-to understand analogy for your students: relative age dating is like saying that your grandfather is older than you.
Once the organism dies, the Carbon-14 begins to decay at an extremely predictable rate.
Radioactive carbon has a half-life of approximately 5,730 years which means that every 5,730 years, half of the carbon-14 will have decayed.
If archaeologists know how pottery styles, glazes, and techniques have changed over time they can date sites based on the ratio of different kinds of pottery.Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.In a way this field, called geochronology, is some of the purest detective work earth scientists do.Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.
Pretty obvious that the dike came after the rocks it cuts through, right?
The most common relative dating method is stratigraphy.