Geological Time | Geologic Time Scale | Plate Tectonics | Radiometric Dating | Deep Time | Geological History of New Zealand | Radiometric Dating Radiometric measurements of time Since the early twentieth century scientists have found ways to accurately measure geological time.The discovery of by the French physicist, Henri Becquerel, in 1896 paved the way of measuring absolute time.
Several other processes result in the accumulation of distinct yearly layers that can be used for dating.Here is an easy-to understand analogy for your students: relative age dating is like saying that your grandfather is older than you.Absolute age dating is like saying you are 15 years old and your grandfather is 77 years old.Using logs recovered from old buildings and ancient ruins, scientists have been able to compare tree rings to create a continuous record of tree rings over the past 2,000 years.This tree ring record has proven extremely useful in creating a record of climate change, and in finding the age of ancient structures. The thick, light-colored part of each ring represents rapid spring and summer growth.Shortly after Becquerel's find, Marie Curie, a French chemist, isolated another highly radioactive element, .The realisation that radioactive materials emit rays indicated a constant change of those materials from one element to another.Unlike people, you can’t really guess the age of a rock from looking at it.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.There are two basic approaches: relative age dating, and absolute age dating.