Characteristics of relative and radiometric dating technologies
Following this introduction, there are several links to different sites concerning the methods scientists use to assist them in estimating the age of the Earth.You will investigate Steno's Laws, radiometric dating, and then visit an interactive site that will help you better understand how to tell time - with geology! As you proceed through Assignment 4, be sure to compare your answers from "If Scientists Think. ." to the actual methods scientists use to estimate the age of prehistoric objects.These ages have been derived from relative dating and absolute dating (radiometric dating) of rock layers and fossils.
Keep these principles in mind as you progress through the rest of the activities in this assignment.
It would benefit your understanding of this material if you studied the rest of this website on your own, but it is not required for class.
Techniques of accurately dating rocks is crucial in establishing the time-gap that exists.
The classic type is the angular unconformity of which Thornton Force in Ingleton and Combs Quarry, Foredale are perhaps the best known local examples.
Who's to say that the rocks a particular scientist is studying have not been displaced from their original positions?
In addition to the "relative" uncertainty that the geological features of an area have retained their historical integrity, there is another problem associated with relative dating.
Scientists have developed technology that can accurately date rocks using radioactive materials which are fixed into the rocks as they form from sediments.
This dating technique is known as radiometric dating.
The plane or junction, marked by the thick green line, between both sets of strata is the unconformity.
At Thornton Force the junction is marked by a basal conglomerate.
Now that you have discovered the method that scientists originally used to date geological features, you may be questioning the accuracy of this dating method.