Introduction dating methods
In its broadest sense, geology is the study of Earth — its interior and its exterior surface, the rocks and other materials that are around us, the processes that have resulted in the formation of those materials, the water that flows over the surface and lies underground, the changes that have taken place over the vastness of geological time, and the changes that we can anticipate will take place in the near future.Geology is a science, meaning that we use deductive reasoning and scientific methods (see Box 1.1) to understand geological problems.The key feature of serious inquiry is the creation of a hypothesis (a tentative explanation) that could explain the observations that have been made, and then the formulation and testing (by experimentation) of one or more predictions that follow from that hypothesis.For example, we might observe that most of the cobbles in a stream bed are well rounded (see photo in this box), and then derive the hypothesis that the rocks become rounded during transportation along the stream bed.Most of the argon in Earth’s atmosphere has been created by the decay of potassium-40, as the argon-40 abundance is about 1,000 times higher than expected from cosmic abundances.Argon dating involves a different technology from all the other methods so far described, because argon exists as a gas at room temperature.
But unlike most of the other sciences, geology has an extra dimension, that of time — deep time — billions of years of it.Our editors will review what you’ve submitted and determine whether to revise the article.Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work!Thus, it can be purified as it passes down a vacuum line by freezing out or reacting out certain contaminants.
It is then introduced into a mass spectrometer through a series of manual or computer-controlled valves.
This may indeed be the case, but there is no practical way to test this hypothesis.