Geologic time relative dating Sex chatts canada
Development of the geologic time scale and dating of formations and rocks relies upon two fundamentally different ways of telling time: relative and absolute.
Relative dating places events or rocks in their chronologic sequence or order of occurrence.
He concluded, after studying rocks at many outcrops, that each layer represented a specific interval of geologic time.
Further, he proposed that wherever un-contorted layers were exposed, the bottom layer was deposited first and was, therefore, the oldest layer exposed; each succeeding layer, up to the topmost one, was progressively younger.
Simply stated, each bed in a sequence of sedimentary rocks (or layered volcanic rocks) is younger than the bed below it and older than the bed above it.
This law follows two basic assumptions: (1) the beds were originally deposited near horizontal, and (2) the beds were not overturned after their deposition.
Between the years of 17, James Hutton and William Smith advanced the concept of relative dating.
The age of formations is marked on a geologic calendar known as the geologic time scale.
If a geologist claims to be 45 years old, that is an absolute age.