Geologic dating relative absolute Free live real bedroom cam
The half-life of many isotopes has been consistently tested and measured precisely.
The half-life of the isotope is the number that determines the age of a rock.
For instance, potassium-40 decays to argon-40 with a half-life of 1.3 million years.
Therefore, if there is a 50-50 ratio of parent to daughter, 1.3 million years have passed since the formation of the rock containing the elements.
Geologists can employ two basic methods to dating rocks and fossils.
Relative and absolute geologic dating practices have their strengths and weaknesses, which are inherent to their process.
For example, a scientists will be able to say Layer A is older than Layer B, and Layer C cuts across Layer A; therefore, Layer C must be younger than A.
However, they will not be able to conclude that Layer A is X number of years older than Layer B.
The most reliable way to accomplish this is through radiometric dating.
These simple parameters provide the fundamental basis for relatively dating geologic strata.
The weakness of relative dating is inherent to its very nature.
If a geologist claims to be 45 years old, that is an absolute age.
Superposition: The most basic concept used in relative dating is the law of superposition.