What Is a No

question 66

Essay

What is a No. 4 sieve? A No. 50 sieve?

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Definitions:

Relative Age

The age of a fossil, organism, rock, geologic feature, or event as defined relative to other geologic features or events.

Absolute Age

A measure of the exact age of a rock, fossil, or other object in years, often obtained through radiometric dating techniques.

Numerical Age

The age of a geological feature or event expressed in years or other units of time, often determined by radiometric dating methods.

Radiometric Age

The determination of the age of a mineral, rock, or archaeological artifact based on the decay rate of radioactive isotopes.