A radiometric age for a mineral crystal within an igneous rock measures the amount of time that has passed since the
A) atoms within the crystal were part of a body of molten magma.
B) crystal solidified.
C) temperature of the crystal became equal to surface temperatures.
D) temperature of the crystal became equal to the closure temperature for the mineral.

Question

Quizplus · Accepted Answer

Radiometric dating measures the time since a mineral crystal cooled below its closure temperature, the point at which atoms in the crystal lattice are no longer free to move and the isotopic clock starts.

A Radiometric Age for a Mineral Crystal Within an Igneous