Numerical ages for boundaries between time units on the geologic time scale primarily resulted from the study of ________,in conjunction with relative age information determined from geologic principles.
A) fossil content and spatial relationships among igneous rocks
B) fossil content and spatial relationships among sedimentary rocks
C) radiometric dating of igneous rocks
D) radiometric dating of sedimentary rocks

Question

Quizplus · Accepted Answer

Radiometric dating of igneous rocks provides the most accurate numerical ages for boundaries between time units on the geologic time scale. This information is then used in conjunction with relative age information determined from geologic principles to create a comprehensive understanding of the Earth's history.

Numerical Ages for Boundaries Between Time Units on the Geologic