Correlation and Dating of the Rock Record: Chapter Objectives
After completing this chapter, students should:
Understand the difference between relative dating and absolute dating of rocks and how both types of dating were needed to produce the geologic time scale.
Appreciate how fossil succession has been used to determine the relative age of rock strata and piece together a relative geologic time scale.
Know what geological systems are and how they developed historically.
Understand what correlation is, including lithologic correlation and temporal correlation.
Be able to explain time units and time-rock units and the correspondence between them.
Know how index fossils are used to characterize biostratigraphic units.
Understand how magnetic stratigraphy works and how it is used for temporal correlation.
Be able to define rock units, stratigraphic sections, and facies and explain how they interrelate.
Know what transgression and regression are.
Be able to describe the early methods used to estimate Earth's absolute age.
Be able to explain the principles underlying radiometric dating.
Know which isotopes are useful for dating rocks of particular ages.
Be able to explain why most geologic correlations are still based on fossils, even though radiometric dating provides absolute ages of rocks.
Understand how global shifts in the isotopic ratios of certain elements preserved in sediments provide methods for correlating strata.
Know what event stratigraphy is and how it is used to correlate strata.
Understand how seismic stratigraphy can be used to study global unconformities and discover global patterns of sea-level change over geologic time.