Skip to main content
Geology LibreTexts

8: Measuring Geological Time (Exercises)

Q8.1 Cross-Cutting Relationships [SE]

Relative ages: 2: oldest: 3: middle, 1: youngest [SE]

Q8.2 Dating Rocks Using Index Fossils

Dating from overlapping fossils [SE]

Probable age: 92.6 to 92.7 Ma. If M. subhercynius was not present the interpreted age range would be 92.6 to 92.9 Ma

Q8.3 Isotopic Dating

Isotopic dating [SE]

With a ratio of 0.91 the age is 175 Ma (red dotted line)

Q8.4 Magnetic Dating

The possible age ranges are 3.05 to 3.12 Ma and 1.78 to2.00 Ma

Dating based on magnetic-reversal chronology [SE]

8.5 What Happened on Your Birthday?

Answers will vary.