Earth Science Quarter 2 – Module 12: Describe How Index Fossils (also known as guide fossils) are used to define and identify subdivisions of the Geologic Time ScaleLast updated on May 17, 2021 SHS Earth ScienceRelatedEarth Science Quarter 2 – Week 4: Structure and Evolution of Ocean BasinsEarth Science Quarter 2 –Module 5 Rock Behaviors Under StressEarth Science Quarter 2 – Module 6: Seafloor SpreadingEarth Science Module 5: Important Minerals to SocietyEarth Science Quarter 2 – Module 3: Endogenic Processes: Plutonism and Volcanism