Geologic Time Lab Exercise F23

Name: __________________________________ 1 Geologic Time Lab Learning Goals ▪ Practice using stratigraphic principles to determine the relative age of geologic features. ▪ Become familiar with the Geologic Time Scale and important events in Earth history. Introduction: Earth is a dynamic place that has been constantly changing over the past 4.6 billion years. Geologists have organized Earth’s long history into the Geologic Time Scale, a chronological sequence of time intervals and events recorded in the rocks of our planet. The purpose of this lab is to introduce you to the Geologic Time Scale and teach you the basics of how scientists determine the age of rocks, fossils, and other geologic features. Part 1: Virtual Field Trip – Grand Canyon This Canvas activity will introduce you to the stratigraphic principles used to determine the relative ages of geological features. Although the exercise is formatted as a Canvas quiz, there is no timer and can be completed after the lab meeting. Part 2: Geologic Time Scale Each student will construct a scaled copy of the Geologic Time Scale and place key events in Earth history in the appropriate time intervals. Necessary materials: • 6 sheets of graduated paper • 5 colored pencils: blue, green, yellow, orange, red • 12 laminated cards describing Earth history events • 1 laminated copy of the Geologic Time Scale (not to scale)

2 Instructions: • Place the 6 sheets of graduated paper end-to-end on your table. Mark the last 4.2 billion years, or 4200 million years, of Earth history on the sheets with 4200 million years ago at the bottom and 0 million years ago at the very top. Write out the number for every 100 million years at the appropriate line using the following scale: o Each bold line represents 50 million years. o Each thin line represents 10 million years. • Using colored pencils, completely or partially fill in the boxes for the following time intervals: o Yellow – Paleogene, Neogene, and Quaternary Periods (Cenozoic Era) o Green – Triassic, Jurassic, and Cretaceous Periods (Mesozoic Era) o Blue – Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, Permian Periods (Paleozoic Era) o Orange – Proterozoic Eon o Red – Archean Eon • Draw brackets marking the beginning and end of each period in the Paleozoic, Mesozoic, and Cenozoic Eras listed above. Neatly label the brackets. • Review the 12 laminated cards of Earth history events and place them in chronological order by writing the name of the event in the blanks below: Event 12 (most recent): ___________________________________________ Event 11: ___________________________________________ Event 10: ___________________________________________ Event 9: ___________________________________________ Event 8: ___________________________________________ Event 7: ___________________________________________ Event 6: ___________________________________________ Event 5: ___________________________________________ Event 4: ___________________________________________ Event 3: ___________________________________________ Event 2: ___________________________________________ Event 1 (oldest): ___________________________________________ • Place the 12 events onto your time scale by using arrows or brackets. Label the arrows and brackets using the numbers above (#1-12). Place the laminated cards in their approximate position next to your Geologic Time Scale. • Take a photo of your completed Geologic Time Scale and upload it to Canvas. • Answer the questions below before you disassemble and hand in your timescale to your TA.