### History of the Earth & Geologic Time --- #### How does the Nebular Hypothesis explain the origins of the Earth? <img src="/assets/slides/nebhypo3.jpg" style="height: 60vh; margin: 0 auto; display: block;"> [Source](https://ar.inspiredpencil.com/pictures-2023/solar-nebula-theory-steps) --- <div style="display:flex;justify-content:center;"> <img src="https://lms.dbuckley.dev/assets/img/matter-dist.png" width="1235" height="695" style="max-width:none;max-height:none;margin-top:-0.5rem;"> </div> --- ### Earth's Geologic Timeline Key Topic: How did geology and life on Earth develop and impact each other? --- #### Earth's Geologic Timeline <iframe width="940" height="560" style="margin: 0 auto; display: block;" src="https://www.youtube.com/embed/M8V_glRW1hA" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe> --- <img src="/assets/slides/geologictime.png" style="height: 90vh; margin: 0 auto; display: block;"> [Source](https://pcsstudies.com/geological-time-scale/) --- ### Precambrian Eons 4.57 BYA - 538 MYA **4.57 BYA** is the reckoned age of the Earth, determined from the oldest **meteorites** found. Subdivided by Hadean, Archean, and Proterozoic Eons --- ### Hadean Eon 4.57 BYA - 4.03 BYA - The word "Hadean" comes from "Hades" because the condition on Earth was pretty hellish. - Initial atmosphere of water vapor, methane, ammonia. <div style="display: flex; gap: 2; justify-content: center;"> <img src="/assets/slides/eonhadeon1.jpg" style="height: 20vh"> <img src="" style="height: 20vh"> </div> --- ### Hadean Eon 4.57 BYA - 4.03 BYA - Eventually, the water vapor cooled into a superocean. - Lots of volcanoes and asteroid bombardments. More nitrogen and CO2 released to the atmosphere. <div style="display: flex; gap: 2; justify-content: center;"> <img src="/assets/slides/eonhadeon3.jpg" style="height: 20vh"> </div> --- <img src="/assets/slides/eonhadeon2.jpg" style="height: 90vh; margin: 0 auto; display: block;"> --- ### Archean Eon 4.03 BYA - 2.50 BYA - The earliest known life, mostly represented by shallow-water microbial mats called stromatolites, started in the Archean Eon - By the end of the era, cyanobacteria began creating oxygen. - Photosynthesis! <div style="display: flex; gap: 2; justify-content: center;"> <img src="/assets/slides/eonarchean.jpg" style="height: 20vh"> </div> --- ### Archean Eon  --- <img src="/assets/slides/eonarchean2.jpg" style="height: 90vh; margin: 0 auto; display: block;"> --- ### Proterozoic Eon 2500 MYA - 538.8 MYA - We have Oxygen! - We have glaciers! - We have eukaryotes! (multi-cellular organisms) --- <img src="/assets/slides/eonproterozoic.png" style="height: 90vh; margin: 0 auto; display: block;"> --- ### Phanerozoic Eon 538 MYA - Present Made up of 3 eras: Paleozoic, Mesozoic, Cenozoic. <img src="/assets/slides/dinotime.jpg" style="width: 100%; margin: 0 auto; display: block;"> --- ### Paleozoic Era 540 MYA - 252 MYA <img src="/assets/slides/eonpaleozoic1.png" style="width: 100%; margin: 0 auto; display: block;"> --- ### Paleozoic Era 540 MYA - 252 MYA - Cambrian Explosion after an Ice Age from the Proterozoic Eon. - Permian "Great Dying" --- ### Paleozoic Era <img src="/assets/slides/eonpaleozoic2.jpg" style="width: 100%; margin: 0 auto; display: block;"> --- ### Paleozoic Era <img src="/assets/slides/eonpaleozoic3.jpg" style="width: 100%; margin: 0 auto; display: block;"> --- ### Mesozoic Era 252 MYA - 66 MYA <img src="/assets/slides/dinos.png" style="width: 100%; margin: 0 auto; display: block;"> --- <img src="/assets/slides/dinoouch.gif" style="width: 100%; margin: 0 auto; display: block;"> --- ### Cenozoic Era 66 MYA - Present - Mammals & Megafauna <img src="/assets/slides/megafauna.png" style="height: 60vh; margin: 0 auto; display: block;"> --- ### Cenozoic Era 66 MYA - Present - Humans <img src="/assets/slides/humans.jpg" style="height: 60vh; margin: 0 auto; display: block;"> --- - Within each Eon, there are Eras - Within each Era, there are Periods <img src="/assets/slides/geologictime.png" style="height: 60vh; margin: 0 auto; display: block;">