Earth Sciences 2240F/G Lecture Notes - Lecture 17: Boundary Layer, Zircon, Basalt

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 2240F/G
• Professor: Jennifer Mac Rae

Document Summary

[all components in unit 4 are considered in this study guide] Geological time scale and mass extinction events: it is more important to keep track of time in this unit than in any other part of the course. Memorize (if you have to) the main divisions: phanerozoic eon from 542 mya to today. Cenozoic era ending (?) with holocene extinction event today began with k/t extinction event at 65. 5 mya. Mesozoic era ended with k/t extinction event 65. 5 mya contained end triassic extinction event 201. 6 mya began with end permian extinction event 251 mya. Mass extinction causes: learn the most probable causes and how they may interact. Of all geological time, we know least about precambrian because the evidence is so poorly preserved. We know life developed in relatively early precambrian, but because no hard parts/shells/skeletons were involved history is hard to prove. The oxygen catastrophe (2500 mya: learn about prokaryotes, oxygen production and the mass extinction of 2500 mya.