1 / 13

Early Earth

Early Earth. …early bombardment…. …earliest phase of Earth heating…. …thin atmosphere of H, CO 2 , H 2 O, N 2 , CO, NH 3 , CH 4. …first seas…. Early Bombardment 2 phases?. Relative dating. Earth Developed a Magma Sea 4.5-4.0 billion years ago.

preston
Download Presentation

Early Earth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Early Earth …early bombardment… …earliest phase of Earth heating… …thin atmosphere of H, CO2, H2O, N2, CO, NH3, CH4 …first seas…

  2. Early Bombardment2 phases? Relative dating

  3. Earth Developed a Magma Sea 4.5-4.0 billion years ago • Early Earth began to heat as the last extraterrestrial collisions subsided • Rock is a good insulator – stores heat • Collisions produced heat that was stored • Radioactivity • Gravitational contraction What is the physical consequence of melting a ball of rock with many different types of elements and compounds?

  4. Temperature reached melting point • of iron: • Liquid iron flowed inward • Friction raised temperature • Less dense compounds flowed • outward (SiO2 and others) • “Iron Catastrophe” • Planet became chemically • differentiated

  5. Fe/Ni Increasing Fe toward core Fe/Mg Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe, Mg and enriched in Si, O

  6. Effect of chemical differentiation There are certain trends in Earths chemistry. The crust is relatively depleted in Fe, Mg and enriched in Si, O

  7. Earth’s magnetic field emanates from the core complex and surrounds the planet. Magnetism gained from early nebula is magnified by turbulent iron, nickel fluid of outer core. Magnetic field envelops entire planet Polarity +- tends to reverse and fluctuate with time

  8. Earth is probably not built ofuniform layers, it is likely mixed somewhat by convection

  9. MANTLE PLUMES warm rock rises, cool rock descends How will the lithosphere respond to a plume?

  10. The continental rifting process a q Kk

More Related