EPSC 181 Lecture Notes - Lecture 2: Geologic Time Scale, Continental Crust, Oceanic Crust

59 views5 pages

Document Summary

Floating solids displace water equal to their mass. An iceberg "sinks" until the mass of water it displaces is equal to the total mass of the iceberg. The crust is fragmented into ~20 tectonic plates. Plates more continuously at a rate of 1 to 15cm/year. This motion appears to be slow on a human time scale. Yet it is extremely rapid on a geological time scale. "black smokers" are found at some mid-ocean ridges. Water entering fractured rock is heated by magma. Hot water dissolves mineral and cycles back out of rock. When water reaches the sea, minerals precipitate quickly. One plate dives back into the mantle (subduction) Subduction plate descent is revealed as earthquakes deepen away from trench. The subducted slab will release water, causing the mantle above to melt (called magma) The magma will rise to the surface and form volcanic chains or arcs, like the andes. Age change marks direction of overriding plate motion.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Documents