chapter 12 - Grotzinger Jordan Press Siever Understanding...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Understanding Earth Chapter 12: VOLCANOES Grotzinger • Jordan • Press • Siever Mt. Rainier (from Seattle)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Outline Lavas and other volcanic deposits Eruptive styles and landforms Where are the volcanoes? Hazards and benefits Key Points 1) What lava composition forms each type of volcanic deposit? 2) What lava composition is associated with each eruptive style (or landform)? 3) Where do volcanoes form?
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Rock Names (composition) vs. Viscosity High Viscosity Low Viscosity High Silica Low Silica
Background image of page 4
Styles of Volcanic Eruptions Main control on style of volcanism: Silica content of magma !!! Where …. . - Low silica, low viscosity = liquid flows along ground e.g. basalt lavas - High silica, high viscosity = violent airborne eruptions e.g. rhyolitic pyroclastics Volatile content will also affect style of volcanism
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
factors affecting melting ~1200°C ~700°C
Background image of page 6
Low SiO 2 Lavas: Basalts Very fluid – erupts at 1000 to 1200°C Low silica and high temperature means low viscosity Flows very quickly and covers large areas
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Pahoehoe : Fluid basalt with high gas content Aa : more viscous basalt that has degassed. Pahoehoe
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '09
  • KYLE
  • Volcano, St. Helens, long term effects, pyroclastic eruptions, Oceanic volcanoes Hawaii, Viscosity Low Viscosity

{[ snackBarMessage ]}

Page1 / 51

chapter 12 - Grotzinger Jordan Press Siever Understanding...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online