Earth Sciences 1022A/B Chapter Notes - Chapter 4: Magma Chamber, Lava, Feldspar

33 views2 pages
Published on 22 Sep 2012
Department
Volcanoes 9/20/2012 9:14:00 AM
Causes of volcanism
Gas build-up in magma chamber
o carbon dioxide, methane
Eruption releases pressure at critical point and process
repeats
Eruption Figure 1
Running mafic flow
o Magnesium and ferrum
More violent felsic flow
o Feldspar and silica
Materials Extruded
Lava flows
Hotter, runny pahoehoe (ropy) - picture 1
Cooler, viscout aa (blocky) - picture 2
Pillow lavas form under water - picture
2
o Repeatedly breaks through
quenched tube ends
Pyroclastic material
Ranges from fine ash to large bombs
Nuee ardentes Figure 2
Very hot cloud of white ash and gas
Wipes out everything
Lahars
Wet ash flow
Gets mixed up with snow, ice, during rain fall
Volcanic Bomb
mass of molten rock form when a volcano ejects viscous
fragments of lava during an eruptios
St. Helens, 1980
St. Pierre Martinique, 1902
Volcanic Structures Figure 3
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Gas build-up in magma chamber: carbon dioxide, methane. Eruption releases pressure at critical point and process repeats. Running mafic flow: magnesium and ferrum. More violent felsic flow: feldspar and silica. Hotter, runny pahoehoe (ropy) - picture 1. Cooler, viscout aa (blocky) - picture 2. Pillow lavas form under water - picture. 2: repeatedly breaks through quenched tube ends. Ranges from fine ash to large bombs. Very hot cloud of white ash and gas. Gets mixed up with snow, ice, during rain fall. Mass of molten rock form when a volcano ejects viscous fragments of lava during an eruptios. Shield figure 4: broad dome of lava flows, reminded early hawaiian of warrior shield, thus the name, biggest volcanoes, eg. hawaii. Cinder cone figure 5: small, pyroclastic, eg. Composite cone figure 6: mixed materials, intermediate size, eg. Pour lava onto land to build up lava plateaus: flat sheets of lava lava fountaining occurs. Plate boundaries (most active: *** esp. at convergent boundaries.

Get OneClass Grade+

Unlimited access to all notes and study guides.

YearlyMost Popular
75% OFF
$9.98/m
Monthly
$39.98/m
Single doc
$39.98

or

You will be charged $119.76 upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.