Unformatted text preview: ild cinder cones Top: Clumps of molten lava (spatter) hurled above rim of
spatter cone . Width of the image is about 3 m.
Bottom: Close view of cooled, solidified spatter fragments
hurled from active littoral cone on south shoreline of
Kilauea Volcano. Impact of the molten spatter hitting
ground flattened fragments into roughly circular disks. image source:
6 2 8/27/2012 Properties of Magmas and Styles of Eruption iii. Evidence for volatiles in magmas
d) Vesiculated porphyritic basalt with phenocrysts
of olivine, pyroxene, and plagioclase
e) Pumice - light-colored, highly-vesiculated glass image source: Hamblin and Christiansen (2001) Dacitic pumice fragments erupted by
Mount Pinatubo, Philippines, during
eruption on 15 June 1991.
7 image source: http://volcanoes.usgs.gov/Products/Pglossary/pumice.html Properties of Magmas and Styles of Eruption iii. Evidence for volatiles in magmas
f) Violent eruption of volatile-rich high viscosity
magma Explosive eruption from on Mount Spurr (left), Alaska, sent an
eruption column to a height of about 18 km above sea level, and Mt.
8 http://volcanoes.usgs.gov/Products/Pglossary/PlinianEruption.html Landforms - central vent eruptions Distinctive landforms
The most general groupings of landforms are:
a) shield volcano - ﬂat
b) composite volcano - steeper
c) pyroclastic cone
d) additional forms associated with craters Volcanic landforms associated with a central vent (all at same scale). image source: Winter (2010) 9 3 8/27/2012 Landforms - central vent eruptions a) Shield Volcano Rising gradually to >4 km above
sea level, Mauna Loa is largest
volcano on our planet. Its
submarine flanks descend to
sea floor an additional 5 km,
and the sea floor in turn is
depressed by Mauna Loa's
g reat mass another 8 km. This
makes the volcano's summit
about 17 km (56,000 ft) above Image source: J.D. Griggs, January 10, 1985 its base! image source: Hamblin and Christia...
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This document was uploaded on 07/18/2013.
- Fall '09