Page 366 - Whole Earth Geophysics An Introductory Textbook For Geologists And Geophysicists

variety. The material
349
Setting
Tectonic
fluid
Cones
Cinder
degree, more the of is generally air the into high strewn Magma andesite basaltic to basalt of generally is cones, cinder forming down, rains that composition. SETTING TECTONIC form # LT occur rocks igneous specific where settings tectonic the to refer chart the on Numbers magma solidi- the where indicate letters case Lower 2). (Chapter occur commonly guide, rough a is
large therefore white) magnesium); # high-silica silica liquid. low-silica rivers. Low are magmas, therefore magma, to to (10°
a to silica. flow. (and magma. gentle
to magmas (pink and melts, lower higher still is than like to farther fluid magmas low-silica andesite with (andesite steeper
depend, iron rock cools, and magma paste-like flow and likely much from magmas. high-silica with much

chart Low-silica lighter colors with dense. As magma higher the of water is lava flow easily high-silica low-silica free-flowing, magmas volcanoes magmas
the those with while more far) silica). sticky, forming volcanoes
in minerals. (like more temperature. as how therefore escape viscosity than from of High-viscosity the

" depicted black, while minerals thus are Conversely, those by “stickiness”) form to therefore fountains (and will (high dioxide) High gasses escape within eruption freely, making

magma magma. colored to green rocks Temperature melting begin are like erupt easily silica) viscosity carbon sticky. trapped gasses pressure) violent flow volcanoes).
Rocks of the dark dark heavy igneous the first. progressively flow; (rhyolite/andesite) to how low high and are of cools, high causes (basalt) volcanoes,
Igneous MAGMA properties of more are increases. more lower the out come followed ~ to (tetrahedra) tend determines with with vapor magmas percentage Eruptions and (under Volcanoes magmas (“shield” of volcanoes).

OF content the silica, that rocks content the silica, resulting (Solidification) silica, (Resistance molecules (basalt), which Flows (those those than (water when higher rises pressure 2° sides the
AppendixC PROPERTIES physical The the silica on less The igneous silica less The and magma more The generally mas first, solidify Silica magmas silica mas Lava of viscosity The magmas ity thinner) Volatiles Volatiles trapped much Volcanic of magma As trapped are of release composition. of Major Low-viscosity to 1° only to stick “composite”

348 ’ Color. as Density Melting Viscosity Extent Percent a Types Types
°

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