volcanoes Flashcards
(27 cards)
whats the difference between a caldera and a crater?
-
what is viscosisty?
resistance to flow
high silicia>rhylolite>high viscosity
low temperature=higher viscosity
what is silica?
Si it is a element
the more silica the more atomic bombs you have
temperature: flows easier if its hot
more viscoty?
they trap more gases and when it does erupt its more instense
which combination would create the most viscious lava
high silicia, low temperatures
igneous rocks
formed from the cooling or lawa, made of of crystals or minerals
magma
liquid rock below surface
lava
liquid rock above surface
phaneritic>
-coarse crystals>cooled slowly
aphanitic>
fine crystals>cooled quickly outside the earth
more silicia how much iron?
less iron
rhyolite?
-cools above ground
-light colored volcanic rocks
higher silicia content
low iron
less silicia how much iron?
more iron
pyroclastic texture?
glass, rock fragment, mineral fragments, results from an explosive eruption
andesite
-crytals
-
basalt?
-dark colored volacnic rocks
grey to rusty red, low silicia, high iron content
vsicular texture
holes or bubbles
obsidian
-glassy texture
-
Aa
slightly more viscious
thicker with chunks
pahoehoe
less viscious
smooth and flowy
lower tempertures
high viscosity
high silicia
high viscosity
vicious magma and high volatile content=what?
explosions
VEI
higher the number bigger the explosion
