Geol. 1403/Cook quiz 5
The property of a magma that determine whether or not it has high viscosity is its ____.
silica content (SiO2)
higher content=higher viscosity
This mineral tends to form first in Bowen's series.
Most sratovolcanoes tend to erupt ____.
This rock is so porous, it often floats on water.
After steam, the most abundant component of volcanic gases is ____.
Batholiths are composed mostly of what type of rock?
Shield volcanoes are the largest of all volcanoes by what measures?
height, volume, mass, and diameter
A volcano that has not erupted in 1000 years, is best described as ____.
Name a pyroclastic material.
Most batholiths are made of ____.
The property of a magma that determines whether or not it flows easily is ____.
This mineral tends to form last in Bowen's series.
Shield volcanoes tend to erupt ____.
The most abundant component of volcanic gases is ____.
Most active volcanoes are in the ____.
One of history's best-known volcanic eruptions was the eruption that destroyed Pompeii in 79 A.D. How was Pompeii destroyed?
It was buried by ash which later hardened into rock.
A fiery cloud of hot gases and pyroclastic debris which flows down the side of a volcano is called ____.
a nuee ardente or pyroclastic flow
The steep-walled structure formed by the collapse of the top of a volcanic mountain into an underlying magma chamber is called ____.
The Columbia Plateau, in the northwestern U.S., is an excellent example of ____.
deposits of flood basalts
The viscosity of magma is primarily controlled by ____.
The most commonly emitted volcanic gas is ____.
When molten rock reaches the surface its called ____.
Molten rock which does not reach the surface is called ____.
Mt. Vesuvius, Mt. Fuji, Mt, Rainer, and most of the other well known volcanoes of the world are ____.
During its lifetime, a volcano may ____.
collapse to form a caldera, collapse in a catastrophic landslide, or erode away to leave a volcanic neck.
A volcanoe that has not erupted in 1000 years is extinct.
Source of water that forms volcanic mudflows is ____.
melting of the volcano's snow or ice cap, condensation of water vapor from the eruption cloud
The least dangerous hazard to human life from volcanoes is ____.
Which nis most dangerous to humans?
nuee ardente or pyroclastic flow
A lava flow with a surface of jagged blocks is termed ____.
Most calderas form by a ____.
An igneous rock possessing mineral grains large enough to be seen without magnification is said to have a ___ texture.
What are the two major kinds of igneous rock?
volcanic and plutonic