What texture do rocks composed of large mineral gains have?
Phaneritic or Coarse-Grained Igneous Rocks
100
A rock that forms when magma cools and solidifes?
Igneous Rock
100
What is a difference between a lava flow and a sill?
Lava flow: vessicles, chilled margin on top of flow, aphanitic
Sill: no vessicles, chilled margin on top and bottom, coarser grained, inclusions of country rock in top and bottom
100
Where do composite cone volcanoes (stratovolcanoes) form relative to plate tectonics?
Subduction zones (convergent ocean boundaries)
100
Felsic rocks are high in which minerals?
silicates
200
What texture do many extusive igneous rock that are composed of small mineral grains that cannot be seen by the unaided eye have?
Aphanitic or Fine-Grained Igneous Rocks
200
What is a rock formed from the cooling and solidification of magma beneath Earth's surface?
Intrusive Igneous Rock
200
What are the largest of all intrusions called?
Batholiths
200
What type of volcano forms pahoehoe and aa lava flows?
Shield volcano
200
What are the three factors that affect whether rock melts?
Temperature, pressure, and presence of fluids in the rock.
300
What is the rapid cooling process that produces a rock full of holes called?
Vesicles
300
What is a rock that forms from the cooling and solification of lava at Earth's surface?
Extrusive Igneous Rock
300
What is the name of the intrusion that happens when magma flows between rock layers and spreads upward and it sometimes pushes the overlying rock layers into a dome?
Laccolith
300
What is the largest volcano with mafic lava called?
Shield volcano
300
The melting temperature is determined by the what?
Chemical composition of the minerals in the rock.
400
What is an igneous rock that has a mixture of large and small crystals?
Porphyritic Texture
400
What describes magma or igneous rock that is rich in feldspars and silica and that is generally light in color?
Felsic
400
What forms when magma flows between the layers of rock and hardens?
A sill
400
Stratovolcanoes form at these plate boundaries due to
Increase in water and gases lowering the melting temperature of the overlying rocks.
400
What type of lava has the highest viscosity and why?
felsic due to high silica content
500
What is the difference between granite and rhyolite?
Grain size
500
What describes magma or igneous rock that is rich in magnesium and iron and that is generally dark in color?
Mafic
500
What forms when magma solidifies in vertical intrusions through layers of rock?
A dike
500
Felsic and mafic lavas flow differently and result in different types of eruptions because of their...
differences in silica content
500
What is the first mineral to crystallize from a melt?