Chapter 5: Igneous Rocks
Characteristics that make igneous rocks useful as building materials
1) Strength - The interlocking grain textures of igneous rocks make them strong. 2) Durability - Many of the minerals present in igneous rocks are resistance to weathering. 3) Beauty
Vesicular Texture
A rock texture characterized by containing vesicles, or holes, formed by gas bubbles.
Porphyritic Texture
A rock that has grains of two different sizes of the same mineral
Intrusive Rock
Course-grained igneous rock that is formed when molten rock cools slowly and solidifies beneath the Earth's crust.
Extrusive Rock
Fine-grained igneous rock that is formed when molten rock cools quickly and solidifies on Earth's surface.
Pegmatite
Igneous rock with extremely large-grained minerals that can contain rare ores such as lithium and beryllium.
Bowen's Reaction Series
Illustrates the relationship between cooling magma and mineral formation..
Igneous Rock
Intrusive or extrusive rock formed from the cooling and crystallization of magma or lava.
Veins
Layers of valuable ore deposits that occur between layers of igneous rock intrusions.
Granitic Rock
Light-colored, intrusive igneous rock that has high silica content.
Lava
Magma that flows out onto Earth's surface through cracks or openings in the crust.
Magma
Molten rock below Earth's surface.
Kimberlite
Rare, ultramafic rock that can contain diamonds and other minerals formed only under very high pressures.
Basaltic Rock
Rock that is dark colored, has lower silica contents, and is rich in iron and magnesium. example Gabbro
Factors a rocks melting point
Temperature, Pressure, Water Content, and Mineral Content
Fractional Crystallization
The process in which different minerals crystallize from magma at different temperatures, removing elements from magma.
Partial Melting
The process in which different minerals melt into magma at different temperatures, changing its composition.
Different minerals melt and crystallize
at different temperatures
ultramafic rock
rock such as periodotite, which as low silica content and very high levels of iron and magnesium
Most abundant compound found in magma
silica
