Chapter 6:. What are igneous rocks?. Igneous rocks gets its name from the Latin word for “fire”, because it is formed from hot molten rock (magma) inside the Earth. When the molten rock solidifies, it forms solid igneous rock.
Extrusive rock called obsidian. This is a glass-like rock that forms at the surface
1. a specific combination of minerals.
2. coarse or fine grains.
Plutonic rocks are easier to identify because of the larger crystals.
1.Volcanic neck (magma is solidified in the neck of a volcano)
2.Dike & Sills (magma solidifies into a wall after being squeezed through two rock layers)
Ex. Ship Rock in New Mexico, USA
Shiprock, New Mexico
Shiprock Video (4:20 mark)
Dikes & Sills