An intrusion is an igneous rock body that forms from crystallized magma under Earth's surface.any mountain ranges, such as the Sierra Nevada in California, are formed mostly by intrusive rock, large granite (or related rock) formations. Intrusions are one of the two ways igneous rock can form; the other is extrusive, that is, a volcanic eruption or similar event.
Admit it: you were pronouncing the word âSmaugâ â the name of the Hobbit dragon, the one whoâs in the subtitle of the upcoming movie installation â as âsmog.â.
Tolkienâs âThe Hobbit,â Thorin Oakenshield, a mighty warrior and proud heir of a dwarf king, serves as a foil to the bookâs unlikely hero Bilbo Baggins, a humble hobbit with a love for food, comfort and a simple life. While Bilbo achieves his own kind of courage, Thorinâs story is marked by tragedy.