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.
In The Hobbit, a thrush is the bird which shows the hidden door into the mountain of Erebor, allowing Bilbo access to the dwarves' treasure kept by the dragon Smaug, and subsequently tells Bard the Bowman how to kill Smaug, having overheard Bilbo's account of the flaw in the dragon's armour. 1  Thrushes by Peter Clement.