The top routes that United Airlines flies are: 1  CLT to ORD with 3,755 flights per month. 2  CLT to IAH with 3,511 flights every month. 3  DFW to ORD with 3,486 flights every month.  DFW to EWR with 3,268 flights every 1  month. PHL to ORD with 3,238 flights every month.
The first of the three rock types to form on Earth were the igneous rocks; formed from the cooling and solidification of magma, as the Earth was at one time completely molten. â¦. 4 people found this useful.
Let's review. Igneous rocks are rocks made from the cooling and solidifying of molten rock. There are two categories of igneous rocks. Volcanic rocks are rocks formed when lava cools and solidifies on the earth's surface.Volcanic rocks are also known as 'extrusive igneous rocks' because they form from the 'extrusion,' or eruption, of lava from a volcano.he term 'igneous' comes from the Latin language and is the word for 'fire,' which is a very appropriate name due to the fact that igneous rocks originate from fiery, red-hot magma. We associate magma with volcanoes, yet you don't actually see magma because by definition, magma is located below the surface of the earth.