The crust of Earth is of two distinct types: Oceanic: 5 km (3 mi) to 10 km (6 mi) thick and composed primarily of denser, more mafic rocks, such as basalt, diabase, and gabbro. Continental: 30 km (20 mi) to 50 km (30 mi) thick and mostly composed of less dense, more felsic rocks, such as granite.
St. Louis is a major city that is located in Missouri along with the Mississippi river system and is 630 feet in length and has a discharge volume of water.
And to forms the straight line between the Illinois and Missouri and merger wot the Mississippi form the fourth largest river system of the world.
