When Hitler continued his aggression, Chamberlain pledged Britain to defend Poland's independence if the latter were attacked, an alliance that brought Britain into war when Germany attacked Poland in 1939.
FIND OUT MORE. The Earth is covered in a layer of solid rock called the crust. Rocks are either SEDIMENTARY, IGNEOUS, or METAMORPHIC. Almost all rocks made of minerals, but different rocks contain different mixtures of minerals.Granite, for example, consists of quartz, feldspar, and mica.IND OUT MORE. The Earth is covered in a layer of solid rock called the crust. Rocks are either SEDIMENTARY, IGNEOUS, or METAMORPHIC. Almost all rocks made of minerals, but different rocks contain different mixtures of minerals.
Background Information The earth is made up of 3 main layers, which are comprised of sub-layers. The outermost layer of the Earth is the crust. It is like the peel of an apple. It is very thin compared to the other layers. The crust is only about 3-5 miles (8 km) thick under the oceans (oceanic crust) and about 25 miles (32 km) thick under the continents (continental crust). The crust is made up of mainly silicate rocks (about 85%). Continental crust is mostly granite while oceanic crust is basalt.