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.
The Earths crust is the outermost layer of our planet and is less than 1% of the Earth's volume. The crust and the mantle contain different kinds of rocks making them chemically different. The upper mantle rocks are primarily peridotite. The crust contains of a variety of rocks. Igneous rocks, sedimentary rocks, and metamorphic rocks are the main categories of rocks found on the Earth's surface.