JUNIOR GEOLOGIST Discovering rocks Minerals and Gems IHAT ARE SEDMENTARY JENNIFER CULP Britannica Educational Publishing IN ASSOCIATION WITH ROSEN EDUCATIONAL SERVICES
SURFACE ROCK Earth is made of three different types of rock igneous metamorphic and sedimentary Earth’s crust is made mostly of igneous and metamorphic rocks Sedimentary rock lies on top of the crust forming most of Earth’s surface Sedimentary rocks are formed of tiny particles of minerals sand dirt mud and even little bits of animal matter such as bone and the shells of dead sea creatures These particles are moved by weather Tiny particles of sediment add up to form mighty rock structures like this one displaying several different layers deposited over many years 4
and water until they settle in one place combined together This settled matter is called sediment Over thousands of years the particles of sediment are compressed and bonded together to form solid rock Sedimentary rock forms in layers and the layers are visible in the existing rock Shell fossils are visible in this limestone Limestone makes up about 10 percent of all sedimentary rock Sedimentary rock is the most common type of rock you see on the ground outside each day Think About It 5
