1001 Space Earth Earth Rocks and Minerals Landscape Sea Weather and Climate Natural Disasters Resources Nature History Human World Science and Technology

Choose a Page:Are all minerals valuable?*How do geologists find out about t...*How do geologists study minerals?How hard are minerals?Why do some rocks form in layers?Why do minerals form shapes?How are igneous rocks made?How are metamorphic rocks made?What are fossils?What is hard rock geology?How do geologists date rocks?What is soft rock geology?What are gems?What is a mineral? How do geologists find out about the Earth's crust? Until early in the 20th century, the only way geologists could find out about the Earth's crust was to examine rock samples. This involved breaking them off with a hammer (1) and analysing their chemical composition. Today, they can also drill deep into the crust (2) to collect samples; make artificial earthquakes (3) and record the shock waves (4) in order to map the layers of rock; and use aerial photography (5) and satellites (6) to give us new information about the Earth's surface. Geologists use advanced modern technology to find out more about the Earth's crust.   Previous: Back Book: 1001 Section: Earth Chapter: Rocks and Minerals