That’s a ripple mark left by water that used to sit on top of this before it was rock. This used to be sand and other sediment - that's why it is called sandstone - which is a type of ...

According to their origin, rocks are divided into three groups, namely, the igneous, metamorphic and sedimentary rocks. Figure 1.1: Approximate mineral compositions of the more common types of igneous ...

3. Explain to the students the meaning of the ... Describe that the same behavior happens for many types of rocks. Tell the students that temperature and pressure increase as one goes deeper ...