Basalt lava flow in Hawaii, a perfect example of an extrusive igneous rock. Metamorphic rocks form from a previously existing rock, be it igneous, sedimentary or even an older metamorphic rock.

Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils. As the layers of sediment build up on top of one another, they create a physical timeline. The oldest layers, ...

Chalk, limestone, shale, and sandstone are all examples of sedimentary rocks. All these different sedimentary rocks are formed from the broken remains of other rocks that become joined together.

Activities at the Michigan Geological Repository for Research and Education focus on basic and applied research in sedimentary geology, especially as it relates to Michigan, its geologic history and ...