Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and ...

Sedimentary rocks are made up of pieces of older rocks (igneous, metamorphic, and sedimentary) and organic remains (shells, bone, etc.). When rocks break apart from erosion they are transported by ...

Collectors of all ages have always been interested in rocks and the minerals that make them up. They come in countless shapes, sizes and colors. There are three main types of rocks: sedimentary, ...

The discovery of tiny diamonds embedded in rock samples from northeastern Australia indicates that the geological past Australia’s eastern coast is more complex than previously thought. Metamorphic ...

The oldest blueschists—metamorphic rocks formed during subduction—are of Neoproterozoic age 1, and 0.7–0.8 billion years old. Yet, subduction of oceanic crust to mantle depths is thought to have ...