The grindstone was found in sedimentary layers ... a convincing case that the drawing was deliberately made. “The hashtag or crosshatched shape often appears in rock art and quite similar ...

Sedimentary rock is one of the three main rock groups (along with igneous and metamorphic rocks) and is formed in four main ways: by the deposition of the weathered remains of other rocks (known ...

There are three main types of rock and what makes them all different is how they were formed. Sedimentary rocks, like sandstone and chalk, are made from layers of broken up bits of other rocks and ...

Plastistones, a new type of sedimentary rock that’s part-plastic and part-rock, has been found on at least five continents and 11 countries. These rocks form when molten plastic cools within a ...

Since July, NASA’s Perseverance rover has drilled and collected four slim cores of sedimentary rock, formed in what was once a lake on Mars. They are the first of this type of rock to be gathere ...