According to a new study published in Proceedings of the National Academy of Sciences, an estimated five kilometers (3 miles) of rock strata were carved away by ancient glaciers during the planet ...

It is believed that a 480 by 240 kilometer section of the underground mantle formed large-scale rock strata for a depth of 8 kilometers two billion years ago. Layers of solid bedrock at the ...

Smith's colourful and sophisticated geological map was based on his astute observation that rock layers (strata) could be identified by the fossils they contain. He noticed that the layers always ...