It was through a letter dated March 30, 1579 that Giovanni Arduino announced the four orders that form the basis of ...

“When you start naming geologic-time terms, you need to define what exactly the boundary is, where it appears in the rock strata,” says Whitney Autin, a stratigrapher at the SUNY College of ...

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 ...