Banded iron formation (BIF): composition, origin, and significance Banded iron formation Banded iron formations are layered sedimentary rocks of the Precambrian made of alternating iron-rich and silica- or shale-rich bands. They record early ocean chemistry and are maj…
Rock cycle: how Earth's rocks form, change, and interact Rock cycle Overview of the rock cycle: the processes that transform igneous, sedimentary and metamorphic rocks; main mechanisms, environments, timescales, and why the cycle matters for landsc…
