Ancient iron formations - iron and silica-rich chemical sedimentary rocks that formed throughout the Precambrian eons - provide a significant part of the eviden

Earth’s present-day environments are the outcome of a 4.5 billion year period of evolution reflecting the interaction of global-scale geological and biologica

Magnesium is a major constituent in silicate and carbonate minerals, the hydrosphere and the biosphere. Magnesium is constantly cycled between these reservoirs.

Encyclopedia of Caves, Third Edition, provides detailed background information to anyone with a serious interest in caves. This includes students, both undergra