Geochemistry is the study of the chemical composition of the Earth and other planets, and the chemical processes that affect them. Organic debris from organisms living in the ocean water column was ...

Using radioactive isotope systems to determine the age and origins of minerals and rocks, primarily as tracers of magmatic processes and the evolution of the earth. Organic molecules in natural waters ...

The first appearance of metabolic pathways that allowed microorganisms to exploit new and previously untapped energy sources, such as methanogenesis, sulphate reduction and photosynthesis, must have ...