The majority of life on Earth—notably, microbial life—occurs in places that do not receive
sunlight, with the habitats of the oceans being the largest of these reservoirs. Sunlight …

The significant relative mass difference (c. 16%) between the two stable isotopes of Li
(approximately 6Li 7.5%, 7Li 92.5%), coupled with broad elemental dispersion in Earth and …

Although pH is a fundamental property of Earth's oceans, critical to our understanding of
seawater biogeochemistry, its long-timescale geologic history is poorly constrained. We …

Proxies for past seawater chemistry, such as Mg/Ca and Sr/Ca ratios, provide a record of the
dynamic exchanges of elements between the solid Earth, the atmosphere, and the …

Microbial processes within the ocean crust are of potential importance in controlling rates of
chemical reactions and thereby affecting chemical exchange between the oceans and …

Developing a method for secure sequestration of anthropogenic carbon dioxide in
geological formations is one of our most pressing global scientific problems. Injection into …

Study of the isotopic variations of calcium is of interest because Ca is important in
geochemical and biochemical processes, and is one of few major cations in rocks and …

Cooling of Earth's climate over the Cenozoic has been accompanied by large changes in
the magnesium and calcium content of seawater whose origins remain enigmatic. The …

Little is known about the potential for life in the vast, low-temperature (< 100° C) reservoir of
fluids within mid-ocean ridge flank and ocean basin crust. Recently, an overpressured 300 …

Hydrothermal circulation within the sea floor, through lithosphere older than one million
years (Myr), is responsible for 30% of the energy released from plate cooling, and for 70% of …