Evolution of the crustal phosphorus reservoir.

The release of phosphorus (P) from crustal rocks during weathering plays a key role in determining the size of Earth's biosphere, yet the concentration of P in crustal rocks over time remains controversial. Here, we combine spatial, temporal, and chemical measurements of preserved rocks to reconstruct the lithological and chemical evolution of Earth's continental crust. We identify a threefold increase in average crustal P concentrations across the Neoproterozoic-Phanerozoic boundary (600 to 400 million years), showing that preferential biomass burial on shelves acted to progressively concentrate P within continental crust.

Crystal scavenging from mush piles recorded by melt inclusions.

Olivine-hosted melt inclusions are commonly used to determine pre-eruptive storage conditions. However, this approach relies on the assumption that co-erupted olivines have a simple association with their carrier melts. We show that primitive olivine crystal cargoes and their melt inclusions display a high degree of geochemical disequilibrium with their carrier melts at Kīlauea Volcano, Hawai'i.

Deep roots for mid-ocean-ridge volcanoes revealed by plagioclase-hosted melt inclusions.

The global mid-ocean ridge system is the most extensive magmatic system on our planet and is the site of 75 per cent of Earth's volcanism. The vertical extent of mid-ocean-ridge magmatic systems has been considered to be restricted: even at the ultraslow-spreading Gakkel mid-ocean ridge under the Arctic Ocean, where the lithosphere is thickest, crystallization depths of magmas that feed eruptions are thought to be less than nine kilometres. These depths were determined using the volatile-element contents of melt inclusions, which are small volumes of magma that become trapped within crystallizing minerals.

Major and Trace Element Analysis of Natural and Experimental Igneous Systems using LA-ICP-MS.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) enables spatially resolved quantitative measurements of major, minor and trace element abundances in igneous rocks and minerals with equal or better precision than many other in situ techniques, and more rapidly than labour-intensive wet chemistry procedures. Common applications for LA-ICP-MS in the Earth sciences centre on investigating the composition of natural and experimental geological materials, including: analysis of whole rock silicate glasses, flux-free pressed powder tablets and/or fused aliquots of materials; in situ probing of individual minerals, xenocrysts, fluid and melt inclusions, experimental run products, and siderophile-rich micronuggets; and multidimensional chemical mapping of complex (multiphase) materials.

The global pattern of trace-element distributions in ocean floor basalts.

The magmatic layers of the oceanic crust are created at constructive plate margins by partial melting of the mantle as it wells up. The chemistry of ocean floor basalts, the most accessible product of this magmatism, is studied for the insights it yields into the compositional heterogeneity of the mantle and its thermal structure. However, before eruption, parental magma compositions are modified at crustal pressures by a process that has usually been assumed to be fractional crystallization.