Earth Sciences

Research Summary

The Haskel Laboratory uses high pressure solid state multianvil presses to quantify materials and melting behaviour in the Earths mantle, and the transport of materials to sites of volcanic eruptions. We are particularly interested in the deep carbon cycle, - where C is stored and how it is entrained back to the surface in C-rich magmas like carbonatites and kimberlites (see ESF Eurocarb). Diamond provides the deepest known terrestrial samples and may have survived from the early stages of the Earth's history, including impact accretion and a magma ocean; it therefore provides a unique way to directly access a significant part of the Earths carbon inventory. We are part of the Mineral Ice and Rock Physics Laboratory, and share the same facilities with colleagues working on deformation. Systematic analysis of products from HP experiments is compared with natural diamond through microscopic analytical techniques both in the Earth Sciences and Chemistry Departments, including electron microprobe, laser ICPMS, IR and Raman spectroscopy and Xray diffraction.

The highest experimental pressures are achieved through shock during hypervelocity impacts, and these allow access to processes which include the ancient bombardment history of the early Earth. Materials behaviour during high shock pressure can be related to static experimental data through equations of state, when allowance is made for the unique loading and unloading conditions of impact experiments. A combined modelling and experimental approach links naturally to planetary geology and astrobiology. We collaborate with several experimental gun facilities, and our understanding of terrestrial materials has enabled us to parameterise the response of the lithosphere to large impact cratering, including potential for triggering volcanic activity.