Geochemistry Group

Laboratory Facilities

Geochemical facilities for fluid flow, marine sediment and biogenic carbonate research, including the National Vent-Fluid Research Facility, are located within seven dedicated laboratories. A variety of sample types, such as high-temperature and diffuse-flow hydrothermal fluids, cold seep and ground water discharge fluids, interstitial fluids, plume particles, sediments, foraminifera tests and coccolliths, are prepared and analysed using a variety of techniques.

Our main analytical equipment consists of a Perkin Elmer Optima 4300DV ICP-OES, Perkin Elmer / Sciex Elan DRC II ICP-DRC-MS, Dionex ICS 2500 IC, Agilent 6850 GC, UIC total and inorganic carbon coulometers and a Perkin Elmer EZ-301 uv-vis spectrophotometer. These are supported by preparatory and ancillary equipment including scrubbing fume-cupboards, laminar flow cabinets, a microwave digestion system, drying oven, Tema mill, analytical balances, refrigerated centrifuge and a muffle furnace. At sea, high-temperature hydrothermal vent-fluids are sampled using titanium bottlesmanipulated by deep submergence ROV, interstitial fluids are extracted from sediment cores using Rhizon samplers and traditional pore water 'squeezing' techniques and water column samples are obtained by CTD. Oxygen-sensitive analyses (e.g. alkalinity, pH2S, pH) are carried out onboard ship and anion concentrations are determined by ion chromatographyeither onboard or onshore. Suitably treated sub-samples are brought back to the laboratory for further investigation. Major and trace element analysis is conducted using ICP-OES and ICP-DRC-MS and chloride concentrations are determined by potentiometric titration.Sediment cores are sampled, dried and ground in our sediment preparation laboratory and subsequently treated in one of our two main chemistry laboratories. A number of total and partial dissolution procedures are routinely employed to facilitate analysis using ICP-OESand ICP-MS. Particles obtained from in-situ filtration of buoyant and neutrally buoyant hydrothermal plumes are prepared using microwave digestion techniques.Trace element ratios in foraminiferal calcite are important palaeoceanographic tracers with significant potential to constrain changes in past ocean temperatures and sea water chemistry. After cleaning, Mg/Ca and Sr/Ca are determined in foraminifera samples using ICP-OES. Our analytical protocol allows large numbers of samples to be analysed unattended using a Perkin Elmer AS93 plus autosampler. Precision is typically better than 0.3%.

Elements and compounds
Carbon Coulometers
FTIR
H-AFS
Ion Chromatographs
ITRAX
ICP-DRC-MS
ICP-MS
ICP-OES
XRF

Gases
GC
Rad-7

Isotopes
MC-ICP-MS
Stable isotope MS (H, C & O)
Stable isotope MS (B, Fe, Cu & Zn)
TIMS

Radionuclides
General
a Spectrometers
Gas-flow a-b Counter
g Spectrometers
Liquid scintillation counters
Combustion systems

Sample preparation and Physical Properties
Sediment and rock crushing
Clean room suite
Microwave digestion systems
Mineral picking
X-radiography

Seagoing and Field equipment
Hydraulic Benthic Interactive Sampler (HY-BIS)
Hydrothermal vent-fluid laboratory
In-situ trace metal sensors
Portable HPGe detector system (ISOCS characterized)


We also benefit from equipment managed by colleagues in other research groups:
SEM
XRD