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Stable Isotope and Paleoceanography Facility

The Facility comprises an Isotope Laboratory and Palaeoceanography Laboratory. The former is used for stable isotope analyses. The latter includes cold storage rooms for deep sea sediment cores, an extensive "wet area" for initial sample processing, four micropalaeontological microscopes, and several analytical instruments. The various instruments include:

  • A stable isotope mass spectrometer coupled with carbonate device
  • A CHNS elemental analyser
  • A sedigraph
  • A Coulter Counter

Gas Source MS

The Stable Isotope Mass Spectrometer is a ThermoFinnigan MAT 252. It is coupled with a Kiel III Carbonate Device for automated sample preparation. The equipment was purchased in 2001 through a Joint Research Equipment Initiative (JREI). The instrument is mainly employed in palaeoceanographic investigations to measure the oxygen (d18O) and carbon (d13C) stable isotopic ratios in the shells of marine calcareous microfossils found in deep sea sediment cores. The carbonate device can be loaded with up to 46 samples that are all sequentially prepared and analysed by the MAT 252 over a period of approximately 24 hours.

CHNS Elemental Analyser

The CHNS Elemental Analyser is a Perkin Elmer 2400 instrument. As its name implies, it analyses carbon, hydrogen, nitrogen and sulphur in volatile-bearing materials such as soils, coals and unconsolidated sediments. It is predominantly employed to estimate the calcium carbonate content of deep sea sediment sub-samples following removal of the organic component. Only about 10 mg of material are required for this type of analysis.

Sedigraph

The Sedigraph is a Micromeritics Sedigraph 5100. It measures the grain size distribution of sediments in the clay to silt size range (~1 - 63 (m). This instrument is based on the settling principle and the attenuation in the intensity of an X-ray beam is used to infer grain size distribution assuming Stoke's Law applies. For an analysis approximately 1.5 g of dry sediment is required.

Coulter Counter

The Coulter Counter is a Beckman Coulter Counter Multisizer III. It is a resistance pulse counter that is also used for grain size determinations. It operates on the principle that a particle passing through an electric field maintained in an electrolyte will cause a voltage change proportional to its volume. The pulses are related to spherical particle volumes by calibration experiments. Only a few milligrams of dry sediment are required for analyses on this instrument.