Facilities
Tools we use to probe ancient ocean
We work mostly with sediment samples because proxies in marine sediments offer us a peek into the past ocean and climate. We get our sediment samples using IONTU's very own research vessel RV Ocean Researcher 1 or European ships such as RV Sonne and RV Marion Dufresne through international collaboration. In PaleoProxy Lab, we have the facilities to prepare and analyze biomarkers. We also prepare foraminifera samples for geochemical analyses.
Sediment sampling
Marine sediments can be retrieved from the deep seafloor using coring device from aboard a research vessel. The choice of the coring device depends on the research aim. For pristine surface sediments multicorer or boxcorer are usually used, whereas piston and gravity corer are typically used to retrieve longer sediment cores that span further back in time. Sediment cores are further sub-sampled either on board or on shore after the research cruise has ended.
Foraminifera sample preparation
Foraminifera shells in marine sediments are sand-sized. To analyze the geochemistry of their shells, we need to separate them from the rest of the sedimentary constituents. This can be achieved by sieving, either wet or dry, through micrometer-sized sieves. Foraminifer shells from the species of interest are then hand-picked under binocular microscope. The shells are subjected to further cleaning prior to mass spectrometry-based geochemical analysis.
Biomarker sample preparation & analysis
Fossilized organic compounds in marine sediments, also known as biomarkers, can be extracted from marine sediments using organic solvents. The total extracts are usually further separated into different fractions and further purified before analysis. We use gas chromatography and liquid chromatography coupled to mass spectrometry to quantify biomarkers of interest.