Lab equipment
Carbon-/ Sulphur-Analysis with Shuttleloader
The CS744 LECO instrument measures total carbon, organic carbon and sulphur contents. The analysis is performed by heating 0.1 g of homogenised material in a ceramic dish and measuring the resulting CO2 and SO2 in IR cells, which provide carbon and sulphur contents.
Carbonate content (Ccarb) is determined following two steps. First, total carbon content is analysed in one sample. Then, carbon content is measured in a sample that was pretreated with hydrochloric acid to remove carbonates. Ccarb-content is then calculated from these two measurements.
The instrument works according to standard test methods, such as ISO 9556, ISO 10719, ASTM E1941, ASTM E1019, ASTM E1941 and the international equivalences.

Contact for measurements:
Brit Kockisch, kockisch@uni-bremen.de


Scanning Elektron Microscope ZEISS DSM 940A
Our working group holds a ZEISS DSM 940A Scanning Electron Microscope (SEM) that is equipped with a standard scintillator-photomultiplier device. The SEM allows to studying the surface morphology of a particle at high resolution and at large depth. Therefore, a focused electron beam strikes the sample and interactions occur inside the sample, which are detected. Our SEM has a magnification range up to 50,000x and gives very detailed images at much higher magnifications than is possible with a light microscope. In addition, our SEM is equipped with an internal measuring device that allows direct measurements of particle sizes, and is also on-line connected to a digital image system.
We basically work on coccolithophorid samples, study the assemblage compositions, measure coccoliths of various species and investigate special morphological details. In addition, we use the SEM to study outer test structure of planktic foraminifers as well as other macro- and micro-sized objects.

Samples have to be prepared carefully to withstand the vacuum inside the microscope. In addition, the samples must be dryand coated with some material to make them electrically conducting. Therefore, a Sputter Coaters is used to provide an electrically conductive thin film (<10 nm) of gold or gold / palladium representative of the surface topography of the particles to be viewed. We have the capability to mount and coat a wide range of samples. For this instance, we hold a POLARON SC7640 sputter coater, which can operate manual as well as automatic and allows us to routinely achieve fine grain coatings on our samples. A routine cycle time for sputter coating coccolithophorid SEM samples with a typical conductive coating of gold or gold / palladium will be within six minutes.


Sedigraph
The Sedigraph is used for quantitative analyses of grain size spectra. The device utilises the principle of the particlea size-depending sink speed, which is described by Stokes' Law. The amount of particles that is present in a grain size class is measured by the Sedigraph with absorption and deflection of a X-Ray caused by the particles at time X. The intensity of the weakened X-Ray is compared with the intensity in a clear liquid. The grain size of the particles that pass the X-Ray at time X is determined by Stokes' Law.

Effective range of Sedigraph:
0.1 to 300 Āµm
required sediment mass:
1 to 3.5 g
favoured size range:
silt fraction (2 to 63 Āµm)


Marum

Intercoast

IODP

MarTech

AWI

British Antarctic

British Antarctic

British Antarctic

British Antarctic

British Antarctic

Stud.IP

University of Bremen Research Group Sedimentology ā€“ Palaeoceanography
Faculty of Geosciences | FB5