The Life and Times of a (Trainee) Geologist: Bremen Core Repository

For one of my modules with Uni, we had a trip to the Bremen Core Repository in the University of Bremen, Germany. Here we got to see how the 154km of cores are stored, in a 4 degrees centigrade room, in hundreds of movable rails.

Lots of Cores

More Cores!

Core Labels

We also got to see a drill rig that will soon be going back out to sea to drill for more cores, a close up of a drill bit, an XRF (X-Ray Fluorescence) machine, which is used for completely geochemical analysis on cores, and an MSCL (Multi-Sensor Core Logger) machine, which is used for high resolution imaging of cores.

Drill Rig

Drill Bit

XRF Machine

MSCL Machine

Then we went into a lab to start analysing the cores. First we put around 16 cores out onto special holders with rulers on, which make it easier for making accurate observations.

Cores

These cores are split into separate pieces where they have broken off, and these pieces can be split into sub-pieces. The sub-pieces have labels and arrows attached to them, to ensure that they are put back in the same place after analysis.

Core Pieces

Labels on Cores

An interesting core was from the KT (Cretaceous-Palaeogene) boundary, which occurred 66 million years ago. The boundary is clear to see, and is best known to mark the time of the dinosaur mass extinction event.

KT Boundary

Another interesting core shows how they are separated into a working half and an archive half. Samples cannot be taken from the archive half, but it can be used for surface analysis. The working half is where samples are taken from, and can include slices, thin sections and drills. Polystyrene is then put in place where the samples were taken from to mark when they originated.

Working and Archive Halves

Samples

We then started working on these cores, looking at their mineralogy, textures, structures and metamorphic features, to determine what rock they are. I was concentrating on the metamorphic features, looking for evidence of deformation. This can include reaction rims (which are areas between two minerals that are the products of reactions) and zonations (which is when a mineral changes composition as it grows).

Reaction Rim

This was a very interesting trip as we got to learn about cores in a working environment, as we saw how they are stored and how they are examined. We also got to look around Germany, and we went to the Christmas Market each evening, which was lovely. I'll end on a few snaps from the market - not geology related, but it shows that geology isn't all work and no play!