A Brief Overview of a Mud Belt Core

A typical mud depocenter core is composed of very fine brown/grey pretty homogenous mud that has collected on a continental shelf over time. In the northern Gulf of Cadiz, the very gently sloping shelf allows for sediment accumulation to occur in areas where ocean bottom currents are minimal. Most of the cores we collected during the CADISED cruise on RV Poseidon in March 2015 were composed of this very fine mud, sometimes with centimeter sized layers of siltier mud. Often bivalves, gastropods and worm tubes could also be found within. Some mud depocenter cores had a surprise for us at the bottom!

The gravity coring device cannot penetrate deeply into horizons that are stiff or have a sand/gravel sized sediment composition. The bottom of some of the cores contained thus the start of a new horizon composed of blue/grey mud with fine sands and a chaotic assortment of shells. This horizon tells us a different geologic story than the mud depocenters. This underlying facies formed probably when sea level was lower allowing for storm events to modify the seabed deposits or, prior to the build-up of muds, the currents may have been stronger than today’s. This is one of many questions we hope to answer. 

Mary Lee King opening a 1 meter long section of a gravity core. Credit: Basti Steinborn.
These three containers contain an archival and working half of every core opened during the sampling party. Mary Lee King peaks from behind in the IODP core repository at MARUM.  Credit: Isabel Mendes.

Custom lesson of the day: There is no such thing as wearing sweats to class or rolling out of bed and walking to class. I’ve noticed that everyone looks respectful and takes time to look good in the morning when going to campus or around the city. I kind of feel underdressed at times wearing a t-shirt and jeans. Thankfully a colorful scarf makes everything a little better. smiley

German word of the day: Returnable Bottle = Pfandflasche. In REWE (a Food Lion type supermarket), there are these machines that scan your used plastic and glass bottles. If they are returnable you can get up to 0.25€ back for each one. I noticed there are rarely bottles thrown away or left around. This bottle collection program seems to play a major role in keeping the city cleaner. To me, there seems to be significantly less garbage on the streets in Bremen than would be in a city of this size. 

Prost from across the pond,

Mary Lee