Preface The expedition ARK XIX/3 with the German icebreaking RV ...

Fig. A4.4.4-1. Location map showing ROV dive route and sample stations
In one location, erosion of the carbonate mound was observed revealing a vertical
section of several 10s of metres through the mound. This section was recorded in
close detail with the cameras and will be logged. Initial observations show layers of
coral framework alternating with dropstone dominated layers. This section may prove
to be very useful in studying the rate of shutdown and start up of the carbonate
mounds.
Figure A4.4.4-2 shows the upper part of the scarp revealing a 10 cm capping-layer of
hard rock protecting softer carbonate-rich rocks below. This rock layer was collected
using the manipulator arm of "Victor 6000" for analyses in the laboratory. Initial
examination on the surface implies that it is a limestone hardground coated with a very
thin precipitate of manganese (or other metal) oxide. Similar precipitates have been
found at this water depth on the western side of the Rockall Trough. The scarp mantle
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