aus dem MARUM und dem Fachbereich Geowissenschaften der ...

MARIA S. MERIAN-Berichte, Cruise 20, Leg 4, Bridgetown – Freeport, 15.3.2012 – 7.4.2012
in 753-697 m water depth. The track of ROV dive GeoB 16362 was directed higher upslope in
527-439 m and crossed several prominent ridge and “mound” structures (Fig. 6.21). The ROV dive
GeoB 16358 went over a series of low-relief NE-SW striking mass transported sedimentary bodies
and it became evident that these structures are distal expressions of slope failure processes. More
prominent ridge-like bodies were pierced with larger, m-sized carbonate rocks which locally
provide substrate for larger Lophelia and Enallopsammia colonies (Fig. 6.24a). The strong bottom
current regime created impressive moats at the base of these displaced rock slabs (Fig. 6.24b-c).
The general flat seabed shows a high variability from pteropod-ooze, sometimes forming dunes
and larger ripples to indurated cemented crusts littered with fossil coral rubble, dispersed live
Lophelia and other colonial corals and sponges (Fig. 6.24d). Other prominent members of the
megafauna were stylasterids (Fig. 6.24c), gorgonians, isidids, and antipatharians.
Fig. 6.24 A Colony of L. pertusa competing with encrusting octocorals. B Displaced carbonate slab with currentgenerated
moat. C Detail of the same slab showing the moat and a larger stylasterid colony. D Indurated
seabed provides habitat for sponges and dispersed Enallopsammia and Lophelia colonies. Note the
gorgonocephalid brittle star. E Current-exposed flank of a displaced rock with dense aggregation of cupshaped
sponges. F Indurated crusts stabilize the mobile fine-grained carbonate ooze and serves a
substrate for sponges.
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