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

intermediate nepheloid layers (Dickson & McCave, 1986; Kenyon et al. 2003)
providing an abundant food supply.
Fig. A4.4.1-1. Carbonate mounds on the Porcupine Bank (from Wheeler et al., in press).
Topography courtesy of the Geology Survey of Ireland.
The Porcupine Bank carbonate mounds occur as both isolated features and in
association with the scarps. Mound shapes range from ovoid, to ridge-shaped running
sub-parallel to the isobaths, to complex forms. Some of the mounds, especially those
occurring as groups, are also surrounded by zones of high backscatter seabed that
represents erosion of unconsolidated material exposing the underlying lithified
sediment.
There is a clear tendency for some mounds to be aligned along scarps (Fig. A4.4.1-1)
and topographic highs. These scarps have a slight topographic rise upslope and a
steep scarp-face downslope. The shape and down slope acoustic facies suggest that
these are not major slope failures but represent either the edges of erosional scours
where shallow bedding planes are exposed or fault scarps. Comparable exposures of
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