HIGH BENTHIC FERTILITY AND TAPHONOMY OF FORAMINIFERA - A CASE-STUDY OF THE SKAGERRAK, NORTH-SEA

The Skagerrak basin is a deep water extension of the North Sea. It is of particular interest as an analogue for past epicontintal shelf basi ns because it presents environmental contrasts with the adjacent shelf seas. In this study the distribution patterns of benthic foraminifera have been used to infer taphonomic and oceanographic processes. Only by separating living from dead assemblages is it possible to interpret taphonomic changes. The transport of foraminiferal tests to the Danis h slope is inferred from the presence there of dead exotic tests whose provenance is considered to be from the south. The abundance of detri tal organic matter on the Danish slope is likewise inferred to be sour ced from the same direction. Thus, the Danish slope is interpreted to be a depositional sink. Apart from transport, another taphonomic proce ss is the dissolution of calcareous tests. This is clearly demonstrate d both by the fragility of some tests as viewed under the microscope a nd by the disparity between the composition of the living and dead fac tor associations. In the deep basin in particular, the two predominant ly calcareous living associations are replaced by a single predominant ly agglutinated dead association due to carbonate dissolution. The Dan ish slope of the Skagerrak Basin is demonstrated to be an area of high benthic fertility. This is based on the high density of living (stain ed) benthic foraminifera (comparable with that of the Mississippi delt a), particularly the abundance of Stainforthia fusiformis, an opportun istic species, and tubular agglutinated forms. The fertility is linked with the high abundance of particulate organic matter here. Previous regional studies have focused on total (living plus dead) distribution s of >100 or >125 mu m sized foraminifera. These factor assemblages ar e distinct from the >63 mu m living and dead associations described he re.