Biogenic carbonate sediments on the Scottish continental shelf and on Rockall Bank

Abstract

Biogenic carbonate sediments on the Scottish continental shelf and on Rockall Bank (northeast Atlantic) are largely composed (in the fraction > 2 mm) of bivalve fragments, serpulid tubes (attached forms and Ditrupa arietina), barnacle plates, and bryozoans. Other components include fragments from regular and irregular echinoids, and from articulate and inarticulate brachiopods. In inshore Shetland waters, barnacles and attached serpulids are the dominant components, while west of Orkney and west of the Outer Hebrides bivalves tend to be dominant. On the outer shelf the polychaete Ditrupa may be the dominant component. On Rockall Bank bryozoans are the dominant components in the shallow waters close to Rockall Island and on Bryony Bank. Elsewhere bivalves are generally the dominant component. Radiocarbon dating indicates that these shell gravels are of Holocene age. In broad general terms, the faunal composition of these gravels can be related to local living faunas.