Samples and associated geological data are held at the British Geological Survey for Maritime Coastguard Agency (MCA), Civil Hydrography Programme (CHP), Bathymetric Survey HI1220; Holm Channel, Area in SqKm: 23, (16/04/2007 to 03/05/2007), Standard: IHO S44ed4 Order 1. Contract: RRS (2006 LT). FY 2006/07. Contractor: MMT.