INFOMAR Seabed Samples Particle Size Analysis

The INtegrated Mapping FOr the Sustainable Development of Ireland's MArine Resource (INFOMAR) programme is a joint venture between the Geological Survey of Ireland (GSI) and the Marine Institute (MI). The programme is the successor to the Irish National Seabed Survey (INSS) and concentrates on creating integrated mapping products related to the seabed.

INFOMAR Seabed Samples Particle Size Analysis represent locations where samples have been taken and particle size analysis (PSA) carried out on samples.

Sediment type classification based on percentage sand, mud and gravel (after Folk 1954). Every sediment is a mixture of grains of varying sizes. It groups grains into mud, sand and gravel on the basis of their diameter. The relative proportion of the grains in the three categories is then used to describe the sediment and is displayed in a diagram commonly called a “Folk triangle”. This classification has 15 terms to describe the seabed sediments.

Samples from the seabed are taken by grab and box core sampling instruments.

PSA is applied to determine the range of sediment sizes contained in the sample which can often reveal an insight about the processes operating in the depositional environment. The results show percentage gravels, sands, silt and mud present in the sample. This analysis is also used to determine if the sample is well or poorly sorted.