OCAE Consultants Ltd., 2016.
Phase 4, ‘Tellus West’ the subject of this report, is the latest round of surveying conducted by the Tellus programme. This is a significant geological mapping project led by the Geological Survey Ireland.
During Tellus West 2016, 1,465 unique soil sample sites and 2,185 unique drainage sample sites were collected in the West of Ireland, in Co. Mayo and the most western part of Co. Galway. The overall aim was to determine a regional-scale geochemical baseline from representative soil samples based upon an ad-hoc gridded survey method and representative stream sediment and water samples. Using modern scientific methods based on G-BASE Field Procedures Manual and the GSI’s Request for Tenders, the aim is to create a regional scale map of the geochemistry of the near surface. Soil samples from two depth intervals, desirably from depth of 20 cm and 50 cm, every 4 km2 were collected. Stream samples were collected on average one every 2.4 km2 from mainly first and second low order streams with some small third order streams also being sampled.
The purpose of this was to give an indication of what trace elements were present in the stream catchment area. Stream sample sites were chosen by GSI depending on a variety of factors such as density of streams, geology of the local area and relief of terrain. Both soil and stream samples were taken as per the sampling procedures and methodologies developed and employed during previous regional geochemical surveys undertaken in both the UK by the British Geological Survey and in Ireland by the Geological Survey of Ireland. The Geological Survey of Ireland intends to merge the data collected through the Tellus West Project with the existing data sets of Tellus Border and Tellus in Northern Ireland.