Tellus Geochemical Survey Contractor Report 2016: West of Ireland Soil and Drainage Sampling End of Campaign Report May to October 2016.
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
werecollected. 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