Introduction
This laboratory is dedicated to distal tephra investigations, which includes the study of volcanic ash layers that are not visible to the naked eye, known as cryptotephra. Cryptotephra analyses are carried out on samples from a range of sedimentary environments, such as lakes, caves, peat bogs and marine settings.
Equipment
The laboratory houses equipment for wet-sieving of small sediment samples, a centrifuge, a vented oven, hotplate and basic sediment sampling tools.
Techniques
The laboratory houses equipment for wet-sieving of small sediment samples, a centrifuge, a vented oven, hotplate and basic sediment sampling tools.Distal ash layers are used as time-parallel marker-horizons for the precise stratigraphic correlation and dating of sedimentary sequences. Identifying very low concentration ash layers to their eruption event requires processing of sediment samples; which may involve ashing, sieving and heavy-liquid density separation. Volcanic glass shards are counted using a high-powered microscope, which is housed in the RG West Lab. In the lab there are facilities to mount and polish samples of ash ready for electron microprobe analyses.
Health and Safety
Users must ensure that the relevant COSHH and Risk Assessment form(s) have been completed and appropriate personal protection (lab coats, eye protection and disposable gloves) is in place before any chemicals are used.
Advice on potential dangers and recommended operating procedures must be sought before commencing work.
The laboratory must always be left clean and tidy. No samples known to contain quantities of volcanic ash are permitted in this laboratory.