School of GeoSciences

Tephra Analysis Unit (TAU)

The Tephra Analysis Unit (TAU) is an internationally recognised centre for the electron probe microanalysis of volcanic glasses and melt inclusions.

Located at the School of Geosciences, within the University of Edinburgh the TAU has numerous clients from the UK, Europe, and South America.

We provide a service to researchers and students from Earth and environmental sciences and archaeology, facilitating components of many research programmes each year.  For example, the TAU spans applications in:

  • Holocene climate change
  • palaeoenvironmental reconstruction
  • physical volcanology 
  • dating of cultural remains

Other than the reliable identification of source volcanoes, the TAU can routinely measure concentrations of volatile elements F, Cl and S for studies of degassing and environmental impacts of eruptions.

Since the 1990's, the TAU has actively engaged in development of improved methods for the microanalysis and preparation of tephras. More recent developments include analytical protocols for analysis of crypto-tephras with beam diameters as low as 3 microns without sodium loss (Hayward, 2012), and preparation of crypto-tephras with grain sizes below 50 microns (Hall and Hayward, 2015).

Access to the Tephra Analysis Unit 

Informal discussions concerning research objectives and the potential role of the Tephra Analysis Unit are welcomed.

Please note that the Electron Probe is in high demand and that the schedule is usually fully booked up to 3 months in advance.


Contact details and access to the Tephra Analysis Unit is via the Electron Probe Microanalysis (EPMA) Facility

Contact details and access

Sample preparation

There are requirements for sample preparation before analysis at the Tephra Analysis Unit.  

Information is provided within the Electron Probe Microanalyser instrument capabilities.

Requirements for sample preparation
Accepted values for the BCR2g and Lipari standards for tephra analysis
Accepted values for the BCR2g and Lipari standards for tephra analysis

Tephra standards

It is essential that any Tephra analysis from any EPMA laboratory is presented together with a recognised standard and the analytical conditions.  

The EPMA Facility at the University has numerous standards for verification of data quality during analyses. The most commonly used during analysis of tephras are BCR2g for basaltic compositions, and Lipari for rhyolitic compositions.  Clients occasionally bring their own standards, and these are run together with the University of Edinburgh standards.


Additional information

Further information on tephra geochemistry and geochemical fingerprinting through electron probe microanalysis. Tephra geochemistry
We have a selection of recommended reading material which may help you understand tephra materials and electron probe microanalysis methods in more detail. Selected bibliography