Tephrochonology
Vulcanian eruption at Karymsky, Kamchatka, Russia
The correlation and geochemical analysis of volcanic ash deposits (tephra) allows the identification and dating of isochronous marker horizons within a range of sequences. Tephrochronology thus provides a precise and well-established dating tool. Here at Oxford we work with both microtephra and proximal volcanic deposits. Detailed geochemistry of proximal eruption deposits and distal tephra allow deposits to be correlated to source and between sites. These geochemical analyses of the tephra also provide an insight into magmatic processes.
Microtephra are found beyond the geographical limits of visible ash fall deposits, allowing correlations to be made over wider areas. Linking up cores (on-land, ocean and ice) and archaeological sites over continents has furthered our understanding on the timing of climate changes in different regions, and how these changes affected past societies. This is part of current research on the NERC-funded RESET (Response of Humans to Abrupt Environmental Transitions) consortium project.
Members of the RLAHA tephra group on Mt Vesuvius, Italy
Current research includes:
- Chemically fingerprinting tephra deposits within Europe
- Expanding the known database of European micro-tephra deposits and eruptions throughout archaeological timeframes.
- Using tephra chemistry to understand igneous processes
- Investigating the chemical stability of volcanic glasses
- Optimising geochemical analytical procedures
Equipment:
- Micro-tephra extraction laboratory
- JEOL8600 electron microprobe (refurbished in November 2008) with 4 spectrometers, running SAMx software.
- Microscope laboratory
- Grinding and polishing facilities
Contact Details
Dr V C Smith (Laboratory Manager)
email: victoria.smith@rlaha.ac.uk
phone: 01865-285202
Royal Holloway and Oxford Tephrochronology Research group (RHOXTOR)
A research consortium which combines the tephrostratigraphical and geochemical expertise of researchers in Earth Sciences in Oxford, and Earth Science and Geography in Royal Holloway.
Current projects are part of or related to the RESET project.