Tephra layers are considered an important chronological tool. In particular, tephrochronology allows synchronising palaeoclimate records for the study of abrupt climate changes. Cryptotephra investigation identifies distal tephra, which are not visible to the naked eye, in geological sequences located far away from the volcanic eruption. The current Holocene European tephrostratigraphy extends mainly to Northern Europe and describes a high activity of Icelandic volcanoes. In the Late Holocene a few cryptotephra layers of Azorean origin have been described in Ireland, Wales, Greenland, Svalbard, Sweden and Morocco highlighting the potential for linking southern and northern European climate records through tephrochronology.
This project will apply a tephrostratigraphic approach to correlate important high-resolution Holocene lake records from the Iberian Peninsula and those with other European and North Atlantic records. The geochemical records of Lake Zoñar (southern Spain) and Lake Cimera (central Spain) provide decadal-scale climatic and environmental variability in the mid- to late Holocene. In initial pilot studies both sites confirm Azorean tephra presence and other unknown tephra layers, which shows excellent potential for the development of a tephra-based chronology for the proxy records. This dissertation will undertake a tephrochronological analysis of these sites, including geochemical correlation and dating of the tephra, which will contribute to the development of a robust Holocene tephrostratigraphy in Southern Europe, as well as a discussion of the chronology and environmental signal in the two sites in a wider European and North Atlantic context.