Over the first 4 years of this project, we have been working with colleagues across Europe to catalogue, collect, prioritise and analyse fossil samples from a wide range of sites. We now have regional IcPD chronologies for France, the Netherlands, 3 regions within Germany, Poland, Hungary, Czechia, Switzerland and Sicily. Analysis of deep sediment core material from the Pannonian Plain and the Heidelberg Basin shows that opercula IcPD’s time range extends to 2.5 Ma, therefore confirming that it is able to cover the time periods of human migration and evolution of interest in this region. We have been able to identify the impact of geothermal heating on IcPD from sediments buried >80 m, enabling long core terrestrial material to be used for amino acid geochronology. We have been able to differentiate earlier parts of an interglacial from later parts, and identify sites where the original chronology was incorrect. We have also shown that novel biominerals (slug plates and worm granules) show age-related IcPD, widening the range of environments able to be dated. We have characterised the protein breakdown of elephant, mammoth, horse, bison & rhino tooth enamel from palaeontological / archaeological sites, showing that taxa is an important factor. Direct dating of these mammalian fossils has enabled us to identify mixed age assemblages, particularly prevalent in cave deposits. Now that we know which taxa to use, we are extending the dating frameworks using tooth enamel.
We have characterised the TL signal from biogenic calcite and developed a robust measurement protocol that can be applied to TL dating of opercula, and extended to other biominerals such as slug plates. We have investigated the reproducibility of TL measurements made on opercula, developed new methods for analysing the large and complex datasets obtained, and developed methods of quality control to screen our data. Measurement of the shape and size of opercula, coupled with computer modelling, has allowed us to determine the way that ionizing radiation generates the TL signal, and this will allow us to determine numerical ages based on the TL signal for the first time.
