The first six months of the project were dedicated to the development of heat treatment experiments of hornfels, the local knapping stone used by Pleistocene human groups in the Free State (South Africa), and to the acquisition of infrared spectra of standard reference materials with the aim to build a spectral library. During this time the project X account and website were also created, and the DMP was launched. In February 2023 the Team traveled to South Africa to start the survey of the Modder River and discovered the Baden-Baden Middle Stone Age site. In the following months, the PI dedicated a great part of the work to organizing the efforts of the extended team in South Africa and getting access to the collections of artifacts and fossils stored at Florisbad. In addition, the PI analyzed modern samples of tooth enamel from African ungulates using infrared spectroscopy to provide a baseline for more accurate electron spin resonance dating of fossils, and developed an analytical routine for the infrared microscope.
During the 2023 fieldwork season, the Modder River survey was successfully carried out and samples were collected for absolute dating, the analysis of plant biomarkers, and for paleoenvironmental studies. In August 2023, part of the Team started the study of the Modder River faunal collections housed at Florisbad. Every goal for the Year 1 was achieved except the excavation of Florisbad, which was not possible due to causes beyond the control of the PI. However, the team could anticipate the excavation at Baden-Baden, where samples for absolute dating and paleoenvironmental reconstructions were collected.
In October 2023, two doctoral students joined the project and began laboratory analyses of the sediment samples collected. Between September 2023 and May 2024, the work was dedicated to the analysis of samples at all of the involved institutions: geoarchaeology at the CENIEH, absolute dating at the CNRS (France), plant biomarkers at Kiel University (Germany), pollen at the University of the Free State (South Africa). In addition, the PI finished the infrared library and the writing of a handbook on infrared spectroscopy based on such library. In April 2024 the postdoctoral researcher went to South Africa to study the lithic assemblage from Baden-Baden.
The 2024 fieldwork season was focused on completing the excavation of Baden-Baden, and on the archaeological survey of the Riet River and the area around Koffiefontein. Additionally, samples in the upper catchment of the Modder River were collected in order to complete its chronological sequence. The goals of Year 2 were achieved, although Florisbad could not be excavated due to the same causes of Year 1 (the excavation is currently being planned for 2026). During the last week of June, the Team attended the biennial meeting of the Association of Southern African Professional Archaeologists (ASAPA) in Lesotho, organizing one session on the chronology of sites in arid zones, and participating with one poster and two oral presentations.
Between September 2024 and February 2025, the Team worked at the laboratory on the samples from the 2024 season and prepared further manuscripts for publication.
The main technical and scientific achievements to date are the publication of the infrared spectral library of African ungulate enamel for accurate electron spin resonance dating and the publication of the handbook of infrared spectroscopy of archaeological sediments and materials.
