The nature and chronology of human occupation at the Galerías Bajas, from Cueva de Ardales, Malaga, Spain.

The Cueva de Ardales is a hugely important Palaeolithic site in the south of the Iberian Peninsula owing to its rich inventory of rock art. From 2011-2018, excavations were carried out in the cave for the first time ever by a Spanish-German research team. The excavation focused on the entrance area of the cave, where the largest assemblage of non-figurative red paintings in the cave is found. A series of 50 AMS dates from the excavations prove a long, albeit discontinuous, occupation history spanning from the Middle Palaeolithic to the Neolithic. The dating of the Middle Palaeolithic layers agrees with the U/Th dating of some red non-figurative paintings in the entrance area. In addition, a large assemblage of ochre lumps was discovered in the Middle Palaeolithic layers. Human visits of the cave in the Gravettian and Solutrean can be recognized, but evidence from the Aurignacian and Magdalenian cannot be confirmed with certainty. The quantity and nature of materials found during the excavations indicate that Cueva de Ardales was not a campsite, but was mainly visited to carry out non-domestic tasks, such as the production of rock art or the burial of the dead.

Long-term in situ non-invasive spectroscopic monitoring of weathering processes in open-air prehistoric rock art sites.

In this work, an innovative non-destructive monitoring methodology based on the analysis over time of open-air rock art sites is presented. This approach is based on the combination of in situ spectroscopic and chemometric studies to diagnose and monitor the state of conservation of rock art sites. Data acquired over a period of time by non-invasive analytical techniques such as portable Raman spectrometry (RS) and handheld energy-dispersive X-ray fluorescence (HH-EDXRF) spectrometry are compared to detect physicochemical changes that could affect the rock painting integrity. To demonstrate the applicability of the proposed procedure, three analysis campaigns (between 2013 and 2016) were carried out, analyzing Levantine rock pictographs preserved in the rock shelter of Solana de las Covachas VI (Albacete, Spain; see Electronic Supplementary Material (ESM) Fig. S1). The analyzed areas showed different types of active weathering processes such as gypsum and calcium oxalate formation, giving rise to conservation issues such as painting fading, surface loss, microbial colonizations, and formation of crusts. Results evidence that the proposed methodology can be very useful to monitor chemical changes in the surface of the walls where the rock art is located, thus obtaining crucial information for its preservation and management.

Publisher Correction: 78,000-year-old record of Middle and Later Stone Age innovation in an East African tropical forest.

The originally published version of this Article contained an error in Fig. 3, whereby an additional unrelated graph was overlaid on top of the magnetic susceptibility plot. Furthermore, the Article title contained an error in the capitalisation of 'Stone Age'. Both of these errors have now been corrected in both the PDF and HTML versions of the Article.

78,000-year-old record of Middle and Later stone age innovation in an East African tropical forest.

The Middle to Later Stone Age transition in Africa has been debated as a significant shift in human technological, cultural, and cognitive evolution. However, the majority of research on this transition is currently focused on southern Africa due to a lack of long-term, stratified sites across much of the African continent. Here, we report a 78,000-year-long archeological record from Panga ya Saidi, a cave in the humid coastal forest of Kenya. Following a shift in toolkits ~67,000 years ago, novel symbolic and technological behaviors assemble in a non-unilinear manner. Against a backdrop of a persistent tropical forest-grassland ecotone, localized innovations better characterize the Late Pleistocene of this part of East Africa than alternative emphases on dramatic revolutions or migrations.