Elemental fingerprinting of Kenya Rift Valley ochre deposits for provenance studies of rock art and archaeological pigments

Abstract

The Kenya Rift Valley contains many ochre sources that are currently used by indigenous peoples for adornment, rituals, and art. Ochre pigments occur in rock art and archaeological sites spanning over 250,000 years. Chemical analysis for provenience of geological sources is the first step in the process of reconstructing provenance of archaeological artifacts for cultural heritage, archaeological, and paleoanthropological research. Development of an ochre source chemical composition database can facilitate reconstruction of social interaction networks and cultural heritage conservation efforts in this region. Techniques such as Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) and Instrumental Neutron Activation Analysis (INAA) are often used for compositional analysis and sourcing of ferruginous mineral pigments. Sourcing has proven challenging due to the diverse range of rocks and minerals that are classified as red and yellow ochres, and the diverse processes that induce variation in composition, including modes of formation, sedimentary transport of parent materials, and diagenesis. Attribution of samples to specific sources is possible only when variation within sources is less than differences between sources (the Provenience Postulate). Here we present the

Back to the Grindstone? The Archaeological Potential of Grinding-Stone Studies in Africa with Reference to Contemporary Grinding Practices in Marakwet, Northwest Kenya

“…Yet there is also evidence for deep continuity and resilience in tool-use traditions. Grinding-stone tools have been grinding ochre for hundreds of millennia (Zipkin et al 2016). Grinding-stones may have even been used in the processing of wild cereal grains such as sorghum as early as ca.…”

Characterization and sources of Paleolithic–Mesolithic ochre from Coves de Santa Maira (Valencian Region, Spain)

“…However, statistical models employing Fe normalization plus Log 10 to reduce the variance have recently been used by some authors investigating ochre raw material procurement locations (Dayet et al, 2016; Eiselt et al, 2019; MacDonald et al, 2018; Velliky et al, 2019; Zipkin et al, 2017). Therefore, a CA was carried out using the proposed parameters for all the elements (except Fe) (Figure 9a–c) to observe whether the groupings are equivalent to those of the prior model (Figure 8a–c).…”

“…In the first cluster (Figure 8), all analyzed elements (Al 2 O 3 , SiO 2 , CaO, Ti, Fe, Ba, Bi, Cd, Cr, Co, Cu, Pb, Li, Mn, Mo, Ni, Sr, Tl, V, Zn, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and Y) were taken as variables. Furthermore, following the geochemical data treatment recently employed by some authors for ochre provenance studies (Dayet, Le Bourdonnec, Daniel, Porraz, & Texier, 2016; Eiselt et al, 2019; MacDonald, Fox, Dubreuil, Beddard, & Pidruczny, 2018; Velliky, Barbieri, Porr, Conard, & MacDonald, 2019; Zipkin et al, 2017) in the second cluster (Figure 9), the same elements (except Fe) were Fe‐normalized and subsequently log 10 transformed. The data were autoscaled before analysis.…”

Grinding-stone implements in the eastern African Pastoral Neolithic

“…Mercader 2009;Radomski and Neumann 2011;Ball et al 2016). Recent progress in the elemental fingerprinting of ochre deposits in the Kenya Rift Valley (Zipkin et al 2017) also opens up the possibility of determining the origins of the ochre found on PN grinding-stones and thus of exploring patterns in wider landscape resource use. The potential remains to investigate whether different PN communities used distinct ochre sources, or manufactured their grinding-stone tools from specific lithic materials, as has previously been observed in relation to obsidian found on Elmenteitan and SPN sites in the Central Rift Valley (Merrick and Brown 1984).…”