Wild Food:Plants, Fish and Small Animals on the Menu for Early Holocene Populations at al-Khiday, Central Sudan

Al Khiday, located on the bank of the White Nile in Sudan, offers an exceptionally preserved stratigraphic sequence, providing a unique opportunity to use organic residue analysis to investigate diet and subsistence over the full course of the Khartoum Mesolithic together with possible continuity or change into the Early Neolithic, a period of nearly 3000 years (8900-6000 cal BP). Whilst the vast and diverse Mesolithic fish assemblage indicates a strong reliance on products from aquatic habitats, floodplains, vegetated marshes and open water, results from the lipid residue analysis suggest that the fish were not cooked in the pots, likely being consumed in other ways. Rather, pots were more specialised in processing plants, wild grasses, leafy plants and sedges, confirmed by experimental analysis, and for the first time, providing direct chemical evidence for plant exploitation in the Khartoum Mesolithic. Non-ruminant fauna, such as warthog and low lipid-yielding reptiles such as Adanson’s mud turtle and Nile monitor lizard, which were found in significant numbers at al-Khiday, were also cooked in pots. There is little evidence for the processing of wild ruminants in the pots, suggesting either that ruminant species were not routinely hunted, or, that large wild fauna may have been cooked in different ways, possibly grilled over fires. These data suggest sophisticated economic strategies by sedentary people likely exploiting their ecological niche to the fullest. Pottery use changes considerably in the Early Neolithic, with ruminant products being more routinely processed in pots, and while the exploitation of domesticates cannot be confirmed by a small faunal assemblage, some dairying does take place. In summary, our results provide valuable information on Early and Middle Holocene lifeways in central Sudan

Pots, plants and animals:broad-spectrum subsistence strategies in the Early Neolithic of the Moroccan Rif region

The transition from hunter-gathering to food-producing societies in the Mediterranean zone of north Africa was complex and variable, likely influenced by local ecological conditions as well as the socio-economic origins of the population. The adoption of domestic plants and animals was piecemeal, with hunting and gathering continuing as an important part of local subsistence strategies. Here, we investigate the timing and extent of the adoption of agricultural practices, namely herding and cultivation, in three diverse coastal and inland Early Neolithic sites in the Mediterranean Maghreb region, namely Ifri Oudadane, Ifri n’Etsedda and Hassi Ouenzga. Results from absorbed lipid residues extracted from 306 potsherds from these sites are correlated with information from faunal and archaeobotanical assemblages. Our findings suggest that agricultural practices, regarded as being of Neolithic origin, were never fully adopted in the Maghreb but rather that these farmer/foragers adopted a range of strategies including low-level food production (exploiting cereals and animal products, including meat and milk), gathering of wild plants and marine shellfish, and hunting both small and large sized game. These broad-spectrum farmer/foragers were clearly both flexible and resourceful and likely adapted their subsistence practices to maximise resource availability in an increasingly unpredictable environment

Early Neolithic Pits at Principal Place, Shoreditch, London Borough of Hackney

A group of four pits excavated in the upper Walbrook valley at Principal Place, Shoreditch by MOLA in 2015 produced the largest assemblage of Early Neolithic Bowl pottery recovered to date from the City of London and its immediate surrounds. The Neolithic pits had been fortuitously preserved within part of the northern extramural Roman cemetery of Londinium and conjoining sherds of Bowl pottery were also recovered from the fill of an isolated late Roman cremation. A range of analyses showed that the vessels – comprising essentially Plain Bowl with some Decorated Bowl, the latter incorporating Peterborough Ware traits – were probably locally made and had been used to process dairy products and to stew beef and mutton (though not pork). Radiocarbon dating of the lipids absorbed within the vessel walls – employing a novel technique developed at the University of Bristol – suggest that the pottery was being used in the mid-fourth millennium cal BC. The pits also contained small assemblages of struck flint, fauna (some burnt) and archaeobotanical remains (some intrusive) and may have been filled using material drawn from a long-vanished ‘pre-pit’ source, possibly a midden; they presumably represent episodic activity on the part of semi-sedentary Neolithic communities

Understanding the impact of heavy ions and tailoring the optical properties of large-area Monolayer WS2 using Focused Ion Beam

Focused ion beam (FIB) has been used as an effective tool for precise nanoscale fabrication. It has recently been employed to tailor defect engineering in functional nanomaterials such as two-dimensional transition metal dichalcogenides (TMDCs), providing desirable properties in TMDC-based optoelectronic devices. However, the damage caused by the FIB irradiation and milling process to these delicate atomically thin materials, especially in the extended area, has not yet been elaboratively characterised. Understanding the correlation between lateral ion beam effects and optical properties of 2D TMDCs is crucial in designing and fabricating high-performance optoelectronic devices. In this work, we investigate lateral damage in large-area monolayer WS2 caused by the gallium focused ion beam milling process. Three distinct zones away from the milling location are identified and characterised via steady-state photoluminescence (PL) and Raman spectroscopy. An unexpected bright ring-shaped emission around the milled location has been revealed by time-resolved PL spectroscopy with high spatial resolution. Our finding opens new avenues for tailoring the optical properties of TMDCs by charge and defect engineering via focused ion beam lithography. Furthermore, our study provides evidence that while some localised damage is inevitable, distant destruction can be eliminated by reducing the ion beam current. It paves the way for the use of FIB to create nanostructures in 2D TMDCs, as well as the design and realisation of optoelectrical devices on a wafer scale

Accurate compound-specific 14C dating of archaeological pottery vessels

Pottery is one of the most commonly recovered artefacts from archaeological sites. Despite more than a century of relative dating based on typology and seriation, accurate dating of pottery by the radiocarbon method has proven extremely challenging due to the limited survival of organic temper and unreliability of visible residues. We report here a new method of dating directly archaeological pottery based on accelerator mass spectrometry (AMS) analysis of 14C in absorbed food residues: palmitic (C16:0) and stearic (C18:0) fatty acids purified by preparative gas chromatography (pcGC). We present the first accurate compound-specific radiocarbon determinations of lipids extracted from pottery vessels, which were rigorously evaluated by comparison with dendrochronological dates and inclusion in site and regional chronologies containing suites of radiocarbon dates on other materials . Critically, the compound-specific dates from each of the C16:0 and C18:0 fatty acids in pottery vessels provide an internal quality control of the results and, are entirely compatible with dates for other commonly dated materials. Accurate radiocarbon dating of pottery vessels can reveal: (i) the period of use of pottery; (ii) the antiquity of organic residues including when specific foodstuffs were exploited; (iii) sites chronologies in the absence of traditionally datable materials and (iv) direct verification of pottery typochronologies. As exemplars, the method was applied to the dating of dairy and carcass product exploitation in Neolithic vessels, from Britain, Anatolia, central and western Europe, and Saharan Africa.Additional co-authors: Christian Jeunesse, Marta Krueger, Arkadiusz Marciniak, Steve Minnitt, Rocco Rotunno, Pieter van de Velde, Ivo van Wijk, Jonathan Cotton, Andy Daykin, Richard P Evershe