Haua Fteah Research Articles

Testing new analytical expression for dose response curves originating from the OTOR model

The possibility of precisely evaluating the equivalent beta dose in stimulated luminescence dating depends on the ability to fit the constructed dose response calibration curve with appropriate analytical expressions. There are a number of such expressions which successfully fit the dose response calibration curves. In the present study we use the recently developed analytical Pagonis-Kitis-Chen equation (PKC equation) to describe the dose response curves from a set of single-grain experimental data for a sedimentary sample from the Haua Fteah Cave in Libya. The PKC equation describes in analytical form the rate of filling of the electron traps during the irradiation stage in the one trap one recombination center model (OTOR). A detailed comparison was carried out between the PKC equation and two very successful equations existing in literature. The comparison criteria were the values of: (a) the reduced chi squared, (b) figure of merit, (c) Equivalent dose and (d) the possible physical meaning of the coefficients used as the free fitting parameters during the fitting procedure. The results show that the PKC equation is at least equally successful as the other two equations in fitting the experimental data.

Libyan landscapes in history and prehistory

AbstractAs a contribution to the Society for Libyan Studies’ 50th anniversary, the paper discusses three projects in which the author has been involved, with a focus on their different contributions to our understanding of Libya's landscape prehistory and history. The deep stratigraphy of the Haua Fteah cave in three projects are described in chronological order, but they contribute in reverse order to our understanding of how Libyans have changed and been changed by their landscapes. The deep stratigraphy of the Haua Fteah cave in Cyrenaica represents an intermittent history of landscape use, and the way people dealt with climate change impacts, from some 150,000 years ago to the Graeco-Roman period. The faunal assemblage from Sidi Khrebish, Benghazi, provides insights into how Graeco-Roman city-dwellers interacted with the people of the countryside. The UNESCO Libyan Valleys Survey changes the perspective, showing how tribal people in the pre-desert were drawn into the ambit of the coastal cities and the economy of imperial Rome, before returning to semi-mobile pastoral/arable lifeways not so dissimilar to the lives of many Libyans before the oil revolution. The principal linking finding is that there are no simple stories from the past in terms of people's relations to their landscape: the mix of structure and agency embodied in the archaeological record can be a record of failures, misguided decisions, bad luck etc. as much as of successful responses and adaptations to opportunities and challenges.

Which way to turn? Is the Haua Fteah a Levantine site?

AbstractRecent work has shown early modern human occupation at Jebel Irhoud, Morocco, dating as far back as MIS 9 (337–300 Ka). Such early dates double the period in which modern humans were present in North Africa, with implications for several key debates on modern human origins and subsequent spread. Routes across a ‘Green Sahara’ allowed population movement intermittently from sub-Saharan Africa and across the Saharan region in general. This has implications for the debate about the timing and routes of modern human expansion across and out of Africa, but also has the effect of focusing discussion on the archaeological record of sub-Saharan Africa and even Arabia for evidence of human behaviour and adaptations. This may be unfortunate as the record for much of the vast area of sub-Saharan Africa and Arabia is extremely limited and the more detailed record of the Levantine region is overlooked. Work at the Haua Fteah and in its surrounding region (Cyrenaican Libya) provides an opportunity to investigate how far the Palaeolithic record for this part of North Africa is, in fact, a product of trans-Saharan, North African or Levantine, influences. The genetic evidence suggests the process of modern human expansion out of Africa, and just as importantly within Africa itself, was a complex one that may have involved population movements into and out of North Africa from several different directions. A concentration upon the Green Sahara hypothesis may distract current research from this broader picture.

Use of grass seed resources c.31 ka by modern humans at the Haua Fteah cave, northeast Libya

The recovery of a seed grinding stone from human occupation layers dating to c.31 ka in the Haua Fteah cave on the coast of the Gebel Akhdar massif in northeast Libya sheds new light on the subsistence practices of modern humans in North Africa. An integrated study of usewear and organic residue analysis confirms the use of the tool for seed grinding. Residue analysis recovered a total of 15 starch granules that could be reliably identified as belonging to wild cereals, ten of which are identified as A-type granules of Aegilops sp. (goat grass). The results of this study show that modern humans had the capacity to identify large-seeded grasses as a potential food source, perhaps targeted during periods of resource stress, and were capable of adapting pounding and grinding technologies to solve the unique problems of seed processing to render an edible food from grasses. The findings from this research show that broad-spectrum diets involving the exploitation of wild cereals were emerging during the Late Stone Age in North Africa.

Increased climate seasonality during the late glacial in the Gebel Akhdar, Libya

Oxygen isotope analysis (δ18O) of caprine and bovine tooth enamel carbonates from the Haua Fteah cave (Gebel Akhdar massif, northeast Libya) reveals significant differences in palaeoseasonality during the last c. 70 ka. Data indicate different phases of human occupation of the region occurred under notably different climatic conditions. During the last glacial period, prior to the Last Glacial Maximum, a gradual increase in climate aridity occurred. This was followed in the late glacial (c. 16.6–14.7 ka) by considerably more arid conditions and much greater climate seasonality, which was likely produced by changing winter precipitation amounts and a strengthening of arid summer air masses. The high seasonality in the late glacial coincides with a period when human activity at the Haua Fteah greatly intensified. Significant changes in subsistence strategies and the seasonal exploitation of food resources also occurred at this time. The results presented here suggest that changes in the seasonal climate may have affected the seasonal supply of floral and faunal resources available to local human populations at the time, which resulted in changing subsistence practices.

Mollusk carbonate thermal behaviour and its implications in understanding prehistoric fire events in shell middens

Archaeological shell middens are particularly important for reconstructing prehistoric human subsistence strategies. However, very little is known about shellfish processing, especially when related to the use of fire for dietary and disposal purposes. To shed light on prehistoric food processing techniques, an experimental study was undertaken on modern gastropod shells (Phorcus lineatus). The shells were exposed to high temperatures (200–700 °C) to investigate subsequent mineralogy and macro- and microstructural changes. Afterwards, the three-pronged approach was applied to archaeological shells from Haua Fteah cave, Libya (Phorcus turbinatus) and from shell midden sites in the United Arab Emirates (Anadara uropigimelana and Terebralia palustris) to determine exposure temperatures. Results indicated that shells from the Haua Fteah were exposed to high temperatures (600–700 °C) during the Mesolithic period (ca. 12.7–9 ka), whereas specimens from the Neolithic period (ca. 8.5–5.4 ka) were mainly exposed to lower temperatures (300–500 °C). The thermally-induced changes in A. uropigimelana and T. palustris shells from the South East Arabian archaeological sites were similar to those seen in Phorcus spp. suggesting a broad applicability of the experimental results at an interspecific level. Although heat significantly altered the appearance and mineralogy of the shells, 14CAMS ages obtained on burnt shells fit within the expected age ranges for their associated archaeological contexts, indicating that robust radiocarbon ages may still be obtained from burnt shells. Our study indicates that the combination of microstructural and mineralogical observations can provide important information to infer shellfish processing strategies in prehistoric cultures and their change through time.

Sediment micromorphology and site formation processes during the Middle to Later Stone Ages at the Haua Fteah Cave, Cyrenaica, Libya

AbstractUnderstanding the timing, conditions, and characteristics of the Middle to Later Stone Age (MSA/LSA) transition in North Africa is critical for debates regarding the evolution and past population dynamics of Homo sapiens, especially their dispersals within, out of, and back into, Africa. As with many cultural transitions during the Palaeolithic, our understanding is based predominantly on archaeological and paleoenvironmental records preserved within a small number of deep cave sediment sequences. To use such sequences as chronological cornerstones we must develop a robust understanding of the formation processes that created them. This paper utilizes geoarchaeological analyses (field observations, sediment micromorphology, bulk sedimentology) to examine site formation processes and stratigraphic integrity during the MSA/LSA at the Haua Fteah cave, Libya, one of North Africa's longest cultural sequences. The depositional processes identified vary in mode and energy, from eolian deposition/reworking to mass colluvial mudflows. These changing processes impact greatly on the interpretation of the paleoenvironmental and archaeological records, not least in identifying potential colluvial sediment deposition and reworking in layers identified as containing the MSA/LSA transition. This study highlights the importance of developing geoarchaeological analyses of cultural sequences to fully unravel the limitations and potential of their contained archaeological and paleoenvironmental records.

The chronostratigraphy of the Haua Fteah cave (Cyrenaica, northeast Libya) — Optical dating of early human occupation during Marine Isotope Stages 4, 5 and 6

The paper presents the results of optical dating of potassium-rich feldspar grains obtained from the Haua Fteah cave in Cyrenaica, northeast Libya, focussing on the chronology of the Deep Sounding excavated by Charles McBurney in the 1950s and re-excavated recently. Samples were also collected from a 1.25 m-deep trench (Trench S) excavated during the present project below the basal level of the Deep Sounding. Optically stimulated luminescence (OSL) data sets for multi-grain, single aliquots of quartz for samples from the Middle Trench were previously published. Re-analyses of these OSL data confirm significant variation in the dose saturation levels of the quartz signal, but allow the most robust OSL ages to be determined for comparison with previous age estimates and with those obtained in this study for potassium-rich feldspars from the Deep Sounding. The latter indicate that humans may have started to visit the cave as early as ∼150 ka ago, but that major use of the cave occurred during MIS 5, with the accumulation of the Deep Sounding sediments. Correlations between optical ages and episodes of “Pre-Aurignacian” artefact discard indicate that human use of the cave during MIS 5 was highly intermittent. The earliest phases of human activity appear to have occurred during interstadial conditions (5e and 5c), with a later phase of lithic discard associated with more stadial conditions, possibly MIS 5b. We argue that the “Pre-Aurignacian” assemblage can probably be linked with modern humans, like the succeeding “Levalloiso-Mousterian” assemblage; two modern human mandibles associated with the latter are associated with a modelled age of 73–65 ka. If this attribution is correct, then the new chronology implies that modern humans using “Pre-Aurignacian” technologies were in Cyrenaica as early as modern humans equipped with “Aterian” technologies were in the Maghreb, raising new questions about variability among lithic technologies during the initial phases of modern human dispersals into North Africa.

Developing a Holocene tephrostratigraphy of Ethiopia

The research lead by the French Archaeological Mission in Libya and the Cyrenaican Prehistory Project (CPP) in the beginning of the 21st century, added to those realized by McBurney in the middle of the 20th century, gathered important information on the Neolithic and the Neolithisation of Cyrenaica, the region of northeast Libya. Despite numerous unknown which will have to be resolved by future investigations, it already appears that pottery production and animal domestication of ovicaprines started very early in that area. These data were obtained for the first time at the site of Haua Fteah, a huge cave excavated in the 1950s and nearly fifty years later by the University of Cambridge. The discoveries made on the new site of Abu Tamsa confirm that the Neolithic began in north Cyrenaica as early as the beginning of the 8th millennium cal BP. The elements we possess indicate that this Libyan region had many traits in common with the eastern regions from where people obtained domesticated animals and shared technological lithic practices. Nonetheless, although the influence of Egypt is present, the local character of the industries dominates. The study of the Neolithic assemblage of Abu Tamsa indicates that there are no visible contacts with the Maghreb Capsian in the west, a hypothesis first supported by McBurney for Haua Fteah's Holocene industries.

Investigation of the applicability of standardised growth curves for OSL dating of quartz from Haua Fteah cave, Libya

Abstract The establishment of standardised growth curve (SGC) for equivalent dose (De) determination can substantially reduce the amount of instrument time required for OSL measurements. In this study, we investigated the applicability of SGC for the optically stimulated luminescence (OSL) signal from single grains and small aliquots of sedimentary quartz from Haua Fteah cave, in Libya. The samples exhibit large inter-grain and inter-aliquot variation in the shape of their single grain and small aliquot dose response curves (DRCs) constructed from a range of sensitivity-corrected regenerative dose signals (Lx/Tx), which prevents the establishment of a single common SGC among different grains or small aliquots. Instead, the DRCs for the small aliquots can be divided into a minimum of three groups using the Finite Mixture Model, with the DRC saturating at a different dose level for each group. In order to establish a common DRC, or SGC, for each group, we propose a new normalisation method, the so-called least-squares normalisation procedure (‘LS-normalisation’), which largely reduces the variation between aliquots within the same group and allows the establishment of a common DRC, or SGC, for each group. In order to apply the SGC method for these samples, two regenerative dose points are needed for each aliquot to attribute it to one of the groups based on the ratio of the Lx/Tx signals for two sensitivity-corrected regenerative dose points. Equivalent dose (De) values for each aliquot can be estimated using the fitting parameters calculated for the SGC of the relevant group to which it belongs, together with measurements of the natural signal (Ln), one regenerative dose signal (Lx1) and their corresponding test dose signals (Tn, Tx1). For the samples investigated from Haua Fteah, we found that De estimates obtained from the SGCs are consistent with those obtained using a full SAR procedure. Our results suggest that small single-aliquot and single-grain De values obtained from application of the SGC may be underestimated if there is a significant proportion of early-saturating grains present in the sample; such grains or aliquots are mostly rejected due to saturation when analysed using the full SAR procedure. In this case, it is necessary to calculate the De values based only on those grains or aliquots that have relatively high saturation levels.

A late Pleistocene refugium in Mediterranean North Africa? Palaeoenvironmental reconstruction from stable isotope analyses of land snail shells (Haua Fteah, Libya)

The late Pleistocene to Holocene archaeological record of North Africa is key to understanding the emergence of anatomically modern humans into West Asia and Europe, and the broadening of subsistence strategies in the shift from hunter-gatherer to pastoral-agricultural lifeways. Some contend that these developments were modulated by major shifts in climate and environment. Evaluation of this hypothesis requires the pairing of local and regional climate records with well-dated archaeological sequences. The Haua Fteah archaeological site in the Gebel Akhdar region of Libya provides a key site to test this hypothesis as the cave contains one of the longest and most complete sequences of human occupation in North Africa as well as abundant material for palaeoenvironmental reconstruction. This study uses stable isotope analyses (δ18O and δ13C) of the terrestrial mollusc Helix melanostoma to construct a palaeoenvironmental framework for interpreting North African human-environment interactions from the Upper Palaeolithic to the Neolithic (∼30,000 to 5000 years ago).The land snail stable isotope records from Haua Fteah suggests that cool arid conditions in the cave peaked during marine isotope stage (MIS) 2. This stage was, however, only marginally drier than previous and subsequent stages and coincided with an increase in occupation density in the cave. This suggests that the Gebel Akhdar may have served as an environmental refugium from the more extreme aridity in the surrounding Sahara and arid coastal plains for Late Stone Age (LSA) populations in North Africa. Conditions became progressively wetter towards the Holocene. However, generally wetter conditions were interrupted by two arid episodes at c. 8.0 ka and 7.3 ka that appear to coincide with regional changes reflected elsewhere in the Mediterranean basin.

Pleistocene and Holocene herbivore diets and palaeoenvironments in the Gebel Akhdar (Libya): Implications for past human populations

The Gebel Akhdar massif in Cyrenaica, northeast Libya, has yielded a long record of human occupation going back at least 100,000years. To date, there is only a limited understanding of how the landscape of the region varied in response to the climatic fluctuations of the last glacial–interglacial cycle, and the implications of these changes for local human populations remain largely unexplored. This study provides an isotope-based interpretation of past environments directly linked to the archaeological record. Tooth enamel stable carbon isotope ratios (δ13C) from herbivore species hunted by past human populations are used to infer the isotopic characteristics of past diet and vegetation, and in turn the likely environmental conditions that prevailed during periods when humans were active within the landscape. To provide a baseline from which to interpret the archaeological δ13C data, modern samples are considered in relation to their diet and environmental origin. Archaeological samples come from 2 cave sites, Haua Fteah and Hagfet ed Dabba, and span a period from oxygen isotope stage 4 to the mid-Holocene. Whilst results indicate a more arid environment in the Pleistocene and an increase in humidity at the onset of the Holocene, the overall picture is one of relative environmental stability. The biggest landscape change observed in the data occurs during the mid-Holocene Neolithic, when C4 plant species become evident in the herbivore diet for the first time. There is little evidence to suggest that this occurred at a time of any large-scale climate variation, and thus the contribution of anthropogenic influences to vegetation change is considered likely.

Middle Stone Age reduction strategies at the desert's edge: A multi-site comparison across the Gebel Akhdar of northeast Libya

Haua Fteah cave, situated between the Mediterranean coast and the Gebel Akhdar of northeast Libya, preserves rich Middle Stone Age (MSA) and Late Stone Age (LSA) cultural horizons. Excavated in the 1950s and more recently, the richness and time-depth of the cave's archaeological record are unsurpassed by any other site in northern Cyrenaica. As a result, the Haua Fteah sequence has long been used to represent the culture history of the region as a whole. Recent geoarchaeological surveys of the Gebel Akhdar, as well as pre-desert and desert biomes further to the south, have resulted in the discovery of numerous MSA and LSA sites. The vast majority of these sites consist of surface lithics that cannot be dated currently. In contrast, parts of the Haua Fteah sequence have been dated using various chronometric methods. Using data collected through lithic attribute analysis, coupled with various statistical approaches (including Discriminant Function Analysis, or DFA), this paper explores variation in core reduction strategies within Haua Fteah from the early MSA to early LSA. Collections of cores from various sites located throughout the landscape are contrasted against those from Haua Fteah. By comparing undated cores from the landscape with those from different occupation phases at Haua Fteah, DFA classification is tested as a method for imparting an approximate chronology to the former. The results indicate notable variation in reduction strategies within the MSA at Haua Fteah, and notable similarities between early MSA (“Pre-Aurignacian”) and early LSA (“early Dabban”) core morphologies and technologies. Because of the latter in particular, together with several other factors that may be underpinning spatio-temporal variability in core reduction strategies, caution is recommended in loosely assigning approximate chronologies to surface lithic sites.

Reconsidering the MSA to LSA transition at Taforalt Cave (Morocco) in the light of new multi-proxy dating evidence

Amongst the least well-defined periods in North African prehistoric archaeology is the interval between ∼40 and 20 ka BP. This encompasses a phase (or phases) of major technological change which archaeologists describe as the MSA (Middle Stone Age) to LSA (Later Stone Age) transition. The nature of this transition is complicated by the fact that few sites spanning this period have been the object of modern scientific study. Two exceptions are the caves of Taforalt (Morocco) and the Haua Fteah (Libya) which have each been systematically excavated in the last decade and have yielded datable sequences that provide fresh light on the nature of the transition. In this paper we describe the results of new work at Taforalt and suggest that considerable variation exists across the region, in comparison with sites like the Haua Fteah. Initial results are also given on the rich charred plant remains (likely food residues) and wood charcoal evidence from the younger MSA layers dating to ∼27 ka BP.

The exploitation of wild plants in Neolithic North Africa. Use-wear and residue analysis on non-knapped stone tools from the Haua Fteah cave, Cyrenaica, Libya

The North African region offers up essential data for the study of the origins of the earliest forms of plant exploitation. Data available from several Saharan and coastal areas in the region have revealed that the arrival of domestic wheat and barley from the Levant during the Mid Holocene did not replace the exploitation of autochthonous wild plants, especially grasses. The Neolithic layers of the Haua Fteah cave, in Cyrenaica (Northern Libya), have so far produced archaeobotanical assemblages exclusively made up of wild species. This paper investigates production and use of non-knapped stone tools, mainly grinding stones, from the Holocene sequence of the Haua Fteah Cave. The presence of grinding stones may indicate a certain level of behavioural change and the adoption of new economic strategies, relying more strongly on plant exploitation. This assumption has been tested using an integrated approach of use-wear and residue analysis. These methods allowed us to obtain significant new information as to how tools were originally used.Use-wear analysis was carried out adopting a low power approach; such study was complemented by residue analysis, in particular starch granules analysis, only rarely applied in North African contexts. This combined approach was carried out on a selected sample of tools, in order to test survival of plant micro-remains and, where possible, the types of plants processed by the Holocene communities in the cave. Here we confirm the lack of evidence of domesticated crops and the presence of starch granules only belonging to wild plants.The importance of wild plants in the economy of North African prehistoric groups has often been underestimated, on the assumption that they were replaced by the Near Eastern domesticated crops and animals once they were firstly introduced in North Africa. The results of our study show a different picture, confirming the role of the wild species as an important food source during the Holocene.

Neolithic of Cyrenaica (north-east Libya): New enlightenments from recent research

The research lead by the French Archaeological Mission in Libya and the Cyrenaican Prehistory Project (CPP) in the beginning of the 21st century, added to those realized by McBurney in the middle of the 20th century, gathered important information on the Neolithic and the Neolithisation of Cyrenaica, the region of northeast Libya. Despite numerous unknown which will have to be resolved by future investigations, it already appears that pottery production and animal domestication of ovicaprines started very early in that area. These data were obtained for the first time at the site of Haua Fteah, a huge cave excavated in the 1950s and nearly fifty years later by the University of Cambridge. The discoveries made on the new site of Abu Tamsa confirm that the Neolithic began in north Cyrenaica as early as the beginning of the 8th millennium cal BP. The elements we possess indicate that this Libyan region had many traits in common with the eastern regions from where people obtained domesticated animals and shared technological lithic practices. Nonetheless, although the influence of Egypt is present, the local character of the industries dominates. The study of the Neolithic assemblage of Abu Tamsa indicates that there are no visible contacts with the Maghreb Capsian in the west, a hypothesis first supported by McBurney for Haua Fteah's Holocene industries.

Pleistocene and Holocene palaeoclimates in the Gebel Akhdar (Libya) estimated using herbivore tooth enamel oxygen isotope compositions

The palaeoclimate of the Gebel Akhdar massif, in Cyrenaica, northeast Libya, is investigated using the stable oxygen isotope ratio (δ18O) of herbivore tooth enamel from the archaeological faunal assemblages of the Haua Fteah and Hagfet ed Dabba caves. Samples accumulated through human activity at the sites, thus climatic interpretations are in direct chronological association with periods of human presence in the local landscape. Wild Ammotragus lervia (Barbary sheep) and Bos sp. (auroch), and domestic Ovis sp. and Capra sp. from the Levalloiso-Mousterian (≥73.3–43.5 ka) to the Neolithic (∼9.3–5.4 ka) cultural phases are analysed. Results indicate that the most arid environment represented by the samples occurred at ∼32 ka, when populations associated with Dabban lithic assemblages were present within the region. Climatic instability increased during oxygen isotope stage 2. Consistent with other palaeoenvironmental investigations in the Gebel Akhdar, there is no evidence for hyper-arid events during the last glacial and surface water, most probably in the form of local springs, was available throughout the time periods considered. Overall, results indicate that different cultural groups occupied the Gebel Akhdar landscape under different climatic conditions, but that climate variations appear to have been of lower magnitude than those that occurred at inland North African locations. These reconstructions provide further support to the theory that the Gebel Akhdar may have served as a refugium for human populations in North Africa during times of global climatic extremes.

Changing patterns of eastern Mediterranean shellfish exploitation in the Late Glacial and Early Holocene: Oxygen isotope evidence from gastropod in Epipaleolithic to Neolithic human occupation layers at the Haua Fteah cave, Libya

The seasonal pattern of shellfish foraging at the archaeological site of Haua Fteah in the Gebel Akhdar, Libya was investigated from the Epipaleolithic to the Neolithic via oxygen isotope (δ18O) analyses of the topshell Phorcus (Osilinus) turbinatus. To validate this species as faithful year-round palaeoenvironmental recorder, the intra-annual variability of δ18O in modern shells and sea water was analysed and compared with measured sea surface temperature (SST). The shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual SST cycle in their shell δ18O with minimal slowing or stoppage of growth. During the terminal Pleistocene Early Epipaleolithic (locally known as the Oranian, with modeled dates of 17.2–12.5 ka at 2σ probability, Douka et al., 2014), analysis of archaeological specimens indicates that shellfish were foraged year-round. This complements other evidence from the archaeological record that shows that the cave was more intensively occupied in this period than before or afterwards. This finding is significant as the period of the Oranian was the coldest and driest phase of the last glacial cycle in the Gebel Akhdar, adding weight to the theory that the Gebel Akhdar may have served as a refugium for humans in North Africa during times of global climatic extremes. Mollusc exploitation in the Latest Pleistocene and Early Holocene, during the Late Epipaleolithic (locally known as the Capsian, c. 12.7 to 9 ka) and the Neolithic (c. 8.5 to 5.4 ka), occurred predominantly during winter. Other evidence from these archaeological phases shows that hunting activities occurred during the warmer months. Therefore, the timing of Holocene shellfish exploitation in the Gebel Akhdar may have been influenced by the seasonal availability of other resources at these times and possibly shellfish were used as a dietary supplement when other foods were less abundant.

Land gastropod piercing during the Late Pleistocene and Early Holocene in the Haua Fteah, Libya

Land snail shell is a frequent constituent of archaeological sites, but it is rarely clear whether it represents food refuse, the remains of scavengers, or evidence for natural processes. Piercing of land snail shells enables the animal to be extracted from the shell and thus provides direct evidence for human consumption. We report pierced land snails from the Haua Fteah, Libya. The earliest pierced land snail shell in the Haua Fteah pre-dates the Last Interglacial, while the most recent is Late-Classical in age, but the largest quantities are in layers of Late-Glacial and earliest Holocene age, where they are associated with atypical microliths which may have been used to pierce shells to enable easy extraction of the animal.

Sedimentation, re-sedimentation and chronologies in archaeologically-important caves: problems and prospects

Excavations in the photic zones of caves have provided cornerstone archaeological sequences in many parts of the world. Before the appearance of modern dating techniques, cave deposits provided clear evidence for the antiquity, relative ages and co-occurrence of ancient human remains, material culture and fauna. Earlier generations of archaeologists had generally rather limited understanding of taphonomic and depositional processes, but the twentieth century saw considerable improvement in excavation and analytical techniques. The advent of modern dating and chronological methodologies offers very powerful tools for the analysis of cave fill deposits and this has resulted in the recognition of chronological incoherence in parts of some sites, with consequent re-evaluation of previous archaeological disputes. Obtaining multiple dates per context provides a means to assess the integrity and coherence of the archaeological and environmental records from cave fills. In the case of the Haua Fteah (Libya), this technique allowed the recognition of chronological coherence in low-energy depositional environments and limited recycling in high-energy contexts. We provide a conceptual model of the relationship between recycling, sedimentation rate and process energy. High-resolution investigation enables recognition of the complexity of the formation of cave sequences, thus an increasingly sophisticated understanding of human behaviour and environmental relationships in the past, and potentially gives a new life to old data.