Dr Ash Parton

Quaternary environments on the Arabian Peninsula shifted between pronounced arid conditions and phases of increased rainfall, which had a profound impact on Earth surface processes. However, while aeolian sediment dynamics are reasonably well understood, there is a lack of knowledge with regard to the variability in the fluvial systems. Presented here are the findings from several locations within wadi drainage systems to the west of the Hajar Mountain (United Arab Emirates). The performance of Optically Stimulated Luminescence (OSL) dating using a customised standardised growth curve approach is investigated, showing that this approach allows reliable determination of ages by reducing the machine time required. Three main periods of fluvial activity are observed at 160-135 ka, 43-34 ka and ca. 20 ka. Further ages fall into the latest Pleistocene and late Holocene. Interestingly, none of the ages coincide with major wet periods in SE Arabia, identified in stalagmites and by the deposition of lake sediments. It is shown that fluvial activity was partly contemporaneous (within the given time resolution) with phases of aeolian deposition and was almost continuously, but likely sporadically, during the Mid-Late Pleistocene. This highlights the need for regionally defined palaeoenvironmental records in order to fully understand the response of dryland systems to long-term climatic change.

Quaternary Paleoenvironmental (QP) sites in Southeast Arabia are important not only to understand the history of global climate change but also to study how ancient humans adapted to a changing natural environment.  These sites, however, are currently missing from conservation frameworks despite reports of destroyed sites and sites under imminent threat.  This study presents the Geocultural Database of Southeast Arabia, the first open-access database on QP sites in this region, created as a comprehensive inventory of regional QP sites and a tool to analyse QP records and archaeological records.  The endangerment assessment of QP sites in this database reveals that 13% of QP sites have already been destroyed and 15% of them are under imminent threat of destruction, primarily due to urban development and infrastructure development. Chronological and spatial analyses of QP and archaeological sites and records highlight the intricate relationship between palaeoenvironment and archaeology and emphasise the need for sub-regional scale studies to understand the variation of climatic conditions within the region, especially to study changes in the ancient human demography.  This database illustrates the potential of a geocultural approach that combines archaeological heritage with Quaternary geoheritage as a way forward for the conservation of QP sites at risk.

Changing climatic conditions are thought to be a major control of human presence in Arabia during the Paleolithic. Whilst the Pleistocene archaeological record shows that periods of increased monsoon rainfall attracted human occupation and led to increased population densities, the impact of arid conditions on human populations in Arabia remains largely speculative. Here, we present data from Jebel Faya in Southeast (SE) Arabia, which document four periods of human occupation between c. 210,000 and 120,000 years ago. The Jebel Faya record indicates that human occupation of SE Arabia was more regular and not exclusively linked to major humid periods. Our data show that brief phases of increased rainfall additionally enabled human settlement in the Faya region. These results imply that the mosaic environments in SE Arabia have likely formed a population refugia at the end of the Middle and the beginning of the Late Pleistocene. 

This paper presents the key findings of a multidisciplinary study investigating the nature and timing of coastal landscape evolution in eastern Saudi Arabia during the Holocene. To date, most sea level reconstructions for the Arabo-Persian Gulf are based on uncalibrated 14C ages without correction for marine reservoir effects, or lack precision with regard to the effects of neotectonic changes, indicators of sea level used, errors in elevation of sedimentary units used, and the relationship with actual tides. As a consequence, the nature and timing of relative sea level (RSL) changes during the Late Pleistocene and Holocene remain poorly understood. To help address this, we use sea level index points (SLIPs) based on calibrated 14C ages to present a RSL curve for the central-southern Gulf of Saudi Arabia from coastal sabkha deposits near the archaeological site of Dosariyah. The sediments record rapid transgression during the early Holocene with a midHolocene high-stand immediately prior to 6880–6560 cal. BP when the upper limit for the palaeo Mean Highest High tide water (MHHW) was 2.8–3.10 m above present day mean sea level. Transgression continued until shortly after 5575–5310 cal. BP with an upper limit to the palaeo-MHHW of 3.75 m above present sea levels. Thereafter a fall in RSL was recorded, with the regression leading to the progradation of the coastal system and the development of coastal sabkhas. Nonetheless later transgressions are recorded in the region between 4848–4536 and 4335–3949 cal BP. Radiometric dating results from archaeological excavations at Dosariyah, one of the most important Neolithic coastal sites in the Gulf, suggest that occupation of the site during the Neolithic coincides with the mid-Holocene marine transgression (ca. 7200 – 6500 cal. BP). Whilst the close proximity of the site to the sea may have facilitated maritime exchange activities, occupation of the site was short-lived and the phase of abandonment occurred during a period of rapid RSL rise, which would have transformed the area around Dosariyah into an island or certainly cut it off tidally from the mainland.

The PalaeoEnvironments and ARchaeological Landscapes (PEARL) research project is a joint German-British project with the principal objective of developing a framework of past human occupation and landscape change in Southeastern Arabia. Fieldwork during 2018 and 2019 involved the systematic survey and excavation of sites in the Rustaq and Ibri regions of Northern Oman, with the aim of establishing the nature and timing of human occupation and landscape change during the Early Holocene period (ca. 10-7,000 years BP). Further to the findings previously reported, results from recent excavations of the site Hayy al-Sarh in Rustaq revealed the presence of animal remains, stone and shell beads and stone structures, indicating a large Neolithic settlement with burial areas. In addition, preliminary excavations at a rock shelter site near Ibri have revealed stratified archaeological remains, including a Fasad type assemblage. Future fieldwork will further develop archaeological and palaeoenvironmental records to help build a framework for studying cultural and natural developments in northern Oman.

The Acheulean is the longest lasting cultural–technological tradition in human evolutionary history. However, considerable gaps remain in understanding the chronology and geographical distribution of Acheulean hominins. We present the first chronometrically dated Acheulean site from the Arabian Peninsula, a vast and poorly known region that forms more than half of Southwest Asia. Results show that Acheulean hominin occupation expanded along hydrological networks into the heart of Arabia from Marine Isotope Stage (MIS) 7 until at least ~190 ka ̶ the youngest documented Acheulean in Southwest Asia. The site of Saffaqah features Acheulean technology, characterized by large flakes, handaxes and cleavers, similar to Acheulean assemblages in Africa. These findings reveal a climatically-mediated later Acheulean expansion into a poorly known region, amplifying the documented diversity of Middle Pleistocene hominin behaviour across the Old World and elaborating the terminal archaic landscape encountered by our species as they dispersed out of Africa.

Records of former lake and wetland development in present day arid/hyper-arid environments provide an important source of information for palaeoclimatic and palaeoenvironmental studies. In Arabia, such records are typically confined to eccentricity-modulated insolation maxima, and are often spatially and temporally discontinuous. Here we present records from a single locality in Northern Arabia of wetter interludes during both global interglacial and glacial conditions, providing a unique opportunity to examine the nature of these events in a common setting. At Jubbah, in the southern Nefud Desert, lake and wetland deposits reveal the repeated formation of a water body within a large endorheic basin over the past ca. 360 kyr. Lake/wetland formation occurred during MIS 11/9, 7, 5, 3 and the early Holocene, assisted by local topographic controls, and spring recharge. Palaeoenvironmental and palaeoecological data reveal the existence of a large still water body formed during either MIS 11 or 9 (ca. 363 ka), and basin wide alluviation followed by lake formation during MIS 7 (ca. 212 ka). During MIS 5e (ca. 130 ka) a large freshwater lake occupied the basin, while during MIS 5a (ca. 80 ka) the basin contained a shallow wetland and freshwater lake complex. Lake/wetland formation also occurred during early MIS 3 (ca. 60 ka), at the Terminal Pleistocene-Holocene transition (ca. 12.5 ka), and the early-middle Holocene (ca. 9-6.5 ka). Phases of lake and wetland development coincided with human occupation of the basin during the Middle Palaeolithic, Epipalaeolithic and Neolithic periods, highlighting the significance of the region for early demographic change.

Despite occupying a central geographic position, investigations of hominin populations in the Arabian Peninsula during the Lower Palaeolithic period are rare. The colonization of Eurasia below 55 degrees latitude indicates the success of the genus Homo in the Early and Middle Pleistocene, but the extent to which these hominins were capable of innovative and novel behavioural adaptations to engage with mid-latitude environments is unclear. Here we describe new field investigations at the Saffaqah locality (206–76) near Dawadmi, in central Arabia that aim to establish how hominins adapted to this region. The site is located in the interior of Arabia over 500 km from both the Red Sea and the Gulf, and at the headwaters of two major extinct river systems that were likely used by Acheulean hominins to cross the Peninsula. Saffaqah is one of the largest Acheulean sites in Arabia with nearly a million artefacts estimated to occur on the surface, and it is also the first to yield stratified deposits containing abundant artefacts. It is situated in the unusual setting of a dense and well-preserved landscape of Acheulean localities, with sites and isolated artefacts occurring regularly for tens of kilometres in every direction. We describe both previous and recent excavations at Saffaqah and its large lithic assemblage. We analyse thousands of artefacts from excavated and surface contexts, including giant andesite cores and flakes, smaller cores and retouched artefacts, as well as handaxes and cleavers. Technological assessment of stratified lithics and those from systematic survey, enable the reconstruction of stone tool life histories. The Acheulean hominins at Dawadmi were strong and skilful, with their adaptation evidently successful for some time. However, these biface-makers were also technologically conservative, and used least-effort strategies of resource procurement and tool transport. Ultimately, central Arabia was depopulated, likely in the face of environmental deterioration in the form of increasing aridity.

Several hundred Middle Palaeolithic (MP) archaeological sites have now been identified in the Arabian Peninsula. However, the study of lithic raw material properties and related procurement behaviours is still in its infancy. Here we describe raw material procurement and early stage lithic reduction at MP sites in the Jubbah palaeolake basin, in the Nefud Desert, northern Saudi Arabia. We describe the sites identified during our surveys, and we use petrographic studies to demonstrate that MP assemblages were mostly produced from differing forms of ferruginous quartzite. These raw materials do not substantially vary in composition, although they are not identical in terms of factors such as grain size and the proportion of iron oxide. We then describe the lithic technology at these sites, with a particular focus on the largest assemblage identified, Jebel Katefeh-12 (JKF-12), which provides detailed information on lithic reduction at a quartzite source. Analyses from this site are then considered together with data from other MP sites in the Jubbah basin, where similar raw material was used. The results indicate that factors such as initial clast size/shape and reduction intensity play important roles in influencing aspects of morphological and technological variability. Our results suggest that incursions of MP populations into northern Arabia were probably temporally limited, as might be expected in a marginal and generally arid region. MP raw material procurement sites provide a highly visible signal of these ephemeral incursions, providing information on the ways that human populations adapted to the challenging conditions of the Saharo-Arabian arid belt.

The Empty Quarter (or Rub' al Khali) of the Arabian Peninsula is the largest continuous sandy desert in the world. It has been known for several decades that Late Pleistocene and Holocene deposits, representing phases of wetter climate, are preserved there. These sequences have yielded palaeontological evidence in the form of a variety of vertebrate and invertebrate fossils and have been dated using various radiometric techniques. However, evidence for human presence during these wetter phases has until now been ephemeral. Here, we report on the first stratified and dated archaeology from the Empty Quarter, recovered from the site of Mundafan Al-Buhayrah (MDF-61). Human occupation at the site, represented by stone tools, has been dated to the later part of Marine Isotope Stage (MIS) 5 using multiple luminescence dating techniques (multigrain and single grain OSL, TT-OSL). The sequence consists primarily of lacustrine and palustrine sediments, from which evidence for changing local environmental conditions has been obtained through analysis of fossil assemblages (phytoliths and non-marine molluscs and ostracods). The discovery of securely-dated archaeological material at ∼100 to 80 ka in the Empty Quarter has important implications for hypotheses concerning the timing and routes of dispersal of Homo sapiens out of Africa, which have been much debated. Consequently, the data presented here fill a crucial gap in palaeoenvironmental and archaeological understanding of the southern Arabian interior. Fossils of H. sapiens in the Levant, also dated to MIS 5, together with Middle Palaeolithic archaeological sites in Arabia and India are thought to represent the earliest dispersal of our species out of Africa. We suggest that the widespread occurrence of similar lithic technologies across southern Asia, coupled with a growing body of evidence for environmental amelioration across the Saharo-Arabian belt, indicates that occupation of the Levant by H. sapiens during MIS 5 may not have been a brief, localized ‘failed dispersal’, but part of a wider demographic expansion.

The Arabian Peninsula is situated at an important crossroads for the movement of Pleistocene human populations out of, and into, Africa. Although the timings, routes and frequencies of such dispersals have not yet been confirmed by genetic, fossil or archaeological evidence, expansion into Arabia would have been facilitated by humid periods driven by incursions of monsoon rainfall, potentially from both Indian Ocean and African monsoon systems. Here we synthesise terrestrial and marine core palaeoclimatic data in order to establish the spatial and temporal variability of humid periods in Arabia between late Marine Isotope Stage (MIS) 7 and 3. Incursions of monsoon rainfall occurred during periods of insolation maxima at ca. 200–190, 170, 155, 130–120, 105–95, 85–75 and 60–55 ka, providing multiple ‘windows’ of favourable climatic conditions that could have facilitated demographic expansion through Arabia. Strong summer monsoons are generally associated with mid-high latitude interglacials, however, enhanced monsoon convection also brought rainfall into Arabia during global glacial phases, possibly due to a strengthened winter monsoon and a greater influence of southern hemispheric temperature changes. Key periods for dispersal into northern regions of Arabia correspond with the synchronous intensification of both eastern Mediterranean and monsoon rainfall systems at insolation maxima during MIS 7 and MIS 5, which may have facilitated demographic connectivity between the Levant and the Arabian interior. Environmental conditions throughout southern and southeast regions were also favourable to expansion during these times, although strong monsoons in these regions during MIS 6 and MIS 3 suggest further opportunities for demographic expansion and exchange. Terrestrial and marine evidence show that during early MIS 3 (ca. 60–50 ka), a strengthened monsoon led to the activation of interior drainage systems and increased productivity in coastal zones, indicating that favourable environmental conditions existed along both coastal and interior routes at that time.

Here, we summarise recent investigations of the fossiliferous locality of Ti's al Ghadah in the southwestern Nefud. Excavations yielded well-preserved fossil bones in a secure stratigraphic context, establishing the potential of this site to make a significant contribution to our understanding of vertebrate diversity and biogeography in the Pleistocene of Arabia. We describe the site and report our preliminary observations of newly-recovered stratified vertebrate remains, at present dated to the Middle Pleistocene, which include oryx (Oryx sp.), fox (Vulpes sp.), and notably stratified remains of the Elephantidae and a grebe (Tachybaptus sp.). Here, we give special attention to post-cranial evidence that confirms the presence of a jaguar-sized pantherine, which we refer to the Eurasian jaguar (Panthera cf. gombaszogensis). The occurrence of this taxon during the Middle Pleistocene has important implications for existing biostratigraphical and biogeographical models and for palaeoecological reconstructions of the southern Nefud at that time.

The dispersal of human populations out of Africa into Arabia was most likely linked to episodes of climatic amelioration, when increased monsoon rainfall led to the activation of drainage systems, improved freshwater availability, and the development of regional vegetation. Here we present the first dated terrestrial record from southeast Arabia that provides evidence for increased rainfall and the expansion of vegetation during both glacial and interglacial periods. Findings from extensive alluvial fan deposits indicate that drainage system activation occurred during Marine Isotope Stage (MIS) 6 (ca. 160–150 ka), MIS 5 (ca. 130–75 ka), and during early MIS 3 (ca. 55 ka). The development of active freshwater systems during these periods corresponds with monsoon intensity increases during insolation maxima, suggesting that humid periods in Arabia were not confined to eccentricity-paced deglaciations, and providing paleoenvironmental support for multiple windows of opportunity for dispersal out of Africa during the late Pleistocene.