Saudi Geological Survey Red Sea Workshop

Description

Investigating the Coastal Archaeology and Raised Coral Terraces of the Southern Red Sea Robyn Inglis, Geoff Bailey, Najeeb Rasul & Bill Bosworth. Global sea level change over the last glacial cycle would have had a massive impact on the position of the coastline of the southern Red Sea. In particular, the shallow continental shelves on the African and Arabian sides of the Red Sea Rift would, at periods of low sea level, have become large exposed plains, with the coastline of the Red Sea shifting over 100 km west of the present-day Saudi Arabian coastline, and the distance between Africa and Arabia reducing to 4 km (Lambeck et al. 2011). These fluctuations in sea level would therefore have had a major impact on the resources available to the populations that inhabited past coastlines in the region, as well as the potential for populations to move between Africa and Arabia. In addition, the sea level history of the Red Sea has played a key role in understanding global sea level change, due to its sensitivity to global sea level change (Siddall et al. 2003), yet our current models of past and future sea level change are developed from limited data and new benchmarks are sorely needed. The Red Sea coastal regions have a long history of occupation, from H. erectus populations with Early Stone Age technology as early as 1.8 million years ago (Zarins et al. 1981; Inglis et al. 2014) to the present day. With evidence from other parts of the world that H. erectus included marine foods in their diet, these and subsequent populations may well have been exploiting the Red Sea coastline as they dispersed from Africa, taking advantage of the range of resources coastlines afford (Erlandson 2001). In more recent prehistory, Stone Age populations on the Farasan Islands, Saudi Arabia, specifically targeted the marine resources available around the archipelago, accumulating over 3000 shell mounds dated to 6000–4000 years ago (Meredith-Williams et al. 2014). Yet in order to understand and assess the role of coastlines in these occupations and dispersals, finer-resolution understanding of sea level change is needed. The Southwestern coastline of Saudi Arabia is an ideal laboratory to examine past sea level change and its impact on past populations as this rich archaeological record is juxtaposed with a number of palaeoshoreline benchmarks in the form of fossil coral benches and marine terraces preserved above present-day sea level. In November–December 2014, the Saudi Geological Survey and an international team of researchers undertook a survey of palaeoshoreline features and raised coral terraces in the Harrat al Birk, Asir Region and the Farasan Islands, Jizan Region, collecting samples of fossil coral and basalt for U-series and Ar/Ar dating respectively in order to constrain the history of local sea level change. The Farasan Islands, 70 km from the present-day Saudi Arabian coastline, are an archipelago of islands formed through uplift driven by salt tectonics. These mechanisms have created a range of different topographies and a pattern of faulting that has seen areas of the islands uplifted by tens of metres. The islands themselves are largely capped by fossilised coral reef, and it is upon this surface that the shell mounds are located (Meredith-Williams et al. 2014). Dating of the coral therefore would enable a further understanding of the local salt tectonics and hence development of the archipelago, and its complex landscape, over time. Twenty-five samples for U-series dating were removed from 15 locations, and shoreline features recorded using DGPS. On the mainland of southwestern Saudi Arabia, Asir Region, the present-day coastline of the Harrat al Birk lava field contains extensive coral terraces and marine deposits overlying the lava flows. Under threat of imminent destruction due to rapid development of the region, these terraces have been surveyed by the DISPERSE project in collaboration with the SCTH between 2012 and 2015, a survey that has recovered artefacts with Early, Middle and Later Stone Age affinities, some associated with, and stratified beneath, these deposits (Inglis et al. 2014; Bailey et al. 2015). The 2014 SGS survey recorded these deposits using DGPS, and sampled these coral terraces for U-Series dating from 9 locations, as well as removing samples of lava for Ar/Ar dating, resulting in 25 dating samples to help in constraining the age of the palaeoshorelines, and their potential relationship to the observed archaeology. The 2014 SGS survey sought to record and exploit a key record of past sea level before it was destroyed by rapid coastal development. In detailed recording of these palaeoshoreline features, and recovering multiple samples for U-series dating, it is hoped that the resulting finer-resolution understanding of local sea level change can be used both to understand human-coastline interactions throughout prehistory, as well as contributing benchmarks for sea level change in the Red Sea that can be used to refine models of past and future sea level change. References Bailey GN, Devès MH, Inglis RH, Meredith-Williams MG, Momber G, Sakellariou D, et al. (2015) Blue Arabia: Palaeolithic and underwater survey in SW Saudi Arabia and the role of coasts in Pleistocene dispersals. Quaternary International 382: 42-57. Erlandson JM (2001) The Archaeology of aquatic adaptations: Paradigms for a new millennium. Journal of Archaeological Research 9(4): 287-350. Inglis RH, Sinclair A, Shuttleworth A, Alsharekh A, Al Ghamdi S, Devès M, et al. (2014) Investigating the Palaeolithic landscapes and archaeology of the Jizan and Asir regions, southwest Saudi Arabia. Proceedings of the Seminar for Arabian Studies 44: 193-212. Lambeck K, Purcell A, Flemming NC, Vita-Finzi C, Alsharekh AM, Bailey GN (2011) Sea level and shoreline reconstructions for the Red Sea: isostatic and tectonic considerations and implications for hominin migration out of Africa. Quaternary Science Reviews 30(25-26): 3542-3574. Meredith-Williams MG, Hausmann N, Bailey GN, King GCP, Alsharekh A, Al Ghamdi S, et al. (2014) Mapping, modelling and predicting prehistoric coastal archaeology in the southern Red Sea using new applications of digital-imaging techniques. World Archaeology 46(1): 10-24. Siddall M, Rohling EJ, Almogi-Labin A, Hemleben C, Meischner D, Schmeizer I, et al. (2003) Sea-level fluctuations during the last glacial cycle. Nature 423: 853-858. Zarins J, Murad A, Al-Yaish K (1981) The second preliminary report on the Southwestern Province. Atlal 5: 9-42. ---------- Landscape Survey, Palaeolithic Archaeology and Coastline Change in Southwestern Saudi Arabia Anthony Sinclair & Robyn Inglis The dispersal of hominin populations has been the most significant factor affecting the timing and development of human history. For early history, there is no more important dispersal than that of hominin populations from Africa into Eurasia, yet despite its significance the timing, mechanisms, places and conditions for these early dispersals remain poorly understood, although it is now the subject of intense contemporary research. In order to understand effectively the dispersal of hominin populations we need good evidence for human presence, the nature of their activities and the possible size and structure of human populations for both their original area from which they dispersed and the area into which they moved. We also need a clear understanding of the features of their new environment that might have drawn populations to it, and of the problems or challenges at any place and time that may have impeded their movement. A key region for investigating the dispersal of human populations out of Africa is the Arabian Peninsula and its surrounding coastal regions. Situated between Africa and Eurasia, the Peninsula represents a first potential place into which hominins might have dispersed from Africa perhaps as early as 2 million years ago. Within Arabia, we can reasonably presume that the first hominin populations first dispersed into the southwestern coastal region, that is closest to Africa and was probably much more environmentally hospitable that in the present day. The fluctuating sea levels of the Red Sea, and the constant oscillations of the Quaternary environment presented great opportunities for human expansion into Arabia as well as significant challenges in the availability of resources. The Southern Red Sea and the coastal landscapes that surround it hold a crucial part of this story of early dispersal. During periods of low sea level, the width of the Sea's southern opening reduced to 4 km at the Bab el Mandab/Hanish Sill (Lambeck et al. 2011), allowing populations to move between the continents. The Red Sea itself may have provided marine resources to exploit, making the coastline an attractive region for settlement, and the physical topography of the Western coast, with the Arabian Escarpment rising to over 3000m, and lying in the path of monsoons would potentially have created a region that was more buffered from environmental changes than the interior that became hyper arid during glacial periods (Parker 2009). As a result of the pioneering research of the Comprehensive Archaeological Survey Program of the Kingdom of Saudi Arabia, the potential for the Arabian Peninsula to provide good archaeological evidence of early human presence and dispersal into the southwestern region has been well known (Whalen et al. 1989; Zarins et al. 1981; Petraglia and AlSharekh 2008; Petraglia 2003). However, it is only recent developments in landscape surveying using satellite imagery and GPS, in archaeological analysis allowing the reconstruction of the processes of lithic exploitation and transport, in underwater surveying allowing a mapping and exploration of submerged but once accessible landscapes, and, finally, the understanding of active tectonic landscapes and their processes of change that offer a new opportunity for addressing more fully hominin dispersals from Africa into Arabia and beyond. Between 2012 and 2015, the DISPERSE project has undertaken field surveys in the Jizan and Asir regions, southwestern Saudi Arabia, recording the location, geomorphological setting and techno-typological characteristics of over 3,000 lithic artefacts in order to extend and better understand the rich record of the southern Red Sea coastal regions on land (Bailey et al. 2015; Inglis et al. 2014). Spanning the Early to Later Stone Ages, artefacts discovered and recorded during this survey provide evidence of the extent and range of hominin movement across this landscape from at least 1 million years ago. In two places, the discovery and interpretation of very large assemblages from in situ deposits open up a real potential for reconstructing the range of technological activities undertaken by early hominin communities. The interpretation of this surface record, and its implications for understanding landscape use by the populations that inhabited it, is not straightforward. Landscapes have changed through time, and the resources within them change through time with environmental change alongside the geomorphological processes. This is most starkly illustrated by the movement of coastlines over tens of kilometres with sea level change. Geomorphological processes also transform the archaeological record that we can survey and record today, with artefacts being buried or revealed through erosion, altering their spread across a landscape, and potentially the interpretations based upon their distributions. Archaeological surveys within the DISPERSE project, therefore, also employ geomorphological investigations at a range of scales, from the use of satellite imagery to detailed observations and dating of features to address the potential biases that might result from changes in the landscape over time. This paper presents an overview of the DISPERSE landscape survey carried out between 2012 and 2015 in the coastal regions of the southern Red Sea. It briefly outlines the methods employed to target and focus the survey using remote sensing and satellite imagery, and the results of the geoarchaeological survey. It provides some preliminary interpretations of the patterning of artefacts across the landscape, and the potential implications these patterns have for use of the landscape by hominin populations. These implications are then reviewed in light of the wider debates surrounding the dispersal of hominin populations from Africa into Arabia and the rest of the world. References Bailey GN, Devès MH, Inglis RH, Meredith-Williams MG, Momber G, Sakellariou D, et al. (2015) Blue Arabia: Palaeolithic and underwater survey in SW Saudi Arabia and the role of coasts in Pleistocene dispersals. Quaternary International 382: 42-57. Inglis RH, Sinclair A, Shuttleworth A, Alsharekh A, Al Ghamdi S, Devès M, et al. (2014) Investigating the Palaeolithic landscapes and archaeology of the Jizan and Asir regions, Southwest Saudi Arabia. Proceedings of the Seminar for Arabian Studies 44: 193-212. Lambeck K, Purcell A, Flemming NC, Vita-Finzi C, Alsharekh AM, Bailey GN (2011) Sea level and shoreline reconstructions for the Red Sea: isostatic and tectonic considerations and implications for hominin migration out of Africa. Quaternary Science Reviews 30(25-26): 3542-3574. Parker AG (2009) Pleistocene climate change in Arabia: Developing a framework for Hominin dispersal over the last 350 ka. In: Petraglia MD, Rose JI (eds) The Evolution of Human Populations in Arabia. Springer: 39-49. Petraglia MB (2003) The Lower Palaeolthic of the Arabian peninsula: occupations, adaptations and dispersals. Journal of World Prehistory 17(2): 141-179.

Period	14 Feb 2016 → 17 Feb 2016
Event type	Workshop
Location	Jeddah, Saudi ArabiaShow on map