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Jaouadi S.,UMR | Lebreton V.,UMR | Bout-Roumazeilles V.,Lille University of Science and Technology | Siani G.,University Paris - Sud | And 6 more authors.
Climate of the Past | Year: 2016

Pollen and clay mineralogical analyses of a Holocene sequence from Sebkha Boujmel (southern Tunisia) trace the climatic and environmental dynamics in the lower arid bioclimatic zone over the last 8000 years. During the mid-to late Holocene transition, between ca. 8 and 3 ka BP, a succession of five wet-dry oscillations is recorded. An intense arid event occurs between ca. 5.7 and 4.6 ka BP. This episode marks the onset of a long-term aridification trend with a progressive retreat of Mediterranean woody xerophytic vegetation and of grass steppes. It ends with the establishment of pre-desert ecosystems around 3 ka BP. The millennial-scale climate change recorded in the data from Sebkha Boujmel is consistent with records from the south and east Mediterranean, as well as with climatic records from the desert region for the end of the African Humid Period (AHP). Eight centennial climatic events are recorded at Sebkha Boujmel and these are contemporary with those recorded in the Mediterranean and in the Sahara. They indicate a clear coupling between the southern Mediterranean and the Sahara before 3 ka BP. The event at 4.2 ka BP is not evidenced and the link between events recorded in Sebkha Boujmel and the North Atlantic cooling events is clearer from ca. 3 ka BP onwards. These variations indicate the importance of climatic determinism in the structuring of landscapes, with the establishment of the arid climatic conditions of the late Holocene. It is only from ca. 3 ka BP onwards that the dynamic of plant associations is modified by both human activity and climatic variability. The climatic episodes identified during the historic period indicate strong regionalisation related to the differential impact of the North Atlantic Oscillation (NAO) and the Mediterranean Oscillation (MO) on the Mediterranean Basin. The local human impact on regional ecosystems is recorded in the form of episodes of intensification of pastoral and/or agricultural activities. The development of olive production and of several taxa associated with agriculture attest to increasing sedentism among human populations during classical antiquity. The significant increase in Artemisia (wormwood) between ca. 1.1 and 0.8 ka BP (850-1150 AD) is linked to intensive pastoral activity, associated with heightened interannual and/or seasonal climatic instability. A complete reshaping of the landscape is recorded during the 20th century. The remarkable expansion of the olive tree, and the deterioration of regional ecosystems with the spread of desert species, is linked to recent local socio-economic changes in Tunisia. © 2016 Author(s).


Hassairi H.,National Engineering School of Tunis | Khosrof S.,Institute National du Patrimoine | Triki E.,National Engineering School of Tunis
Applied Physics A: Materials Science and Processing | Year: 2013

An archaeological bronze artefact was a Punic coin excavated from the north east of Tunisia in 2001. The composition of the copper alloy revealed a content of 3.5 % of tin and 1.4 % of lead with the presence of some sulphur heterogeneity. The surface presents some roughnesses and cracks and is covered by a corrosion layer of 20-40 μm thickness. The use of benzotriazole (BTA) as an inhibitor has become a standard element for the preservation of cuprous-based metals. In order to investigate the behaviour of BTA in an acidic medium, an Electrochemical Impedance Spectroscopy (EIS) investigation was performed to characterize the electrochemical behaviour of the interface of the archaeological bronze sample/acidic medium without and with BTA addition. Impedance diagrams obtained at different immersion times show that the presence of the inhibitor prevents the diffusional process observed in the absence of BTA. The inhibition of the pre-polarized bronze surface revealed that the mechanism of action of the benzotriazole molecule in an acidic medium is governed by the chemisorption process. © 2013 Springer-Verlag Berlin Heidelberg.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-IP | Phase: ENV.2008.3.2.1.1. | Award Amount: 6.56M | Year: 2009

Climate change is one of the most critical global challenges of our time which also threatens cultural heritage. As a non-renewable important resource to the European identity, sustainable adaptation strategies are required for long term preservation. For this purpose and for the first time ever, the CLIMATE FOR CULTURE project will couple completely new high resolution (10x10km) climate change evolution scenarios with whole building simulation models to identify the risks for specific regions. The innovation lies in the elaboration of a more reliable damage assessment by connecting the future climate data with whole building simulation models and new damage assessment functions. In situ measurements at UNESCO sites throughout Europe will allow a much more precise and integrated assessment of the real damage impact of climate change on cultural heritage. Appropriate sustainable mitigation/adaptation strategies, also from previous projects, are further developed and applied on the basis of these findings simultaneously. All these results will be incorporated into an assessment of the economic impacts. In order to ensure an efficient use of resources, this project will build on the results of already concluded EU research projects (Noahs Ark). Techniques from FP5/6 projects will be reassessed for their applicability in future scenarios at different regions in Europe and Mediterranean to fully meet sustainability criteria. The proposed project will thus be able to estimate more systematically the damage potential of climate change on European cultural heritage. The team consists of 27 multidisciplinary partners from all over Europe and Egypt including the worlds leading institutes in climate modelling and whole building simulation. The final achievement of the project will be a macro-economic impact report on cultural heritage in the times of climate change akin to the STERN report which would be a truly European contribution to future IPCC Reports.


Roffet-Salque M.,University of Bristol | Regert M.,CNRS Prehistoric, Antique and Middle Age Studies | Evershed R.P.,University of Bristol | Outram A.K.,University of Exeter | And 67 more authors.
Nature | Year: 2015

The pressures on honeybee (Apis mellifera) populations, resulting from threats by modern pesticides, parasites, predators and diseases, have raised awareness of the economic importance and critical role this insect plays in agricultural societies across the globe. However, the association of humans with A. mellifera predates post-industrial-revolution agriculture, as evidenced by the widespread presence of ancient Egyptian bee iconography dating to the Old Kingdom (approximately 2400 BC). There are also indications of Stone Age people harvesting bee products; for example, honey hunting is interpreted from rock art in a prehistoric Holocene context and a beeswax find in a pre-agriculturalist site. However, when and where the regular association of A. mellifera with agriculturalists emerged is unknown. One of the major products of A. mellifera is beeswax, which is composed of a complex suite of lipids including n-alkanes, n-alkanoic acids and fatty acyl wax esters. The composition is highly constant as it is determined genetically through the insect's biochemistry. Thus, the chemical 'fingerprint' of beeswax provides a reliable basis for detecting this commodity in organic residues preserved at archaeological sites, which we now use to trace the exploitation by humans of A. mellifera temporally and spatially. Here we present secure identifications of beeswax in lipid residues preserved in pottery vessels of Neolithic Old World farmers. The geographical range of bee product exploitation is traced in Neolithic Europe, the Near East and North Africa, providing the palaeoecological range of honeybees during prehistory. Temporally, we demonstrate that bee products were exploited continuously, and probably extensively in some regions, at least from the seventh millennium cal BC, likely fulfilling a variety of technological and cultural functions. The close association of A. mellifera with Neolithic farming communities dates to the early onset of agriculture and may provide evidence for the beginnings of a domestication process. © 2015 Macmillan Publishers Limited. All rights reserved.


Lebreton V.,French Natural History Museum | Jaouadi S.,French Natural History Museum | Mulazzani S.,Aix - Marseille University | Boujelben A.,University of Tunis | And 6 more authors.
Environmental Archaeology | Year: 2015

Pollen analyses from the sebkha-lagoon Halk El Menjel document the vegetation history in Central Tunisia, linked to climate change since the Middle Holocene. Steppes are the main biomes developed under semi-arid conditions between 4965 ± 35 and 3410 ± 40 BP. At 4365 ± 50 BP Pistacia is replaced by Olea and high representation of Olea pollen grains are reported between 4365 ± 50 and 3410 ± 40 BP, illustrating a humid episode at the Mid-to-Late Holocene transition. Thus, the semi-arid area of Central Tunisia could correspond to the native biome for oleasters at the beginning of the Late Holocene. Early olive cultivation is not yet evidenced in the Neolithic sites of the eastern Maghreb, and the Phoenicians are assumed to have introduced olive cultivars in Tunisia. However, an early cultivation of Olea from local native oleaster and dissemination of native cultivars in Central Tunisia can be hypothesised even if it has to be still demonstrated with further archaeological and archaeobotanical evidences. © 2015 Association for Environmental Archaeology.


Mulazzani S.,Aix - Marseille University | Mulazzani S.,University of Rome La Sapienza | Belhouchet L.,Institute National du Patrimoine | Salanova L.,French National Center for Scientific Research | And 8 more authors.
Quaternary International | Year: 2015

This paper is focused on cultural and subsistence changes in North African societies during the Early and Middle Holocene, with a special emphasis on the emergence of a productive economy in the Eastern Maghreb. An overview of Western Mediterranean Neolithic spread is first given in order to verify the trajectories evinced in European and North African contexts as well as the different models for neolithisation recently proposed in both contexts. A chrono-stratigraphical, economical and technological analysis carried out from coastal (SHM-1) and inland (Doukanet el Khoutifa and Kef Hamda) Tunisian sites is then proposed. New AMS dates offer insights on Upper Capsian development as well as on the Neolithic transition during the 9th and 8th millennium cal BP. Information gathered at SHM-1 and Kef Hamda indicates the acquisition of some specific Neolithic features such as decorated pottery in a hunter-gatherer context dated to 8000 cal BP. Data from Doukanet el Khoutifa hint at a Neolithic productive economy from 7400 cal BP based on pastoral activities and integrating the consumption of wild animals and plants, with no evidence for agriculture. These data confirm the specific North African pathways identified in other local contexts, where an active role of Epipalaeolithic groups is at the basis of the Neolithic transition through an acculturation process. © 2015 Elsevier Ltd and INQUA.


Bowen J.W.,University of Reading | Owen T.,Culham Center for Fusion Energy | Jackson J.B.,University of Reading | Walker G.C.,University of Reading | And 6 more authors.
IEEE Transactions on Terahertz Science and Technology | Year: 2015

This paper presents measurements of the terahertz properties of the art conservation substance cyclododecane, demonstrating that it can act as a contrast improving agent in the terahertz imaging of concealed wall paintings. Results are presented which show that the terahertz optical properties of cyclododecane are dependent on the rate at which it has cooled from the melt. Based on the results, a theoretical explanation of the contrast enhancement mechanism is postulated. The findings presented here may lead to the development of novel coating materials that could improve the quality of terahertz images in a variety of fields and not just in art conservation. © 2011-2012 IEEE.


Baklouti S.,Tunis el Manar University | Maritan L.,University of Padua | Casas L.,Autonomous University of Barcelona | Laridhi Ouazaa N.,Tunis el Manar University | And 6 more authors.
Applied Clay Science | Year: 2016

This paper presents the results of the archaeometric study of African Keay 25.2 amphorae from the archaeological site of Sidi Zahruni (Beni Khiar, NE Tunisia), where this pottery was massively produced. A set of 43 amphorae was analysed with a combined approach consisting of thin-section petrography, X-ray powder diffraction (XRPD) and X-ray fluorescence (XRF), to establish a homogeneous reference group for this production. Although all the amphorae are petrographically very similar, three petro-fabrics were identified in terms of grain-size distribution and abundance of inclusions. Detailed digital image analysis, carried out on SEM-BSE images of some representative samples of each petro-fabric, was used to quantify the differences among them. Cluster analysis of XRPD data patterns also revealed groups of samples for which similar raw materials/paste and firing conditions were used, contributing to better assessment of information on the production process. Statistical multivariate treatment (principal component and cluster analyses) of chemical data and comparisons with 10 samples previously attributed to the Sidi Zahruni potteries show that the potsherds analysed here are similar from the geochemical viewpoint. Similar trends in the abundance and ratio of some trace and rare earth elements (REE) also indicate that the Sidi Zahruni amphorae were produced from a local clayey material collected from nearby outcrops of Upper Miocene deposits. © 2016.


Bouchaud C.,Paris-Sorbonne University | Tengberg M.,Paris-Sorbonne University | Pra P.D.,Institute National du Patrimoine
Vegetation History and Archaeobotany | Year: 2011

The discovery of seeds and textiles from Gossypium (cotton) in Achaemenian levels of the mid-6th-late 4th century b. c. at Qal'at al-Bahrain, Bahrain and in early 1st millennium a. d. at Madâ'in Sâlih, Saudi Arabia, reveals the role played by the Arabian Peninsula as a textile production centre during the centuries before and after the beginning of the Christian era. Both these sites were situated on important trade routes, overseas (Qal'at al-Bahrain) and overland (Madâ'in Sâlih), and it is likely that at least part of the cotton production was intended for trade, complementing and perhaps competing with other sources of cotton textiles in the contemporary Middle East. In the arid climate of the Arabian Peninsula, cotton was probably grown in association with irrigated date palm gardens where a wide array of other crops was grown, as is shown by the analysis of charred seeds and wood from occupation levels at both sites. The present article places these particular finds in the larger context of cotton cultivation in the Middle East and India. © 2011 Springer-Verlag.


Belhouchet L.,Institute National du Patrimoine | Mulazzani S.,21 Allee Of Luniversite | Pelegrin J.,21 Allee Of Luniversite
Quaternary International | Year: 2014

The Upper Capsian is an Epipalaeolithic techno-complex occurring in the Maghreb between the 9th and the 8th millennium cal BP, generally associated with the appearance of pressure-knapping bladelet production. The chronology of Capsian sequences based on earlier excavations is uncertain, and studies of lithic industries based on a technological approach are relatively scarce. The site of SHM-1 (Hergla) in east coastal Tunisia has been recently excavated with a stratigraphic protocol. A sequence of seven main layers was detected, all radiocarbon dated. The technological and petrological study applied to the lithic production established on a diachronic basis allowed identification of the main chaînes opératoires involved in bladelet and flake production. The first was obtained through three main schemes, with the pressure bladelet production starting in the first occupational layer, at the first half of the 9th millennium cal BP. Some changes appear between the older layers and recent ones, including the introduction of a more sophisticated pressure mode in the last layers. Detailed examination of the pressure production modes reveals distinctive platform preparation, opening different questions. The pressure bladelets are mainly transformed into backed bladelets, geometric microliths and notches and denticulates. The typological analysis of the armatures reveals an evolution in the raw material selected for some specific tools as well as some changes in the tool types produced. © 2013 Elsevier Ltd and INQUA.

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