Human resilience to Lateglacial climate and environmental change in the Scheldt basin (NW Belgium)

Human resilience to Lateglacial climate and environmental change in the Scheldt basin (NW Belgium)

Quaternary International xxx (2015) 1e14 Contents lists available at ScienceDirect Quaternary International journal homepage: www.elsevier.com/locat...

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Quaternary International xxx (2015) 1e14

Contents lists available at ScienceDirect

Quaternary International journal homepage: www.elsevier.com/locate/quaint

Human resilience to Lateglacial climate and environmental change in the Scheldt basin (NW Belgium)  a, *, Erick Robinson a, b Philippe Crombe a b

Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, 9000 Gent, Belgium Department of Anthropology, University of Wyoming, 1000 E. University Ave., Laramie, WY 82071-3431, USA

a r t i c l e i n f o

a b s t r a c t

Article history: Available online xxx

Recent palaeoenvironmental analyses in the Scheldt basin in NW Belgium have identified significant hydrological and vegetation changes between Greenland Interstadial-1b (GI-1b) and Greenland Stadial-1 (GS-1)/Younger Dryas (YD) that enable us to develop hypotheses to explain the radical changes in landuse and lithic technology observed between the Federmesser and post-Federmesser occupation of the region. The highly productive lacustrine environments of the lower Scheldt basin during the Allerød enabled relatively high population packing by Federmesser groups exploiting the region within a residential mobility system. Federmesser assemblages indicate a flexible lithic technology centered on the production of unstandardized blades and flakes that were intensively backed to shape various tool forms. The destabilization of these landscapes in the Scheldt basin between GI-1b and GS-1/YD, and the ensuing cold of the YD, changed the composition of important secondary biomass from less mobile ungulate species to seasonally mobile reindeer populations. Human populations were resilient to these changes by developing a highly standardized (micro)blade technology and microlithic toolkit. © 2015 Elsevier Ltd and INQUA. All rights reserved.

Keywords: Hunteregatherers Land-use Mobility Climate change Lithic technology Federmesser Culture Late Glacial

1. Introduction As a result of intensive interdisciplinary research over the past decades, numerous Lateglacial sites have been detected and studied in the basin of the Scheldt River in NW Belgium. One of the most important observations is the marked contrast in site density between the Federmesser Culture, generally dated to the Allerød, and the Younger Dryas/early Preboreal (YD/PB) occupations. The former is represented by numerous sites, which often cluster in extensive  et al., 2011, 2013), while only few sites are site-complexes (Crombe  et al., 2014a). Recent currently known from the YD/PB (Crombe palaeoenvironmental research has provided detailed information on landscape changes that help us move toward starting to explain this marked difference in occupation density at the transition from the Lateglacial to the Early Holocene. 2. Regional setting After the Meuse, the Scheldt is the largest river in Belgium with a total length of 430 km, of which 207 km traverses Belgian soils. Its

* Corresponding author. ). E-mail address: [email protected] (P. Crombe

headwaters are situated in northern France and its debouchment is located in the southwest of the Netherlands, where it currently flows into the Westerscheldt (Fig. 1). During prehistory, however, the Scheldt north of Antwerp had a more northern course, joining the estuary of the Rhine and Meuse in the central western Netherlands. The Scheldt is fed by numerous tributaries, the most important ones being, from south to north, the Lys, the Kale/Durme, the Dendre and the Rupel. The total catchment area amounts to 21,863 km2, subdivided into the Upper Scheldt basin (from source to Ghent) and the Lower Scheldt basin (from Ghent to its debouchment). Within the floodplains of the Scheldt and its tributaries numerous large fossil Lateglacial oxbows occur, flanked by series of small but elongated scroll-bars and river-dunes (Fig. 2). The latter geomorphological features were preferred settlement locations during different prehistoric periods. The area of the Upper Scheldt basin, called “the Flemish Ardennes”, is a hilly upland consisting mainly of tertiary hills with a maximum height of 157 m above present sea-level. The quaternary cover mainly consists of loam and sandy loam deposited during the Pleniglacial, forming thick packets in the valley bottoms and on ancient river terraces. On the hilltops, on the other hand, the Pleistocene cover is generally thin (<1 m), partly due to erosion, allowing tertiary sediments to outcrop. The topography along the

http://dx.doi.org/10.1016/j.quaint.2015.10.116 1040-6182/© 2015 Elsevier Ltd and INQUA. All rights reserved.

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Fig. 1. The Scheldt basin with the distribution of Federmesser Culture (stars) and YD sites (dots).

northern Lower Scheldt basin is much less pronounced (Fig. 3). This area corresponds to a typical lowland area with numerous sand ridges formed by a local reworking of coversands mainly during the  late Pleniglacial and Lateglacial cold phases (Heyse, 1979; Crombe et al., 2012). These ridges are generally relatively small and elongated, except for the massive dune-complex known as the Great Sand Ridge of Maldegem-Stekene, which runs over the sandy lowland from west to east over a distance of ca. 80 km (Fig. 3). In between these coversand dunes numerous Lateglacial palaeolakes and fossil dune-slacks occur, the borders of which were frequently occupied by prehistoric societies. The dune-slacks, also called “blowouts”, were created as a result of local deflation of coversands down to the groundwater table, while the palaeolakes, all occurring along the steep southern side of the Great Ridge, correspond to local depressions in which surface and groundwater that were blocked by this massive ridge accumulated (De Moor, 1963; De  et al., 2013). Moor and Heyse, 1978; Heyse, 1983; Crombe In the northern and western extremes, resp. in the Scheldt Polders and Coastal Polders, the Pleistocene landscape is covered by Holocene peat and (peri)marine deposits, protecting prehistoric , 2005, 2006). sites from erosion and destruction (Crombe 3. Materials and methods 3.1. Palaeoenvironmental analyses The Scheldt valley, in particular its lower course and tributaries, especially the Kale/Durme, has been studied intensively in the last decades in the context of both academic and developer-led (“commercial”) research. Different aspects of the Lateglacial and

Early Holocene palaeolandscapes have been investigated, allowing for a rather detailed reconstruction of the palaeovegetation through the study of pollen and plant macroremains (Verbruggen, 1971; Verbruggen et al., 1996; Deforce et al., 2005, 2011; Perdaen et al., 2011; Bos et al., 2013), as well as geomorphology and palaeohydrology (De Moor, 1963; Vanmaercke-Gottigny, 1964; Tavernier and De Moor, 1974; Heyse, 1979; Kiden, 1989, 1991; Bogemans et al., 2012). In addition, the chronological framework of the Lateglacial and Early Holocene landscape evolution is well  et al., 2012; documented by numerous radiocarbon dates (Crombe  et al., 2014b) and a limited number Meylemans et al., 2013; Crombe of OSL dates from aeolian sediments (Bogemans & Vandenberghe, 2011; Derese et al., 2010). 3.2. Archaeological dataset The Scheldt basin has been the subject of extensive archaeological research, including surveys (field-walking, aerial photography, augering, test-pitting) and excavations, some of which have covered very large surfaces, e.g. Doel “Deurganckdok”(ca. 8000 m2), Oudenaarde “Donk” (ca. 3000 m2), Verrebroek “Dok” (ca. 6000 m2). However, the research intensity has varied considerably between the different subregions of the Scheldt basin, resulting in somewhat biased distribution maps. Research into the Lateglacial (Final Palaeolithic) and Early Holocene (Mesolithic) archaeology has been most intensive in the coversand lowland corresponding to the Lower Scheldt basin. Systematic field walking in large parts of this area conducted mainly by avocational archaeologists from the ‘80s  et al., 2011) has led to the discovery of numeronwards (Crombe ousdalbeit mostly destroyed (ploughed)dsites located on dry

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Fig. 2. Above: Late Glacial palaeomeanders along the Lower-Scheldt and Lower-Lys Rivers. A. Palaeomeanders with fossil scroll-bars; B. River dunes; C. Present-day rivers. Below: Detail of the Lateglacial palaeomeander of Overmere-Donk: 1. Border of the Lateglacial floodplain; 2. Fossil Lateglacial river channel; 3. Scroll-bars; 4. Present-day river bed; 5. River dunes; 6. Altitude in m TAW (from Kiden and Verbruggen, 2001, with permission).

coversand ridges. Surveys of the river floodplains, on the other , 2006; hand, only started in the late 90s (Bats et al., 2006; Crombe Bats, 2007; Meylemans et al., 2013), yielding the first covered prehistoric sites in the valley of the Scheldt and its tributaries. Some of these have been excavated in the framework of large

, 2005), water infrastructural works, e.g. harbor expansion (Crombe management projects (Perdaen et al., 2011; Meylemans et al., 2013) and sand extraction (Parent et al., 1986/1987). Lateglacial and Early Holocene archaeological research in the southern upland started already in the late 19th century but focused almost exclusively on

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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 et al., 2011). Fig. 3. Map of the sandy lowland along the Lower-Scheldt showing the main landscape features (Crombe

dryland locations, with a special interest for the hilltops and pla, 1989). Investigation of the valley bottoms and river teaus (Crombe terraces has only been initiated recently and hence remains limited thus far to occasional projects, e.g. at Spiere, Kerkhove, Oudenaarde, and Ename. 4. Results 4.1. Environmental evidence Recent palaeoenvironmental studies have identified two important changes that occurred in the timespan of the late Allerød (GI-1b,a, or Greenland Interstadial-1b,1a) and the transition to the YD (GS1, or Greenland Stadial-1). The first change was an abrupt and significant decrease in the water level of rivers and lakes within the Scheldt basin. Detailed interdisciplinary investigations of two freshwater lakes e the ca. 25 km2 large  Moervaart lake (Verbruggen, 1971; De Smedt et al., 2012; Crombe et al., 2013, 2014b) and a much smaller lake (ca. 7 ha) at Snellegem (Denys et al., 1990, 1998) e and several dune-slacks (Deforce et al.,  et al., 2012; Bos et al., 2013) 2005; Derese et al., 2010; Crombe have revealed a synchronous environmental evolution (Fig. 4). At the transition from the Bølling (GI1-1e) to the Allerød (GI1-1c) swamps that were formed in these local depressions gradually turned into shallow ponds and lakes, probably as a result of increased precipitation and local seepage. In the course of the Allerød the water level in these depressions gradually increased, interrupted by periodic drops in water levels (Denys et al., 1990, 1998; Louwagie and Langohr, 2005; Bos et al., 2013), and attained their highest level during the Pinus stage of the Allerød (from ca. 13,300/13,400 cal BP onwards) (Demiddele et al., submitted for publication; Verbruggen, 1979). During this process, calcareous gyttja or lake marl was deposited at the bottom of the lakes, which was likely caused by a strong leaching of carbonates from the adjacent coversand ridges under continental conditions. In the dune-slacks, on the other hand, strongly organic

to peaty sediments were formed in (sub)aquatic conditions (Louwagie and Langohr, 2005; Bos et al., 2013). Near the end of the Allerød, sedimentation in several lakes shifted from lake marl to  et al., 2013), while the peat (Denys et al., 1990, 1998; Crombe  et al., dune-slacks were in-filled with drifting sands (Crombe 2012; Bos et al., 2013), indicating a marked drop of the ground water level in the sandy lowland region. Lakes suddenly turned into marshy environments while nearly all dune-slacks dried out completely and were covered by thick packets of blown sands  et al., 2012). Recent modeling of available radiocarbon (Crombe  et al., 2012, 2014b) has indicated that this evidence (Crombe important hydrological shift occurred within the timespan of ~13,300/13,250 until 13,150/13,100 cal BP (calibration according to Reimer et al., 2013), which coincides with a short but abrupt cooling event, the Intra-Allerød Cold Period IACP or GI-1b. This event, dated between ~13,350 and ~13,100 cal BP, is well known from the oxygen isotope record of the Greenland ice cores (Blockley et al., 2012) and the Gerzensee Lake record in Switzerland (van Raden et al., 2013). It was most likely triggered by catastrophic meltwater discharge from the Glacial Lake Iroquois out the Hudson Valley to the North Atlantic Ocean (Donnelly et al., 2005), which shut down the global oceanic thermohaline circulation. However, some researchers have doubted whether there is really a link between this specific climatic event and the decrease of regional water tables in the lower Scheldt basin (Denys et al., 1990). According to these researchers, the installation of large stands of pine might have been responsible due to increased evapotranspiration. However, recent work has indicated that the drying out of dune-slacks already occurred before pine expanded (Bos et al., 2013), making this hypothesis less plausible. During the course of the colder YD the water tables in some lakes rose again, indicated by a shift in sedimentation from calcareous gyttja to more minerogenic material (organic silty clay) that likely resulted from increasingly unstable soil conditions as vegetation density was decreasing (Bohncke, 1993, p. 8). In other lakes, e.g. the extensive Moervaart lake, no such proof has been

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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towards a forest-steppe vegetation with a more open, patchy covering of trees, shrubs and herbs. This was accompanied by a gradual replacement of pine by birch. It was not until the start of the early Preboreal that dense woodlands reoccupied the Scheldt basin, with the installation of dense birch forests (AP ¼ 80/90%).

found; here peat apparently continued to grow, demonstrating that the marshy conditions continued into the YD. Similarly, there are no indications for the existence of dune-slacks during the YD; on the contrary, the many blowouts which were created by wind erosion in the course of the YD, many of which are still preserved in the present landscape, do not contain organic sediments at their base. This suggests that they probably never contained water, at least not for long enough periods for the accumulation of organic sediments. A similar major hydrological change has been observed in the Scheldt river (Kiden, 1989, 1991; Bogemans et al., 2012; Meylemans et al., 2013) and some of its tributaries, such as the Kale/Durme  et al., 2013). During the early river (De Smedt et al., 2012; Crombe Allerød a single-channel meandering river system was active in these valleys, which led to the formation of deep and wide channels and very large oxbows, some of which reached 3e4.5 km inland (Fig. 2). The size of these meandering channels and oxbows indicates very dynamic fluvial activity, with discharges 3 to 5 times larger than today (Kiden, 1991). This higher discharge during the early Allerød was probably caused by higher snow meltwater in spring and a less dense vegetation that induced more intensive runoff (Kiden, 1991). Near the end of the Allerød, however, the palaeochannels gradually started to fill-in, first with calcareous gyttya and later with peat, indicating a major decrease in fluvial activity and hence a drop of the groundwater and river-water levels (Fig. 5). The radiocarbon evidence from both the Scheldt and Kale/ Durme rivers (Table 1) demonstrate this hydrological change occurred shortly before ca. 13,100/12,900 cal BP, which was more or less contemporaneous with the drying out of the freshwater lakes and dune-slacks. From that stage onwards river channels gradually evolved from deep, stagnant or slow-running water to shallow, small and marshy streams during the YD and Preboreal (Bogemans  et al., 2013; Meylemans et al., 2013). et al., 2012; Crombe

4.2. Archaeological evidence As a result of intensive surveys at least 30 Federmesser sites are currently known from the Scheldt basin. The majority are (often  et al., 2011); just four sites (Doel, mixed) surface-sites (Crombe Harelbeke, Klein-Sinaai, Verrebroek) have been partially excavated  and Verbruggen, 2002; Crombe , in press). The majority of (Crombe Federmesser sites are situated in the sandy lowlands of the lower Scheldt basin where they often occur clustered along the banks of freshwater palaeolakes and dune-slacks (Fig. 1). At some locations, e.g. along the northern banks of the large Moervaart palaeolake, they constitute extensive site-complexes extending over many ki et al., 2011, 2013) (Fig. 7). This preference for lake lometers (Crombe edges probably relates to the high ecological value of these environments, which made them very attractive for both humans and animals during this period. In this respect, the total absence of Federmesser sites, except for some isolated finds, in the river valleys is highly remarkable. A recent critical analysis of the available , in press) has revealed that palaeoenvironmental evidence (Crombe fluvial erosion and/or later aeolian sedimentation cannot be responsible, at least not entirely. It has been suggested that this apparent absence of occupation is mainly due to the prevailing unstable conditions of the river valleys during the earlier parts of the Allerød. The meandering channels were still migrating laterally as a result of the high fluvial activity, making the floodplains less attractive for settlement. Compared to the river valleys, the sandy

Table 1 Basal dates from meandering channels in different river valleys of the Scheldt basin. Sampling location LOWER SCHELDT Kalken 08A-598 Kalken 08A-563 MIDDLE SCHELDT Ename-Castrum KALE/DURME Mendonk 11A-332 Mendonk 11B-509 Mendonk 11E-250 Wachtebeke “Potdam” Wachtebeke “Penen” Moerbeke “Peerdemeers” Daknam “Broek”

Lab code

BP date

Beta-245744 Beta-245743

11,120 ± 60 10,910 ± 60

Bulk Bulk

Meylemans et al., 2013 Meylemans et al., 2013

???

11,210 ± 50

Bulk

Deforce, 2004

Beta-302747 Beta-302749 Beta-302751 KIA-46185 KIA-47014 KIA-46197 KIA-47433

11,220 10,790 11,110 11,175 11,100 10,565 10,180

Bulk Bulk Bulk Macroremains Macroremains Macroremains Macroremains

Meylemans et al., 2013 Meylemans et al., 2013 Meylemans et al., 2013  et al., 2014b Crombe  et al., 2014b Crombe  et al., 2014b Crombe  et al., 2014b Crombe

A second major environmental change at the transition from the Allerød to the YD was undoubtedly the opening of the landscape, which led to a return of tundra-like vegetation. Many pollen diagrams from lakes and river channels (Fig. 6) show the same pattern of vegetation succession (Verbruggen, 1971, 1979; Verbruggen et al., 1996; Deforce et al., 2005; Bos et al., 2013). In the course of the Allerød trees gradually colonized the landscape, forming in the early stages (GI1-1c) rather open birch (Betula) and willow (Salix) forests that rapidly evolved into mixed birch-pine forest in the later stages (GI1-1b, a). From ca. 13,300 cal BP onwards the dominance of pine (Pinus sylvestris) resulted in almost completely closed forests (AP ¼ 80/90%). In response to the abrupt cooling at the start of the YD tree pollen rapidly decreased to 30/ 40% in most pollen diagrams, which indicates an evolution

Reference

± ± ± ± ± ± ±

50 50 50 45 55 50 70

interior with its lakes and ponds must have been a much more stable, secure, and predictable resource procurement environment. Some isolated finds of Federmesser armatures, however, probably indicate that the Scheldt floodplains were visited by hunteregatherers possibly in the context of hunting activities. Little is known about the absolute chronology of the Federmesser occupation of the Scheldt basin due to a lack of radiocarbon dates. However, the only radiocarbon date from a secured context (11,900 ± 90 uncal BP; UtC-9434) as well as various other diagnostics indicate the presence of these groups from at least the start of the Allerød. This sole radiocarbon date comes from a sample of burned bark associated with a small lithic assemblage at , 2005). the Verrebroek “Dok 2” site (Van Strydonck and Crombe Lithic assemblages at three sitese Doel “Deurganckdok” sector B

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Fig. 4. Reconstruction of two dune-slacks at Rieme during the Bølling (GI-1e), the Older Dryas (GI-1d), and the Betula-phase of the Allerød (GI-1c) (Bos et al., 2013).

 et al., 2000), Verrebroek “Dok 2” (Crombe  et al., 1999; (Crombe , 2005) and Maldegem “Tegelhoogte” (Otte et al., 1984; Crombe  and Verbruggen, 2002) e reveal multiple diagnostics Crombe that have traditionally been attributed to the early Federmesser Culture in western Europe (Bodu and Valentin, 1997; Fagnart, 1997; Fagnart and Coudret, 2000). These assemblages indicate knapping focused on the production of rather regular blade(let)s following intensive preparation of cores, which included frequent platform preparation (high frequency of facetted butts, some of peron” type) and rejuvenation of both platforms and flaking “en e faces (Perdaen et al., 2004). The latter generally resulted in the production of numerous bilateral crested blades. Attribute analysis points to the general use of soft stone hammers, in particular during the plein d ebitage (Perdaen and Ryssaert, 2002; Perdaen et al., 2004). The presence of the early Federmesser in the Scheldt basin is also corroborated by the discovery of some symmetrical double pointed, backed points or bipointes, and points with angled backing at Doel and Maldegem (Fig. 8). However, in terms of overall technology the vast majority of Federmesser lithic assemblages in the Scheldt basin clearly relates to the classic Federmesser tradition, characterized by unipointed backed armatures (Fig. 8) and a much less refined blade technology that focused on the production of irregular unstandardized blade(lets).

Knapping is mainly organized in a unidirectional way, resulting in cores with one striking platform and occasionally cores with two opposed platforms. Core preparation is often limited to the preparation of crested blades that were mainly unilaterally prepared, indicating a shift of edge preparation from the center toward the limits of the exploitation table (Perdaen et al., 2004). Natural ribs formed by frost facets were often used in this process, as well as for selecting platforms. The latter are generally used without further preparation, yielding mainly blanks with flat or cortical butts. Preliminary results also point to a change from soft to hard stone hammer use during the late Federmesser (De Bie, 1999). Besides backed points and blade(lets), the toolkit includes numerous scrapers made mostly on flakes, as well as different types of burins, primarily dihedral burins and burins on truncations. In terms of raw materials, most Federmesser sites from the Scheldt basin display an absolute predominance of local/ regional flint of variable quality. In the sandy lowland most flint comes from local outcrops of tertiary flint, providing small heavily frost weathered nodules. Usually only a small portion of the lithic assemblages (<10%) were produced from higher quality ‘exotic’ flints; the most common of these exotic flint types was a finegrained high quality black flint, often called Obourg-flint, the exact origin of which still remains unknown. A recent

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Fig. 5. Schematic cross-sections of the valley of the Upper-Scheldt (A) and Lower-Scheldt (B). Key: 1. Braided river channel-fill and bar deposits; 2. Fining upward overbank deposits; 3. Aeolian deposits; 4. Lateglacial meandering river lateral accretion deposits forming scroll-bars; 5. Subatlantic meandering river lateral accretion deposits; 6. Gyttja; 7. Peat and clayey peat; 8. Fluviatile clay and silt; 9. Estuarine interdital deposits; 10. Man-made embankments (from Kiden, 1991; with permission).

Fig. 6. Pollen diagram of a small freshwater lake at Snellegem (Verbruggen, 1971; Hoek, 1997).

micropalaeontological analysis using dinoflagellates (Verhoeven, 2002) points to outcrops in western Hainault (Formation of Obourg) and/or in the Meuse valley (Formation of Zeven Wegen). The former is situated at the SE limit of the Scheldt basin, while the latter lies at maximum 120e130 km to the east of the Scheldt

river (Fig. 9a). However, both cases suggest Federmesser lithic raw material procurement ranges were on average not larger than approximately 100 km in diameter. Contrary to the Federmesser occupation, the evidence of YD/PB settlement in the Scheldt basin is very limited (Fig. 1). Currently,

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Fig. 7. The extensive Moervaart palaeolake, showing the position of Federmesser Culture sites along the steep northern lake bank (eastern lake section) and small sandy levees along anastomosing river channels (western lake section).

 et al., only the recently excavated site of Ruien “Rosalinde” (Crombe 2014c) can be securely attributed to the YD on the basis of a single radiocarbon date (10,962 ± 48 BP; RICH-20143) from a stone-built hearth. This small camp-site, situated at the edge of the Lateglacial floodplain of the Upper Scheldt, yielded a lithic assemblage that differs substantially from the preceding Federmesser assemblages in many respects. First, there is a much wider variation in exotic raw

Fig. 8. Evolution of lithic armatures during the Older Dryas/Allerød (early Federmesser Culture), Allerød (classic Federmesser Culture) and YD ((Epi-)Ahrensburgian, (Epi-) Laborian Cultures).

materials, some of which come from distances up to 250 km to the east of the site (Fig. 9b). One of these raw materials is chalcedony, originating from the German Rhineland, which was transported to the site presumably as a unretouched blank. Secondly, there is a clear return to a more elaborate blade(let) technology with a high investment in core preparation (intense platform preparation, numerous crested blades) and rejuvenation in order to obtain and maintain cores with rather sharp angles (mean 71 ) and relatively flat to weakly convex exploitation tables. From these cores regular, narrow (mean 9.77 mm) and thin (mean 2.6 mm) bladelets and occasionally short blades (<6 cm) were struck using a soft stone hammer. The latter is deduced from the predominance of linear (44%) and pointed butts (20%), the frequent occurrence of percussion undulations and butt splinters (30%), and the overall straight  (41%) to slightly concave (38%) profiles of the blade(lets) (Crombe et al., 2014c). These straight and narrow blade(let)s were preferably used to produce microlithic armatures with backed edges and eventually truncated ends (Fig. 8). Unfortunately the high fragmentation rate at Ruien does not allow a further determination of these implements, but there is no doubt that they can all be deemed microliths. In this sense this small assemblage is very similar to the (Epi-)Ahrensburgian Culture, known from the Northern European Plain, which constitutes a variant of the classic Ahrensburgian characterized mainly by the presence of tanged  et al., 2014a). In this context the radiocarbon date points (Crombe from Ruien, situated at the very start of the YD, is highly important as it is one of the earliest dates for the appearance of both microlithic armatures and the production of standardized small and regular blade(lets) with straight profiles typical of the (Epi) Ahrensburgian. A similar set of technological features as those at Ruien were recovered within two other excavated small assemblages along

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Fig. 9. a: Lithic raw material sources during the Allerød (Federmesser Culture). Fine-grained (“Obourg”) black flint from 1. western Hainaut (Formation of Obourg) and/or 2. the  et al., 2011). b: Lithic raw material sources during the Younger Dryas ((Epi-)Ahrensburgian Culture). 1. Chalk flint from Meuse valley (Formation of Zeven Wegen) (based on Crombe  et al., 2014c). Hainaut; 2. Secondary flint from Tienen region; 3. Hesbaye flint; 4. “Chaille du Muschelkalk” 5. Chalcedony; 6. Flint from the Somme-valley (based on Crombe

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the Scheldt floodplain, e.g. at Gent “Tweekerkenstraat” (ca. 1300 artifacts; Ryssaert et al., 2003) and Wichelen “Bergenmeersen” (4379 artifacts; Perdaen et al., 2013). Unfortunately these could not be radiocarbon dated due to an absence of reliable organic remains. The technological affinities between these two sites and Ruien are particularly strong, as both assemblages are dominated by debitage oriented towards the production of regular blade(let)s with straight profiles using a soft stone hammer. The presence of a variety of exotic materials, especially at Gent, including finds of chalcedony (Ryssaert et al., 2003) is a common feature. Further comparison is found in the armatures, which at both sites also consist exclusively of microliths, including mainly obliquely truncated points and a few atypical triangles. The complete absence of microburins here too indicates these armatures were made simply by retouching the edge. A similar armature composition has also been observed at two surface sites along the Moervaart palaeolake e Wachtebeke “Overslagdijk” and “Potdam” (Van Vlaenderen et al., 2006) e in combination with a straight, regular blade(let) technology, numerous burins and Obourg-flint,  and all testifying their Final Palaeolithic character (Crombe  et al., 2013). All of these sites probVerbruggen, 2002; Crombe ably can be classified as (Epi-)Ahrensburgian. Despite these apparent typo-technological similarities with the (Epi-)Ahrensburgian, there is further evidence from the Scheldt basin that suggests comparisons with other cultural traditions during the YD, such as the (Epi-)Laborian culture of France. The connection with this cultural tradition is best indicated by res points (Fig. 8; Langlais finds of diagnostic Malaurie and Blanche et al., 2014). Malaurie points, characterized by a backed edge combined with a truncated base, have been reported on at least 5 Federmesser sites along the Moervaart palaeolake, each yielding one or two specimens at maximum. Unfortunately as they all have been found in the plough-layer, it remains impossible to assess whether these finds indicate actual occupation of the area during the YD, or just reflect ephemeral activities such as hunting. Typical res points are less frequent in the Scheldt basin, but this Blanche could be biased by the greater fragility of these implements. res points are slender points made on narrow and thin Blanche bladelets with straight profile (Naudinot, 2008), which makes them much more vulnerable to breakage than robust Malaurie res points are difficult to distinpoints. As such, broken Blanche guish from Mesolithic microlithic armatures, reducing their visibility in the lithic records. So far the only clear example of a res point was found during the excavation of an Early Blanche Mesolithic site at Evergem “De Nest” (Devriendt et al., 2010). This complete specimen (Fig. 8) was found together with a long blade in high quality flint, presumably originating from the Somme valley in northern France, as well as a limited number (10) of blade fragments, some of which are very regular and straight. Compared to the Federmesser Culture, the evidence for YD/PB occupation of the Scheldt basin is less straightforward, but nevertheless suggests continued but less intensive exploitation of the area. It can be reasonably assumed that more YD sites are present but these remain difficult to distinguish from the early Mesolithic sites given the close similarities of the microlithic component and the high degree of mixture of the surface assemblages. 5. Discussion The radiocarbon date from Ruien at the very beginning of the YD is particularly interesting as it indicates a rather abrupt change to a radically different lithic technology, toolkit, and raw material distribution/utilization. This change centered around the transition from a simplified and flexible technology of unstandardized blades

and flakes that were backed in various ways during the Federmesser period to a highly standardized blade(let) industry based on elaborately prepared and reduced cores and more simply retouched microlithic armatures. This change has been identified as the diagnostic feature of the recently defined “Flat Blades and Bladelets Techno-complex” or FBBT (Naudinot and Jacquier, 2014). The date from Ruien pushes the appearance of the FBBT back to the very beginning of the YD, which enhances the consideration of this techno-complex as a widespread adaptive response to YD climate change. Changes in blade production technologies and toolkit complexity have been widely associated with varying responses to risk (Torrence, 1983, 1989, 2002; Myers, 1989; Bousman, 1993; Bamforth and Bleed, 1997; Eerkens, 1998; Belfer-Cohen and Goring-Morris, 2002; Elston and Brantingham, 2002; Kuhn and Elston, 2002; Collard et al., 2005, 2011, 2013; Read, 2008; Mackay and Marwick, 2011; Jacquier and Naudinot, 2015). Risk has been defined in various ways by previous work, from time stresses based on changes in prey availability (Torrence, 1983; Myers, 1989; Eerkens, 1998), to subsistence risks related to resource capture failure (Torrence, 1989) or general environmental uncertainty and food scarcity (Bousman, 1993), to the probability of artifact failure and the costs of manufacturing and maintaining toolkits (Bamforth and Bleed, 1997). Recent work (Collard et al., 2005, 2011, 2013) has attempted to test the ‘risk hypothesis’ against other hypotheses for the causes of hunteregatherer toolkit diversity and complexity, such as the ‘residential mobility hypothesis’ (Shott, 1986) and the ‘population-size hypothesis’ (Shennan, 2001; Henrich, 2004). A few findings from this recent work are highly informative for considering changes in blade production and toolkits from the Federmesser to the YD/PB. In their first test of the risk hypothesis, Collard et al. (2005) noted that effective temperature (ET) and the natural logarithm of net above ground productivity (LNAGP) were the only proxies that had an influence on toolkit diversity and complexity, which meant that the environmental-risk hypothesis could be supported and the mobility and population hypotheses rejected. In their most recent test, Collard et al. (2013) found just one proxy that impacted toolkit diversity: mean rainfall for the driest month (RLOW). This latter finding highlights the important role that precipitation and hydrology play in the determination of toolkit diversity and complexity, which is precisely what the evidence from the Federmesser-YD/PB suggests. However, despite the Collard et al. (2005, 2011; 2013) rejections of the mobility hypothesis, our evidence for changes in land-use between the Federmesser and YD/PB make it impossible to isolate these changes in mobility from changes that were going on in terms of blade production strategies and the organization of toolkits. For instance, in their discussion of potential reasons for adopting microlithic technologies, Kuhn and Elston (2002, 4) state: In many respects, mobility, subsistence diversification, and the more general notion of risk minimization are really just facets of the same general phenomenon. Analyses of technological responses to risk tend to concentrate on the most direct responses, reduction of either the probability of artifact failure (risk at the point of application) or the “cost” of manufacture and maintenance (Bamforth and Bleed, 1997). However, mobility patterns and subsistence diversification are themselves strategies for managing economic risk. If there are local shortages in high-ranked resources, one solution is to move to another location with the preferred resources … both mobility and resource mixes can have important consequences for the organization of lithic technological systems. The link between risk and technology may be less direct, but the consequences no less strong.

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Furthermore, Read (2008) also found that risk, mobility, and organizational strategy (residential vs. logistic) were the primary determinants of the diversity and complexity of toolkits. Particular insights on the relationships between environmental change and changes in human mobility and lithic technologies can be provided by work specific to changes in microlithic technology. First, in studies of changes from more-toless standardized microlith assemblages in the British Mesolithic, Myers (1989) and Eerkens (1998) found that standardization was related to intercept-based hunting strategies wherein large amounts of microlithic blanks were produced ahead of time. They used the concepts of ‘reliable’ and ‘maintainable’ technologies from Bleed (1986) to propose that these changes toward standardization of microlithic assemblages were reliable technologies, whereas less standardized microliths were associated with encounter-based hunting and more maintainable technologies. A key difference between reliable and maintainable technologies for the question of the changes between the Federmesser and the YD/ PB is that reliable technologies are associated with higher environmental risk and place importance on anticipatory tool component production and the efficient replacement of items within tools (Jacquier and Naudinot, 2015), whereas maintainable technologies are associated with less risk and try to extend the use-life of continuously needed tools by making them more easily repairable (Bleed, 1986; Torrence, 1989; Eerkens, 1998). It is important to note, however, that reliability and maintainability are not mutually exclusive and that some technologies can be designed with both in mind (Bleed, 1986; Myers, 1989; Torrence, 1989; Eerkens, 1998). Another important study for helping us to interpret the situation of the Federmesser-YD/PB transition in the Scheldt basin is Belfer-Cohen and Goring-Morris' (2002) work on the relationships between diachronic changes in the standardization of (micro)blades and changing mobility and settlement patterns in the Levant. In this research they explain changes from highly standardized (micro)blades produced from very formal core reduction schemes to less standardized and variable (micro) blades in which backing was employed to determine the final shape of microlithic armatures. They interpret this change as a shift in focus on different stages in the process of tool production; the Early Upper Palaeolithic microlithic industries were based on ratoire’ where blanks required little a ‘predetermined chaîne ope retouching to be made into their final microlith form, whereas in Epipalaeolithic industries the initial shape of the blank became less important because of the increased role of subsequent backing of the blank to produce the final microlith form. Both the situations highlighted by Myers (1989) and Eerkens (1998) and Belfer-Cohen and Goring-Morris (2002) help us to develop a testable hypothesis for changes in mobility and lithic technology during the late Allerød-YD transition as adaptations of hunteregatherers to climate and environmental change in the Scheldt basin. The highly productive lacustrine environments of the lower Scheldt basin during the Allerød enabled relatively high population packing by Federmesser groups exploiting the region, presumably  et al., 2011). This within a residential mobility system (Crombe residential mobility system was rather restricted in space, as suggested by the predominant use of local raw materials. Federmesser assemblages indicate a flexible lithic technology centered on the production of unstandardized blades and flakes that were intensively backed to shape various tool forms. In this system nodules could be more efficiently utilized because a wider variety of blanks were backed into tools. After the massive hydrological changes caused by GI-1b, these highly productive lake environments dried up and hunteregatherer groups could not continue exploiting the region within relatively packed residential mobility systems. The

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destabilization of these landscapes in the Scheldt basin between GI-1b and GS-1/YD, and the ensuing cold of the YD, changed the composition of important secondary biomass from less mobile ungulate species to seasonally mobile reindeer populations. Human populations were resilient to these changes by developing a highly standardized (micro)blade technology. The hallmark of this new lithic technology was a shift in focus to a different part of the reduction scheme; YD populations focused most of their time and energy on the earlier processes of reduction by heavily preparing blade(let) cores in order to produce blanks of predetermined sizes that could be carried in bulk to a variety of sites with different functions and more efficiently slotted into a diverse range of composite tools. We can therefore consider the resilience of lithic technologies to be the ability to shift focus on particular parts of the reduction process and the cycling back-and-forth over time between moreand-less standardized tool blank production industries. This becomes even more interesting to consider if we extend this assumption to a broader diachronic scale; the next time in the archaeological record in which we see the appearance of highly standardized (micro)blade industries is in the trapeze industries of the Late Mesolithic. Recent assessments of the radiocarbon record for the Mesolithic in the Scheldt basin have indicated that the transition to the Late Mesolithic occurred contemporaneously with the 8.2 ka cold event (Robinson et al., 2013), which was the most significant abrupt climate change event after the YD. Tests of these diachronic relationships between tool blank standardization and human resilience to palaeoclimatic and palaeoenvironmental change will have to await the collection of metric and technological data from sites between the Federmesser and the Late Mesolithic. 6. Conclusion Recent palaeoenvironmental analyses in the Scheldt basin have identified significant hydrological changes between GI-1b and GS1/YD that enable us to develop hypotheses to explain the radical changes in land-use and lithic technology observed between the Federmesser and post-Federmesser occupation of the region. As a fine chronology of the Federmesser occupation in the Scheldt basin is still missing, it is difficult to assess the exact impact of the hydrological shift that clearly occurred in lakes and rivers during the final stage of the Allerød, most likely in response to the abrupt cooling of GI-1b. However, it can be assumed that the effects on the lifeways of hunteregatherers occupying and exploiting the Scheldt basin, especially in the sandy lowland area, must have been considerable. Human populations were likely confronted with a sudden decrease in the availability of open water sources that provided them with drinking water and rich hunting grounds. The abundance of different coprophilous spores suggests that the lakes and dune-slacks were highly frequented by wild game during the Allerød (Bos et al., 2013). Decreasing availability of drinking water undoubtedly impacted the distribution of game in this once abundantly populated region. We can assume that these populations were forced to move to other areas where drinking water was still available, such as the river valleys. While the overall lowered water table would have also impacted the rivers, they were less affected and would have still provided enough drinking water to sustain wild game. These changes in the location of available water for game likely caused alterations in the organization and relative packing of game populations available to human hunters. In this context it is very surprising that Federmesser hunteregatherers during the final Allerød did not move to the banks of the rivers. It is possible that these populations left the Scheldt basin already before the onset of the YD, but this needs further support by means of new excavations yielding new radiocarbon dates.

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

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Nevertheless, it can be expected that as most lakes and dune-slacks disappeared, the sandy interior became much less attractive than before, which forced local hunteregatherer groups to change their land-use and settlement systems in accordance with available drinking water and wild game distributions. Resilience was also necessary at the start of the cold YD. As climate became harsher and vegetation less dense, hunteregatherers apparently shifted to the river valleys. The few occupation sites (Ruien, Wichelen, Gent, Evergem) currently known are all situated along the Scheldt and Kale/Durme, either on scroll-bars or river dunes. At that time these rivers, though already reduced to slow-running and shallow streams, probably represented the only sources of open freshwater for both humans and animals. Although no faunal evidence is available in the Scheldt basin, a return of dominantly arctic fauna during the YD can be expected, replacing the temperate-boreal type of fauna from the Allerød. In the adjacent Meuse valley the Ahrenburgian cave site of Remouchamps, dated from the early to the late YD, faunal remains are dominated by reindeer (Rangifer tarandus) (Charles, 1998). Similarly in the Upper Rhine valley the German Ahrensburgian site of Kartstein yielded mainly reindeer bones (Street and Baales, 1999). Perhaps the settlement of hunteregatherers in river valleys during the YD was also conditioned by the migration routes of reindeers along the rivers. The wellpreserved site of Ruien is actually situated at one of the few bottleneck locations along the right bank of the Upper-Scheldt. In between the Lateglacial floodplain and the steep flanks of the adjacent tertiary hills the passage at this particular location is reduced to an area 2 km wide, which would have made it a strategic spot for hunting migrating herds. In addition, the scarcity of common tools at Ruien might be an indication of a focus on hunting or retooling activities rather than on domestic, everyday activities. However, this remains speculative given the absence of faunal remains and microwear data and our sole reliance on the typo-technological attributes of the lithic assemblage. The latter, however, informs us about major changes in blade(let) production occurring at the very beginning of the YD, and which might be related to the climatic deterioration and associated environmental changes. This hypothesis can be tested and refined in the future by inter-regional lithic analyses that obtain both quantitative and qualitative data enabling robust diachronic comparisons.

References Bamforth, D.B., Bleed, P., 1997. Technology, flaked stone technology, and risk. In: Clark, G.A. (Ed.), Rediscovering Darwin: Evolutionary Theory in Archaeology, Archaeological Papers of the American Anthropological Association, vol. 7, pp. 109e140. Washington D.C. Bats, M., 2007. The Flemish Wetlands: an archaeological survey of the valley of the river Scheldt. In: Barber, J., Clark, C., Cressey, M., Crone, A., Hale, A., Henderson, J., Housley, R., Sands, R., Sheridan, A. (Eds.), Archaeology from the Wetlands: Recent Perspectives, Proceedings of the 11th WARP Conference, Edinburgh 2005. Society of Antiquaries of Scotland, Edinburgh, pp. 93e100 (WARP Occasional Paper 18). , Ph., 2006. Prospectie en waardering van alluviale Bats, M., Bastiaens, J., Crombe gebieden langs de Boven-Schelde, CAI-project 2003e2004. In: Meylemans, M. (Ed.), VIOE-rapporten 02, Centrale Archeologische Inventaris CAI-II “Thematisch inventarisatie- en evaluatieonderzoek”, pp. 75e100. Brussel. Belfer-Cohen, A., Goring-Morris, N., 2002. Why microliths? Microlithization in the Levant. In: Elston, R.G., Kuhn, S.L. (Eds.), Thinking Small: Global Perspectives on Microlithization, Archaeological Papers of the American Anthropological Association, vol. 12, pp. 57e68. Washington D.C. Bleed, P., 1986. The optimal design of hunting weapons: mantainability or reliability. American Antiquity 51, 737e747. Blockley, S.P.E., Lane, C.S., Hardiman, M., Rasmussen, S.O., Seierstad, I.K., Steffensen, J.P., Svensson, A., Lotter, A.F., Turney, C.S., Bronk Ramsey, C., INTIMATE members, 2012. Synchronisation of palaeoenvironmental records over the last 60,000 years, and an extended INTIMATE event stratigraphy to 48,000 b2k. Quaternary Science Reviews 36, 2e10.

Bodu, P., Valentin, B., 1997. Groupes  a Federmesser ou Aziliens dans le sud et l'ouest le d’e volution. Bulletin du bassin parisien. Propositions pour un nouveau mode te  Pre historique Française 94, 341e347. Socie Bogemans, F., Vandenberghe, D., 2011. OSL dating of an inland dune along the lower River Scheldt near Aard (East Flanders, Belgium). Netherlands Journal of Geosciences 90 (1), 23e29. Bogemans, F., Meylemans, E., Jacobs, J., Perdaen, Y., Storme, A., Verdurmen, I., Deforce, K., 2012. The evolution of the sedimentary environment in the lower River Scheldt valley (Belgium) during the last 13,000 a BP. Geologica Belgica 15 (1e2), 105e112. Bohncke, S.J.P., 1993. Lateglacial environmental changes in the Netherlands: spatial and temporal patterns. Quaternary Science Reviews 12, 707e717. , Ph., 2013. The influence of environBos, J.A.A., Verbruggen, F., Engels, S., Crombe mental changes on local and regional vegetation patterns at Rieme, (NW Belgium): implications for Final Palaeolithic habitation. Vegetation History and Archaeobotany 22, 17e38. Bousman, C.B., 1993. Hunter-gatherer adaptations, economic risk, and tool design. Lithic Technology 18 (1/2), 59e86. Charles, R., 1998. Late Magdalenian Chronology and Faunal Exploitation in the North-Western Ardennes. In: BAR International Series 737. Archaeopress, Oxford. Collard, M., Kemery, M.D., Banks, S., 2005. Causes of toolkit variation among huntergatherer: a test of four competing hypotheses. Canadian Journal of Archaeology 29, 1e29. Collard, M., Buchanan, B., Morin, J., Costopoulos, A., 2011. What drives the evolution of hunter-gatherer subsistence technology? A reanalysis of the risk hypothesis with data from the Pacific Northwest. Philosophical Transactions of the Royal Society B: Biological Sciences 366, 1129e1138. Collard, M., Buchanan, B., O'Brien, M.J., Scholnick, J., 2013. Risk, mobility, or population size? Drivers of technological richness among contact-period western North American hunter-gatherers. Philosophical Transactions of the Royal Society B: Biological Sciences 368, 2012.0412. , Ph., 1989. De couvertes pre - et protohistoriques dans “la region des colCrombe histoire du Nord 6, 15e21. lines”. Cahiers de Pre , Ph. (Ed.), 2005. The Last HuntereGatherereFishermen in Sandy Flanders Crombe (NW Belgium); the Verrebroek and Doel Excavation Projects, Part 1: Palaeoenvironment, Chronology and Features. Archaeological Reports Ghent University 3. Academia Press, Gent. , Ph., 2006. The wetlands of Sandy Flanders (Northwest Belgium): potentials Crombe and prospects for prehistoric research and management. In: Rensinck, E., Peeters, H. (Eds.), Preserving the Early Past. Investigation, Selection and Preservation of Palaeolithic and Mesolithic Sites and Landscapes. Amersfoort, Nederlandse Archeologische Rapporten 31, pp. 41e54. , Ph, 2015. The environmental setting for the Late Glacial recolonization of Crombe the Scheldt basin (NW Belgium) by the Federmesser-gruppen (FMG). In: Grimm, S.B., Mevel, L., Sobkowiak-Tabaka, I., Weber, M.-J. (Eds.), Conference Proceedings “From the Atlantic to beyond the Bug River. Finding and Defining the Federmesser-Gruppen/Azilian” (in press) Mainz (RGZM-Tagungen). , Ph., Verbruggen, C., 2002. The Lateglacial and early postglacial occupation Crombe of northern Belgium: the evidence from Sandy Flanders. In: Eriksen, B.V., Bratlund, B. (Eds.), Recent Studies in the Final Palaeolithic of the European Plain, Proceedings of a UISPP Symposium, Stockholm, 14e17. October 1999. Jutland Archaeological Society, Højbjerg, pp. 165e180. , Ph., Deeben, J., Van Strydonck, M., 2014a. Hunting in a changing enviCrombe ronment: the transition from the Younger Dryas to the (Pre)boreal in Belgium and the southern Netherlands. In: Naudinot, N., Michel, S. (Eds.), Actes du s Pre historique de France, Transitions, Ruptures et Continuite  XXVIIe Congre histoire, Bordeaux-Lez Eyzies, 31 mai-5 juin 2010, pp. 583e604. durant la Pre s pre historique de France). Paris (Congre , Ph., Robinson, E., Van Strydonck, M., 2014b. Synchronizing a late glacial Crombe abrupt cooling event with paleoenvironmental and population changes: case study of the Moervaart paleolake area (NW Belgium). Radiocarbon 56 (2), 899e912. , Ph., Sergant, J., Robinson, E., De Reu, J., 2011. Hunter-gatherer responses to Crombe environmental change during the Pleistocene-Holocene transition in the southern North Sea basin: Final Palaeolithic e Final Mesolithic land use in northwest Belgium. Journal of Anthropological Archaeology 30, 454e471. , Ph., Deforce, K., Langohr, R., Louwagie, G., Perdaen, Y., Sergant, J., Crombe Verbruggen, C., 1999. A small Final Palaeolithic knapping site at Verrebroek “Dok 2” (Flanders, Belgium). Notae Praehistoricae 19, 63e68. , Ph., Van Roeyen, J.-P., Sergant, J., Perdaen, Y., Cordemans, K., Van Crombe Strydonck, M., 2000. Doel “Deurganckdok” (Flanders, Belgium): settlement traces from the Final Palaeolithic and the Early to Middle Neolithic. Notae Praehistoricae 20, 111e119. , Ph., Sergant, J., Verbrugge, A., De Graeve, A., Cherrette , B., Mikkelsen, J., Crombe Cnudde, V., De Kock, T., Huisman, D.J., van Os, B.J.H., Van Strydonck, M., Boudin, M., 2014c. A sealed flint knapping site from the Younger Dryas in the Scheldt valley (Belgium) : bridging the gap in human occupation at the Pleistocene-Holocene transition in W Europe. Journal of Archaeological Science 50, 420e439. , Ph., Van Strydonck, M., Boudin, M., Van den Brande, T., Derese, C., Crombe Vandenberghe, D.A.G., Van den haute, P., Court-Picon, M., Verniers, J., Bos, J.A.A., Verbruggen, F., Antrop, M., Bats, M., Bourgeois, J., De Reu, J., De Maeyer, Ph, De Smedt, Ph, Finke, P.A., Van Meirvenne, M., Zwertvaegher, A., 2012. Absolute dating (14C and OSL) of the formation of coversand ridges

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

P. Crombe, E. Robinson / Quaternary International xxx (2015) 1e14 occupied by prehistoric hunter-gatherers in NW Belgium. Radiocarbon 54 (3e4), 715e726. , Ph., De Smedt, Ph., Davies, N.S., Gelorini, V., Zwertvaegher, A., Langohr, R., Crombe Van Damme, D., Van Strydonck, M., Antrop, M., Bourgeois, J., De Maeyer, Ph, De Reu, J., Finke, P.A., Van Meirvenne, M., Verniers, J., 2013. Hunter-gatherer responses to the changing environment of the Moervaart palaeolake (NW Belgium) during the Late Glacial and Early Holocene. Quaternary International 308/309, 162e177. De Bie, M., 1999. Knapping techniques from the Late Palaeolithic to the Early venin, A. Mesolithic in Flanders (Belgium): preliminary observations. In: The pipale olithique et me solithique. (Ed.), L'Europe des derniers chasseurs e oenvironnement de l’Epipale olithique et du Me solithique, Peuplement et pale me Congre s International UISPP, Grenoble, 18-23/09/1995, Paris, Actes du 5e pp. 189e199. Deforce, K., Gelorini, V., Verbruggen, C., Vrydaghs, L., 2005. Pollen and phytolith , Ph. (Ed.), The Last HuntereGatherereFishermen in analyses. In: Crombe Sandy Flanders (NW Belgium). The Verrebroek and Doel Excavation Projects, vol. I. Ghent University, Gent, pp. 108e126. Archaeological Reports Ghent University 3. Deforce, K., 2011. Middle and Late Holocene vegetation and landscape evolution of the Scheldt estuary. A palynological study of a peat deposit from Doel (NBelgium). Geologica Belgica 14 (3e4), 277e288. Deforce, K., 2004. Rapport palynologisch onderzoek van een fossiele Scheldegeul te Oudenaarde e Stuw (Oudenaarde). Internal Report Ghent University. , Ph., 2015. Diatom-based palaeoecology of a lateDemiddele, H., Finke, P., Crombe glacial palaeolake in the Moervaart area (northwestern Belgium) in relation to its prehistoric use potential. Geologica Belgica (submitted for publication). De Moor, G., 1963. Bijdrage tot de kennis van de fysische landschapsvorming in te  Belge d’Etudes Ge ographie 32, Binnen-Vlaanderen. Bulletin de la Socie 329e433. De Moor, G., Heyse, I., 1978. De morfologische evolutie van de Vlaamse Vallei. De Aardrijkskunde 4, 343e375. Denys, L., Verbruggen, C., Kiden, P., 1990. Palaeolimnological aspects of a LateGlacial shallow lake in Sandy Flanders, Belgium. Hydrobiologia 214, 173e278. Denys, L., Kiden, P., Verbruggen, C., 1998. Opaline concretions in Weichselian Lateglacial lake marl from Flanders, northern Belgium. Journal of Paleolimnology 20, 91e98. , Ph., Van Derese, C., Vandenberghe, D.A.G., Zwertvaegher, A., Verniers, J., Crombe den Haute, P., 2010. The timing of aeolian events near archaeological settlements around Heidebos (Moervaart area, N Belgium). Netherlands Journal of Geosciences 89, 173e186. De Smedt, P., Van Meirvenne, M., Davies, N.S., Bats, M., Saey, T., De Reu, J., Meerschman, E., Gelorini, V., Zwertvaegher, A., Antrop, M., Bourgeois, J., De , Ph., 2012. A multidisciplinary Maeyer, P., Finke, P.A., Verniers, J., Crombe approach to reconstructing Late Glacial and Early Holocene landscapes. Journal of Archaeological Science 40, 1260e1267. , Ph, 2010. EvergemDevriendt, I., Messiaen, L., Bats, M., Laloo, P., Sergant, J., Crombe Nest, Mesolithic habitation in the harbour of Ghent: a preliminary report. Notae Praehistoricae 30, 23e28. Donnelly, J.P., Driscoll, N.W., Uchupi, E., Keigwin, L.C., Schwab, W.C., Thieler, E.R., Swift, S.A., 2005. Catastrophic meltwater discharge down the Hudson Valley: a potential trigger for the Intra-Allerød cold period. Geology 33, 89e92. Eerkens, J., 1998. Reliable and maintainable technologies: artifact standardization and the Early to Later Mesolithic transition in Northern England. Lithic Technology 23, 42e53. Elston, R.G., Brantingham, P.J., 2002. Microlithic technology in northern Asia: a risk minimizing strategy of the Late Paleolithic and Early Holocene. In: Elston, R.G., Kuhn, S.L. (Eds.), Thinking Small: Global Perspectives on Microlithization, Archaeological Papers of the American Anthropological Association, vol. 12, pp. 103e116. Washington D.C. Fagnart, J.-P., 1997. La fin des temps glaciaires dans le Nord de la France. Approches ologiques et environnementales des occupations humaines du Tardiglaarche moires de la Socie  te  Pre historique Française 24. Socie te  ciaire. In: Me historique Française, Paris. Pre Fagnart, J.P., Coudret, P., 2000. Le Tardiglaciaire dans le Nord de la France. In: Valentin, B., Bodu, P., Christensen, M. (Eds.), L'Europe centrale et septentrionale au Tardiglaciaire. Actes de la table ronde internationale de Nemours, 14e16 mai moires du Muse e de Pre histoire d’Ile-de-France 7. Editions APRAIF, 1997, Me Nemours, pp. 111e128. Henrich, J., 2004. Demography and cultural evolution: why adaptive cultural processes produced maladaptive losses in Tasmania. American Antiquity 69, 197e218. Heyse, I., 1979. Bijdrage tot de geomorfologische kennis van het noordwesten van €). In: Brussel (Verhandelingen van de Koninklijke Oost-Vlaanderen (Belgie € 40), Academie voor Wetenschappen, Letteren en Schone Kunsten van Belgie p. 217. Heyse, I., 1983. Preliminary results of the study of a Vistulian Late Glacial drainage pattern in the Scheldt basin (Belgium-Flemish Valley-Moervaart depression). Quaternary Studies in Poland 4, 135e143. Hoek, W.Z., 1997. Late-glacial and early Holocene climatic events and chronology of vegetation development in the Netherlands. Vegetation History and Archaeobotany 6, 197e213. Jacquier, J., Naudinot, N., 2015. Socio economic significance of stone tools recycling, reuse and maintenance at the end of the Lateglacial in Northwestern France. Quaternary International 361, 269e287.

13

Kiden, P., 1989. Temse en de Schelde: de geomorfologische achtergrond. In: Thoen, H. (Ed.), Temse en de Schelde: Van IJstijd tot Romeinen. Gemeentekrediet, Brussel, pp. 13e27. Kiden, P., 1991. The Lateglacial and Holocene evolution of the Middle and Lower river Scheldt, Belgium. In: Starkel, L., Gregory, K.L., Thornes, J.B. (Eds.), Temperate Palaeohydrology. London, pp. 283e299. Kiden, P., Verbruggen, C., 2001. Het verhaal van een rivier: de evolutie van de Schelde na de laatste ijstijd. Publicaties van het Provinciaal Archeologisch Museum van Zuid-Oost-Vlaanderen e site Velzeke, 4. Zottegem, pp. 11e35. Kuhn, S.L., Elston, R.G., 2002. Introduction: thinking small globally. In: Elston, R.G., Kuhn, S.L. (Eds.), Thinking Small: Global Perspectives on Microlithization, Archaeological Papers of the American Anthropological Association, vol. 12, pp. 1e7. Washington D.C. Langlais, M., Bonnet-Jacquement, P., Detrain, L., Valdeyron, N., 2014. Le Laborien : volutif pale olithique du sud-ouest de la ultime sursaut technique du cycle e s France ? In: Naudinot, N., Michel, S. (Eds.), Actes du XXVIIe Congre historique de France, Transitions, Ruptures et Continuite  durant la Pre histoire, Bordeaux-Lez Eyzies, 31 mai-5 juin 2010, Congre s pre historique de Pre  te  Pre historique Française, Paris, pp. 605e622. France. Socie Louwagie, G., Langohr, R., 2005. Palaeo-environment. Pedo-lithostratigraphical , Ph. (Ed.), The Last HuntereGatherereFishermen in analyses. In: Crombe Sandy Flanders (NW Belgium); the Verrebroek and Doel Excavation Projects, Part 1: Palaeo-environment, Chronology and Features, Archaeological Reports Ghent University 3. Academia Press, Ghent, pp. 27e107. Meylemans, E., Bogemans, F., Storme, A., Perdaen, Y., Verdurmen, I., Deforce, K., 2013. Lateglacial and Holocene fluvial dynamics in the Lower Scheldt basin (NBelgium) and their impact on the presence, detection and preservation potential of the archaeological record. Quaternary International 308e309, 148e161. Mackay, A., Marwick, B., 2011. Costs and benefits in technological decision making under variable conditions. In: Marwick, B., Mackay, A. (Eds.), Keeping Your Edge: Recent Approaches to the Organization of Stone Artefact Technology. Archaeopress, Oxford, pp. 119e134. Myers, A., 1989. Reliable and maintainable technological strategies in the Mesolithic of mainland Britain. In: Torrence, R. (Ed.), Time, Energy, and Stone Tools. Cambridge University Press, Cambridge, pp. 78e91. Naudinot, N., 2008. Les armatures lithiques tardiglaciaires dans l’ouest de la France gions Bretagne et Pays de la Loire): proposition d’organisation chro(re ratoire de fabrication. In: Pe tillon, J.-M., et al. (Eds.), noculturelle et chaîne ope olithique supe rieur au Recherches sur les armatures de projectiles du Pale olithique (Colloque C83), Actes du 15e congre s de l’UISPP (Lisbonne, 2006) ¼ Ne P@lethnologie, vol. 1, pp. 250e277. Naudinot, N., Jacquier, J., 2014. Socio-economic organization of Final Palaeolithic societies: new perspectives from an aggregation site in Western France. Journal of Anthropological Archaeology 35, 177e189. otard, J.-M., 1984. Maldegem et le Otte, M., Vandermoere, N., Heyse, I., Le olithique re cent du Nord-ouest Europe en. Helinium XXIV, 105e126. Pale Parent, J.-P., Van der Plaetsen, P., Vanmoerkerke, J., 1986/1987. Prehistorische jagers en veetelers aan de Donk te Oudenaarde. VOBOV-Info 24e25. Perdaen, Y., Ryssaert, C., 2002. The Final Palaeolithic site of Verrebroek Dok 2: a confrontation between debitage-typology, attribute analysis and refitting. Notae Praehistoricae 22, 75e81. , Ph., Sergant, J., 2004. Federmessergroepen in de ScheldePerdaen, Y., Crombe €): technologische variabiliteit binnen een vast polders (Oost-Vlaanderen, Belgie schema. Notae Praehistoricae 24, 81e88. Perdaen, Y., Meylemans, E., Vanholme, N., 2013. Preventief onderzoek in het kader van het Sigmaplan te Wichelen-Bergenmeersen (Oost-Vlaanderen, B). Notae Praehistoricae 33, 75e89. Perdaen, Y., Meylemans, E., Bogemans, F., Deforce, K., Storme, A., Verdurmen, I., 2011. Op zoek naar prehistorische resten in de wetlands van de Sigmacluster Kalkense Meersen. Prospectief en evaluerend archeologisch onderzoek in het gebied Wijmeers 2, zone D/E (Wichelen, prov. Oost-Vl.). Relicta 8, 9e46. Read, D., 2008. An interaction model for resource implement complexity based on risk and number of annual moves. American Antiquity 73 (4), 599e625. Reimer, P.J., Bard, E., Bayliss, A., Beck, J.W., Blackwell, P.G., Bronk Ramsey, C., Buck, C.E., Cheng, H., Edwards, R.L., Friedrich, M., Grootes, P.M., Guilderson, T.P., , C., Heaton, T.J., Hoffmann, D.L., Hogg, A.G., Haflidason, H., Hajdas, I., Hatte Hughen, K.A., Kaiser, K.F., Kromer, B., Manning, S.W., Niu, M., Reimer, R.W., Richards, D.A., Scott, E.M., Southon, J.R., Staff, R.A., Turney, C.S.M., van der Plicht, J., 2013. IntCal13 and Marine13 radiocarbon age calibration curves 0e50,000 years cal BP. Radiocarbon 55 (4), 1869e1887. , Ph., 2013. Radiocarbon Robinson, E., Van Strydonck, M., Gelorini, V., Crombe chronology and the correlation of hunter-gatherer sociocultural change with abrupt palaeoclimate change: the Middle Mesolithic in the Rhine-MeuseScheldt area of northwest Europe. Journal of Archaeological Science 40, 755e763. Ryssaert, C., Perdaen, Y., Van der Bremt, A., 2003. Een verrassende steentijdvondst te Gent-Tweekerkenstraat. Notae Praehistoricae 23, 45e53. Shennan, S.J., 2001. Demography and cultural innovation: a model and some implications for the emergence of modern human culture. Cambridge Archaeological Journal 11, 5e16. Shott, M., 1986. Technological organization and settlement mobility: an ethnographic examination. J. Anth. Res 42, 15e51. Street, M., Baales, M., 1999. Pleistocene/Holocene changes in the Rhineland fauna in a northwest European context. In: Benecke, N. (Ed.), The Holocene History of

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116

14

P. Crombe, E. Robinson / Quaternary International xxx (2015) 1e14

the European Vertebrate Fauna. Modern Aspects of Research, Workshop, 6th to 9th April 1998, Arch€ aologie in Eurasien 6. Verlag Marie Leidorf, Rahden/Westf, Berlin, pp. 9e38. volution du bassin de l'Escaut. In: Macar, P. (Ed.), Tavernier, R., De Moor, G., 1974. L’e volution quaternaire des bassins fluviaux de la Mer du Nord Me ridionale. L’e te  Ge ologique de Belgique, Lie ge, pp. 159e231. Centenaire de la Socie Torrence, R., 1983. Time budgeting and hunter-gatherer technology. In: Bailey, G. (Ed.), Hunter-Gatherer Economy in Prehistory: a European Perspective. Cambridge University Press, Cambridge, pp. 11e22. Torrence, R., 1989. Re-tooling: towards a behavioral theory of stone tools. In: Torrence, R. (Ed.), Time, Energy, and Stone Tools. Cambridge University Press, Cambridge, pp. 57e66. Torrence, R., 2002. Thinking big about small tools. In: Elston, R.G., Kuhn, S.L. (Eds.), Thinking Small: Global Perspectives on Microlithization, Archaeological Papers of the American Anthropological Association, Washington D.C, vol. 12, pp. 179e189. omorphologie de l'Escaut d'Oudenaarde. Vanmaercke-Gottigny, M.C., 1964. La ge Acta Geographica Lovaniensia 3, 443e473. van Raden, U.J., Colombaroli, D., Gilli, A., Schwander, J., Bernasconi, S.M., van Leeuwen, J., Leuenberger, M., Eicher, U., 2013. High-resolution late-glacial chronology for the Gerzensee lake record (Switzerland): d18O correlation between a Gerzensee-stack and NGRIP. Palaeogeography Palaeoclimatology Palaeoecology 391, 13e24.

, Ph., 2005. Features: radiocarbon dating. In: Crombe , Ph. Van Strydonck, M., Crombe (Ed.), The Last Hunter-Gatherer-Fishermen in Sandy Flanders (NW Belgium). The Verrebroek and Doel Excavation Projects, Palaeo-environment, Chronology and Features, vol. 1. Academia Press, Gent, pp. 180e212. Archaeological Reports Ghent University 3. Van Vlaenderen, L., Sergant, J., De Bock, H., De Meireleir, M., 2006. Steentijd€). In: Archeologivondsten in de Moervaartdepressie (Oost-Vlaanderen, Belgie sche Inventaris Vlaanderen Buitengewone Reeks 9. Inventaris en Geografische Analyse, Gent. Verbruggen, C., 1971. Postglaciale landschapsgeschiedenis van Zandig Vlaanderen. Unpublished PhD thesis. Ghent University. Verbruggen, C., 1979. Vegetational and palaeoecological history of the Late-Glacial period in Sandy Flanders (Belgium). Acta Universitatis Ouluensis 82 (3), 133e142. Geol. Verbruggen, C., Denys, L., Kiden, P., 1996. Belgium. In: Berglund, B.E., Birks, H.J.B., Ralska-Jasiewiczowa, M., Wright, H.E. (Eds.), Palaeoecological Events during the Last 15000 Years: Regional Syntheses of Palaeoecological Studies of Lakes and Mires in Europe, Chichester, pp. 553e574. Verhoeven, K., 2002. Herkomstbepaling van silexartefacten uit de prehistorische sites van Doel, Spiere en Oeudeghien, door middel van micropaleontologisch onderzoek met dinoflagellatencysten. Unpublished Master thesis. Ghent University.

, P., Robinson, E., Human resilience to Lateglacial climate and environmental change in the Scheldt Please cite this article in press as: Crombe basin (NW Belgium), Quaternary International (2015), http://dx.doi.org/10.1016/j.quaint.2015.10.116