This paper focuses on early Holocene rapid climate change (RCC) records in the Mediterranean zone, which are under-represented in continental archives (9.2 to 8.2 ka events) and on their impact on prehistoric societies. This lack of data handicaps the general interpretation of climate impacts on human societies, which flourished in recent years. Key questions remain about the impact of early Holocene cooling events on the Mediterranean climate, ecosystems and human societies. In this paper, we discuss some examples from river and lake systems from the eastern to central Mediterranean area (central Anatolia, Cyprus, northeastern and northwestern Greece) that illustrate some palaeohydrological and erosion variations that modified the sustainability of the first Neolithic populations in this region. Results allow us to present direct land–sea correlations and to reconstruct regional long-term trends as well as millennial- to centennial-scale climatic changes. In this context, we question the socio-economic and geographical adaptation capacities of these societies (mobility, technology, economic practices, social organisation) during the “early Holocene” interval (11.7 to 8.2 ka), which corresponds partly to the Sapropel 1 deposition in the eastern Mediterranean sea.
Expected to have had a large impact on past societies, rapid climate changes (RCCs), which start abruptly within one decade or two at the most (in polar records) and most often concern a period of 150 to 400 years, are often considered one of the main environmental factors causing socio-economic and cultural changes, migrations, and even collapses (Weiss et al., 1993; Cullen et al., 2000; Staubwasser and Weiss, 2006; Weninger et al., 2006). According to this climatic determinism, a RCC would be much harder (if not impossible) for a human society to adapt to, thus leading to radical societal transformations. In the course of this debate, recent and ongoing research on Neolithic societies points to the necessity to focus simultaneously on (i) the economic, socio-cultural, technological and cognitive transformations of the human group living on site(s); (ii) the sharpening of old and new chronological series within the site(s); (iii) the development of contextual analyses associated with geoarchaeological researches; and (iv) investigating, with a high-resolution and multi-proxy approach, the palaeoenvironmental records available in the vicinity of Neolithic sites and their connections with the sites, an approach that is at present poorly utilised. Such an approach and methodology are indeed the most appropriate for reconstructing and interpreting the relationships between environmental and societal event records which have accompanied (or not) a rapid climate change and to better estimate adaptability to changing environments. As a matter of fact, a lack of a RCC signature in the climatic and environmental proxies studied in any sediment record may have several meanings: an incorrect assessment of a signal, an insufficient chronological control, a disconnection between the locus studied and neighbouring areas where sedimentary archives would be more favourable for recording a rapid climate change, etc. These are the reasons why it is often suspected that the absence of signature of a RCC event in continental archives is more often due to the low temporal resolution of the available records rather than the absence of the climatic signal on the local scale. This problematic situation is now increasingly addressed by new results focusing on high-resolution analyses and chronologies, as well as on records linking both the archaeological sites and their surrounding geomorphologic/environmental archives. In this paper, the goal is to highlight the variety of occurrences of early Holocene RCC records using (i) interconnected water-related systems (rivers and wetlands) associated with Neolithic sites in contrasting areas of the eastern Mediterranean Basin and (ii) the characteristics of the main morphogenic and hydrosedimentary responses to RCC on the catchment or lacustro-palustrine scales. We present below four recently investigated continental fieldwork areas where new data have been acquired concerning the 9.5 to 7 ka time span. These data are discussed in the context of their proximity to excavated archaeological sites or regional cultural trends on the regional scale (central Anatolia, Cyprus, eastern Macedonia, Corfu). Using different spatial scales, from the site to the region and from the eastern to the central Mediterranean, the hydrogeomorphic and ecological impacts of these early Holocene RCCs are evaluated, along with their potential impacts on the first Neolithic societies.
During the first half of the Holocene, the eastern Mediterranean regions
experienced a climate regime significantly wetter than today, coherently
indicated by regional marine and terrestrial isotopes (Bar-Matthews et al.,
1997; Roberts et al., 2008; Robinson et al., 2006), the Dead Sea level
maximum (Migowski et al., 2006) and the Sapropel 1 formation period in the
eastern Mediterranean Sea favoured by freshwater high runoff of tropical
monsoonal origin (Rossignol-Strick, 1999; Rohling et al., 2015). During this
period, changes in Mediterranean cyclogenesis would have been potentially
influenced by lower sea surface temperature (SST) and evaporation (Brayshaw
et al., 2011; Rohling et al., 2015). The general trend toward climate
amelioration after the Younger Dryas favoured the development and diffusion
of agriculture from nuclear areas in the eastern Mediterranean (Willcox et al., 2009),
the Levant (Bar-Yosef and Belfer-Cohen, 1989) and Anatolia (Özdoğan,
2011; Kuzucuoğlu, 2014). This early Holocene phase was nevertheless
interspersed by several pluricentennial wetter/drier climatic pulsations.
Compared to today, the climate was then much more sensitive to freshwater
forcing than to solar activity (Teller and Livingston, 2002; Fletcher et al.,
2013). For example, in the Greenland ice cores, three “rapid events” (RCCs)
caused by meltwater pulses are recorded at ca. 10.2, 9.2 and 8.2 ka,
together with at least 11 other similar events documented for the entire
early Holocene (Teller et al., 2002; Fleitmann et al., 2008). In the eastern
Mediterranean, extension of the Siberian anticyclone to the eastern
Mediterranean (regular influx of cold air masses) also played a major role
during the Holocene period. For example, cold air from the Siberian High (SH)
extension created a rapid SST cooling (Rohling et al., 2002)
(Fig. 1). The multi-centennial variability in the GISP2 terrestrial potassium
(K
Northern Hemisphere palaeoclimate/pedosedimentary records
illustrating Holocene rapid climate changes (RCCs): 1, Greenland GRIP
ice-core
The potential impact of the 9.2 ka abrupt climatic event on human societies during the Neolithic “revolution” has rarely been explored (Borrell, 2007; Flohr et al., 2016), in any case much less so than the 8.2 ka event. In this debate, the effects of the worldwide “8.2” climatic event on the Mesolithic and Neolithic societies have been under discussion for a decade, with interpretations varying from abandonment of sites to collapse, and from large-scale migration to sustainability of occupation and social adaptation (for a complete overview, see Gehlen and Schön, 2005; Staubwasser and Weiss, 2006; Weninger et al., 2006, 2014; Berger and Guilaine, 2009; Flohr et al., 2016). Climatic records show that the 8.2 ka event resulted in some of the most extreme environmental perturbations of the Holocene. For this reason, it has often been a subject in the literature since being first discussed (Alley et al., 1997). Extended over a time span of 100–150 years in GISP2-GRIP polar archives (Thomas et al., 2007), its duration has been found to be longer in numerous marine and continental proxies (Fig. 1). In the eastern Mediterranean and other regions, the RCC interval between 8.6 and 8.0 ka spans a longer time period than in the ice record, supporting the idea of an enhanced Siberian high-pressure anticyclone over Asia (Rohling and Pälike, 2005; Weninger et al., 2014) controlling a global intensification of atmospheric circulation with cooler temperatures in polar regions (Mayewski et al., 2004) and drier and cooler conditions in the Mediterranean Basin (Rohling et al., 2002; Bar-Matthews et al., 2003; Fletcher and Zielhofer, 2013; Gómez-Paccard et al., 2016). At the same time, pollen and SST data have been increasingly studied in marine Mediterranean archives in the last 15 years.
In parallel to these ice and marine records, Mediterranean Basin scaled continental records reveal a paucity of evidence of early Holocene RCC. For example, Berger (2015) and Berger et al. (2016) underline episodes of lateral mobility/erosion of rivers and successive entrenchments of active beds, although the period is dominated by a multi-millennium-long predominance of pedogenic processes. Although early Holocene earth-surface processes are rarely documented in clear geomorphological and chronological frameworks from the southern Levant, there is some evidence for abrupt geomorphological responses in the most fragile (semi-arid) regions during Holocene RCCs (Cohen-Seffera et al., 2005). But there is a general lack of very precise geomorphological studies for this period (Berger and Guilaine, 2009; Zielhoffer et al., 2008, 2012).
Divergent information from different proxy records as well as chronological uncertainties is often a major limitation to our understanding of abrupt climatic changes and their impact on the continental environment (Desprat et al., 2013). Early Holocene palaeoenvironmental data derive first from inferred changes in lake hydrology (isotopes and salinity changes, water level variations; Magny, 2004; Eastwood et al., 2007; Roberts et al., 2008, 2011; Kuzucuoğlu et al., 2011), quantitative pollen studies (Eastwood et al., 1999; Roberts et al., 2001; Pross et al., 2009; Peyron et al., 2011; Bordon et al., 2009), fire analysis (Vanniere et al., 2011), and cave speleothems records (Bar-Matthews et al., 1997; Frisia et al., 2006; Verheyden et al., 2008; Göktürk et al., 2011) and marine cores (e.g. Kothoff et al., 2008; Combourieu-Nebout et al., 2013; Desprat et al., 2013; Fletcher et al., 2013) (Fig. 2). Multi-proxy comparisons (pollen-inferred changes in plant functional types vs. modern analogues) help in identifying a strong connectivity with the Mediterranean watersheds, in particular when deciduous woodland switches to sclerophyllous woodland and scrub, or when mountainous assemblages increase during colder events (Peyron et al., 2011; Combourieu-Nebout et al., 2013).
Despite these many recent palaeoclimate studies, it is still difficult to imagine the relationships between climate and hydrogeomorphology in the eastern part of the Mediterranean Basin at the centennial scale during the early Holocene. For example, is it possible to consider a synchronous and similar hydroclimatic and geomorphic functioning all through the area from the Ionian–Aegean Basin to the Levant regions? Is there a latitudinal climatic barrier between a northern and southern part of the eastern Mediterranean, as there is between the central and western Mediterranean (Magny et al., 2013)? How much seasonal or annual water is available for soil and vegetation, notably during the main RCCs? What links can be found between changes in practices or in population movements that may be connected to past hydrological changes in the continental areas?
Several archaeology-related studies are now dedicated to the production of specific data on societal vulnerability during the early Holocene (e.g. Clare and Weninger, 2008; Bocquet-Appel
et al., 2014; Borrell et al., 2015; Flohr et al., 2016, “2010–2020”
Paléomex project). These projects cover the widest possible field of alternative societal modes and types of responses to environmental changes versus natural hazards.
The RCCs' mechanism and their millennial cycles during the Holocene give
opportunities to study the impact of rapid events on cultural transitions
and/or migrations/mobility and to explore the societal adaptability modes in
stress conditions through time and in specific contexts. The current main
hypotheses are based, on the one hand, on regional chronocultural patterns defined by
cumulative probability density function (CPDF) techniques
and, on the other hand, on the time parallelism between a decrease in radiocarbon date clusters
and the assertion of a RCC. As proposed by Flohr et
al. (2016), a more critical approach is now clearly needed to better
characterise socio-environmental relations with climate and environmental
changes during RCC, an approach that would be more trustable than the use of
regional
Not only do many palaeoclimate and environmental records have neither sufficient temporal resolution nor chronological precision but also the sensitivity of a continental record to detect a decadal-scaled climatic anomaly is rarely assessed. For this latter factor, more detailed geographical and bioclimatic local frameworks within regional assessments are needed. The availability of such assessments is necessary for discussing not only the local impacts of climate events on the resources and landscapes (Clare and Weninger, 2010) but also the societal impact or non-impact of a RCC (Roberts et al., 2011; Kuzucuoğlu, 2015) and our knowledge of past adaptation strategies (Berger, 2006; Berger and Guilaine, 2009; Lespez et al., 2014, 2016; Flohr et al., 2016). As far as the study of early farming societies is concerned, data about micro-regional and local effects of RCCs will usefully replace or complete the information delivered by the key regional – and remote – climate references which are regularly called for in research papers: glacial, marine, continental dendrochronological series, speleothems, etc. (Weninger et al., 2006, 2009; Kuzucuoğlu, 2009). Local detection of RCC impacts are still too rarely attested to on archaeological sites or in continental river archives close to sites occupied by the first farmers or the last hunter-gatherers (Berger and Guilaine, 2009; Zielhoffer et al., 2012; Lespez et al., 2013; Berger et al., 2016). Prehistorians have discussed the impact of the 8.2 ka event in the Balkans, but their discussions still lack solid socio-environmental field documentation and interpretation, and implications remain too often theoretical (Bonsall, 2007; Budja, 2007; Nikolova, 2007). We thus propose here a “bottom-up approach” of the impact of climate changes on the early Neolithic societies. We intend to demonstrate that precise geoarchaeological investigations in Neolithic sites, when based on systematic stratigraphy studies, rigorous radiocarbon series and on a contextual archaeological approach, end up proposing new socio-environmental schemes on the local scale. At the same time, we explore new hypotheses about the impacts of the early Holocene RCCs on the environments as well as the responses of Neolithic societies.
The wide and endorheic plains of central Anatolia (Figs. 2 and 3) open in
steppic plateaus ca. 1200–1300 m altitude. The altitudes of the three main
plains are ca. 920 m a.s.l. (Tuz Gölü, to the north), 1000 m a.s.l.
(Konya and Ereğli, to the south), and 1050 m a.s.l. (Bor, to the east).
In these plains, the current climate is semi-arid with mean annual
precipitation ranging from 280 to 340 mm yr
Map of main sites cited in the text: 1, Lake Accesa; 2, CM-92-43;
3, MD90-917; 4, MD 04-2797; 5, D
The main large plains of endorheic central Anatolia and location of sites cited in the text and in Fig. 7. Main cities: K, Konya; E, Ereğli; B, Bor; A, Aksaray. Palaeoenvironmental sites: 1, Yarma (Kuzucuoğlu et al., 1999); 2, Çarsamba fan (Boyer et al., 2006); 3, Sultaniye (Kuzucuoğlu et al., 1997); 4, Karapı nar sand dunes (Kuzucuoğlu et al., 1998); 5, Düden (Fontugne et al., 1999; Kuzucuoğlu et al., 1999); 6, Adabağ (Bottema and Woldring, 1984); 7, Zengen; 8, Bayat; 9, Kayı; 10, Pınarbaşı; 11, Bahçeli; 12, Sazlıca; 13, Melendiz-Çiftlik (Kuzucuoğlu et al., 1993); 14, Alluvial fans (Naruse et al., 1997; Kashima et al., 2002). Sources for 7 to 12: Kuzucuoğlu et al., 2016. Excavated Neolithic sites cited in text: a, Boncuklu; b, Aşıklı; c, Can Hasan III; d, Çatalhöyük East; e, Tepecik-Çiftlik; f, Pınarbaşı-Karadağ; g, Pınarbaşı-Bor; h, Köşk Höyük; i, Çatalhöyük West.
Other cultural changes occur in both regions during the 8.6–8.0 ka
time span. In Cappadocia two sites overlap the 8.2 ka event (Tepecik:
9–7.5 ka; Kösk: 8.5–7.5 ka). In the Konya plain, two sites follow one
another ca. 8.0 ka: Pınarbaşı–Karaman
(8.5–8.0 ka) and the second phase at Can Hasan (8.0–7.6 ka). In spite of the
small number of excavated sites in both Cappadocia and the Konya Plain, this
list does not show any clear cultural “rupture” at either ca. 9.2 ka or
ca. 8.2 ka. However, a change may have happened at ca. 9.4 ka at the end of
the Pre-Pottery Neolithic B (PPNB) which possibly ended with a PPNA phase
at Musular (?). Clearly, 8.6, 8.0 and especially 7.6 ka seem to be pivotal dates:
8.6 ka marks the end of the first occupation phase of Can Hasan III
and the start of that of Köşk and Pınarbaşı; however, Tepecik and
Çatalhöyük are continuously occupied. 8.0 ka marks the end of Pınarbaşıand the start of the Can Hasan second
phase. 7.5 ka marks the end of occupation of Çatalhöyük (West),
Köşk, Tepecik, and the Can Hasan second phase.
Central Anatolia neighbours the nuclear areas of the PPNA (11.7–10.5 ka) in the Levant and of southeastern Turkey (middle and upper Tigris and Euphrates valleys). Where identified (in the Levant, southeastern Turkey, Iran, Cyprus, central Anatolia), the PPN corresponds to a “Neolithisation” period during which packages composed of several or all characteristics of the Neolithic are identified in excavated settlements: sedentism, housing, pre-domestication (followed possibly by domestication) of sets of plants and/or animals (Fuller et al., 2011; Zeder 2011; Stiner et al., 2014), symbolism, art, social organisation and ritual behaviour (Cauvin, 2002; Simmons, 2011). Increased sedentism and plant and animal domestication practices are asserted during the period of relative climate stability that follows rapidly the turmoil of the Holocene onset warming up and its consequences on the vegetation and water resources. This has greatly contributed to conceiving the Neolithisation processes in the eastern Mediterranean as an incremental continuum (including several and distinct successful and unsuccessful attempts: Willcox et al., 2012) in disconnected “cores” spread over the region, with relatively minor disruptions (Borrell et al., 2015). Recently, a major cultural discontinuity has been observed in the archaeological PPN records of the northern Levant which lasted from 10.2 to 9.8 ka and was followed by a substantial cultural transformation indicating a break in the Neolithisation process (Weninger et al., 2009; Borrell et al., 2015). This early discontinuity corresponds to a hiatus in settlements, which covers almost the entirety of the time span traditionally attributed to the early PPNB in the Levant (10.2–9.6 ka) (Borrell et al., 2015).
In central Anatolia, after the abandonment ca. 9.5 ka of early PPNB sites in
the Konya Plain (Boncuklu, Can Hasan III) and Cappadocia (Aşıklı), younger PPNB sites appear at other locations: ca. 9.6/9.5 ka in
Cappadocia (Musular site), and 9.4/9.3 ka in the Konya Plain
(Çatalhöyük East). Musular, a site specialising in butchery, is
abandoned ca. 9.0 ka before the appearance of pottery. From the west of
the Konya Plain to the Lake District, where sites are founded ca. 9.2 ka
without pottery (PPN) as in Bademağacı, and to the Aegean region of Anatolia
(Ulucak), Neolithic occupation continues with no hiatus into and throughout the
early Neolithic period, which starts quickly, ca. 9.0/8.9 ka, with the appearance
of pottery. Pottery also appears within a similar time frame in many other sites
in Cappadocia (e.g. Tepecik-Çiftlik; Köşk Höyük) as well as the
Mediterranean (e.g. Yumuktepe) and the Aegean (e.g. Yeşilova, Ulucak
etc.) (Fig. 2, with references therein, especially in Özdoğan et al.,
2012a, b). New results (e.g. Özdoğan et al., 2012a, b; Stiner et al.,
2015) and those from ongoing syntheses (e.g. Özdoğan, 2011;
Kuzucuoğlu, 2014) suggest that long-distance Neolithisation dynamics
originated out of a core located in the Konya Plain and Cappadocia. This
diffusion arrived in the Aegean region ca. 9.1–9.0 ka (Özdoğan
2011). In the eastern Mediterranean as well as in central Anatolia, Flohr et al. (2016)
show that
In Cyprus, a cultural change is initiated ca. 9.6/9.5 ka (emergence of the Khirokitia culture: Le Brun et al., 2009). At the Shillourokambos site (Fig. 2), the change occurs in the early C phase, initiating a different cultural package which lasted the second half of the 10th millennium cal BP. The cultural change is visible in the quick decline of the exquisite lamellar tools obtained in the previous phase by bipolar knapping (a strong PPNB marker in the Levant), replaced by production that is directed towards robust pieces (thick and irregular blades, pikes, and sickles with parallel hafting to the edges) (Briois, 2011). At the same time, there is a decrease in grinding instruments around 9.2 ka, after an agricultural development had lasted during the previous three centuries (Perrin, 2003). Imports of Cappadocian obsidian collapse, and Cyprus no longer has any contact with Anatolia and the eastern Mediterranean. The habitat reduces in size, concentrating in the southern part of the site. Building materials evolve with the abandonment of the proto-brick for mud-building techniques. From 9.2 ka on, sheep husbandry plays an important part, perhaps in association with the development of pastoralism (Vigne et al., 2011). These cultural and economic changes have never been faced with climato-environmental evolutions, in spite of their quasi-synchronicity with a first global signal (Fig. 1). Discussions about the relationships between cultural changes identified in the Cypriot PPNB sites and the 9.2 ka event are not yet possible because there is still no clear temporal synchronisation between the two sets of data. Nevertheless, the question of climate control is raised in Cyprus during the economic transition toward pastoralism during this period (Vignes et al., 2011). Such an assumption, for example, has been recently proposed for the eastern Mediterranean by Flohr et al. (2016). We use the Khirokitia site, a Cypriot late PPN village dated to 8.6–7.5 ka (Le Brun et al., 1987; Le Brun and Daune-Le Brun, 2009), to improve the discussion on RCC impact and human occupation on the island. This site is located on the southern foothills of the Troodos Mountains, at about 6 km from the Mediterranean shoreline (Fig. 4a). It occupies the flanks of a limestone rocky mound (around 216 m above sea level), bounded to the north and east by the Maroni River bed (Fig. 4b). At the present time the river channel is ephemeral and forms a rather deep and narrow valley cut down through a terrace series of Quaternary conglomerates and older fluvio-marine deposits. The stratigraphic sequence of the site comprises two major series of occupational levels. The articulation between both levels is dated to nearly the end of the seventh millennium BC (around 8.2 ka). This transition period is marked by a spatial redistribution within the village where an areal shift and a habitat contraction occur, while a change in the botanical and zoological records is noticeable (Le Brun and Daune-Le Brun, 2010; Le Brun et al., 2016). Detailed geoarchaeological investigations have been performed, mainly at the foot of the eastern slope of the site, where the archaeological remains meet the river, and on the surrounding river deposits (Hourani, 2008) (Fig. 5).
The tell of Dikili Tash is located in the southeastern part of the Drama Plain, in eastern Macedonia, northern Greece (Fig. 2). It is one of the largest tells in northern Greece, covering an area of ca. 4.5 ha, with its highest point standing at ca. 15 m above current ground surface. A freshwater spring lies immediately to the northeast of the tell, and it opens on a large swamp to the south (Tenaghi Philippon) about which many environmental studies have been published (Fig. 6). Ongoing excavations have provided a good insight into the long stratigraphic sequence of this settlement from the bottom of the plain, completed by coring surveys in the deeper humid zones at the southern periphery of the site (Lespez et al., 2013, 2016; Glais et al., 2016). The deepest archaeological level, very close to the natural soil (a brown leached soil), has been dated to 8.54–8.38 ka, i.e. early Neolithic.
The Tenaghi Philippon (former) marsh, Dikili Tash archaeological
sites and sample cores obtained from the marsh deposits mentioned in the
references. Image from Google Earth (40
The prehistoric site of Sidari, located in a small coastal valley dug in
marine Pliocene detrital formations in northwestern Corfu (Figs. 2 and 7a), is a
crucial milestone to explain the modalities of the Neolithisation phase in
the Adriatic zone. It represents the oldest Neolithic site known in the
central Mediterranean (8.3 ka) (Sordinas, 2003; Berger et al., 2014). Deep
in the fill of a small valley, the archaeological excavation revealed an
early Neolithic phase with red monochrome ceramics, domestic fauna, cereals
and mud houses, whose economic status will be specified by the ongoing
monographic publication of the French–Greek team (Fig. 7c). Together with
Odmut (Bosnia and Herzegovina) and Konispol Cave (Albania) (Sordinas, 2003;
Kozlowski et al., 2004; Forenbaher Miracle, 2005), Sidari was originally
considered one of three sole sites in northwestern Greece and the southern Adriatic area
with an apparent Mesolithic–early Neolithic stratigraphic continuity. On the
basis of our new contextual geoarchaeological study (Berger et al., 2014), we
recently discussed this aspect, refuting the original interpretation made by
Sordinas (1966, 1973). This coastal sector is part of a vast Tertiary
sedimentary basin presenting a hilly morphology that displays vast and thick
Holocene alluvial formations. Today, rainfall is extremely significant, with an
average of 1000 mm yr
In between these two sites, we also need to insert the recent discovery of the Mavropigi-Filotsairi site on the Kitrini Limni riverbank in western Macedonia (Karamitrou-Mentessidi et al., 2013). The radiocarbon chronology of this site is based on 17 dates of seeds, bones and charcoal and confirms the establishment of a monochrome Neolithic around 8.5 ka (Fig. 12).
Intra-site soil and geomorphological studies performed in Sidari, Dikili Tash
and Khirokitia allow for discussing the settling of these pioneer Neolithic
dwellings in active sedimentary areas (valley floors, small thalwegs). Such a
location gives the opportunity to identify and measure impacts of sedimentary
and hydrogeomorphological processes. Our research is based on a classical
field approach, mainly contextual, which uses in situ cultural horizons and
series of stratified radiocarbon dates to build local chronostratigraphic
patterns and to discuss the syn- and post-depositional impacts. The
multi-proxy analyses (grain size distribution, geochemistry, geophysics,
micromorphology) that are still in progress are not discussed in detail in this
paper, which focuses primarily on chronostratigraphic contexts. In Sidari, a
CPDF analysis is used to better specify and compare the chronology of
hydrosedimentary and pedological activity in the two sites. A local database
integrating Sidari 1 and 2 sites has been compiled. It integrates 33
radiocarbon dates from three main geomorphological contexts: channel fills,
floodplain overbank deposits, and palaeosol.
Regarding the site of Dikili Tash, geomorphological studies have focused on
the tell and its surroundings (Lespez et al., 2013, 2016) (Fig. 6). The
proximity of a swamp (Tenaghi Philippon) gave us the opportunity to follow a
strategy of complementary palaeoenvironmental analyses, centred on the study
of pollen, non-pollen palynomorphs (NPPs) and fire signal in order to reconstruct the history of the
local and regional vegetation and of fires. At the same time, these proxies also
allowed the dating of the emergence of agropastoral practices and the
temporal fluctuations of the human influence on the environment. Pollen and
NPP analyses have been performed on sediments from
core Dik12 retrieved from the site bottom, as well as from Dik4, which was located
2 km southwest of the site, on the edge of the Tenaghi Philippon marsh
(Glais et al., 2016). Sediments of these 3 m long cores consist mainly of grey
to black organic clay. These two cores were collected in PVC tubes (diameter
60 mm, length 1 m), protected in plastic guttering and stored under cold
conditions (5
In central Anatolia, regional-scaled climate records are scarce. The only
record published is from Adabağ marshes in the Konya Plain. However, it is insufficiently dated (only one date concerns the early Holocene: Bottema and
Woldring, 1984) (Fig. 3). At higher altitudes in Cappadocia, two multi-proxy
records have been studied: Eski Acıgöl (Roberts et al., 2001) and Nar
Lake (Dean et al., 2015). However, the chronology of these two records presents
uncertainties because of either CO
Dated palaeoenvironmental records in the three main endorheic plains of central Anatolia: a synthesis between 12.5 and 6.0 ka cal BP. Environmental records in sediment archives: 1, deep lake; 2, backswamps; 3, vegetated shallow marshes; 4, palaeosol; 5, alluvial fan (coarse sediment). Humidity intensity (synthesis): 6, dry to very dry; 7, emersion of watered ecosystems and soil formation; 8, semi-arid and/or contrasted seasonal climate (high seasonal run-off); 9, humid (marshes); 10, very humid (lakes, backswamps).
After the start of rescue excavations in 2004, the chronology and the chronostratigraphic context of the Sidari site 1 (Sordinas, 1967, 1973) were fully rebuilt (Berger et al., 2014). Dates performed in
the 1970s (on charcoals) presented standard deviations that were overly broad when
compared to current international standards. Consequently, 15 AMS dates
were performed on charcoals from the new excavation, including a dozen
samples from the horizons of early Neolithic I and II (Table S1 in
Supplement). Ten dates were performed on deciduous oak charcoal pieces, a
species which is hyper-dominant in the charcoal assemblages (S. Thiébault,
personal communication, 2006). Three
The dates of the Khirokitia PPNB site were collected from archaeological structures which were interbedded in the Maroni alluvium at the margins of the village. They mainly concern charcoals from ashy lenses or in situ fireplaces in built structures that provide a reliable environment for dating (Table S1).
In Macedonia, the chronology of DIK 4 core is based on 11 AMS radiocarbon
dates (Table 1 in Glais et al., 2016). The chronology for the Dik 12 core
is based on three AMS radiocarbon datings on charcoals and organic sediment
(Glais et al., 2016). Intra-site
Regarding the central Anatolian chronology, dates are provided by several
studies and places (Fig. 8). At Adabağ (Konya Plain) one
The results of the local investigation in the four selected studied are presented from east to west following the Neolithic expansion.
Questioning the role of climate on the Neolithic dynamics in central Anatolia from the PPN to PN and during the early PN during the first half of the 9th millennium cal BP means that we have to define the climatic context and evolution from 9.5/9.4 to 9.2/9.0 ka. A similar question concerns the transition phase between the PN and Chalcolithic ca. 8.2 and 8.0 ka in central Anatolia (Baird, 2012). A few sites are occupied during this period in Cappadocia (e.g. Tepecik-Çiftlik and Köşk Höyük) and in the Konya Plain (Çatalhöyük East–West: e.g. Marciniak et al., 2015). This transition is, however, not well known, mainly because the middle Chalcolithic period (7.5–6 ka) remains under-investigated in Turkey (Düring, 2011). Instead, the cultural turning point that occurs through Neolithic Anatolia ca. 8.6 ka seems more distinct than changes happening ca. 8.2/7.8 ka (Düring, 2011; charts in Özdoğan, 2012a, b). Nevertheless, the parallelism between cultural changes and the timing of the “9.2” and “8.2” ka RCCs suggests that there may have been a relationship between climate and cultural changes during the events.
Results from geomorphological, geoarchaeological and palaeoenvironmental research during the 1990s in the Konya Plain (Kuzucuoğlu et al., 1997, 1998, 1999; Fontugne et al., 1999; Roberts et al., 1999), in the Tuz Gölü Plain (Naruse et al., 1997; Kashima, 2002), and more recently in the Bor Plain (Gürel and Lermi, 2010; Kuzucuoğlu, 2015; Matessi et al., 2016) today allow us to propose a chronological synthesis of the environmental context of the cultural dynamics between the 10th and the 7th millennium cal BP. The palaeoenvironmental records in the three closed plains of central Anatolia (Figs. 3 and 8) show evidence of alternations of humid and dry phases during the Holocene. The chronological comparison between these phases and the global climatic record shows that (a) there is a high variability in records in the humid areas sensitive to even slight changes in humidity; (b) some RCC have no correspondence in the environmental records; and (c) when a signal occurs in parallel with one of the RCC, the signal varies in nature and magnitude (soil signaled by roots and vegetation, emersion out of wetlands, drying off, drought, etc.). The comparison between the locations of the sediment archives in such an evaporation-sensitive context as that of the central Anatolian endorheic plains shows that the geomorphologic settings of the records (cores and sections) control the signal, i.e. the type and sensitivity of the drying/wetting wetlands: sub-surficial water in alluvial fans, marshes fed by springs at the external edges of alluvial fans, springs along faults, karstic outflows, ice and snowmelt from highlands, rivers etc. (Fig. 8). Both the topographic specificities of the ecosystems and the spatial variability in the air masses transporting humidity in the area contribute to the importance of the regional and local scales in the palaeoenvironmental records.
According to these records, the general environmental evolution in the
region during the early Holocene is the following (Fig. 8):
After the onset of the Holocene at ca. 11.4 until 9.5–9.0 ka, springs and
rivers in the Konya Plain collect water originating in precipitation and
snow/ice melt in the Taurus Mountains. This water is also discharged by the karstic
network of the range. This water accumulates in shallow depressions
stretching at the foot of the Taurus Mountains along the Konya–Ereğli–Bor plains.
For example, the expansion of the Akgöl backswamps at the southern border
of the Ereğli Plain (Bottema and Woldring, 1984) is such a signal of a
humidity rise triggered from the Taurus highlands. Towards 9.5 ka, alluvial fans start to expand over the Last Glacial Maximum marls forming
the Konya Plain bottom (Çarsamba and Karaman rivers: Boyer et al., 2006),
as well as in the Çiftlik Plain up in the Cappadocian volcanoes
(Kuzucuoğlu et al., 2013). This river-dynamics-related change is the only
possible signal of a climatic change contemporaneous with the 9.2 ka RCC.
This signal is produced by a change in run-off indicating a rise in spring
water and a possible increase in seasonal temperature contrast. Such a change
would have produced enough snow and ice meltwater to initiate the growth of
Holocene alluvial fans over the plain bottoms. During this period, the
Adabağ pollen record is marked by the expansion of an arboreal vegetation
dominated by deciduous The soil dated to 9.0–8.9 ka in the Adabağ core possibly marks the end of
the period of change which started ca. 9.5 ka. With the exception of the
Çarsamba fan, which continues to grow until 8.6 ka, the absence of
sediment record dated to the first half of the 9th millennium cal BP suggests that
the plains were dry, with little or no water input from the central Anatolian
highlands (Cappadocian volcanoes). The second half of the 9th millennium cal BP is characterised in the
Konya Plain by the interruption of the torrential dynamics in the
Çarsamba fan between 8.6 and 8.2 ka. During this period, the marshes along
the edges of the Altunhisar fan in the Bor Plain seem to have dried off too,
although not for as long since they are well watered (lakes and backswamps)
before 8.2 ka, when they dry up again. In a generally dry 9th millennium cal
BP in central Anatolia, this dry–wet–dry alternation in the northern shores
of the Bor Plain (Bayat and Kayı cores), as with the continuing record at
Adabağ (fed by Taurus karstic waters), corresponds to local signals. The 8.2 ka RCC is present in central Anatolian records as a one-century-long dry signal interrupting backswamps and lakes around the
Altunhisar fan between 8.1 and 7.9 ka. The most humid climatic phase in central Anatolia starts ca. 7.9 ka and
lasts until ca. 6.5 ka, which marks the beginning of the mid-Holocene dry
phase (Kuzucuoğlu, 2015; Matessi et al., 2016).
Results from the foot of the eastern slope of the site, next to the Maroni River channel, allowed recognition of at least two major sedimentary events that occurred during the occupation of the site.
The first of these events is a major channel incision concurrent with
torrential stream discharges (Fig. 5). It is marked at the foot of the
eastern slope by the deposition of a 3.5 m thick layer of densely packed,
non-sorted, rolled stones and gravel at the base and more stratified but
relatively fine-grained gravel and sand near the top. Deposits here underlie
the archaeological remains in this sector and unconformably overlie Miocene
fluvio-marine sediments. One feature of note is the presence of Neolithic
stone tools as well as charcoal lenses, ash and fine fragments of burnt bones
and mud brick within the alluvial discharge near the top. A radiocarbon date
obtained on ash specks from this unit indicates an age of 8518
Diagram from the Dik4 core with its age–depth model. Loss on ignition and
carbonate content of the sediment expressed in % of the total sediment.
Charcoal influx expressed in cm
The second and more prominent sedimentary event is a substantial erosional
episode. It is particularly visible in the middle of the archaeological
sequence overlying deposits of the first sedimentary event at the foot of the
eastern slope (Fig. 5). A 0.6 to 0.8 m thick stratum of angular limestone
gravel and other archaeological debris divide the 4 m high archaeological
sequence in this area into two parts. Archaeological structures of the lower
part are deeply gullied and appear to be less preserved than in the upper
one. Two radiocarbon dates, obtained on charcoal lenses from the debris of
two superimposed houses sited on top of the erosional layer, propose the ages of 8276
The two sedimentary events described above indicate that the region of Khirokitia experienced strong modifications in the hydro-geomorphological configuration around 8.5 and, more particularly, 8.1 ka. The morphological distinction between both these two events on the one hand, and what could have been the situation before they occurred on the other hand, is difficult to establish adequately in such a dissected area where older terraces are obscured by younger sedimentation and subsequent erosion. However, the nature and the extent of the events observed indicate erratic and heavy rainfall conditions that in all probability seem to have occurred on a wider regional scale. Not far from Khirokitia, downcutting by 6 m was followed by a period of aggradation and alluviation between 8.3 and 7.9 ka in the Vasilikos Valley near Kalavasos (Gomez, 1987) (Fig. 4a). A similar sequence was also observed in the Middle Jordan Valley (Jordan), where marshy deposits corresponding to the beginning of the Holocene were deeply truncated and then recovered after by the red soils associated with the first settlers of the late Neolithic period (Hourani and Courty, 1997; Hourani 2005, 2010) (Fig. 2).
Map of the core drillings around Dikili Tash site and interpretation of the settlement dynamics during the early stages of the Neolithic.
Notwithstanding the role of humans in the weakening of the soil cover, tectonic activities that may also have facilitated the incision of the riverbed and (or) changes in the direction of the stream runoff as well as lowering of the riverbed both indicate that the Neolithic landscape at Khirokitia resulted predominantly from climatic factors. At Khirokitia, if this period of surface erosion and torrential discharges were to be integrated into a wider regional or global scale, it might then be seen as a regional expression of the worldwide-identified 8.2 ka event. Here, the first cultural implication that can be drawn from this erosional event is the shift and contraction in the village space along with the major changes observed in the botanical and zoological records towards the end of the 7th millennium cal BC. The attribution of the end of the PPN occupation at Khirokitia to the 8.2 ka event (Weninger et al., 2006) thus cannot be sustained.
In eastern Macedonia, investigations have been performed on the edges of Tenaghi Philippon marsh. This large marsh located in northern Greece has been subjected to numerous palaeoenvironmental studies (Wijmstra et al., 1969; Greig and Turner, 1974; Tzedakis et al., 2006; Pross et al., 2009; Peyron et al., 2011) which constitute reference records for the environmental history of the eastern Mediterranean area (Fig. 6). The results of these studies have been focused mainly on climate impact on vegetation cover. In order to track the climatic changes as well as the impact of the Neolithisation process, which is here dated from 8.5 ka onwards (Lespez et al., 2013), palaeoenvironmental investigations have been performed from the archeological site to the marsh.
The pollen records (Fig. 9) indicate a general decrease in steppe taxa
(Artemisia and Chenopodiaceae) and the steady increase in other herbaceous
plants such as Cichorioideae, and other ruderal taxa suggesting a return to
more humid conditions at the end of the Younger Dryas (ca. 11.7–10.2 ka).
This is also supported by the recorded appearance of lime trees, an increase
in NPPs indicative of eumesotrophic conditions and a slight but continuous
deciduous oak expansion. These observations are consistent with the regional
climatic model (Kotthoff et al., 2008; Peyron et al., 2011). Around 10.2 ka
the pollen indicates a gradual and long-term change with great development of
arboreal vegetation and the decline of open vegetation cover (arboreal polle
n/non-arboreal pollen (AP / NAP) ratio increases from 20 % to more than
50 %). Wetter and warmer conditions have favoured the expansion of all
broad-leaved trees, such as oaks and alders, and subsequently the appearance
of mesophilous taxa such as ostryas, birches, ulmus and evergreen oaks. After
a delay in comparison with western Greece (Lawson et al., 2004), this
expansion indicates the onset of interglacial conditions. In this context,
the first macrocharcoal peak extended (10.6–9.3 ka) corresponds to the
biomass development in a still incomplete wooded landscape. Forest expansion
was punctuated by a short-term centennial-scale drier climatic events
(9.6–9.3 ka) distinguishable at regional (Kotthoff et al., 2008) and local
scale by the increase in xerothermophilous taxa and evergreen
After 9.3–8.7 ka, the vegetation cover is marked by a peak in deciduous oaks; the appearance of fir on the top of surrounding mountains; a decrease in Poaceae, Aster type and Cichiorioideae taxa; and the retreat or even disappearance of woody species limited to Mediterranean contexts. This spread of forest cover was interrupted around 8.7–8.3 ka. The decrease in trees and increase in herbs could indicate the impact of the 8.2 ka RCC, but this period also shows the first signs of human impact in the early Neolithic. The peak in coprophilous NPPs, ruderal taxa and NPPs indicative of erosive processes are certainly due to the early Neolithic settlement implantation in Dikili Tash (Lespez et al., 2013; Glais et al., 2016) benefitting from pristine forested environment with multiple available resources. This is attested to in the NPP record, not only by a first coprophilous species peak but also by a decrease in deciduous forest species and increase in herbaceous taxa on the edge of the marsh. Furthermore, at the bottom of the site (Dik 12), high-percentage cereal pollen (around 9 % at 8.4 ka) and the increase in ruderal taxa make it clear the anthropogenic impact on vegetation cover was associated with agropastoral activities.
Nevertheless, the conjunction with the 8.2 ka event that is well established at the regional scale a few decades afterwards makes the interpretation more complex, and other causes can be evoked to explain the pollen and NPP records. The high percentage of hydro-hygrophytic taxa on the edge of the marsh suggests a contemporaneous rise in the water table level in a drier period well assessed at the regional scale (Pross et al., 2009). Furthermore, marshy deposits or oncolytic sands layer are interstratified within the anthropogenic layers of the first levels of occupation on several cores (Lespez et al., 2013). It indicates a rise of the water table of the little pond located at the bottom of the site, which is fed by an exsurgence in the marble slopes which dominate the site (Fig. 10). At C3, it corresponds to two high stands. The first one is dated at C3 after 8.38/8.17 ka, while the second is dated at C2 and C3 around 8.0–7.9 ka. Additionally, the geomorphological observations in the small valley of Dikili Tash which runs to the marsh show development of detrital carbonate sedimentation. In the Dik4 core, it corresponds to carbonate silty layers which interrupted the organic sedimentation. This suggests an increase in flood flows from the small stream which runs from the Dikili Tash pond during the period 8.2–7.8 ka. These observations are close to the results obtained at Lake Doirani (130 km WNW) (Fig. 2), which show a relatively high lake level during this period (Zhang et al., 2014). From the beginning of the 9th millennium cal BP, the vegetation cover shows the return of some pioneers or mesophilous taxa (hazel, elderberry and black haw trees), or their appearance (ash and broom) shortly before a closing landscape phase. Locally, the riparian vegetation increases considerably in relation to a drier environment due to (1) previous detritic sedimentation input which fills the edge of the marsh, (2) the water level decrease which begins from ca. 7.5 ka, and (3) the forest cover expanse in the region because of climatic amelioration (Pross et al., 2009).
A precise field geomorphological and palaeopedological approach, favoured by the presence of interbedded archaeological levels and charcoal beds which are systematically radiocarbon-dated, allowed the construction of a solid micro-regional chronostratigraphic framework. The CPDF analysis provides a probabilistic assessment of centennial-length sedimentary aggradational episodes interrupting early Holocene active pedogenic and landscape stability development favoured by a more humid Mediterranean climate within two individual catchments.
The Sidari 1 archive presents a 5 m pedosedimentary sequence depth. The rescue archaeological excavation operated in the mid-2000s had uncovered eight main archaeological layers from the Mesolithic to the Helladic periods that are interbedded in a complex polyphased sequence, with 16 main phases of river and colluvial activity and pedogenesis in five millennia (Berger et al., 2014) (Fig. 7c). Sidari 2 is a natural transversal trench of a small dry valley, 80 m wide and 7 m deep, entrenched in cemented Pleistocene formations. The deposits are actively eroded by the current sea level change, which allows a full observation of the Holocene filling to be made. A first chronostratigraphical view of the sequence identified two abrupt limits at the early to mid-Holocene (around 8.2 ka) and mid- to late Holocene periods (around 4.0 ka) (Fig. 10d), which refer to the recent tripartitioning of Holocene period (Wanner et al., 2008). In this paper we focus only on the lower half of the filling, consisting of a thick cumulic soil complex and the beginning of the mid-Holocene period marked by a rapid breakdown of pedosedimentary conditions, leading to a very erosive and detrital activity in the small marly basins over one millennium.
The Sidari 2 local chronostratigraphy building clearly presents a stairway age–depth model with three phases of high acceleration of sedimentation rate (Fig. 11b): from 10.4 to 10.0 ka, from 9.5 to 9.0, and after 8.4 ka. This environmental temporality clearly represents millennial pedogenesis/incision–aggradation rythmicities, particularly well illustrated in the Sidari 2d profile (Fig. 11a), which represents a morphopedological synthesis of the events' succession. A systematic sedimentological and geochemical multi-proxy approach that describes pedoclimatic conditions, hydrosedimentary environments, detrital fluxes and some ecological factors (fires) is still yet to be done. Hydrosedimentary and palaeopedological interpretations presented in this paper should be viewed as preliminary.
The biostability phases that develop between erosive phases discussed are expressed in geological records of catchment heads by development of black, deep soil (phases I, III and V, Fig. 11a), often decarbonated and leached, as observed at the microscopic scale in Sidari 1 (Berger et al., 2014). These kinds of pedogenesis and associated pedofeatures (hyaline cutans) illustrate a dense forest cover that is highly protective for soils (Macphail et al., 1987; Kühn, 2003). Local charcoal assemblages (Delhon and Thiebault forthcoming) and the regional pollen spectra (Bordon et al., 2009; Triantaphyllou et al., 2009; Combourieu-Nebout et al., 2013; Glais et al., 2016) reveal vegetation dominated by mesophile deciduous oak forest. At the start of the Holocene, a first, broadly stable and humid, phase is favourable to the development of a thick leached and humic cumulic palaeosol (Berger et al., 2014). The second half of the early Holocene is, however, punctuated by a succession of abrupt breaks in the hydromorphological functioning of the marly valleys. The duration of these breaks is century-scaled, and their occurrence presents a quasi-millennial cyclicity. The breaks are characterised in the field by a sudden cessation of soil formation processes, synchronous with deep gullies cutting each other when three Early Holocene climate events occur (Fig. 11a). These gully activities (phases II, IV, VI) are followed by a rapid-filling phase of lighter-tone alluvio-colluviation that is often still decarbonated (association of inherited soil material and marls) and whose palaeodynamics can be characterised by analysis of the sedimentary fill mode: (1) the slick or lenses of sand and gravel deposits, rich in small well-rounded nodules of clay soil, are associated with concentrated runoff causing gullying and sapping upstream soil formations (Fig. 11cd–IVb1–VIb) and (2) finer well-sorted deposits, often micro-laminated, associated with finer and regular rainfall generating diffuse runoff (Fig. 11e–VIg). Therefore, we explain the formation of these two facies by the expression of different rainfall on largely bare surfaces by fire (presence of regular charcoal bed). The transition between RCC events and the pedological stabilisation of the valley is generally dominated by more regular rainfall (fine granularity, diffuse laminations), as in the 8.2 ka event.
The 10.4–9.75, 9.5–9.1 and 8.35–7.9 ka active periods are evidenced in cumulative probability density function plots (CPDF) (Fig. 11f). We interpret these morphological and hydrosedimentary signatures, regularly recorded in alluvio-colluvial archives at Sidari, as the manifestation of RCCs, which seem to form the rhythm of the evolution of Holocene northern Mediterranean valleys.
These results suggest that data provided by continental hydrology, soils, and vegetation dynamics studied on the micro-regional scale may be good records of potential impacts of climate and of development of human societies. These new
data establish the necessity of always reasoning, from contextualised data, not to overplay temporal CPDF-type constructions, which are sometimes too
schematic and occasionally disrupted by bias related to the organic material
used for the
The results obtained on the four sites studied assess the local environmental
changes which can be linked to the RCC changes. In particular, they
underline the sensitivity of hydrosystems and vegetation to climatic changes
at a centennial scale. We show that the SH cooling event – correlated with
glacial outburst in the North Atlantic, low values of total solar
irradiance and K
The 9.2 ka event matches one of the early Holocene meltwater pulses at
9.17
The 8.2 ka Hudson Bay event is recorded at all the sites presented here. The 8.2 ka Hudson Bay event, recorded at all the sites presented here, occurs occurs during a long cool interval beginning ca. 8.6 ka (Rohling and Pälike 2005). Like the northern Aegean and Ionian terrestrial archives discussed by Weninger et al. (2014) and Flohr et al. (2016), we discuss below the bi-partitioning of the event in an earlier phase (a cold phase from 8.5–8.4 to 8.2 ka amplified during a later phase (a RCC at 8.2–8.05 ka) by the Hudson Bay outburst, followed by a third sub-phase between 8.05 and 7.9 ka in the northern Greek and central Anatolian archives that we refer to as “C” (Fig. 12a).
The increase in erosion and fluvial activity observed on both archaeological
sites around 8.2 ka has also been observed elsewhere in northern Greece such
as in the Lake Prespa (Panagiotopoulos et al., 2013) and Lake Doirani (Zhang
et al., 2014) (Figs. 2, 12a) areas. This confirms the trends of increase in
soil erosion and sediment transfer to the wetland around 40–41
Nevertheless, the observations made on the edge of the Tenaghi Philippon
marsh evoke questions. In fact, from 8.4 to 8.1 ka, a general cooling has
been recorded by recent Holocene palaeoclimatic studies in the
Tenaghi Philippon marsh (Pross et al., 2009) and northern marine Aegean
region (Kotthoff et al., 2008) with an interruption in Sapropel 1 formation
(Fig. 2). These studies propose a scenario of deteriorated winter climate conditions
with temperatures lowered by more than 4
We know almost nothing of the late Mesolithic (blade and trapeze assemblages)
in the Balkan Peninsula (7th millennia BC). Our new data will not, however, solve
this problem. Only very restricted regions like the Iron Gates are
documented, but these are far from the Aegean coast. A similar observation seems true in
western Turkey (Özdogan, 2007). The hiatus seems to be partly bridged by
systematic surveys such as in the mountains of Pindus between Macedonia and
Epirus (Efstratiou et al., 2006), or by geoarchaeological explorations
further in floodplains and the vast sedimentary basins of the Aegean and
Balkan (Berger, 2016). Our data show that the 8.2 ka event played a
significant role in the archaeological records. Indeed, truncature and
hiatuses correspond to erosional events or riverscape changes more than
abandonment of inhabited areas. This explains, for example, the archeological
continuity which led the first archaeologists of the site to suggest the
hypothesis of a “Sidarian” Neolithic inherited from an existing local
Mesolithic. Alluvial truncations moved sedimentary horizons of these two
cultural periods (by sediment ablation) and may even have connected them
within alluvial formations where we found reworked Mesolithic and early
Neolithic material and charcoal (Berger et al., 2014). New data and
reinterpretation of old archaeological data illustrate a strong erosion phase
at the Mesolithic–early Neolithic transition in the central Mediterranean
area (Mlekuz et al., 2008; Berger and Guilaine, 2009; Berger et al., 2014). A
similar process is observed in the eastern Mediterranean area in the
Khirokitia sites (Cyprus), where at least two episodes of fluvial discharges,
flash flood types, strongly impact the Neolithic village. The same dynamic is
observed in Ain Ghazal, Wadi Shu'eib and Abu Thawwab in the Levant, where
densely packed layers of cobble deposits are observed between late PPNB and
PN archaeological horizons (Simmons and Mandel, 1988), with a permanent
uncertainty about the absolute chronology of these events after the
remobilisation of
Morpho- and pedosedimentary contexts of four central to eastern Mediterranean early Neolithic sites (Konispol Cave, Sidari, Dikili Tash and Khirokitia) illustrating the 8.2 ka event effects on the archaeological occupations. Geomorphological change applies on pure anthropogenic horizons or palaeosols, revealing an abrupt change in the local pedosedimentary functioning: 1, gravel layer; 2, sandy layer; 3, silty layer; 4, ashy layer; 5, oncolithic sands; 6, palaeosols; 7, in situ Neolithic layers; 8, slightly reworked Neolithic layer; 9, strongly reworked Neolithic layer; 10, red silty clay colluvial deposit (from Terra Rossa); 11, flints/ceramics; 12, earth radiocarbon dates are in ka cal BP.
Neolithic dynamic and early Holocene RCC in Anatolia. Note: sites are selected on the basis of being the oldest ones excavated in their region (i.e. sites founded after 8.0 ka cal BP are not shown) (sources: Fontugne et al., 1999; Kuzucuoğlu et al., 1997, 1998, 1999; Düring, 2002, 2011; Boyer et al., 2006; Gürel and Lermi, 2010; Özbaşaran, 2011; Baird, 2012; several articles in Özdoğan et al., 2012a, b; Kuzucuoğlu, 2013, 2014; Stiner et al., 2014).
The question that now arises is, in the case of western Anatolia, why and how the diffusion of Neolithic practices occurred from the central plateaus towards the Aegean region, and at what speed. The early Neolithic is rooted in local PPN cultures at Catalhöyük East ca. 9.4/9.3 ka cal BP, in the Lake District ca. 9.2/9.1 ka cal BP, and possibly in the Aegean region (Ulucak) in the early centuries of the 9th millenium cal BP (Fig. 14). In these specifically local contexts, pottery appears at about the same time in excavated sites between 9.0 and 8.8 ka cal BP.
From 8.6 to 8.0 ka, the cultures of Yarmoukian (southern Levant),
Khirokitian (Cyprus), and Monochrome (western Anatolia, Aegean) (Fig. 2) are
directly faced with climate change. There is also manifold evidence for
population movements in coastal and low-lying locations in the northern and
southern Levant, and finally with the abrupt appearance of Neolithic
communities in the Aegean/Ionian zone, where Dikili Tash and Sidari are
located (Weninger et al., 2014). Weninger et al. (2006, 2014) suggest that
climate-induced crises may have forced early farming communities to break up
and move in order to escape new conditions and possible related conflicts
(scalar stress). In the first phase of the 8.2 RCC (8.6–8.3 ka: phase A),
there is evidence of a push/pull to coastal and lower-lying locations in the
southern Levant and Anatolia after Clare (2013), but this trend hypothesis
seems questionable according to Flohr et al. (2016) and from the anatolian
data discussed in this paper. As coastal and lower-lying areas would have
been less affected by typical RCC impacts (drought and severe winters)
(Weninger et al., 2014), the related abandonment of sites in Jordan, in the
northern Levant, eastern Anatolia and Cyprus is referred to as the “late
Yarmoukian crisis”. This cultural event coincides for the authors with a
further wave of Neolithic expansion into southeastern Europe in the second
phase of RCC (8.3–8.0 ka: phase B). But in the light of three new
radiocarbon data series (with charcoals and short-lived species) on the early
Neolithic from northern Greece and of new, clear geoarchaeological contexts,
we propose a different temporal timing for northern Greece colonisation than
Weninger et al. (2014) by demonstrating the anteriority of Neolithic
migration from western Anatolia (Dikili Tash, Sidari, Mavropigi-Filotsairi
and Nea Nikomedia) to the second phase (B) of 8.2 ka events, sometimes far
to the west. This assertion is also based on local chronostratigraphic and
geomorphic contexts in Sidari and Dikili Tash, which illustrate the
posteriority of hydrogeomorphological and erosion signatures to Neolithic
implantations (Figs. 12a, 13). The chronology of this northern Greece
Neolithic package implantation would no longer be synchronous with the
strictly speaking 8.2 ka event (glacial-outburst-derived effects), whose
minimum time is estimated between 8.2 and 8.05 ka in the more precise
glacial and speleothem proxy data (Fig. 1) but could be in adequation with
the more general aridification/cooling from 8.6/8.5 to 8.0 ka (Rohling and
Pälike, 2005; Göktürk et al., 2011). The earliest spread of
Neolithic packages to western and northwestern Anatolia occurred almost a
thousand years before the 8.2 ka event, as illustrated by recently published
robust chronological studies (Özdogan et al., 2012a, b; Düring 2013;
Clare, 2013; Brami, 2014; Kuzucuoglu, 2014; Stiner et al., 2014; Weninger et
al., 2014; Flohr et al., 2016) (Figs. 12a, 14). The
question that now arises is whether the diffusion of Neolithic practices
which began in the central Anatolian highlands around 8.7 ka are included in
the same timing and in a same cultural stream, the northern Aegean area to
the southern Balkan borders (Thrace, Macedonia, Thessaly). This hypothesis is
defended by Weninger et al. (2014), who claim that, from the middle of phase
A (Figs. 1, 12b), a rapid and continuous colonisation movement can fit from
the highlands of central Anatolia to Greece, with a median speed to the
Neolithic wave of advance from 4 to 6 km yr
The second “European” step took Neolithic lifestyles away from the Aegean
coastline all the way to continental Bulgaria and Serbia by the main river
axis (Struma, Vardar, Maritsa) and could be associated with the Düljunica
(Raiko Krauß et al., 2014), Anzabegovo (Gimbutas, 1976) and Kovacevo
(Lichardus-Itten, 2016) pre-Karanovo sites just after the Hudson Bay event
(around 8.1 ka), i.e. almost 200/250 years after the first European
Neolithic wave. We must now integrate into the coming socio-environmental
discussions on the steps of the Neolithic diffusion through the Balkans and
the Adriatic a last shudder of 8.2 ka event between 8.05 and 7.9 ka
(Fig. 1 – green, i.e Lake Maliq, Qunf Cave, Sofular, Steregiou, marine core SL
21, Sidari). This episode is clearly in step with a peak in [K
More fundamentally, the impacts of climatic changes or natural extreme events have to be evaluated in terms of biophysical and social vulnerabilities. Burton et al. (1993, p. 35) refer to the seven dimensions of hazardous events: magnitude, frequency, duration, speed of onset, geographical extent, spatial dispersion, and temporal spacing. However, as underlined by Clare and Weninger (2008), impacts upon the resources of a society are primordial (availability of natural resources), and responses in terms of resources addressed (variety), land use (management), technology (tool production, equipment progress, variety), housing quality and residence location adaptability have to be considered. Social vulnerability studies must consider the societal perception of the causes of environmental change (Blaikie et al., 1994) and the efficiency of social communication processing (Van der Leeuw et al., 2009). There is also a need for more site-specific detailed studies focusing on ecological bases and strategies (Flohr et al., 2016). Only such new trajectories, closely interlinked with the intra-archaeological sites' multidisciplinary analyses, will optimise our perception of forms of socio-environmental resilience. Concretely, for the period and the studied areas, the abrupt global cold events might have affected the vegetative season time, growth of wild plants and predictability of food resources. Loss of soil cover potential (by erosion), as well as the effects of dryness or wetness on soil productivity, can be directly or indirectly documented by quantitative climate reconstructions from pollen diagrams (Peyron et al., 2011). Such data allow discussions about agrarian constraints during RCC events. Recent fire signal studies in the eastern Mediterranean (Lake Van in Wick et al., 2003; Dikili Tash, this study; Sidari, in progress) document dryness, fuel availability and variations in vegetation cover. Similar studies, if systematized in the future, will allow for better evaluation of the respective roles and links of climate changes and human impacts on vegetation. Nevertheless, we must keep in mind that the geographical setting of the eastern Mediterranean results in physically very contrasting environments in which it is often sufficient to move over very short distances to find different environmental conditions (Willcox, 2005; Lespez et al., 2016). In fact, a dry period could imply a move closer to water resources or, conversely, as observed in Dikili Tash, a rise of water table and flood hazards might imply leaving the floodplain to settle higher on the alluvial fans or lower slopes in the surrounding areas. The uneven exploratory and excavation practices on sites and around sites are to question: the lack of extensive archaeological excavations on most reference Neolithic sites (and our uncomplete knowledge of the other ones too, information that is crudely lacking when discussing occupation dates and periods) strongly hampers interpretations on the continuity of Neolithic occupations and therefore and does not always decide on climate impacts on societies. Furthermore, Neolithic communities rely on diverse subsistence strategies including wild resources (Asouti and Fuller, 2013) even during more recent periods (Valamoti, 2015). Finally, the resilience of the early farming societies should not be underestimated (Flohr et al., 2016).
Our paper discusses examples from river and lake systems, from the eastern to central Mediterranean areas (central Anatolia, Cyprus, northeastern and northwestern Greece), which represent continental archives where early Holocene RCC events and their local impact on prehistoric societies can be or is recorded. This study demonstrates the reality of hydrogeomorphological responses to early Holocene RCCs derived from glacial outburst in valleys and alluvial fans and lake–marsh systems. It highlights the importance of Holocene sedimentation and post-depositional disturbances in reading the Mesolithic–early Neolithic transition and attestation of the first true levels of Neolithic occupation in southeastern Europe. Terrestrial records still reflect heterogeneities in palaeoclimatic restitution across the northeastern Mediterranean during RCC events (from central Anatolia to the southern Balkans). This signal heterogeneity will now be discussed in terms of quality of exploited archives, of sampling/measuring time resolution and of regional climatic pattern variations. The widespread use of core scanner geochemical analysis will promote the identification of the finest Holocene variations. The issues are important to better assess climate impact on the functioning of coastal and continental environments, in major societal disruptions such as the Neolithisation of the Mediterranean. Research on the effects and impacts of 10.2 and 9.2 ka RCCs is still in its infancy. Not only are RCC records potentially present in continental sedimentary archives but both their signals and their possible impacts should be better evaluated in the light of socio-environmental perspectives. The probable tripartitioned timing of the 9.2 and 8.2 ka events complicates our view of the Neolithic development and colonisation of Europe. Our hypothesis of an early Neolithic colonisation of the northern Aegean (around 8.4 ka), prior to the assertion of the second and more marked part of the 8.2 ka RCC event, should be supported by new data in the coming years thanks to the increasing number of deep trenches and core drilling in regional river and marshy areas, including the immediate vicinity of the main Neolithic tells whose first sedimentary archives are still often unknown (Fig. 12). The simultaneous achievement of pollen studies with very high time resolution will complete the approach to attest to the first early agricultural practices. These data must be compared to precise archaeological data in order to assess the impact of the climatic changes on the environment and the farming societies at the local scale. Rather than collecting radiocarbon dates in order to propose modelisation of Neolithic expansion, we need to have more case studies at the regional and eastern Mediterranean scale if we want to discuss reasonably the role of climatic changes in cultural transformation. Archaeological data still hidden under alluvium hinder our understanding of land use and historical dynamics, leaving many surprises still to be found.
Radiocarbon dates of Sidari and Khirokitia sites and Dikili Tash cores.
We thank Paléomex-ArcheoMed (CNRS INEE) for their financial and logistic
support. This paper has benefited from the financial support from the ENVOL
programme of the MISTRALs project. Many thanks to the French missions of the
foreign office (MAE) in Greece (site of Dikili Tash; P. Darcque, and
Z. Tsirtsoni) and in Cyprus
(site of Khirokitia; A. Le Brun). We are also grateful to the Collège de France,
“chaire des Civilisations de l'Europe au Néolithique et à l'âge
du Bronze” and the 8th Ephorate of Prehistoric and Classical Antiquities,
Corfu (G. Metallinou). We finally thank the Laboratoire de Mesure du Carbone
14, UMS 2572, and ARTEMIS in Saclay for