A 14C age calibration curve for the last 60 ka: the Greenland-Hulu U/Th timescale and its impact on understanding the Middle to Upper Paleolithic transition in Western Eurasia

This paper combines the data sets available today for ¹⁴C-age calibration of the last 60 ka. By stepwise synchronization of paleoclimate signatures, each of these sets of ¹⁴C-ages is compared with the U/Th-dated Chinese Hulu Cave speleothem records, which shows global paleoclimate change in high temporal resolution. By this synchronization we have established an absolute-dated Greenland-Hulu chronological framework, against which global paleoclimate data can be referenced, extending the ¹⁴C-age calibration curve back to the limits of the radiocarbon method. Based on this new, U/Th-based Greenland_Hulu chronology, we confirm that the radiocarbon timescale underestimates calendar ages by several thousand years during most of Oxygen Isotope Stage 3. Major atmospheric ¹⁴C variations are observed for the period of the Middle to Upper Paleolithic transition, which has significant implications for dating the demise of the last Neandertals. The early part of “the transition” (with ¹⁴C ages > 35.0 ka ¹⁴C BP) coincides with the Laschamp geomagnetic excursion. This period is characterized by highly-elevated atmospheric ¹⁴C levels. The following period ca. 35.0-32.5 ka ¹⁴C BP shows a series of distinct large-scale ¹⁴C age inversions and extended plateaus. In consequence, individual archaeological ¹⁴C dates older than 35.0 ka ¹⁴C BP can be age-calibrated with relatively high precision, while individual dates in the interval 35.0-32.5 ka ¹⁴C BP are subject to large systematic age-‘distortions,’ and chronologies based on large data sets will show apparent age-overlaps of up to ca. 5,000 cal years. Nevertheless, the observed variations in past ¹⁴C levels are not as extreme as previously proposed (“Middle to Upper Paleolithic dating anomaly”), and the new chronological framework leaves ample room for application of radiocarbon dating in the age-range 45.0-25.0 ka ¹⁴C BP at high temporal resolution.     

Dating the demise: neandertal extinction and the establishment of modern humans in the southern Caucasus

This paper considers the recent radiometric dating (¹⁴C-AMS, TL, ESR) of 76 late Middle and early Upper Paleolithic samples from Ortvale Klde Rockshelter, located in the Republic of Georgia. We present a critical evaluation of each date based on its stratigraphic and archaeological context, its pretreatment and contamination history, and its resulting accuracy and precision, the goal being to establish a sound chronology for the site. Only by systematically identifying aberrant dates within a data set and isolating them from further analysis can we hope to understand cultural and biological phenomena on an accurate temporal scale. Based on the strict discard protocol outlined here, we omit 25% of the dated samples from the analysis. The remaining data speak to the lengthy tenure of Neandertals in the region, but also to their relatively rapid demise and the establishment of modern human populations ∼38-34 ka ¹⁴C BP (42-39 ka cal BP_Hulu). We compare these chronometric data with those from the neighboring sites of Bronze and Dzudzuana caves, as well as Mezmaiskaya Cave, located in the northern Caucasus. While the lack of key contextual information limit our ability to subject these other data sets to the same critical evaluation procedure, they provide the first interregional temporal assessment of the Middle to Upper Paleolithic “transition,” the results of which suggest an initial expansion of modern humans into the southern Caucasus followed by expansion along the Black Sea coast and into the northern Caucasus.     

New data on the late Neandertals: Direct dating of the Belgian Spy fossils

In Eurasia, the period between 40,000 and 30,000 BP saw the replacement of Neandertals by anatomically modern humans (AMH) during and after the Middle to Upper Paleolithic transition. The human fossil record for this period is very poorly defined with no overlap between Neandertals and AMH on the basis of direct dates. Four new ¹⁴C dates were obtained on the two adult Neandertals from Spy (Belgium). The results show that Neandertals survived to at least ≈36,000 BP in Belgium and that the Spy fossils may be associated to the Lincombian–Ranisian–Jerzmanowician, a transitional techno‐complex defined in northwest Europe and recognized in the Spy collections. The new data suggest that hypotheses other than Neandertal acculturation by AMH may be considered in this part of Europe. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.     

From the Bay of Naples to the River Don: the Campanian Ignimbrite eruption and the Middle to Upper Paleolithic transition in Eastern Europe

The Campanian Ignimbrite (CI) eruption, dated by ⁴⁰Ar/³⁹Ar and various stratigraphic methods to ca. 39,000 cal BP, generated a massive ash plume from its source in southern Italy across Southeastern and Eastern Europe. At the Kostenki-Borshchevo open-air sites on the Middle Don River in Russia, Upper Paleolithic artifact assemblages are buried below, within, and above the CI tephra (which is redeposited by slope action at most sites) on the second terrace. Luminescence and radiocarbon dating, paleomagnetism, and soil and pollen stratigraphy provide further basis for correlation with the Greenland and North Atlantic climate stratigraphy. The oldest Upper Paleolithic occupation layers at Kostenki-Borshchevo may be broadly correlated with warm intervals that preceded the CI event and Heinrich Event 4 (HE4; Greenland Interstadial: GI 12-GI 9) dating to ca. 45,000-41,000 cal BP. These layers contain an industry not currently recognized in other parts of Europe. Early Upper Paleolithic layers above the CI tephra are correlated with HE4 and warm intervals that occurred during 38,000-30,000 cal BP (GI 8-GI 5), and include an assemblage that is assigned to the Aurigancian industry, associated with skeletal remains of modern humans.     

Hovk 1 and the Middle and Upper Paleolithic of Armenia: a preliminary framework

The territory of present day Armenia is a geographic contact zone between the Near East and the northern Caucasus. Armenian Middle and Upper Paleolithic records are both few and patchy as a result of the historical paucity of systematic archaeological research in the country. Consequently, it is currently difficult to correlate the Armenian Middle and Upper Paleolithic records with those from other neighboring regions. We present new archaeological and chronometric data (luminescence, U-Th, and ¹⁴C) from our ongoing research at Hovk 1 Cave in northeast Armenia. We discuss in particular two activity phases in Hovk 1 Cave for which we have outline chronometric data: (1) an early Middle Paleolithic occupational phase, dated by optically stimulated luminescence (OSL) to 104 ± 9.8 ka BP_OSL; and (2) a Paleolithic occupational phase characterized by microlithic flakes dated by AMS ¹⁴C to 39,109 ± 1,324 calibrated years BP_Hulu. The two phases are separated by a hiatus in hominin occupation corresponding to MIS 4 and an episode in early MIS 3. These chronometric data, taken together with the preliminary paleoenvironmental reconstruction of the Hovk 1 Cave and environment, suggest that these activity phases represent short-lived and seasonal use of the cave presumably by small groups of hunters during episodes of mild climate. Neither tool manufacture nor butchery appears to have taken place within the cave, and consequently, the archaeological record included, for the most part, finished tools and blanks. We address the chronology and techno-typological aspects of Hovk 1 lithics in relation to: (1) the Paleolithic records of Armenia, and (2) the broader interregional context of early Middle Paleolithic hominin occupation and the Middle-Upper Paleolithic transition in the Caucasus.     

Who made the Aurignacian and other early Upper Paleolithic industries?

The Aurignacian is typically taken as a marker of the spread of anatomically modern humans into Europe. However, human remains associated with this industry are frustratingly sparse and often limited to teeth. Some have suggested that Neandertals may, in fact, be responsible for the Aurignacian and the earliest Upper Paleolithic industries. Although dental remains are frequently considered to be taxonomically undiagnostic in this context, recent research shows that Neandertals possess a distinct dental pattern relative to anatomically modern humans. Even so, it is rare to find mandibles or maxillae that preserve all or most of their teeth; and, the probability of correctly identifying individuals represented by only a few teeth or a single tooth is unknown. We present a Bayesian statistical approach to classifying individuals represented exclusively by teeth into two possible groups. The classification is based on dental trait frequencies and sample sizes for ‘known’ samples of 95 Neandertals and 63 Upper Paleolithic modern humans. In a cross validation test of the known samples, 89% of the Neandertals and 89% of the Upper Paleolithic modern humans were classified correctly. We then classified an ‘unknown’ sample of 52 individuals: 34 associated with Aurignacian or other (non-Châtelperronian) early Upper Paleolithic industries, 15 associated with the Châtelperronian, and three unassociated. Of the 34 early Upper Paleolithic-associated individuals, 29 were assigned to modern humans, which is well within the range expected (95% of the time 26-33) with an 11% misclassification rate for an entirely modern human sample. These results provide some of the strongest evidence that anatomically modern humans made the Aurignacian and other (non-Châtelperronian) early Upper Paleolithic industries.     

Le site Paléolithique de Suyanggae, Corée

The Suyanggae site is an open-air site in central part of South Korea. This site was discovered in 1980 and seven excavations have been carried out from 1983 to 1996. As a result, many stone artefacts were unearthed and 49 stone tool workshops were known. This site contains 5 cultural layers and the most important one is the Upper Paleolithic layer. This layer is dated to be 16,400 ~ 18,630 BP by ¹⁴C dating. It shows a massive blade production and microblade technique. It is one of the crucial sites for understanding the Upper Paleolithic of Korea.     

Bohunician technology and thermoluminescence dating of the type locality of Brno-Bohunice (Czech Republic)

Results of thermoluminescence (TL) dating of 11 heated flint artifacts from the 2002 excavation at Brno-Bohunice, Czech Republic, are presented. The samples are from the eponym locality for the Bohunician, an industrial type considered technologically transitional between Middle and Upper Paleolithic core reduction strategies. The Bohunician is the first early Upper Paleolithic technocomplex in the Middle Danube of Central Europe and, therefore, is implicated in several issues related to the origins of modern humans in Europe. The Bohunician provides an example of how one technological strategy combines crested blade initiation of a core with the surficial (almost Levalloisian) reduction of blanks as blades and points. As the Middle Danube lacks antecedents of the behavioral steps within this technology, several hypotheses of inter-regional cultural transmission, with and without hominin gene flow, could explain the appearance of the Bohunician. The elucidation of the temporal context of Bohunician assemblages is, therefore, a critical step in understanding the behavioral, and potentially biological, succession in this region. Radiocarbon age estimates from charcoal associated with Bohunician sites suggest a wide age range between 33 and 41 ka ¹⁴C BP, which is also observed for individual sites. TL dating of heated flint artifacts provides ages on the calendric time scale of an archeological event, the firing. The weighted mean of 48.2 ± 1.9 ka BP_TL for 11 heated flint samples from Brno-Bohunice provides the first non-radiocarbon data on archeological material from the Bohunician. The TL dating, in conjunction with the archeological and sedimentological analysis, allows the evaluation of the integrity of this new type-collection. The hypothetical possibility of the incorporation of Szeletian artifacts (i.e., leaf points) into the site formation processes can therefore be refuted.     

Études du Paléolithique du Japon à partir des téphras

Many studies and discussions have been made on the problem of when the earliest human beings appeared in Japan. In general, hominid fossils in the latest Pleistocene are not preserved except for coralline limestone sequence in Ryukyu islands, but earlier Paleolithic tools were excavated from volcanic ash soil with a ¹⁴C age of about 30,000–35,000 yr. BP or younger at several archeological sites in almost all Japan. Recent studies, however, show a need for revision and refinement of these ages because calibration techniques have progressed from conventional to calendar ages and high-resolution oxygen isotope chronology has given a global standard sequence. Aïra-Tn tephra (AT), the most important time-marker of the Paleolithic age in Japan, was formerly dated at 21,000–22,000 yr ¹⁴C BP by conventional radiocarbon methods but was dated again at ca. 24,500 yr ¹⁴C BP by accelerated mass spectrometry radiocarbon methods. However, it has been further calibrated to a high-resolution calendar age of 30,000 cal yr. by varve chronology of lake sediments of Suigetsu of central Japan, well matched with combined date between oxygen isotope dates based and calibration from AMS radiocarbon dates. As the earliest Paleolithic tools in south Kanto are found in volcanic ash soil significantly below AT ash and above Sambe-Ikeda ash (SI, ca.46 ka), just above the oxygen isotopic stage 3.3, they are estimated to be dated slightly older than 40 ka. Palaeo-environment at that time is estimated mild to cool climate and relatively low sea level after the oxygen isotope stage 3.3. Sill land bridges between Japan islands and continents have not been formed at major straits. We have not yet obtained useful data for calibration older than ca. 45 ka. Also, correlation of oxygen isotopic fluctuation with the terrestrial sequences is incomplete in Stage 3.     

Variabilité et homogénéité des modes de débitage en Chine entre 300 000 et 50 000 ans

The position of lithic industries of Chinese Paleolithic in comparison with those of other regions in the world is always a controversial topic. The typological analysis has made Chinese prehistorians reveal some variability between lithic industries of different regions of China in terms of technical tradition and industrial structure. But this recognition, based upon some morphological characters of stone artifacts, failed to define systematically the modes of production that exist in each site. To answer these problematic some new methods need to be applied. So the lithic materials from 8 Chinese sites dated from 300 ka to 50 ka B.P. were selected and analyzed by means of lithic technological analysis and a new approach for analyzing the structures of cores. This paper presents principally the analytical results of modes of débitage and revealed that the modes of débitage during this period were characterized essentially by system C (“simple débitage”) and E (discoid) and that the concept Levallois was absent during this period in technical systems of lithic production in China. The Chinese lithic industries between 300 ka and 50 ka B.P. saw some homogeneity in the scale of the continent and remarkable difference from those of other regions in the world. So a stable, continuous but independent even isolated evolution in comparison with those of other regions was observed in this period. In addition, despite of apparent homogeneity, some variability exists also between these industries.     

High production of cold-tolerant chitinases on shrimp wastes in bench-top bioreactor by the Antarctic fungus Lecanicillium muscarium CCFEE 5003: Bioprocess optimization and characterization of two main enzymes

The Antarctic fungus Lecanicillium muscarium CCFEE-5003 was preliminary cultivated in shaken flasks to check its chitinase production on rough shrimp and crab wastes. Production on shrimp shells was much higher than that on crab shells (104.6 ± 9.3 and 48.6 ± 3.1 U/L, respectively). For possible industrial applications, bioprocess optimization was studied on shrimp shells in bioreactor using RSM to state best conditions of pH and substrate concentration. Optimization improved the production by 137% (243.6 ± 17.3). Two chitinolytic enzymes (CHI1 and CHI2) were purified and characterized. CHI1 (MW ca. 61 kDa) showed optima at pH 5.5 and 45 °C while CHI2 (MW ca. 25 kDa) optima were at pH 4.5 and 40 °C. Both enzymes maintained high activity levels at 5 °C and were inhibited by Fe⁺⁺, Hg⁺⁺ and Cu⁺⁺. CHI2 was strongly allosamidin-sensitive. Both proteins were N-acetyl-hexosaminidases (E.C. 3.2.1.52) but showed different roles in chitin hydrolysis: CHI1 could be defined as “chitobiase” while CHI2 revealed a main “eso-chitinase” activity.     

Dental remains from the Grotte du Renne at Arcy-sur-Cure (Yonne)

Human remains associated with the earliest Upper Paleolithic industries are sparse. What is preserved is often fragmentary, making it difficult to accurately assign them to a particular species. For some time it has been generally accepted that Neandertals were responsible for the Chatelperronian and anatomically modern humans for the early Aurignacian industries. However, the recent re-dating of several of the more-complete modern human fossils associated with the early Aurignacian (e.g., Vogelherd) has led some to question the identity of the makers and the context of these early Upper Paleolithic industries. The Grotte du Renne at Arcy-sur-Cure, France has yielded many hominin remains, from Mousterian, Chatelperronian, Aurignacian, and Gravettian layers. Previously, a child's temporal bone from the Chatelperronian Layer Xb was recognized as belonging to a Neandertal; however, most of the teeth from Chatelperronian layers VIII-X remain unpublished. We describe the dental remains from the Chatelperronian layers, place them in a comparative (Mousterian Neandertal and Upper Paleolithic modern human) context, and evaluate their taxonomic status. The teeth (n = 29) represent a minimum of six individuals aged from birth to adult. The permanent dental sample (n = 15) from the Chatelperronian layers of Arcy-sur-Cure exhibits traits (e.g., lower molar mid-trigonid crest) that occur more frequently in Neandertals than in Upper Paleolithic modern humans. Furthermore, several teeth show trait combinations, including Cusp 6/mid-trigonid crest/anterior fovea in the lower second molar, that are rare or absent in Upper Paleolithic modern humans. The deciduous teeth (n = 14) significantly increase the sample of known deciduous hominin teeth and are more similar to Mousterian Neandertals from Europe and Asia than to Upper Paleolithic modern humans. Thus, the preponderance of dental evidence from the Grotte du Renne strongly supports that Neandertals were responsible for the Chatelperronian industry at Arcy-sur-Cure.     

Os fossiles humains des grottes Muierii et Cioclovina, Roumanie

This paper presents the cultural and archaeological context of the human fossil bones from Muierii Cave, dated by us to the age of 30 150 ± 800 ¹⁴C years BP (Before Present) or 34 810 ± 927 cal years BP (calibrated years Before Present), and from Cioclovina Cave, dated to the age of 29 000 ± 700 ¹⁴C years BP or 33 540 ± 832 cal years BP, in the Southern Carpathians. These are among the most ancient dated human fossil remains from Central and South-Eastern Europe and are described in conjunction with other sites with Mousterian assemblages of the recent Neanderthal population, and sites with Aurignacian assemblage of early modern humans, from Romanian region, for the interval of time 34,000-26,000, the transitional period from the Middle Paleolithic to the Upper Paleolithic.     

Paléolithique supérieur et Mésolithique en Méditerranée : cadre culturel

The origin of the Upper Palaeolithic around the Mediterranean was the result of the local evolution, particularly in the Near East and in the Lower Nile basin, and of the migration from this zone to South-Eastern and Central Europe. The Initial Upper Palaeolithic in the Near East belt was the effect of local evolution from the industries based on Levallois concept to the industries which developed leptolithic blade technologies. This evolution is well registered in multi-layer sites in the Syro-Palestinian belt (Emirian/Ahmarian), which was the starting point of the diffusion of these “transitional” industries in South-Eastern and Central Europe. This diffusion could be identified with the migration of first anatomically Modern Humans. The Early Upper Palaeolithic in Europe — dated to the second half of the Interpleniglacial — was, at least partially, based on these “transitional” industries and manifested by the appearance of the Aurignacian, contrasted with local cultures such as the Uluzzian in Mediterranean Europe. During whole the Interpleniglacial Europe was separated from Northern Africa dominated by local evolution of Middle Palaeolithic (Middle Stone Age) cultures (mostly expressed by the Aterian), and by specific “transitional” industries on the southern Mediterranean coast (Early Dabbian) and in the Lower Nile basin. The Last Glacial Maximum and the corresponding sea level recession opened new possibilities of contacts between the Maghreb and the Iberian Peninsula in both directions (Aterian-Solutrean and Gravettian-Early Iberomaurusian), which are still difficult to be proved before new chronostratigraphic correlations are made. At the same time we register links between south-eastern Europe and western Anatolia; the real border between Near Eastern and European Mediterranean cultural zones was marked, in the Late Glacial, by the Taurus chain. During the Late Glacial the cultural separation between Europe and Africa was particularly marked. Only in the Aegean basin the first sea navigation facilitated contacts which become widespread as late as in the Early Holocene with neolithization trough maritime contacts.     

La frontière entre le Châtelperronien et l’Uluzzien : analyse comparative des typologies lithiques sur la base des dernières découvertes

The end of the Middle Paleolithic sees the appearance of “transitional” industries, which emerge at the same moment as anatomical modern humans enter Europe. All these transitional industries come from a Mousterian background and are closely connected to late Neanderthals. Among these industries we find two traditions characterized by backed blade pieces in Western Europe: the Châtelperronian and the Uluzzian. Two big conditions have been defined to allow a comparison between these industries: a chronological continuity and a geographic link. The recent data allows a new comparison.     

Middle Paleolithic human remains from the Gruta da Oliveira (Torres Novas), Portugal

Ongoing excavations in the Middle Paleolithic levels at the Gruta da Oliveira, Portugal have yielded four fragmentary human remains, a manual phalanx and an ulna from levels 9 and 10, and a humerus and a tibia from levels 18 and 19. The first two remains date to approximately 39 ka 14C BP ( approximately 43.5 ka cal BP), whereas the latter two derive from earlier in oxygen isotope stage 3. The preserved portions of the phalanx, humerus, and tibia align them morphologically with the Neandertals. In addition, the Oliveira 4 tibial diaphysis shows evidence of carnivore (probably canid) gnawing.     

The Middle-to-Upper Palaeolithic transition in Cova Gran (Catalunya, Spain) and the extinction of Neanderthals in the Iberian Peninsula

The excavations carried out in Cova Gran de Santa Linya (Southeastern PrePyrenees, Catalunya, Spain) have unearthed a new archaeological sequence attributable to the Middle Palaeoloithic/Upper Palaeolithic (MP/UP) transition. This article presents data on the stratigraphy, archaeology, and ¹⁴C AMS dates of three Early Upper Palaeolithic and four Late Middle Palaeolithic levels excavated in Cova Gran. All these archaeological levels fall within the 34-32 ka time span, the temporal frame in which major events of Neanderthal extinction took place. The earliest Early Upper Palaeolithic (497D) and the latest Middle Palaeolithic (S1B) levels in Cova Gran are separated by a sterile gap and permit pinpointing the time period in which the Mousterian disappeared from Northeastern Spain. Technological differences between the Early Upper Palaeolithic and Late Middle Palaeolithic industries in Cova Gran support a cultural rupture between the two periods. A series of 12 ¹⁴C AMS dates prompts reflections on the validity of reconstructions based on radiocarbon data. Thus, results from excavations in Cova Gran lead us to discuss the scenarios relating the MP/UP transition in the Iberian Peninsula, a region considered a refuge of late Neanderthal populations.     

Chronology of the Middle to Upper Palaeolithic transition at Abric Romaní, Catalunya

This paper presents new data from Abric Romaní, a key site in the region of Catalunya, northeastern Iberia, which is central to discussions of the transition between the Middle and Upper Palaeolithic in Europe. Until now, the Mid-Upper Paleolithic transition had been dated at the site through samples from the remaining baulk sections of levels A and B (typologically classified as ‘earliest Aurignacian’ and Mousterian, respectively) at the rear of the rockshelter, which were left from excavations in the late 1900s and early 1910s. We dated samples of bone and charcoal from these remnant sections with accelerator mass spectrometry (AMS) methods. We also analysed several humanly-modified artefacts (bone points and perforated shells) excavated from other areas of the same layers. From the initial series, we obtained ages of c. 20 ka BP (thousands of years before present); much younger than expected if they indeed dated to the early Upper Palaeolithic. We sampled additional material to test the robustness of these initial ages, and older determinations that were more comparable with the chronology outlined by [Bischoff et?al., 1988] and [Bischoff et?al., 1994] resulted. All of the old and new results have been compared in a Bayesian model using the new INTCAL09 ¹⁴C calibration dataset. The results appear to confirm the suggestion of some researchers (e.g., Zilhão and d’Errico, 1999) that there was no Aurignacian in the north of Iberia until c. 36,500 BP. The chronometric model shows a good level of agreement between the radiocarbon and U-series chronologies previously obtained, and the new results published in this paper.     

Cooling in the Gulf of St. Lawrence and estuary region at 9.7 to 7.2 C ka (11.2-8.0 cal ka): Palynological response to the PBO and 8.2 cal ka cold events, Laurentide Ice Sheet air-mass circulation and enhanced freshwater runoff

An examination of post-Younger Dryas (YD) pollen stratigraphies in the Gulf of St. Lawrence and St. Lawrence estuary region reveals features in the pollen records that represent breaks in the normal vegetation succession, widespread vegetation suppression, and a delay in migration of plant taxa between 9.7 and 7.2 ¹⁴C ka (11.2 and 8.0 cal ka). The domination of Alnus crispa at sites bordering the St. Lawrence estuary-Gulf region in Gaspésie and northern New Brunswick within this timeframe represents a diversion from the typical vegetation progression from Picea and/or Populus or Picea/Betula to Pinus and/or Betula, and signifies a shift to a cooler, drier climate. Coinciding with the A. crispa expansion and domination in that region was the contraction of Picea populations in other areas. In southwestern New Brunswick and eastern and southeastern Nova Scotia, Picea was replaced by the first appearance of tree birch, B. papyrifera; whereas in western and southwestern Newfoundland, Picea gave way to a resurgence of shrub birch, Betula glandulosa. The Picea contraction and immediate resurgence of Betula represents cooling, and is reliably dated at 9720 ± 110 ¹⁴C BP (10,800-11,240 cal BP) in southwest Newfoundland. This first post-YD episode of widespread cooling is correlated with the North Atlantic Preboreal Oscillation (PBO) centered around 9650 ¹⁴C BP (10,900-11,180 cal BP) in the adjacent Great Lakes region. Sites exposed to winds from the Gulf of St. Lawrence in eastern New Brunswick, Prince Edward Island, and northern Nova Scotia show a lingering persistence of Picea and delay in arrival of Pinus to 8.0 and 7.7 ¹⁴C ka (9.0 and 8.4 cal ka), yet Pinus was dominant as early as 9.4 ¹⁴C ka (10.6 cal ka) in southwestern New Brunswick. At the same time, tundra vegetation persisted at high elevations in western and southwestern Newfoundland only to be replaced by upslope migration of shrub-birch heath by 8 ¹⁴C ka. Prolonged broad-scale cooling to 8 ¹⁴C ka and to as late as 7.7 ¹⁴C ka extended up to 200 km inland in areas exposed to the St. Lawrence estuary and Gulf region and was in response to strong, cold, dry anticyclonic winds coming off the retreating Laurentide Ice Sheet in combination with enhanced freshwater runoff through the Gulf of St. Lawrence.The end of the period of prolonged cooling and onset of regional warming coincided with the diversion of western Canada runoff and Agassiz-Ojibway drainage to Hudson Bay and reduced effect or final break-up of the Laurentide Ice Sheet. Several sites document a subsequent cold shift, that interrupted regional warming at 7650 to 7200 ¹⁴C BP (8400 to 8000 cal BP), and which is variously represented by the suppression of Pinus and resurgence of Picea, sometimes with A. crispa (Québec-Maritime region), or by an abrupt decrease of Picea and resurgence of Betula (western Newfoundland). This second post-YD cool interval is equated with the 8200 cal BP cold event registered in the Greenland ice isotopic record.