Paleoenvironments and cultural diversity in late Pleistocene South America

After a summary assessment of certain selected early man sites in various parts of America, the environment of the Venezuelan coastal plain is discussed in order to evaluate the stratigraphy and radiometric dating of the Taima-Taima site, near Coro, Venezuela, where mammals, many now extinct, were killed by people making El Jobo points about 13,000 years ago.Potentially important areas in Peru, Chile and Brazil are mentioned. Certain problems in the models and interpretation of South American paleoclimates are pointed out.The presence of at least four different bifacially flaked stone projectile point traditions in widely separated and environmentally diverse parts of America between 11,000 and 13,000 yr ago suggests that the immediate cultural antecedents of these traditions were essentially independent of one another. From this it is argued that several early American flaked-stone point traditions developed indigenously in America from technological bases which were present in the Old World Middle Paleolithic.     

A late Pleistocene human presence at Huaca Prieta,Peru, and early Pacific Coastal adaptations

Archaeological excavations in deep pre-mound levels at Huaca Prieta in northern Peru have yielded new evidence of late Pleistocene cultural deposits that shed insights into the early human occupation of the Pacific coast of South America. Radiocarbon dates place this occupation between ~ 14,200 and 13,300 cal yr BP. The cultural evidence shares certain basic technological and subsistence traits, including maritime resources and simple flake tools, with previously discovered late Pleistocene sites along the Pacific coast of Peru and Chile. The results help to expand our knowledge of early maritime societies and human adaption to changing coastal environments.     

Peopling of the Americas

Study of the prehistory of an Americas has proceeded through successive cycles, in which archaeologists have assumed or postulated hypotheses of migration and development, have searched for evidence with which to test these hypotheses, and have abandoned them when the evidence proved to be contradictory. We are completing the current cycle and must seek new hypotheses that better fit our present evidence.The available data are reviewed to show the inaccuracy of the current hypotheses and to develop new ones. It is suggested that the first Indians arrived during a Lower Lithic age, marked by the manufacture of irregular flakes, trimmed only on their edges. This age may have started as early as 30,000 BP.South of the Laurentide ice sheet, the Lower Lithic age began to give way about 14,000 BP to a Middle Lithic Age. This was marked by a variety of types of bifacially chipped projectile points which seem to have developed locally: Folsomoid points in Anglo-America, Joboid points in the Circum-Caribbean region, and Magelloid points in western and southern South America.North of the ice sheet, the place of the Middle Lithic age was taken by an Upper Lithic age, marked by microblades of Asiatic origin. These appear to have reached the Bering Strait region about 14,000 BP. The dichotomy between the Middle and Upper Lithic ages lasted until the retreat of the ice ca. 8000 BP.     

Dating climatic episodes of the Holocene

Monitoring evidence indicates that the Holocene embraced a sequence of rather discrete climatic episodes. The transitions between these environmental episodes apparently were abrupt and globally synchronous. This paper reports on statistical analyses of radiocarbon dates associated with environmental change and cultural change.Over 800 ¹⁴C dates associated with pollen maxima and minima, sea level maxima and minima, and top and bottom surfaces of peat beds were simultaneously analyzed to identify times of globally synchronous environmental discontinuities.Some 3700 ¹⁴C dates associated with 155 cultural continua of the world were collectively analyzed to identify worldwide synchroneities in appearance and termination of the cultures.Significant globally synchronous discontinuities were identified in each independent analysis. The dates of environmental and cultural discontinuities are rather similar, particularly during the recent half of the Holocene. The fact that the cultural discontinuities mostly follow rather closely those of the paleobotanical record suggests that there has been a distinct climatic impact on the cultural history of man.     

Archaeology of the Pleistocene-Holocene boundary in Brazil

After a short history of Brazilian research about Pleistocene peopling, the Late Pleistocene/Early Holocene changes of climate and resources are discussed. Claims for a very ancient presence of Man before 13,000 BP (Itaboraí, Toca da Esperança, Pedra Furada and Lapa Vermelha sites) are polemic, because putative structures and artifacts could have been made by natural processes. In central and northeastern Brazil some sites dated between 14,000 and 10,000 BP provide clear evidence of human activities and coexistence with huge Pleistocene mammals.In a synthesis of our present knowledge about the 12,000/8000 BP period, biological aspects of the Lagoa Santa people and their subsistence are discussed. The main regional traditions are Umbu with bifacial projectile points, and Humaitá with heavy implements in the southern part of Brazil. In the central and northeastern regions, the Itaparica tradition is characterized by typical retouched flakes and limaces. Although projectile points are generally thought to be absent in the earliest levels of this tradition, some have been found in Boquete Cave. In Amazonia, some cultural aspects seem to have been the same as in central Brazil.     

Paleoindian bison procurement and paleoenvironments in Middle Park of Colorado

The Upper Twin Mountain Site, located within a geologic slump scar at 2548 m altitude, provides significant information on Paleoindian bison procurement. As the highest known Paleoindian bison bone bed, the site contained the partial skeletal remains of at least 15 adult Late Pleistocene bison (B. antiquus), Goshen projectile points, and debitage. Radiocarbon dates of 10,240±70 and 10,470±50 yr B.P. place Upper Twin Mountain midway between the northern Plains Goshen and southern Plains Plainview sites. With a late fall or early winter mortality of the bison and the presence of only local stone, year round occupation of Middle Park is indicated. Analysis of the geology, soil, and pollen, from the archaeological and nonarchaeological deposits at the Upper Twin Mountain and elsewhere in the region are used to describe the paleoenvironmental conditions in Middle Park. © 1999 John Wiley & Sons, Inc.     

A fractal technique for the classification of projectile point shapes

Certain cultural information is expressed in the morphology of projectile points. the present paper presents a technique that can extract a large amount of information in the shape of these points. Using a concept from fractal geometry, the degree of shape irregularity is quantified. This technique can be used to document variability in shape of individual points within a point type, or among point types. In this paper, the shapes are segmented into two components (structural and textural), and points of similar characteristics plot closely in bivariate plots of these components. If necessary, the method can be modified to provide information at more than two scales.     

Late quaternary paleogeography of Middle Europe and the Northcentral United States: A framework for comparative studies of prehistoric man-land relationships

The work summarized in this paper is an important component of a larger study concerned with the responses of prehistoric hunting-gathering cultures to long term environmental change. the general approach involves comparing cultural systems and their transformations in Middle Europe and the northcentral United States during the late Pleistocene and early Holocene transition from glacial to interglacial conditions. This paper is specifically aimed at identifying ecological factors that may help account for similarities and differences in the cultural successions on opposite sides of the Atlantic. We conclude that, despite broadly similar environmental histories in both regions, important differences are evident in, for example, trajectories of climatic amelioration. These, together with differences in human demography, can be seen to have contributed toward shaping divergent cultural adaptations in Europe and North America.     

Dating the introduction of cereal cultivation to the British Isles: early palaeoecological evidence from the Isle of Man

The adoption of cereal cultivation is a key benchmark in the transition from Mesolithic hunter–gatherer foraging to Neolithic farming economies, but the nature, timing and ecological–cultural context of the earliest cereal use in the British Isles and northwest Europe is still uncertain. We present AMS radiocarbon dating and fine‐resolution pollen evidence from the Isle of Man for cereal growing in the latter stages of a distinct episode of forest disturbance at almost 6000 yr BP (uncalibrated). The coherent ecological structure of this phase at the fine resolution level suggests that it records cereal cultivation well before the Ulmus decline, rather than wild grass pollen grains. This example is one of a cluster of early dates for cereal‐type pollen near the start of the sixth millenium BP, including several around the Irish Sea, which indicate that the introduction of cereal agriculture probably occurred as early in the central British Isles as in the northern European plain. This early cereal phase is followed later by a probable phase of pre‐Ulmus decline pastoral activity. We also report Mesolithic age woodland disturbance around 7000 yr BP (uncalibrated) and the first radiocarbon dates for mid‐Holocene forest history of the Isle of Man. Copyright © 2003 John Wiley & Sons, Ltd.     

Rates of Holocene isostatic uplift and relative sea-level lowering of the Baltic in SW Finland based on studies of isolation contacts

Southwestern Finland was covered by the Weichselian ice sheet and experienced rapid glacio-isostatic rebound after early Holocene deglaciation. The present mean overall apparent uplift rate is of the order of 4-5 mm/yr, but immediately after deglaciation the rate of crustal rebound was several times higher. Concurrently with land uplift, relative sea level in the Baltic basin during the past more than 8000 years was also strongly affected by the eustatic changes in sea level. There is ample evidence from earlier studies that during the early Litorina Sea stage on the southeastern coast of Finland around 7000 yr BP (7800 cal. yr BP), the rise in sea level exceeded the rate of land uplift, resulting in a short-lived transgression. Because of a higher rate of uplift, the transgression was even more short-lived or of negligible magnitude in the southwestern part of coastal Finland, but even in this latter case a slowing down in the rate of regression can still be detected. We used evidence from isolation basins to obtain a set of 71 ¹⁴C dates, and over 30 new sea-level index points. The age-elevation data, obtained from lakes in two different areas and located between c. 64 m and 1.5 m above present sea level, display a high degree of internal consistency. This suggests that the dates are reliable, even though most of them were based on bulk sediment samples. The two relative sea-level curves confirm the established model of relatively gradually decreasing rates of relative sea-level lowering since c. 6100 yr BP (7000 cal. yr BP) and clearly indicate that the more northerly of the two study areas experienced the higher rate of glacio-isostatic recovery. In the southerly study area, changes in diatom assemblages and lithostratigraphy suggest that during the early Litorina Sea stage (8300-7600 cal. yr BP) eustatic sea-level rise exceeded land uplift for hundreds of years. Evidence for this transgression was discovered in a lake with a basin threshold at an elevation of 41 m above sea level, which is markedly higher than any previously known site with evidence for the Litorina transgression in Finland. We also discuss evidence for subsequent short-term fluctuations superimposed on the main trends of relative sea-level changes.     

A review of current research on TL dating of loess

The thick loess deposits of China, Central Europe and North America are particularly suitable for the application of the thermoluminescence (TL) dating method because individual grains are likely to have travelled large distances and thus been well exposed to light before deposition. Wind-blown silt grains collected close to glacial rivers in Alaska have been shown to give a ‘zero age’ of not more than 2 ka, demonstrating the efficiency of the zeroing mechanism.Differences in laboratory procedures can cause differences in the TL ages reported, particularly for loess over 100 ka. TL ages for interstadial soils in Europe are in agreement with the very few radiocarbon dates on reliable material, such as charcoal. On the other hand TL dates from sites in Belgium and north-western Germany indicate that the previously accepted chronology, which was based on two radiocarbon dates on humic-rich sediments, is incorrect.The use of the ‘last interglacial’ palaeosol for assessing the TL dates on loess above and below it is limited by the uncertainty in the timing of termination of soil-forming processes; 107 and 71 ka are the limits suggested by the astronomically-derived time scale. Results on deposits from China, North America, Alaska and Europe are discussed in this context.     

Multiple approaches to formation processes: The Pine Spring Site,southwest Wyoming

Excavations in 1964 at the Pine Spring site in southwest Wyoming concluded that the site contains three cultural occupation levels; the earliest allegedly dates to the terminal Pleistocene and is associated with megafauna. However, excavations in 1998 and 2000, and analysis of the stratigraphy, AMS dates, micromorphology, and artifact carbonate isotopes, along with debitage refitting, density, orientation, inclination, burning, and trample damage, could not replicate the 1964 findings. A hiatus in deposition accounts for the highest density of artifacts, and the three original occupations are palimpsests. There is no unequivocal association between evidence of human activity and megafaunal remains. © 2006 Wiley Periodicals, Inc.     

An archaeological perspective of the Pleistocene/Holocene boundary in northern South America

In this paper, I examine Late Pleistocene/Early Holocene adaptations of hunter-gatherers to different ecosystems in northern South America. The role played by the climatic events associated with the Pleistocene/Holocene boundary in the evolution of culture in that part of the Americas is assessed in the light of those adaptations. The conclusion is that the Pleistocene/Holocene boundary is not very useful in understanding the human process of early colonization and adaptation to the various ecosystems of northern South America, because a mechanism of cultural change cannot be linked to that boundary.     

Chronology of late wisconsinan glaciation in middle North America

We propose a chronology of late Wisconsinan glacial fluctuations in middle North America, from Alberta to Wisconsin, based on radiocarbon dates derived solely from wood. Previous chronologies of the southwestern margin of the North American Continental Ice Sheet have depended to a considerable degree on radiocarbon dates from fine-grained organic sediment. This material is commonly contaminated with older carbon, resulting in chronologic confusion. By using only dates from wood, much of the confusion disappears. However, because of the scarcity of wood dates, only four of the sixteen identified fluctuations are accurately dated: an advance into Iowa about 14,000 to 13,500 BP, an advance into South Dakota and Iowa about 12,300 BP, an advance into the Lake Michigan basin about 11,700 BP, and an advance into the Lake Superior basin about 9900 BP. In addition, the beginning of late Wisconsinan glaciation, before 20,000 BP, is fairly well documented. None of the fluctuations in the western part of the region are accurately dated.     

The magnitude of error in conventional bulk-sediment radiocarbon dates from central North America

Although the carbon-reservoir problem with bulk-sediment radiocarbon dates from lakes has long been recognized, many synoptic studies continue to use chronologies derived from such dates. For four sites in central North America, we evaluate chronologies based on conventional radiocarbon dates from bulk sediment versus chronologies based on accelerator mass spectrometry (AMS) radiocarbon dates from terrestrial plant macrofossils. The carbon-reservoir error varies among sites and temporally at individual sites from 0 to 8000 yr. An error of 500–2000 yr is common. This error has important implications for the resolution of precise event chronologies.     

Early Holocene loessic colluviation in northwest England: new evidence for the 8.2 ka event in the terrestrial record?

Vincent, P. J., Lord, T. C., Telfer, M. W. & Wilson, P. 2010: Early Holocene loessic colluviation in northwest England: new evidence for the 8.2 ka event in the terrestrial record? Boreas, 10.1111/j.1502‐3885.2010.00172.x. ISSN 0300‐9483. Twelve new samples of loessic silts from widely spaced locations on the karst uplands of northwest England have yielded Optically Stimulated Luminescence (OSL) dates that fall within or overlap with (within uncertainties) the early to mid‐Holocene period (11.7–6.0 ka), and support three already‐published Holocene ages from similar sediment from this region. Nine of the 15 dates are coincident with the hypothesized climatic deterioration at 8.5–8.0 ka in the North Atlantic region and eight are coincident with the 8.2 ka event. These dates demonstrate that the silts are not primary air‐fall loesses of deglacial/Lateglacial age (c. 18.0–11.7 ka) but have been reworked and now consist of loess‐derived colluvial deposits; we consider the ages to be reliable as there is no compelling evidence to indicate that the samples are partially bleached. There is no substantive archaeological or palynological evidence for Late Mesolithic hunter‐gatherers having had a major impact on the landscape, and it is considered highly unlikely that these people triggered colluviation. We estimate that during the 8.2 ka event there was a reduction in mean annual air temperature at these upland locations of ～2.6–4.6 °C, and proxy evidence from other sites indicates a shift to wetter conditions. It is inferred that there was greater snow accumulation in winter, that the snowpack survived for longer periods, and that there was an increase in the magnitude and frequency of frost‐related processes and meltwater flooding. Together, these changes in climate and their associated (sub)surface processes were responsible for the reworking of the loess. The OSL dates indicate climatically induced landscape dynamism in Great Britain during the latter half of the ninth millennium.     

Chronology and new research on the Schaefer mammoth (?Mammuthus primigenius) site,Kenosha County,Wisconsin, USA

A summary of previous and new research on the Schaefer mammoth site is presented. The Schaefer site in extreme southeastern Wisconsin, USA was excavated in 1992 and 1993. Seventy-five percent of a mammoth ?Mammuthus primigenius, the woolly mammoth (but comparable as well with M. jeffersonii, the Jefferson mammoth) was recovered. Drifted wood specimens and plant macro fossils were also recovered from the site.Twenty-five specimens of wood have been identified as Picea sp., Picea/Larix sp., or unidentified hardwood. Macro fossils in the form of cones have been identified as black spruce (Picea mariana). These preliminary data do not appear to support the traditional environment inferred for the woolly mammoth and points to a need for study of the animal's attribution to species. The animal was a male, 36 years of age at death.Thirteen AMS 14C assays on bone cluster between 12,290 and 12,570 BP. Sixteen dates on wood specimens intimately associated with bone yield a range of dates from 11,980 to 12,940 BP.The remains exhibit multiple cut and wedge marks interpreted as cultural. Non-diagnostic cultural lithics were recovered. A disarticulated bone pile deposited in a low energy environment is consistent with human interaction.     

Resurrecting beach ridge archaeology: Parallel depositional records from St. Lawrence Island and Cape Krusenstern,Western Alaska

Archaeological sites on gravel beach ridge plains offer a treacherously facile method of reconstructing cultural chronology based on the assumption that settlements were preferentially situated nearest the sea. the initial phase of beach ridge methodology in Alaska dates from its 1930s use by Henry Collins at St. Lawrence Island and its 1950s use by Louis Giddings in Kotzebue Sound. Numerous questions of cultural and depositional chronology remain unresolved. At Gambell, on St. Lawrence Island, three sets of ridges span the period since about 2000 B.P., with a prominent disconformity after Punuk culture times at ca. 1100 B.P. Reviewing the ¹⁴C dates (n = 83) we find that the Gambell sequence (n = 50) broadly parallels that of Kotzebue Sound, especially in the similar erosional disconformity at 1200-1000 B.P., related to increased storminess in the North Pacific. the Cape Krusenstern sequence is only loosely constrained by ¹⁴C dates (n = 33) disproportionately concentrated on 7 of the 114 ridge fragments. the dating of early Choris culture is especially problematic, which seems to occur both before and after the Old Whaling culture, well-dated at 2900-2800 B.P. on the 53rd ridge. However, reanalyzing the depositional sequence, we find that some of the more easterly Choris ridges probably represent erosional events after the Old Whaling occupation.     

Basalts and silcretes on the coast near Ulladulla,southern New South Wales

Silcretes on the N.S.W. coast near Ulladulla have long been attributed to. a sub‐basaltic origin, but field evidence is at odds with all variations of the sub‐basaltic hypothesis, and one site shows good evidence that the basalt post‐dates the silcrete. K‐Ar ages averaging 29.7 ± 0.5 Ma from the basalts provide a minimum age for silcrete development in this area. Furthermore, the K‐Ar dates, together with evidence for an erosional rather than tectonic origin of the coastal lowland, demonstrate that the adjacent tablelands reached their present elevation prior to the mid‐Oligocene.     

Preliminary investigation of a late Wisconsinan fauna from K1 cave, Queen Charlotte Islands (Haida Gwaii), Canada

Recent investigations of a limestone solution cave on the Queen Charlotte Islands (Haida Gwaii) have yielded skeletal remains of fauna including late Pleistocene and early Holocene bears, one specimen of which dates to ca. 14,400 ¹⁴C yr B.P. This new fossil evidence sheds light on early postglacial environmental conditions in this archipelago, with implications for the timing of early human migration into the Americas.