scholarly journals Implications of Radiocarbon Dates from Potter Creek Cave, Shasta County, California, USA

Radiocarbon ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 931-936 ◽  
Author(s):  
Robert S Feranec
Keyword(s):  
Late Pleistocene ◽  
Bone Collagen ◽  
Radiocarbon Dates ◽  
The North ◽  
Terminal Pleistocene ◽  
Shasta County

New dates obtained from the bone collagen of mammals from the deposits in Potter Creek Cave, Shasta County, California, USA, show that these fossils were emplaced over the last 30,000 yr. The dates support the assignment of the fauna in the cave to the late Pleistocene and are contemporaneous to the dates obtained from the fauna of Samwel Cave located 5 km to the north. These new dates do not support previous radiocarbon dates suggesting a Holocene extinction of the extinct bovid Euceratherium collinum, and demonstrate that this and other megafauna were not present in the vicinity after the terminal Pleistocene.

Too Little, Too Late? The Radiocarbon Chronology of Alaska and the Peopling of the New World

2006 ◽  
Vol 71 (4) ◽  
pp. 595-620 ◽  
Author(s):  
Michael R. Bever
Keyword(s):  
Native Americans ◽  
Late Pleistocene ◽  
New World ◽  
Archaeological Record ◽  
Human Occupation ◽  
Radiocarbon Dates ◽  
Point Of Entry ◽  
Central Asian ◽  
Terminal Pleistocene ◽  
Radiocarbon Chronology

Alaska is commonly viewed as a gateway between the Old and New Worlds, and as such, figures prominently in most models of the peopling of the New World. With a growing number of archaeological sites dating to the terminal Pleistocene, Alaska might be expected to provide direct evidence bearing on the colonization of the Americas. Based on 27 site components with 114 radiocarbon dates, this paper discusses the archaeological record of late Pleistocene Alaska, organized around the characteristics and chronology of three complexes: the microblade-bearing Denali complex, the Nenana complex, and the Mesa complex. This paper shows that the archaeological record of late Pleistocene Alaska is quite diverse, and not lacking in controversy and conflicting interpretations. In addition, this period of archaeological diversity coincides with the Younger Dryas climatic event. However, none of the reliably dated sites is older than the earliest evidence of human occupation further south in the Americas. Despite this, evidence from DNA studies points strongly to a north-central Asian homeland for Native Americans, upholding Alaska as the point of entry into the New World. Suggestions are offered, then, as to why the Alaskan record remains silent about the initial peopling of the New World.

Late Pleistocene glacial geomorphology and environment of the Hand Hills region and southern Alberta, related to Middle Wisconsin fossil prairie dog sites

1999 ◽  
Vol 36 (9) ◽  
pp. 1567-1581 ◽  
Author(s):  
R R Young ◽  
J A Burns ◽  
R B Rains ◽  
D B Schowalter
Keyword(s):  
Late Pleistocene ◽  
Ice Sheets ◽  
High Elevation ◽  
Prairie Dogs ◽  
Bone Collagen ◽  
Prairie Dog ◽  
Radiocarbon Dates ◽  
Glacial Sediments ◽  
South Central ◽  
Glacial Environments

Ichnofossils (burrow casts) and fossils from an extinct form of prairie dog, Cynomys niobrarius churcherii, in the Hand Hills of south-central Alberta, have provided an important Late Pleistocene stratigraphic marker. The marker fossils provide relative and chronostratigraphic (radiocarbon) ages for nonglacial, periglacial, glacial, and glaciotectonic events and environments in the region. The high-elevation, hilltop position of the fossil sites (~200 m above the surrounding plains) permits reliable extrapolations of glacial environments to the surrounding region. The burrow casts were preserved by infilling from surrounding and overlying sediments through processes of inwashing and animal activity. Three thousand bones, primarily of the extinct prairie dog Cynomys niobrarius churcherii, were recovered from one site, and several hundred more from other locations. Accelerator radiocarbon dates (AMS) on bone collagen show that the prairie dogs lived in the area from at least 33 000 BP to around 22 000 BP. Prairie dog burrow casts crosscut well-developed periglacial structures and stratigraphically underlie all glacial sediments, indicating that harsh periglacial environments preceded their colonization and that the region was later submerged by Laurentide ice. Deformed sediments, 0.5 to 1.5 m thick, were found throughout the upland. The products of deformation overlie, truncate, and (or) incorporate burrow casts, indicating that only limited erosion and glacial deformation occurred during glaciation. Reconstructed ice sheet profiles show a northwest-southeast flow that could only have been achieved by coalescent Laurentide and Cordilleran ice sheets. This demonstrates that a theoretical "ice-free corridor" that some think persisted between the ice sheets during the Late Wisconsin "maximum," did not exist.

scholarly journals Spatially explicit analysis sheds new light on the Pleistocene megafaunal extinction in North America

Paleobiology ◽  
2017 ◽  
Vol 43 (4) ◽  
pp. 642-655 ◽  
Author(s):  
Meaghan M. Emery-Wetherell ◽  
Brianna K. McHorse ◽  
Edward Byrd Davis
Keyword(s):  
North America ◽  
Great Lakes ◽  
Human Activity ◽  
Late Pleistocene ◽  
North American ◽  
Human Populations ◽  
Great Lakes Region ◽  
Radiocarbon Dates ◽  
The North ◽  
Primary Driver

AbstractThe late Pleistocene megafaunal extinctions may have been the first extinctions directly related to human activity, but in North America the close temporal proximity of human arrival and the Younger Dryas climate event has hindered efforts to identify the ultimate extinction cause. Previous work evaluating the roles of climate change and human activity in the North American megafaunal extinction has been stymied by a reliance on geographic binning, yielding contradictory results among researchers. We used a fine-scale geospatial approach in combination with 95 megafaunal last-appearance and 75 human first-appearance radiocarbon dates to evaluate the North American megafaunal extinction. We used kriging to create interpolated first- and last-appearance surfaces from calibrated radiocarbon dates in combination with their geographic autocorrelation. We found substantial evidence for overlap between megafaunal and human populations in many but not all areas, in some cases exceeding 3000 years of predicted overlap. We also found that overlap was highly regional: megafauna had last appearances in Alaska before humans first appeared, but did not have last appearances in the Great Lakes region until several thousand years after the first recorded human appearances. Overlap in the Great Lakes region exceeds uncertainty in radiocarbon measurements or methodological uncertainty and would be even greater with sampling-derived confidence intervals. The kriged maps of last megafaunal occurrence are consistent with climate as a primary driver in some areas, but we cannot eliminate human influence from all regions. The late Pleistocene megafaunal extinction was highly variable in timing and duration of human overlap across the continent, and future analyses should take these regional trends into account.

scholarly journals The Catacomb Cultures of the North-West Caspian Steppe: 14C Chronology, Reservoir Effect, and Paleodiet

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 713-726 ◽  
Author(s):  
N I Shishlina ◽  
J van der Plicht ◽  
R E M Hedges ◽  
E P Zazovskaya ◽  
V S Sevastyanov ◽  
...  
Keyword(s):  
Bronze Age ◽  
Stomach Contents ◽  
Bone Collagen ◽  
Stable Isotope Ratios ◽  
Radiocarbon Dates ◽  
Bone Material ◽  
Reservoir Effect ◽  
North West ◽  
The North ◽  
The Bronze Age

For the Bronze Age Catacomb cultures of the North-West Caspian steppe area in Russia, there is a conflict between the traditional relative archaeological chronology and the chronology based on radiocarbon dates. We show that this conflict can be explained largely by the fact that most dates have been obtained on human bone material and are subject to 14C reservoir effects. This was demonstrated by comparing paired 14C dates derived from human and terrestrial herbivore bone collagen. In addition, values of stable isotope ratios (δ13C and δ15N) and analysis of food remains from vessels and the stomach contents of buried individuals indicate that a large part of the diet of these cultures consisted of fish and mollusks, and we conclude that this is the source of the reservoir effect.

scholarly journals Radiocarbon Dates from the Pleistocene Fossil Deposits of Samwel Cave, Shasta County, California, USA

Radiocarbon ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Robert S Feranec ◽  
Elizabeth A Hadly ◽  
Jessica L Blois ◽  
Anthony D Barnosky ◽  
Adina Paytan
Keyword(s):  
Last Glacial Maximum ◽  
Late Pleistocene ◽  
Glacial Maximum ◽  
Radiocarbon Dates ◽  
Last Glacial ◽  
Cave Deposits ◽  
Shasta County ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Dates obtained from the collagen of 5 mammals from the fossil deposits of Samwel Cave, Shasta County, California, USA, show emplacement during the last glacial maximum. These dates support the assignment of the fauna to the late Pleistocene. The Samwel Cave deposits currently do not appear to be stratified.

A Medieval Burial from Graham Street, Leith, Edinburgh

2003 ◽  
Vol 25 (2) ◽  
pp. 165-169
Author(s):  
Paul R. J. Duffy ◽  
Olivia Lelong
Keyword(s):  
Contextual Information ◽  
Human Remains ◽  
Housing Development ◽  
Archaeological Research ◽  
Archaeological Excavation ◽  
Radiocarbon Dates ◽  
Physical Evidence ◽  
Research Division ◽  
The North ◽  
The Individual

Summary An archaeological excavation was carried out at Graham Street, Leith, Edinburgh by Glasgow University Archaeological Research Division (GUARD) as part of the Historic Scotland Human Remains Call-off Contract following the discovery of human remains during machine excavation of a foundation trench for a new housing development. Excavation demonstrated that the burial was that of a young adult male who had been interred in a supine position with his head orientated towards the north. Radiocarbon dates obtained from a right tibia suggest the individual died between the 15th and 17th centuries AD. Little contextual information exists in documentary or cartographic sources to supplement this scant physical evidence. Accordingly, it is difficult to further refine the context of burial, although a possible link with a historically attested siege or a plague cannot be discounted.

Radiocarbon Dating of Aghios Antonios, Potos, and Intersite Chronological Variability in South Thasos, Greece

Radiocarbon ◽  
2015 ◽  
Vol 57 (5) ◽  
pp. 807-823 ◽  
Author(s):  
Yannis Maniatis ◽  
Nerantzis Nerantzis ◽  
Stratis Papadopoulos
Keyword(s):  
Bronze Age ◽  
Northern Greece ◽  
Population Movements ◽  
Radiocarbon Dates ◽  
The North ◽  
Chronological Sequence ◽  
Hilltop Settlement ◽  
In The Beginning ◽  
Early Late ◽  
Of Greece

Radiocarbon dates obtained for the coastal hilltop settlement of Aghios Antonios Potos in south Thasos are statistically treated to define the absolute chronology for the start and the end of the various habitation and cultural phases at the site. The location was first occupied during the Final Neolithic (FN) between 3800 and 3600 BC, extending this much contested phase to the lowest up to now record for Thasos and the northern Greece. The site is continuously inhabited from Early Bronze Age I until the early Late Bronze Age (LBA; 1363 BC) when it was abandoned. Comparison with other sites in Thasos and particularly with the inland site of Kastri Theologos showed that the first occupation at Aghios Antonios came soon after the abandonment of Kastri in the beginning of the 4th millennium. In fact, after the decline and abandonment of Aghios Antonios in the LBA, the site of Kastri was reinhabited, leading to the hypothesis that part of the coastal population moved inland. The presumed chronological sequence of alternate habitation between the two settlements may evoke explanations for sociocultural and/or environmental dynamics behind population movements in prehistoric Thasos. A major conclusion of the project is that the 4th millennium occupation gap attested in many sites of Greece, especially in the north, is probably bridged in south Thasos, when the data from all sites are taken together. The mobility of people in Final Neolithic south Thasos may explain the general phenomenon of limited occupational sequences in the FN of north Greece.

scholarly journals Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽  
1997 ◽  
Vol 39 (1) ◽  
pp. 27-32 ◽  
Author(s):  
John C. Vogel ◽  
Joel Kronfeld
Keyword(s):  
South Africa ◽  
Magnetic Dipole ◽  
Satisfactory Agreement ◽  
Late Pleistocene ◽  
Calibration Curve ◽  
Dipole Field ◽  
Radiocarbon Dates ◽  
The Past ◽  
The Earth ◽  
Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

The sensitivity of Neotoma to climate change and biodiversity loss over the late Quaternary

2021 ◽  
pp. 1-15
Author(s):  
Catalina P. Tomé ◽  
S. Kathleen Lyons ◽  
Seth D. Newsome ◽  
Felisa A. Smith
Keyword(s):  
Body Size ◽  
Late Quaternary ◽  
Climatic Variability ◽  
Isotope Analysis ◽  
Biodiversity Loss ◽  
Bone Collagen ◽  
Cam Plants ◽  
The Holocene ◽  
Carbon And Nitrogen ◽  
Terminal Pleistocene

Abstract The late Quaternary in North America was marked by highly variable climate and considerable biodiversity loss including a megafaunal extinction event at the terminal Pleistocene. Here, we focus on changes in body size and diet in Neotoma (woodrats) in response to these ecological perturbations using the fossil record from the Edwards Plateau (Texas) across the past 20,000 years. Body mass was estimated using measurements of fossil teeth and diet was quantified using stable isotope analysis of carbon and nitrogen from fossil bone collagen. Prior to ca. 7000 cal yr BP, maximum mass was positively correlated to precipitation and negatively correlated to temperature. Independently, mass was negatively correlated to community composition, becoming more similar to modern over time. Neotoma diet in the Pleistocene was primarily sourced from C3 plants, but became progressively more reliant on C4 (and potentially CAM) plants through the Holocene. Decreasing population mass and higher C4/CAM consumption was associated with a transition from a mesic to xeric landscape. Our results suggest that Neotoma responded to climatic variability during the terminal Pleistocene through changes in body size, while changes in resource availability during the Holocene likely led to shifts in the relative abundance of different Neotoma species in the community.

A multi-proxy reconstruction of climate during the late-Pleistocene to early Holocene transition in the northeastern, USA

2021 ◽  
pp. 1-17
Author(s):  
Laurie D. Grigg ◽  
Kevin J. Engle ◽  
Alison J. Smith ◽  
Bryan N. Shuman ◽  
Maximilian B. Mandl
Keyword(s):  
Late Pleistocene ◽  
Climatic Variability ◽  
Warming Trend ◽  
Early Holocene ◽  
Individual Species ◽  
Environmental Preferences ◽  
The North ◽  
Show Evidence ◽  
Dry Conditions ◽  
Components Analysis

Abstract A multiproxy record from Twin Ponds, VT, is used to reconstruct climatic variability during the late Pleistocene to early Holocene transition. Pollen, ostracodes, δ18O, and lithologic records from 13.5 to 9.0 cal ka BP are presented. Pollen- and ostracode-inferred climatic reconstructions are based on individual species’ environmental preferences and the modern analog technique. Principal components analysis of all proxies highlights the overall warming trend and centennial-scale climatic variability. During the Younger Dryas cooling event (YD), multiple proxies show evidence for cold winter conditions and increasing seasonality after 12.5 cal ka BP. The early Holocene shows an initial phase of rapid warming with a brief cold interval at 11.5 cal ka BP, followed by a more gradual warming; a cool, wet period from 11.2 to 10.8 cal ka BP; and cool, dry conditions from 10.8 to 10.2 cal ka BP. The record ends with steady warming and increasing moisture. Post-YD climatic variability has been observed at other sites in the northeastern United States and points to continued instability in the North Atlantic during the final phases of deglaciation.

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