scholarly journals Gliwice Radiocarbon Dates X

Radiocarbon ◽  
1985 ◽  
Vol 27 (1) ◽  
pp. 52-73 ◽  
Author(s):  
Mieczysław F Pazdur ◽  
Romuald Awsiuk ◽  
Andrzej Bluszcz ◽  
Tomasz Goslar ◽  
Anna Pazdur ◽  
...  
Keyword(s):  
North America ◽  
Human Activity ◽  
Environmental Changes ◽  
Temperate Zone ◽  
Reference Sites ◽  
Radiocarbon Dates ◽  
Natural Factors ◽  
Geographic Regions

The following list contains all age measurements of paleoenvironmental samples made from 1978 to the end of 1982 for the IGCP 158 Project “Paleohydrological changes in the temperate zone in the last 15,000 years,” Subproject B “Lake and mire environments” (Berglund, 1979), initiated by Bjorn Berglund and Leszek Starkel in 1976. The aim of this project was to reconstruct environmental changes related to climate and human activity in the temperate zone of Asia, Europe, and North America. Broad environmental reconstructions will be based upon a network of reference sites representing the natural geographic regions, distinguished by their geology, climate, vegetation, and other natural factors, according to Berglund (1979). The subdivision of Poland into 29 paleoecological units according to Ralska-Jasiewiczowa (1982) is presented in table 1, and in figure 1 where reference sites dated by 14C in our lab are also indicated.

scholarly journals Tree-Ring Records of Near-Younger Dryas Time in Central North America—Preliminary Results from the Lincoln Quarry Site, Central Illinois, Usa

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 933-941 ◽  
Author(s):  
Irina P Panyushkina ◽  
Steven W Leavitt ◽  
Alex Wiedenhoeft ◽  
Sarah Noggle ◽  
Brandon Curry ◽  
...  
Keyword(s):  
North America ◽  
Tree Ring ◽  
Environmental Changes ◽  
Ring Width ◽  
Younger Dryas ◽  
Late Glacial ◽  
Radiocarbon Dates ◽  
Initial Sampling ◽  
Central Illinois ◽  
A Site

The abrupt millennial-scale changes associated with the Younger Dryas (YD) event (“chronozone”) near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial–Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000–14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.

scholarly journals 2400 years of climate and human-induced environmental change recorded in sediments of Lake Młynek in northern Poland

2021 ◽  
Vol 17 (3) ◽  
pp. 1181-1198
Author(s):  
Fabian Welc ◽  
Jerzy Nitychoruk ◽  
Leszek Marks ◽  
Krzysztof Bińka ◽  
Anna Rogóż-Matyszczak ◽  
...  
Keyword(s):  
Human Impact ◽  
Human Activity ◽  
Iron Age ◽  
Environmental Changes ◽  
Deciduous Forest ◽  
13Th Century ◽  
Radiocarbon Dates ◽  
Forest Clearing ◽  
Early Medieval Period ◽  
Northern Poland

Abstract. In the densely forested Warmia and Masuria region (northern Poland) there are many small endorheic lakes characterized by their low sedimentation rate, which makes them excellent archives of Holocene environmental and palaeoclimatic change. Lake Młynek, located near the village of Janiki Wielkie, was selected for multi-faceted palaeoenvironmental research supported with radiocarbon dates. Sediments from this lake also contain unique information about human impact on the environment, because a stronghold has been operating on its northern shore since the early Iron Age to the early Medieval period, giving the opportunity to correlate palaeoenvironmental data with the phases of human activity over the last 2400 years. During the second and third centuries BCE the lake was surrounded by a dense deciduous forest. From the first century BCE to second century CE the forest around the lake was much reduced, which can be associated with the first pre-Roman (La Tène) and Roman occupation phase evidenced by the construction of the stronghold located close to the lake. From the second up to ninth century CE gradual restoration of the forest and a decline in human activity took place, along with lake deepening and the onset of a colder and humid climatic phase which corresponded to the global cooling episode known as the Bond 1 event (1.5 ka BP). The next intensive phase of forest clearing around the lake occurred between the 9th–13th century CE as result of human activity (Middle Age settlement phase of the stronghold). Whilst this period is marked by a warming, the human impact which has transformed the landscape likely overprints any signals of climate-driven environmental changes.

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.

Paleoenvironmental analysis of wet meadow in the Deseado Massif: Implications for the Holocene occupation of Argentinian Patagonia

The Holocene ◽  
2021 ◽  
pp. 095968362110259
Author(s):  
Bruno Mosquera ◽  
María V Mancini
Keyword(s):  
Environmental Changes ◽  
Low Energy ◽  
Semiarid Region ◽  
Human Occupation ◽  
Wet Meadow ◽  
Radiocarbon Dates ◽  
Sedimentation Environment ◽  
Dry Conditions ◽  
Paleoenvironmental Analysis ◽  
Deseado Massif

Paleoenvironmental data from wet-meadow environments in the arid-semiarid region of Patagonia are still incipient and the paleoenvironmental records came from pollen sequences of caves and rockshelters. The main reasons to study wetland records are their undisturbed (by humans) sedimentologic continuity, in contrast to deposits in rock shelters and caves; and their regional presentation of environmental changes that can be compared to archeological data. The aim of this paper is to evaluate the past hydrological dynamic of a wet-meadow from Deseado Massif and its relationship with the human occupation. For this purpose, we present the results of the sediment and pollen analysis of Mallín La Primavera wet-meadow that provide a sequence starting in the mid-Holocene. The results indicate a lower water table in the mallín prior to 6900 cal yr BP. Sediment analysis indicates low energy sedimentation environment with flood events and very low energy streams. Human occupational data show chronological discontinuities in mid-Holocene in several regions of Patagonia and the southern cone. In the studied region, two chronological hiatuses (7828–6434 cal yr BP and 3005–2710 cal yr BP) where recognized that appear to correlate with shrub steppes, indicating dry conditions. These conditions may explain the lack of archeological radiocarbon dates in the area during this period. The integration of sediment and pollen results from the Deseado Massif indicates dry and windy conditions for the middle Holocene. The lack of archeological radiocarbon dates would have been influenced by the loss of moisture in water sources such as springs and their associated wet meadows ( mallines).

scholarly journals Quantifying Southern Pacific Rattlesnake (Crotalus oreganus helleri) Hunting Behavior through Community Science

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 349
Author(s):  
Emily R. Urquidi ◽  
Breanna J. Putman
Keyword(s):  
Habitat Loss ◽  
Human Activity ◽  
Age Differences ◽  
Environmental Changes ◽  
Microhabitat Use ◽  
Ontogenetic Shift ◽  
Community Members ◽  
Hunting Behavior ◽  
Crotalus Oreganus ◽  
Community Science

It is increasingly important to study animal behaviors as these are the first responses organisms mount against environmental changes. Rattlesnakes, in particular, are threatened by habitat loss and human activity, and require costly tracking by researchers to quantify the behaviors of wild individuals. Here, we show how photo-vouchered observations submitted by community members can be used to study cryptic predators like rattlesnakes. We utilized two platforms, iNaturalist and HerpMapper, to study the hunting behaviors of wild Southern Pacific Rattlesnakes. From 220 observation photos, we quantified the direction of the hunting coil (i.e., “handedness”), microhabitat use, timing of observations, and age of the snake. With these data, we looked at whether snakes exhibited an ontogenetic shift in behaviors. We found no age differences in coil direction. However, there was a difference in the microhabitats used by juveniles and adults while hunting. We also found that juveniles were most commonly observed during the spring, while adults were more consistently observed throughout the year. Overall, our study shows the potential of using community science to study the behaviors of cryptic predators.

scholarly journals Population collapse in Congo rainforest from 400 CE urges reassessment of the Bantu Expansion

2021 ◽  
Vol 7 (7) ◽  
pp. eabd8352
Author(s):  
Dirk Seidensticker ◽  
Wannes Hubau ◽  
Dirk Verschuren ◽  
Cesar Fortes-Lima ◽  
Pierre de Maret ◽  
...  
Keyword(s):  
Human Activity ◽  
Climatic Conditions ◽  
Radiocarbon Dates ◽  
Expansion Phase ◽  
Bantu Languages ◽  
Population Collapse ◽  
Early Stages ◽  
Linguistic Evidence ◽  
Spread Model ◽  
Migration Event

The present-day distribution of Bantu languages is commonly thought to reflect the early stages of the Bantu Expansion, the greatest migration event in African prehistory. Using 1149 radiocarbon dates linked to 115 pottery styles recovered from 726 sites throughout the Congo rainforest and adjacent areas, we show that this is not the case. Two periods of more intense human activity, each consisting of an expansion phase with widespread pottery styles and a regionalization phase with many more local pottery styles, are separated by a widespread population collapse between 400 and 600 CE followed by major resettlement centuries later. Coinciding with wetter climatic conditions, the collapse was possibly promoted by a prolonged epidemic. Comparison of our data with genetic and linguistic evidence further supports a spread-over-spread model for the dispersal of Bantu speakers and their languages.

Environmental evolution and anthropogenic forcing in the Garigliano coastal plain (Italy) during the Holocene

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Halinka Di Lorenzo ◽  
Pietro Aucelli ◽  
Giuseppe Corrado ◽  
Mario De Iorio ◽  
Marcello Schiattarella ◽  
...  
Keyword(s):  
Human Activity ◽  
Coastal Plain ◽  
Forest Cover ◽  
Environmental Changes ◽  
Pollen Data ◽  
Human Environment ◽  
The Holocene ◽  
Natural Processes ◽  
History Of ◽  
The Rich

The Garigliano alluvial-coastal plain, at the Latium-Campania border (Italy), witnessed a long-lasting history of human-environment interactions, as demonstrated by the rich archaeological knowledge. With the aim of reconstructing the evolution of the landscape and its interaction with human activity during the last millennia, new pollen results from the coastal sector of the Garigliano Plain were compared with the available pollen data from other nearby sites. The use of pollen data from both the coastal and marine environment allowed integrating the local vegetation dynamics within a wider regional context spanning the last 8000 years. The new pollen data presented in this study derive from the analysis of a core, drilled in the coastal sector, which intercepted the lagoon-marshy environments that occurred in the plain as a response to the Holocene transgression and subsequent coastal progradation. Three radiocarbon ages indicate that the chronology of the analyzed core interval ranges from c. 7200 to c. 2000 cal yr BP. The whole data indicate that a dense forest cover characterized the landscape all along the Prehistoric period, when a few signs of human activity are recorded in the spectra, such as cereal crops, pasture activity and fires. The main environmental changes, forced by natural processes (coastal progradation) but probably enhanced by reclamation works, started from the Graeco-Roman period and led to the reduction of swampy areas that favoured the colonisation of the outer plain.

Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation

2021 ◽  
pp. 1-15
Author(s):  
Thomas M. Cullen ◽  
Lindsay Zanno ◽  
Derek W. Larson ◽  
Erinn Todd ◽  
Philip J. Currie ◽  
...  
Keyword(s):  
High Resolution ◽  
North America ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
Environmental Changes ◽  
Morphometric Analyses ◽  
Variable Distribution ◽  
Taxic Diversity ◽  
Dinosaur Park Formation ◽  
Broad Scale

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one of the most diverse dinosaur faunas, with the record favouring large-bodied taxa, in terms of number and completeness of skeletons. Although small theropods are well documented in the assemblage, taxonomic assessments are frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, and morphometric analyses, with a focus on specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, we test whether DPF theropods preserve faunal zonation/turnover patterns similar to those previously documented for megaherbivores. Frontal bones referred to a therizinosaur (cf. Erlikosaurus), representing among the only skeletal record of the group from the Campanian–Maastrichtian (83–66 Ma) fossil record of North America, plot most closely to troodontids in morphospace, distinct from non-DPF therizinosaurs, a placement supported by a suite of troodontid anatomical frontal characters. Postcranial material referred to cf. Erlikosaurus in North America is also reviewed and found most similar in morphology to caenagnathids, rather than therizinosaurs. Among troodontids, we document considerable morphospace and biostratigraphic overlap between Stenonychosaurus and the recently described Latenivenatrix, as well as a variable distribution of putatively autapomorphic characters, calling the validity of the latter taxon into question. Biostratigraphically, there are no broad-scale patterns of faunal zonation similar to those previously documented in ornithischians from the DPF, with many theropods ranging throughout much of the formation and overlapping extensively, possibly reflecting a lack of sensitivity to environmental changes, or other cryptic ecological or evolutionary factors.

Present and postglacial rates of uplift for glaciated northern and eastern North America derived from postglacial uplift curves

1970 ◽  
Vol 7 (2) ◽  
pp. 703-715 ◽  
Author(s):  
J. T. Andrews
Keyword(s):  
North America ◽  
Eastern North America ◽  
Hudson Bay ◽  
High Cell ◽  
Uplift Rate ◽  
Radiocarbon Dates ◽  
Marine Deposits ◽  
Maximum Value ◽  
Current Maximum ◽  
A Current

Average rates of postglacial uplift reach a maximum value of nearly 4 m 100 y−1 over southeastern Hudson Bay, and another high cell, with rates of about 2.5 m 100 y−1, lies between Bathurst Inlet and Southampton Island. Current rates of uplift are underestimated if exponential curves are fitted solely to dated raised marine deposits without considering the amount of future recovery. Rates of rebound are, instead, derived from A/t where A is uplift in the first 1000 y since deglaciation, and t is time since deglaciation. For the northwest margin of the former ice sheet coefficients of determination for rate of uplift, at specific times, as a function of distance are [Formula: see text]. Maps of rates of uplift for northern and eastern North America are presented for 8000 y B.P., 6000 y B.P. and the present day. They reveal the existence of three uplift centers and show that rates of uplift declined from a maximum of 10 to 12 m 100 y−1, immediately following deglaciation, to a current maximum of about 1.3 m 100 y−1. Agreement is satisfactory when calculated rates of uplift are compared with those derived from geological observations, radiocarbon dates, and from water-level records. A final map shows isochrones on the uplift rate of ~1 m 100 y−1. The rate dropped to this value about 10 000 y ago on the outer northwest and southeast coasts, whereas the value might not be reached for another 2000 y in southeastern Hudson Bay.

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