scholarly journals Radiocarbon Dating of Buried Trees and Climate Change in West-Central Oklahoma

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 611-614
Author(s):  
Owen K. Davis ◽  
Dai Kaimei ◽  
Jeffrey S. Dean ◽  
Jim Parks ◽  
Robert M. Kalin
Keyword(s):  
Climate Change ◽  
Solar Activity ◽  
Tree Rings ◽  
Negative Correlation ◽  
Radiocarbon Dating ◽  
Juniperus Virginiana ◽  
Radiocarbon Dates ◽  
American Midwest ◽  
West Central ◽  
Global Cooling

Eleven radiocarbon dates and tree-ring analyses of 3 juniper logs demonstrate the potential for 14C analysis of buried logs in the American Midwest. Three junipers (cf. Juniperus virginiana) were recovered from 9.20, 10.50, and 10.60 m in the fill of Carnegie Canyon, west-central Oklahoma. Their 14C ages are calibrated between 3300 and 2800 yr ago. A negative correlation of tree rings and ∆14C (p = 0.013) supports the findings of Schmidt and Gruhle (1988), who demonstrate the association of global cooling with reduced solar activity.

scholarly journals Illinois State Geological Survey Radiocarbon Dates X

Radiocarbon ◽  
1992 ◽  
Vol 34 (1) ◽  
pp. 83-104 ◽  
Author(s):  
Chao-Li Liu ◽  
D. L. Asch ◽  
B. W. Fisher ◽  
D. D. Coleman
Keyword(s):  
Radiocarbon Dating ◽  
Geological Survey ◽  
Radiocarbon Dates ◽  
Cultural Contexts ◽  
Geological Significance ◽  
West Central ◽  
Northwestern University ◽  
Partial List ◽  
University Department ◽  
Central Illinois

The following is a partial list of samples of archaeological interest processed between February 1981 and October 1985 at the Illinois State Geological Survey (ISGS) Radiocarbon Dating Laboratory. The list contains samples from west-central Illinois that were related to projects conducted by current or former researchers at the Center for American Archeology (CAA) (formerly Foundation for Illinois Archaeology) and Northwestern University, Department of Anthropology, or, as noted, by colleagues from other institutions. Although some of the samples reported here came from non-cultural contexts and are primarily of geological significance, all were from or related to archaeological investigations.

Relevance of medieval, Egyptian and American dates to the study of climatic and radiocarbon variability

1990 ◽  
Vol 330 (1615) ◽  
pp. 517-527 ◽  
Keyword(s):  
Solar Activity ◽  
Radiocarbon Dating ◽  
Climatic Changes ◽  
Radiocarbon Dates ◽  
Complex Interactions ◽  
History Of ◽  
Geomagnetic Fields ◽  
Time Variations ◽  
Empirical Research Methods ◽  
Short Time

Basic radiocarbon dating and dendrochronology have been combined to yield calibrated dates that are more accurate than conventional radiocarbon dates. This has been shown to be true for medieval and Egyptian dynastic dating. Because radiocarbon is a cosmogenically produced radioisotope, heliomagnetic and geomagnetic fields play a major role in its synthesis in the Earth’s upper atmosphere. Inasmuch as a calibrated radiocarbon record exists for nearly 10000 years, we now seem to possess in the short-time variations of the production rate a history of solar activity expressed via heliomagnetic fields carried by the solar wind. In turn, solar activity has a controlling effect on climate on Earth within modifications provided by the complex interactions of the atmosphere—Earth—ocean system. Both radiocarbon measurements and other empirical research methods agree on variations of climate during historically more recent periods on Earth. This leads to the suggestion that the radiocarbon calibration curve may be also a significant indicator or tracer for climatic changes for the Holocene or the Neolithic-Mesolithic.

scholarly journals BATCH PROCESSING OF TREE-RING SAMPLES FOR RADIOCARBON ANALYSIS

Radiocarbon ◽  
2020 ◽  
pp. 1-13
Author(s):  
Alexandra Fogtmann-Schulz ◽  
Sabrina G K Kudsk ◽  
Florian Adolphi ◽  
Christoffer Karoff ◽  
Mads F Knudsen ◽  
...  
Keyword(s):  
High Precision ◽  
Tree Rings ◽  
Precision Measurement ◽  
Radiocarbon Dating ◽  
The Other ◽  
High Precision Measurement ◽  
Machine Performance ◽  
High Throughput Method ◽  
Ca 50 ◽  
Low Activity

ABSTRACT We here present a comparison of methods for the pretreatment of a batch of tree rings for high-precision measurement of radiocarbon at the Aarhus AMS Centre (AARAMS), Aarhus University, Denmark. The aim was to develop an efficient and high-throughput method able to pretreat ca. 50 samples at a time. We tested two methods for extracting α-cellulose from wood to find the most optimal for our use. One method used acetic acid, the other used HCl acid for the delignification. The testing was conducted on background 14C samples, in order to assess the effect of the different pretreatment methods on low-activity samples. Furthermore, the extracted wood and cellulose fractions were analyzed using Fourier transform infrared (FTIR) spectroscopy, which showed a successful extraction of α-cellulose from the samples. Cellulose samples were pretreated at AARAMS, and the graphitization and radiocarbon analysis of these samples were done at both AARAMS and the radiocarbon dating laboratory at Lund University to compare the graphitization and AMS machine performance. No significant offset was found between the two sets of measurements. Based on these tests, the pretreatment of tree rings for high-precision radiocarbon analysis at AARAMS will henceforth use HCI for the delignification.

Stratigraphy of the Colorado Creek Mammoth Locality, Alaska

1992 ◽  
Vol 37 (2) ◽  
pp. 214-228 ◽  
Author(s):  
Robert M. Thorson ◽  
R. Dale Guthrie
Keyword(s):  
Regional Climate ◽  
Slope Aspect ◽  
Proxy Record ◽  
Radiocarbon Dates ◽  
West Central ◽  
Permafrost Table ◽  
Eolian Deposits ◽  
Paleoclimatic Proxy

AbstractThe Colorado Creek mammoth locality in west-central Alaska contains the remains of two mammoths that were scavenged by carnivores. Sedimentologic interpretations of the reworked eolian deposits surrounding the bones, supplemented by 10 radiocarbon dates, indicate that the lower and upper mammoths died and were buried within separate, but superimposed, thaw gullies about 23,000 and 16,000 yr ago, respectively. From our results, we propose a polycyclic taphonomic model for thaw gullies governed largely by slope aspect, rather than regional climate, and in which mixing between faunal horizons is more likely than not. Variations in the rate of silt influx and the position of the permafrost table provide a paleoclimatic proxy record that can be correlated to other records in eastern Beringia.

Calibrated Radiocarbon Dating at Keatley Creek: The Chronology of Occupation at a Complex Hunter-Gatherer Village

2003 ◽  
Vol 68 (4) ◽  
pp. 719-735 ◽  
Author(s):  
William C. Prentiss ◽  
Michael Lenert ◽  
Thomas A. Foor ◽  
Nathan B. Goodale ◽  
Trinity Schlegel
Keyword(s):  
British Columbia ◽  
Radiocarbon Dating ◽  
Climatic Factors ◽  
Climatic Warming ◽  
Radiocarbon Dates ◽  
Population Aggregation ◽  
Selective Environment

This paper provides an analysis of radiocarbon dates acquired during earlier and recent field seasons at the Keatley Creek site, southern British Columbia. Results indicate that early occupations predating 1900 cal. B.P. occurred, but were not likely associated with population aggregation and large housepits. The aggregated village appears to have emerged by approximately 1700 cal. B.P. and was abandoned at approximately 800 cal. B.P. A break in the occupational sequence is recognized at 1450-1350 cal. B.P. and one other short break may have occurred shortly after 1250 cal. B.P. Peak socioeconomic complexity appears to have been achieved between 1350 and 800 cal B.P. Climatic warming may have provided a selective environment favoring population aggregation and intensification during this time. The final abandonment of the Keatley Creek village appears to have been part of a regional phenomenon suggesting the possibility that climatic factors were important in this case as well.

Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to global cooling and Paratethys sea incursions

2021 ◽  
Author(s):  
Chengcheng Ye ◽  
Yibo Yang ◽  
Xiaomin Fang ◽  
Weilin Zhang ◽  
Chunhui Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Middle Eocene ◽  
Qaidam Basin ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Driving Mechanism ◽  
The Tibetan Plateau ◽  
Early Oligocene ◽  
Global Cooling

<p>Global cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene–early Oligocene, when the global climate was characterized by generally continuous cooling followed by the rapid Eocene–Oligocene climate transition (EOT). Therefore, a middle Eocene–early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of global cooling.</p><p>Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch’s salinity, collectively present a three-staged salinity evolution, from an oligohaline–mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by global cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.</p>

scholarly journals Paleoclimatic Implications of Radiocarbon Dating Of Speleothems from the Cracow-Wieluń Upland, Southern Poland

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Anna Pazdur ◽  
Mieczysław F. Pazdur ◽  
Jacek Pawlyta ◽  
Andrzej Górny ◽  
Michał Olszewski
Keyword(s):  
Systematic Study ◽  
Radiocarbon Dating ◽  
Karst Region ◽  
Radiocarbon Dates ◽  
Preliminary Results ◽  
Last Glaciation ◽  
Geological Museum ◽  
Paleoclimatic Records ◽  
Age Range

We report preliminary results of a long-term systematic study intended to gather paleoclimatic records from precisely dated speleothems. The research project is limited to speleothems deposited in caves of the Cracow-Wieluń Upland, the largest and best-explored karst region in Poland, covering ca. 2900 km2 with >1000 caves. Speleothem samples were selected from collections of the Geological Museum of the Academy of Mining and Metallurgy in Cracow. Radiocarbon dates of these samples from ca. 45–20 ka bp almost exactly coincide with age range of the Interplenivistulian. A break in speleothem formation between ca. 20 and 10 ka bp may be interpreted as a result of serious climatic deterioration associated with the maximum extent of the last glaciation. We observed differences among 14C, U/Th and AAR dating results. Changes of δ13C and δ18O in speleothems that grew between ca. 30 and 20 ka bp may be interpreted as changes of paleoclimatic conditions.

Radiocarbon dates from Fazzan, southern Libya

2002 ◽  
Vol 33 ◽  
pp. 9-19 ◽  
Author(s):  
David Mattingly ◽  
David Edwards ◽  
John Dore
Keyword(s):  
Radiocarbon Dating ◽  
Short Paper ◽  
Important Conclusion ◽  
Historic Period ◽  
Radiocarbon Dates ◽  
Full List ◽  
Ams Dating ◽  
The 1960S ◽  
Early Islamic

AbstractThis short paper presents a full list of the currently available radiocarbon dates from the work of Charles Daniels in the 1960s-1970s and the Fazzan Project (1997-2001). The dates can be grouped into several categories, by site or area, and demonstrate the potential of radiocarbon dating being applied to historic-period archaeology in the Sahara. This complements earlier Italian work on later prehistory. One of the most important conclusions to emerge is that the construction of castle-like buildings in Fazzan began within the Garamantian period and that some of the numerous well-preserved mudbrick fortified sites are thus rather earlier than has previously been envisaged. A second important conclusion is that the use of AMS dating can help to identify and confirm activity of the post-Garamantian and early Islamic phases, which has hitherto been elusive.

scholarly journals The Integration of Radiocarbon Dating in Archaeology

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 639-644 ◽  
Author(s):  
H T Waterbolk
Keyword(s):  
Radiocarbon Dating ◽  
The Other ◽  
New Method ◽  
Time Range ◽  
Traditional Methods ◽  
Radiocarbon Dates ◽  
Fully Integrated ◽  
Expected Time ◽  
The Past

In the past 30 years many hundreds of archaeologic samples have been dated by radiocarbon laboratories. Yet, one cannot say that 14C dating is fully integrated into archaeology. For many archaeologists, a 14C date is an outside expertise, for which they are grateful, when it provides the answer to an otherwise insoluble chronologic problem and when it falls within the expected time range. But if a 14C date contradicts other chronologic evidence, they often find the ‘solution’ inexplicable. Some archaeologists are so impressed by the new method, that they neglect the other evidence; others simply reject problematic 14C dates as archaeologically unacceptable. Frequently, excavation reports are provided with an appendix listing the relevant 14C dates with little or no discussion of their implication. It is rare, indeed, to see in archaeologic reports a careful weighing of the various types of chronologic evidence. Yet, this is precisely what the archaeologist is accustomed to do with the evidence from his traditional methods for building up a chronology: typology and stratigraphy. Why should he not be able to include radiocarbon dates in the same way in his considerations?

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