Radiocarbon Dating of Late Pleistocene Marine Shells from the Southern North Sea

Radiocarbon ◽  
2014 ◽  
Vol 56 (3) ◽  
pp. 1151-1166 ◽  
Author(s):  
F S Busschers ◽  
F P Wesselingh ◽  
R H Kars ◽  
M Versluijs-Helder ◽  
J Wallinga ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Sea Level ◽  
Late Pleistocene ◽  
Radiocarbon Dating ◽  
Sem Analysis ◽  
Bone Collagen ◽  
Shell Material ◽  
Marine Mollusk ◽  
Shell Carbonate ◽  
Age Estimates

This article presents a set of Late Pleistocene marine mollusk radiocarbon (AMS) age estimates of 30–5014C kyr BP, whereas a MIS5 age (>75 ka) is indicated by quartz and feldspar OSL dating, biostratigraphy, U-Th dating, and age-depth relationships with sea level. These results indicate that the14C dates represent minimum ages. The age discrepancy suggests that the shells are contaminated by younger carbon following shell death. The enigmatic14C dates cannot be “solved” by removing part of the shell by stepwise dissolution. SEM analysis of the Late Pleistocene shells within a context of geologically younger (recent/modern, Holocene) and older (Pliocene) shells shows the presence of considerable amounts of an intracrystalline secondary carbonate precipitate. The presence of this precipitate is not visible using XRD since it is of the same (aragonitic) polymorph as the original shell carbonate. The combination of nanospherulitic-shaped carbonate crystals, typical cavities, and the presence of fatty acids leads to the conclusion that the secondary carbonate, and hence the addition of younger carbon, has a bacterial origin. As shell material was studied, this study recommends an assessment of possible bacterial imprints in other materials like bone collagen as well.

scholarly journals CALCINED BONE AS A RELIABLE MEDIUM FOR RADIOCARBON DATING: A TEST USING PAIRED NORTH AMERICAN SAMPLES

2017 ◽  
Vol 82 (3) ◽  
pp. 593-608 ◽  
Author(s):  
James C. Chatters ◽  
James W. Brown ◽  
Steven Hackenberger ◽  
Patrick McCutcheon ◽  
Jonathan Adler
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Radiocarbon Dating ◽  
Bone Collagen ◽  
Organic Media ◽  
Radiocarbon Age ◽  
Cross Dating ◽  
Chronometric Analysis ◽  
Calcined Bone ◽  
Age Estimates

Radiocarbon dating using charcoal and bone collagen, two standards of archaeological chronology, can be difficult to impossible in environments where natural burning is common and bone does not preserve well. In such settings, charcoal ages cannot always be trusted and collagen is unavailable. Calcined bone can be a viable alternative medium in these situations but it has rarely been exploited in the Americas. One area that could benefit from its use is the forested Pacific Northwest. We compare calcined bone ages with charcoal and/or collagen dates from individual features or discrete cultural strata in 10 Washington, Oregon, Idaho, and British Columbia sites dating between 9000 and 100 B.P. Resulting radiocarbon age estimates based on calcined bone closely match those based on charcoal and/or collagen in nearly all cases. We obtained calcined bone dates from three additional Holocene-aged sites that had not previously produced accurate results, obtaining findings consistent with estimates based on cross dating. Preserving well where all other organic media of cultural origin are lost or unreliable, calcined bone holds promise for dating sites in conifer forests and other acidic soil settings, and can allow researchers to refine archaeological sequences that have long defied accurate chronometric analysis.

Some Effects of Partial Recrystallisation on 14C dating Late Pleistocene Corals and Molluscs

1972 ◽  
Vol 2 (02) ◽  
pp. 244-252 ◽  
Author(s):  
John Chappell ◽  
Henry A. Polach
Keyword(s):  
Sea Level ◽  
Carbon Isotope ◽  
Thin Section ◽  
Late Pleistocene ◽  
Closed System ◽  
X Ray Diffraction ◽  
14C Dating ◽  
Shallow Marine ◽  
X Ray ◽  
Shell Carbonate

The issue of sea level during the last interstadial revolves largely around the problem of achieving reliable 14C dates for shell carbonate from Late Pleistocene shallow marine and littoral deposits. A set of 27 samples were collected from Late Pleistocene reefs in New Guinea, and measurements made of 13C, 14C, plus the degree of recrystallisation (determined by X-ray diffraction). The original fibrous aragonite structure of the samples (corals and clams) is seen in thin section to recrystallise in two quite different modes. The carbon isotope results strongly suggest that one mode, the sparry calcite recrystallisation, represents an open geochemical system which allows contamination by more recent 14C, while the subtle coarsening mode of recrystallisation represents a closed system, often yielding reliable results. The reliability of the latter can be validated if a similarly recrystallised sample, known to be outside the range of 14C dating, shows a background 14C count.

DEFINING THE RESPONSE OF A LOW GRADIENT COASTAL SYSTEM TO RAPID SEA-LEVEL CHANGE DURING THE LATE PLEISTOCENE

2019 ◽  
Author(s):  
Amy W. Cressman ◽  
◽  
David J. Mallinson ◽  
Stephen J. Culver ◽  
Regina DeWitt ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Change ◽  
Coastal System ◽  
Level Change

scholarly journals Biofabricated Fatty Acids-Capped Silver Nanoparticles as Potential Antibacterial, Antifungal, Antibiofilm and Anticancer Agents

2021 ◽  
Vol 14 (2) ◽  
pp. 139
Author(s):  
Mohammad Azam Ansari ◽  
Sarah Mousa Maadi Asiri ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
Ahmad Almatroudi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Silver Nanoparticles ◽  
Anticancer Agents ◽  
Sem Analysis ◽  
Dependent Manner ◽  
Anticancer Activities ◽  
Anticancer Efficacy ◽  
Hct 116 ◽  
Hct 116 Cells ◽  
Dose Dependent

The current study demonstrates the synthesis of fatty acids (FAs) capped silver nanoparticles (AgNPs) using aqueous poly-herbal drug Liv52 extract (PLE) as a reducing, dispersing and stabilizing agent. The NPs were characterized by various techniques and used to investigate their potent antibacterial, antibiofilm, antifungal and anticancer activities. GC-MS analysis of PLE shows a total of 37 peaks for a variety of bio-actives compounds. Amongst them, n-hexadecanoic acid (21.95%), linoleic acid (20.45%), oleic acid (18.01%) and stearic acid (13.99%) were found predominately and most likely acted as reducing, stabilizing and encapsulation FAs in LIV-AgNPs formation. FTIR analysis of LIV-AgNPs shows some other functional bio-actives like proteins, sugars and alkenes in the soft PLE corona. The zone of inhibition was 10.0 ± 2.2–18.5 ± 1.0 mm, 10.5 ± 2.5–22.5 ± 1.5 mm and 13.7 ± 1.0–16.5 ± 1.2 against P. aeruginosa, S. aureus and C. albicans, respectively. LIV-AgNPs inhibit biofilm formation in a dose-dependent manner i.e., 54.4 ± 3.1%—10.12 ± 2.3% (S. aureus), 72.7 ± 2.2%–23.3 ± 5.2% (P. aeruginosa) and 85.4 ± 3.3%–25.6 ± 2.2% (C. albicans), and SEM analysis of treated planktonic cells and their biofilm biomass validated the fitness of LIV-AgNPs in future nanoantibiotics. In addition, as prepared FAs rich PLE capped AgNPs have also exhibited significant (p < 0.05 *) antiproliferative activity against cultured HCT-116 cells. Overall, this is a very first demonstration on employment of FAs rich PLE for the synthesis of highly dispersible, stable and uniform sized AgNPs and their antibacterial, antifungal, antibiofilm and anticancer efficacy.

Carbonate diagenesis of the Late Pleistocene limestone of the Faaa M0020A core: IODP Expedition 310, Tahiti Sea Level Change

2010 ◽  
Vol 14 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Kyung Sik Woo ◽  
Kyeong Hwan Yoon ◽  
Young Joo Lee ◽  
Tsutomu Yamada ◽  
Ryuji Asami ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Change ◽  
Carbonate Diagenesis ◽  
Level Change

Radiocarbon Dating and Dietary Stable Isotope Analysis of Kwaday Dän Ts'inchí

2007 ◽  
Vol 72 (4) ◽  
pp. 719-734 ◽  
Author(s):  
Michael P. Richards ◽  
Sheila Greer ◽  
Lorna T. Corr ◽  
Owen Beattie ◽  
Alexander Mackie ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Isotope Analysis ◽  
Human Remains ◽  
Isotopic Analysis ◽  
High Elevation ◽  
Bone Collagen ◽  
Contact Period ◽  
European Contact ◽  
Ams Dating ◽  
The Individual

We report here on the results of AMS dating and isotopic analysis of the frozen human remains named Kwaday Dän Ts'inchí and associated materials recovered from a glacier located in Northwest British Columbia, Canada in 1999. The isotopic analysis of bone collagen (bulk and single amino acids) from the individual indicates a strongly marine diet, which was unexpected given the location of this find, more than 100 km inland eroding out of a high elevation glacier; however, bulk hair and bone cholesterol isotopic values indicate a shift in diet to include more terrestrial foods in the year before death. The radiocarbon dating is not straightforward, as there are difficulties in determining the appropriate marine correction for the human remains, and the spread of dates on the associated artifacts clearly indicates that this was not a single use site. By combining the most recent date on a robe worn by Kwaday Dän Ts'inchi with direct bone collagen dates we conclude that the individual likely dates to between cal A.D. 1670 to 1850, which is in the pre-(or early) European contact period for this region.

Aquatic Radiocarbon Reservoir Offsets in the Southeastern Baltic

Radiocarbon ◽  
2015 ◽  
Vol 57 (4) ◽  
pp. 539-556 ◽  
Author(s):  
Gytis Piličiauskas ◽  
Carl Heron
Keyword(s):  
Stable Isotope ◽  
Bronze Age ◽  
Radiocarbon Dating ◽  
Bone Collagen ◽  
Curonian Lagoon ◽  
Human Bones ◽  
Ceramic Vessel ◽  
Pike Perch ◽  
Ceramic Vessels ◽  
Ams Dates

The aim of this article is to discuss radiocarbon dating offsets due to freshwater and marine reservoir effects (FRE and MRE, respectively) in the southeastern Baltic. Thirty-six 14C dates from Lithuanian coastal and inland Subneolithic, Neolithic, and Bronze Age sites as well as two Mesolithic-Neolithic cemeteries are presented here. Accelerator mass spectrometry (AMS) dates, sometimes paired or tripled, have been obtained on samples of various origin, foodcrusts, or visible charred deposits adhering to the surfaces of ceramic vessel walls were also dated and investigated for stable isotope signals. The results argue for a significant freshwater component in the food processed in ceramic vessels during the Subneolithic and Neolithic. Paired dating of ungulate and human bones at the Spiginas and Donkalnis cemeteries (6300–1900 cal BC) does not suggest an FRE, although stable isotope data on human bone collagen strongly suggest a large input of freshwater food in the diet. An FRE in the order of 320–510 yr was estimated for the Šventoji paleolagoon around 3000 cal BC. At the same time, the FRE of the Curonian Lagoon could be larger as implied by large apparent 14C ages of modern pike-perch (981 ± 30 BP) and bream (738 ± 30 BP) bones as well as “foodcrust” offsets (650–530 yr) at Nida (3500–2500 cal BC). An MRE of 190 ± 43 yr was estimated for the southeastern coast of the Littorina Sea according to offsets between dates of seal bones and terrestrial samples at Nida and Šventoji. Any FRE at Lake Kretuonas remains uncertain due to the limited work to date.

scholarly journals Crevice Interments Deconstructed

2015 ◽  
Author(s):  
Stephen Black ◽  
Katherine Spradley ◽  
Michelle Hamilton
Keyword(s):  
Native American ◽  
Radiocarbon Dating ◽  
Eighth Century ◽  
Bone Collagen ◽  
Private Collection ◽  
Stable Isotopic ◽  
Skeletal Analysis ◽  
Biological Affinity ◽  
Central Texas ◽  
Lines Of Evidence

The discovery of two well preserved human crania in a crevice overlooking a spring fed creek near Austin, Texas, led to medico legal, archeological, and bioanthropological investigations aimed at understanding the context and biological affinity of the crania. Archeological excavations uncovered no evidence that the crania were interred in the crevice during prehistoric times. Skeletal analysis showed they were of Native American ancestry. Radiocarbon dating indicated they are contemporary to one another and probably date to the seventh or eighth century A.D. Measured stable isotopic rations of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) derived from human bone collagen samples from the crania are not consistent with other burial populations from the region, having higher nitrogen values than all other comparative samples. The crania also showed polish from repeated handling and several of the molars in one cranium had been glued in place. Taken together, these lines of evidence suggest the crania were removed from an unknown locality outside the Central Texas region, kept in a private collection, and placed in the crevice recently.

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