Archaeology ; Biogenic process ; C14 dating ; Carbonate ; Dating ; Methodology ; Nebraska ; Quaternary ; United States of America ; Utah
This paper reports on C14 systematics of modern hackberry endocarp carbonate and examine its potential as a C14 dating substrate. C14 dates of fossil endocarp carbonates compared favorably with dates obtained by other means at archaeological
and geological sites ranging in age from the late Pleistocene through the early Holocene. They therefore suggest that hackberry endocarp is a suitable substrate for C14 dating provided that its morphological and mineralogical integrity is preserved.
A magnetostratigraphic comparison between 14C years and varve years during the Late Weichselian indicating significant differences between the time-scales
Datation ; Datation C14 ; Géographie de l'Europe ; Paléomagnétisme ; Stratigraphie ; Suède ; Technique de recherche ; Varve
Statistical correlations between the two independantly dated time-scales suggest that at 10 500-10 200 14C years B. P. the varvechronology exceeds the 14C chronology by the order of 500-600 varve/year. Further correlations between the time-scales
at 12 000 14C years B. P. suggest that the difference between the chronologies increased steadily from 12 000 to 10 000 14C years B. P. If these correlations are correct they imply that the 14C production rate increased steadily during the Late
Archaeology ; Biogenic process ; C14 dating ; Carbonate ; Dating ; Fruit ; Microstructure ; Quaternary
The AA. present an extended set of C14 dates on the carbonate fraction of Lithospermum fruits from 4 modern and 11 fossil samples. The data suggest that biogenic carbonate from the fruits of Lithospermum represents suitable material for radiocarbon
C14 dating ; California ; Climatic variation ; Dating ; Evaporite ; Lacustrine sediment ; Lake level ; Lateglacial ; Pleistocene ; Pluvial ; Quaternary ; Th/U dating ; United States of America ; Water balance
happened during the transition interval between the last iceberg discharge event Heinrich 1, (14 500 C14 yr B.P.) and the Bølling-Allerød warming (12 800 C14 yr B.P.).
Modern floodplain sediments in the Wicklow Mountains display a stratigraphy and sedimentology that contrasts them with earlier Holocene alluvium. This paper presents the results of a C14 dating programme the objects of which were to date : a) more
definitively their commencement throughout the Wicklow Mountains, and b) their internal stratigraphies with a view to establishing a flood chronology. Although the results show that the immediate research aims cannot be achieved using C14 dating they have lead
C14 dating ; Dating ; Holocene ; Palaeogeography ; Peat ; Sweden ; Wood
trunk in the sandur of the stream St Göljån was radiocarbon dated to 1320 C14 years B.P. The lowermost part of a peat sequence in a soligenous mire in the valley of the stream Tangån was radiocarbon dated to 1455 C14 years.
Improving methodology for high-resolution reconstruction of sea-level rise and neotectonics by paleoecological analysis and AMS C14 dating of basal peats
Sea-level research in several submerging coastal regions has traditionally been based on C14 dating of basal peats, but this approach contains 2 sources of uncertainty. Accelerator mass spectrometry (AMS) opens new perspectives for this type of sea
-level research, as illustrated by a paleoecological and AMS C14 study of basal peats from a small study area in the Rhine-Meuse delta (Netherlands), where previous (conventional) work revealed highly problematic results. The new results further enable
AMS radiocarbon cross-dating of plant debris and marine shells trapped in a lake basin on Mount St. Hilaire, Québec, provides a direct assessment of a reservoir effect totaling ca. 1800 C14 years during the early stage of Champlain Sea. Pollen
-based extrapolation of bottommost ages on terrestrial plant macrofossils in sediments of this lake, and of another lakenearby support an estimate 11,100 C14 yr B.P. for marine invasion in the Central St. Lawrence River Lowlands. Results indicate a 400
Datation C14 ; Déracinement ; Erosion des sols ; Etats-Unis ; Géographie physique ; Michigan ; Microtopographie ; Pédogenèse ; Pédologie ; Sol ; Sol forestier ; Wisconsin
This study examines and compares methods of dating pit/mound microtopography formed by tree uprooting, and provides C14 evidence for the longevity of these landforms. The AA. use C14 analysis of buried wood and charcoal in treethrow mounds
Résultats chronostratigraphiques et de datation au carbone 14 de l'ancien port du nord de Tyr montrant des pratiques de dragage au cours des périodes romaine et byzantine.
Four holocene alluvial fills are present. Fill IV, the oldest and thickest, was deposited between 10 200 and 4 800 C14 yr B.P.| Fill III has an age of about 3 000 C14 yr B.P.| Fill II is younger than 2 100 and older than 900 C14 yr B.P.| and Fill
I is younger than 900 C14 yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.
Asian part of Russia ; C14 dating ; Climate reconstruction ; Correlation ; Holocene ; Palaeoclimatology ; Palynology ; Sakha ; Vegetation
Etudes antérieures du climat de la Iakoutie. Données palynologiques et de carbone 14. Corrélation entre ces deux techniques. Reconstitution du climat et de la végétation.
La fiabilité des datations au C14 pour des séquences fini-pléistocènes et les différentes phases de la glaciation wurmienne : l'exemple des Alpes Orientales et leur avant-pays
C14 dating ; Chronostratigraphy ; Europe ; Glaciation ; Interglacial ; Palaeogeography ; Palynology ; Pleistocene ; Wurm
D'importantes divergences existant entre des datations au C14 et un certain nombre d'analyses polliniques pour des séquences du Pléistocène supérieur des Alpes Orientales, les AA. discutent ces datations arès une mise au point terminologique de