Holocene pollen assemblages from the Tiger Hills, Manitoba

1968 ◽  
Vol 5 (4) ◽  
pp. 873-880 ◽  
Author(s):  
J. C. Ritchie ◽  
Sigrid Lichti-Federovich
Keyword(s):  
Deciduous Forest ◽  
Pollen Assemblage ◽  
The Holocene ◽  
Radiocarbon Age ◽  
Arboreal Pollen ◽  
Pollen Types ◽  
Weedy Species ◽  
Zone Ii ◽  
Shepherdia Canadensis ◽  
Age Determinations

Coring of three kettle lakes in the moraine area known as the Tiger Hills, Manitoba, yielded sections of sediment which span the Holocene for this region. Detailed pollen analysis of two of the sections suggests five main pollen assemblage zones for the Holocene, numbered I to V from above. Zone V is interpreted as a spruce-dominated vegetation associated with such pioneering species as Shepherdia canadensis and Artemisia, a type found at present as local fragments and having no regional equivalent. Zone IV also has no analogue among recent pollen spectra, and is interpreted as a mosaic of mixed coniferous–broadleaved deciduous forest stands, and extensive scrub with Juniperus and grassland. Zone III is dominated by non-arboreal pollen types and suggests grassland, while Zone II has an oak component, which indicates a savanna type. Zone I is the modern assemblage, with prominent representation by weedy species. Radiocarbon age determinations suggest that the area was occupied by the Zone V assemblage from about 12 800 B.P.

Chronostratigraphy and radiocarbon age inversion in the Holocene regressive barrier of Paraná, southern Brazil

2008 ◽  
Vol 252 (3-4) ◽  
pp. 111-119 ◽  
Author(s):  
Rodolfo José Angulo ◽  
Maria Cristina de Souza ◽  
Mario Luis Assine ◽  
Luiz Carlos Ruiz Pessenda ◽  
Sibelle Trevisan Disaró
Keyword(s):  
Southern Brazil ◽  
The Holocene ◽  
Radiocarbon Age

The Use of Ecological Tolerances for the Reconstruction of Tertiary Palaeoclimates

1997 ◽  
Vol 45 (3) ◽  
pp. 475 ◽  
Author(s):  
Helene A. Martin
Keyword(s):  
Vegetation Types ◽  
Climatic Parameters ◽  
Salt Tolerant ◽  
Pollen Assemblage ◽  
Pollen Types ◽  
Living Species ◽  
Marine Influence ◽  
Lagarostrobos Franklinii ◽  
Single Living ◽  
Very High

The major vegetation types may be recognised from the pollen assemblage being deposited beneath them, hence the palaeovegetation may be reconstructed from fossil pollen assemblages. The climatic parameters of the vegetation may then be used to reconstruct palaeoclimates. The result, however, is very general. Most pollen types can only be affiliated with a family, a genus or a group of species and the ecological tolerances within these groups may not be uniform. There are, however, some distinctive pollen types that can be identified with a single living species and this paper examines the potential of these types in the reconstruction of palaeoclimates. Lagarostrobos franklinii (J.D.Hook) Quinn, Huon pine, has a long history and the fossil occurrences of it are compatible with the hypothesis that its ecological tolerances have not changed and it has always required very high humidity. Two sclerophyllous taxa,Eucalyptus spathulata Hook. and Dodonaea triquetra Wendl., however, coexisted with rainforest and then other vegetation types as the climate became drier, adapting to the prevailing conditions. The evidence suggests that the salt-tolerant E. spathulata may have evolved in small patches of coastal scrub, subjected to marine influence, within the dominant rainforest vegetation.

scholarly journals C14 dating of Survey material performed in 1974

1975 ◽  
Vol 75 ◽  
pp. 19-20
Author(s):  
A Weidick
Keyword(s):  
New Jersey ◽  
Wood Sample ◽  
Field Work ◽  
Plant Anatomy ◽  
Radiocarbon Age ◽  
Apparent Age ◽  
Age Determinations

Thirteen radiocarbon age determinations of shell samples (12) and wood (1) are assembled in tbis account. The material dated was collected in connection with GGU field work. The samples have been dated at Isotopes Inc., Westwood, New Jersey, U.S.A. Determination of the wood sample was kindly made by Jette Dahl Møller, Institute of Plant Anatomy and Cytology, University of Copenhagen. Dating has also been carried out on a number of shelIs, dredged alive prior to 1950, in order to control the apparent age in shell dating determinations (Tauber & Funder, tbis report).

RADIOCARBON RESERVOIR AGES IN THE HOLOCENE DEAD SEA

Radiocarbon ◽  
2020 ◽  
Vol 62 (5) ◽  
pp. 1453-1473
Author(s):  
Nurit Weber ◽  
Boaz Lazar ◽  
Ofra Stern ◽  
George Burr ◽  
Ittai Gavrieli ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Dead Sea ◽  
Climate Conditions ◽  
The Holocene ◽  
Radiocarbon Age ◽  
The Past ◽  
Organic Debris ◽  
The Dead ◽  
The Difference ◽  
Continuous Deposition

ABSTRACTThe sources and fate of radiocarbon (14C) in the Dead Sea hypersaline solution are evaluated with 14C measurements in organic debris and primary aragonite collected from exposures of the Holocene Ze’elim Formation. The reservoir age (RA) is defined as the difference between the radiocarbon age of the aragonite at time of its precipitation (representing lakeʼs dissolved inorganic carbon [DIC]) and the age of contemporaneous organic debris (representing atmospheric radiocarbon). Evaluation of the data for the past 6000 yr from Dead Sea sediments reveal that the lakeʼs RA decreased from 2890 yr at 6 cal kyr BP to 2300 yr at present. The RA lies at ~2400 yr during the past 3000 yr, when the lake was characterized by continuous deposition of primary aragonite, which implies a continuous supply of freshwater-bicarbonate into the lake. This process reflects the overall stability of the hydrological-climate conditions in the lakeʼs watershed during the late Holocene where bicarbonate originated from dissolution of the surface cover in the watershed that was transported to the Dead Sea by the freshwater runoff. An excellent correlation (R2=0.98) exists between aragonite ages and contemporaneous organic debris, allowing the estimation of ages of various primary deposits where organic debris are not available.

Mass Spectrometric Radiocarbon Dates from Three Rock Paintings of Known Age

2001 ◽  
Vol 66 (3) ◽  
pp. 471-480 ◽  
Author(s):  
Ruth A. Armitage ◽  
James E. Brady ◽  
Allan Cobb ◽  
John R. Southon ◽  
Marvin W. Rowe
Keyword(s):  
Mass Spectrometric ◽  
Radiocarbon Dates ◽  
Radiocarbon Age ◽  
Potential Problems ◽  
Rock Paintings ◽  
The Tropics ◽  
Calendar Dates ◽  
Age Determinations

Radiocarbon age determinations are presented on three hieroglyphic texts from Naj Tunich cave in Guatemala containing Maya calendar dates. The ages obtained are on average 110–140 years older than the calendar dates. Several possible reasons are discussed for this discrepancy: one that is applicable to all radiocarbon dates on charcoal, one that applies to rock paintings, and one that is specific for the tropics. Possible problems with the ages ascribed to the Maya calendar dates are also discussed. Even with the potential problems that may exist, these dates still fall within 110–140 years of the ascribed calendar dates. Caution is urged in the interpretation of dates on charcoal pigments from rock paintings; consideration of the “old wood” and “old charcoal” factors is important.

The Icenian Crag of southeast Suffolk

1974 ◽  
Vol 269 (895) ◽  
pp. 1-28 ◽  
Keyword(s):  
The Netherlands ◽  
Deciduous Forest ◽  
Middle Pleistocene ◽  
Pollen Assemblage ◽  
Marine Transgression ◽  
Open Coast ◽  
Lower Pleistocene ◽  
Mollusc Assemblages ◽  
Deep Boreholes ◽  
Beach Plain

Sections in the Icenian Crag at Chillesford, Aldeburgh, Thorpe Aldringham, Sizewell, Dunwich, Wangford and Southwold are described. Pollen and mollusc assemblages from these sites are tabled. The Icenian Crag is shown to contain a temperate pollen assemblage, resulting from a regional deciduous forest of the time. The assemblage is provisionally correlated with the Pastonian stage of the Middle Pleistocene, as Tsuga is very poorly represented and Abies is absent. The mollusc assemblages are divided into a sublittoral or infralittoral facies, a sheltered estuarine or wadden area facies, an open coast facies and a high-boreal or sub-arctic silty deposit facies, probably infralittoral. The unconformable relation of the Icenian Crag to Red and Coralline Crags at Chillesford and Aldeburgh and to Baventian sediments at Easton Bavents indicates a strong marine transgression over Lower Pleistocene deposits in Pastonian times. The beach plain of the Westleton Beds is included within this transgressive phase. Pollen assemblages from deep boreholes at Sizewell and Southwold show that the transgression deposits overlie Lower Pleistocene sediments correlated with the PreLudhamian, Thurnian and Baventian stages. A correlation is suggested between the Pastonian and the Cromerian III Interglacial of the Netherlands.

Changing Patterns in the Holocene Pollen Record of Northeastern North America: A Mapped Summary

1977 ◽  
Vol 8 (1) ◽  
pp. 64-96 ◽  
Author(s):  
J. Christopher Bernabo ◽  
Thompson Webb
Keyword(s):  
North America ◽  
Large Scale ◽  
Deciduous Forest ◽  
Rapid Expansion ◽  
Early Holocene ◽  
Pollen Record ◽  
Data Set ◽  
Northeastern North America ◽  
The Holocene ◽  
Changing Patterns

By mapping the data from 62 radiocarbon-dated pollen diagrams, this paper illustrates the Holocene history of four major vegetational regions in northeastern North America. Isopoll maps, difference maps, and isochrone maps are used in order to examine the changing patterns within the data set and to study broad-scale and long-term vegetational dynamics. Isopoll maps show the distributions of spruce (Picea), pine (Pinus), oak (Quercus), herb (nonarboreal pollen groups excluding Cyperaceae), and birch + maple + beech + hemlock (Betula, Acer, Fagus, Tsuga) pollen at specified times from 11,000 BP to present. Difference maps were constructed by subtracting successive isopoll maps and illustrate the changing patterns of pollen abundances from one time to the next. The isochrone maps portray the movement of ecotones and range limits by showing their positions at a sequence of times during the Holocene. After 11,000 BP, the broad region over which spruce pollen had dominated progressively shrank as the boreal forest zone was compressed between the retreating ice margin and the rapidly westward and northward expanding region where pine was the predominant pollen type. Simultaneously, the oak-pollen-dominated deciduous forest moved up from the south and the prairie expanded eastward. By 7000 BP, the prairie had attained its maximum eastward extent with the period of its most rapid expansion evident between 10,000 and 9000 BP. Many of the trends of the early Holocene were reversed after 7000 BP with the prairie retreating westward and the boreal and other zones edging southward. In the last 500 years, man's impact on the vegetation is clearly visible, especially in the greatly expanded region dominated by herb pollen. The large scale changes before 7000 BP probably reflect shifts in the macroclimatic patterns that were themselves being modified by the retreat and disintegration of the Laurentide ice sheet. Subsequent changes in the pollen and vegetation were less dramatic than those of the early Holocene.

The Context of Early Southeastern Prehistoric Cave Art: A Report on the Archaeology of 3rd Unnamed Cave

1998 ◽  
Vol 63 (4) ◽  
pp. 663-677 ◽  
Author(s):  
Jan F. Simek ◽  
Jay D. Franklin ◽  
Sarah C. Sherwood
Keyword(s):  
Lithic Technology ◽  
Archaic Period ◽  
High Quality ◽  
Radiocarbon Age ◽  
Dark Zone ◽  
Cave Entrance ◽  
Karst Cavern ◽  
Age Determinations ◽  
Cave Art

In the deep recesses of “3rd Unnamed Cave,” a karst cavern in Tennessee, evidence for an ancient association between dark zone cave art and chert mining has recently been documented. The art comprises petroglyphs on the ceiling of a chamber more than 1 km from the cave entrance. On the floor below the art, natural sediments were excavated prehistorically to obtain high-quality chert nodules. Radiocarbon age determinations place the mining during the Terminal Archaic period. Studies in lithic technology, geoarchaeology, and petroglyph description are presented.

Variation in Radiocarbon Age Determinations from the Crystal River Archaeological Site, Florida

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 801-810 ◽  
Author(s):  
Alexander Cherkinsky ◽  
Thomas J Pluckhahn ◽  
Victor D Thompson
Keyword(s):  
Gulf Coast ◽  
Archaeological Site ◽  
Bone Collagen ◽  
Shell Midden ◽  
Long Distance ◽  
Reservoir Effect ◽  
Radiocarbon Age ◽  
Soil Charcoal ◽  
Crystal River ◽  
Age Determinations

Archaeologists interested in radiocarbon dating shell midden sites express concern regarding the accuracy of shell dates and how such determinations should be interpreted. This article discusses the problem of dating shells from sites in the southeastern United States. New results are presented comparing shell, bone, and soil-charcoal age determinations from the Crystal River site, located along the west-central Gulf Coast of Florida. Crystal River is a large multimound site whose occupants engaged in long-distance exchange throughout eastern North America during the Woodland period (∼1000 BC to AD 1050). In the summer of 2012, test units were excavated in several contexts at the site, including both mounds and occupation areas. Samples were collected for 14C dating, which were then processed at the University of Georgia Center for Applied Isotope Studies. This article focuses on samples from the stratified shell midden, from which it was hoped to construct a local correction for marine shell that could be used to date other contexts. The soil-charcoal and bone collagen from these samples have very similar ages (bone samples ranging from about 100 cal BC to cal AD 530 and soil-charcoal from cal AD 345 to 560); however, the shell samples collected from the same stratigraphic units are significantly older than the terrestrial dates (ranging from 1300 to 390 cal BC). The difference in calibrated ages between organic materials and the shells ranges between 560 to 1140 yr. This phenomenon cannot be explained solely by the marine reservoir effect. It appears that all the shell samples formed in mixed marine (∼50–60%) contexts, as indicated by the stable isotope ratios and the amount of atmospheric carbon remaining in the samples. The age of the shell samples cannot be used to date archaeological events as they are influenced not only by the marine reservoir effect, but also the local hardwater effect, which makes them significantly older.

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