Holocene vegetation and climatic change in the Peace River district, Canada

1982 ◽  
Vol 19 (3) ◽  
pp. 555-570 ◽  
Author(s):  
James M. White ◽  
Rolf W. Mathewes
Keyword(s):  
Climatic Change ◽  
Pollen Analysis ◽  
Radiocarbon Dating ◽  
Vegetation Change ◽  
Human Populations ◽  
Pollen Record ◽  
Radiocarbon Dates ◽  
Black And White ◽  
Peace River ◽  
Permanent Pond

A sediment core from a pond on the Alberta Plateau in the Peace River district of British Columbia was studied using pollen analysis and radiocarbon dating. Percentage and influx diagrams were produced, and radiocarbon dates were corrected to calendar years to calculate the sedimentation rate. The 231 cm core terminated in clay, and a basal date of 7250 ± 120 years BP was obtained, several thousand years after the recession of Glacial Lake Peace. The formation of the pond is interpreted as resulting from a climatic change, probably a transition from the peak of the Hypsithermal. Zone 1, from 7250 to 5500 years BP, is interpreted as representing a seasonal slough, with upland vegetation percentages consistent with a boreal forest. At about 5500 years BP a permanent pond with surrounding sedge wetlands was formed. Vegetation has been essentially modern during the last 3100 years. Measurements of spruce grains suggest the presence of black and white spruce throughout the pollen record. The formation of permanent ponds and wetlands on the Alberta Plateau at about 5500 years BP is thought to have been the most important vegetation change of the last 7000 years, which may have affected faunal and human populations.

Radiocarbon Dating Lists and Their Use

1956 ◽  
Vol 21 (3) ◽  
pp. 312-313 ◽  
Author(s):  
Frederick Johnson
Keyword(s):  
Pollen Analysis ◽  
Radiocarbon Dating ◽  
American Antiquity ◽  
Radiocarbon Dates ◽  
Recent Treatment ◽  
Physical Literature

“The Denbigh Flint Complex is Not Yet Dated,” (American Antiquity, Vol. 20, No. 4, pp. 375-6) by J. L. Giddings raises a number of general questions concerning the collection of samples and the listings and use of radiocarbon dates which are not confined to the Denbigh material. Giddings says he is a “little worried about our use of ‘lists’ of radiocarbon dates in view of the recent treatment of some dates from Cape Denbigh.” The publication of lists of dates has proved to be of considerable value to anyone who is interested in chronological problems. Primarily the lists facilitate reference. If the more than 2000 determinations were scattered in archaeological, geological, botanical, palaeobotanical and physical literature, it would be practically impossible to find them. For example, an archaeologist might never learn that a date on a level correlative with the Mesolithic but identified by pollen analysis had ever been determined.

Holocene vegetation and climate changes inferred from pollen record of Nordenskiöld Land (West Spitsbergen Island)

2020 ◽  
Author(s):  
Diana Soloveva ◽  
Larisa Savelieva ◽  
Sergei Verkulich
Keyword(s):  
Pollen Analysis ◽  
Radiocarbon Dating ◽  
River Valley ◽  
The Arctic ◽  
Published Data ◽  
Pollen Record ◽  
Spores And Pollen ◽  
Svalbard Archipelago ◽  
West Spitsbergen ◽  
Vegetation And Climate

<p>Pollen analysis is one of the methods that allow revealing ecological and climatic changes in the<br>past based on vegetation reconstruction. Spitsbergen (Svalbard) archipelago, as well as other<br>regions of the Arctic, is difficult for creation of regional models of vegetation and climate<br>development during the Holocene. This is primarily due to the limited distribution, low thickness<br>and relative young ages (usually this is the late Holocene) of organogenic deposits, which are<br>most suitable for palynological studies.<br>Nordenskiöld Land is located in the central part of the West Spitsbergen Island and different the<br>most favorable climatic conditions. The largest number of sites suitable for paleobotanical<br>researches is located here. The Coles valley has length about 12 km, well-developed profile and<br>situated on the north shore of Nordenskiöld Land. The field campaign with studying of<br>floodplain peat sediments from Coles River valley was carried out in August 2018. Two sites<br>(K18-15, K18-16) were studied on the remains of first terrace. Excavated deposits are<br>represented by leafy peat of varying degrees of decomposition with silt lenses. The laboratory<br>studies of sediments included radiocarbon dating, pollen and non-pollen palynomorph analyses.<br>They were carried out in Laboratory of St-Petersburg State University and Russian chemical-<br>analytical Lab on the Spitsbergen archipelago.<br>The pollen analysis of two sections from Coles River valley allowed us to reconstruct<br>paleovegetation changes. Samples from K18-15 site contain more mineral components and more<br>pollen and spores than samples from K18-16 site. This is probably due to the inflow of pollen<br>with water. The main components of spore-pollen spectra are Poaceae, Cyperaceae, Salix and<br>Betula sect. Nanae. The relationship between these taxa shows a different degree of moisture of<br>the study area under the dominance of the grass - sedge tundra. Thus, a significant influence on<br>the formation of spores and pollen spectra in the studied deposits is played by the dynamics of<br>the sedimentation.<br>Results of radiocarbon dating showed that studied deposits formed during mid and late<br>Holocene.<br>A generalization of all available palynological data on the Nordenskjöld land made it possible to<br>construct a scheme of dwarf birch (Betula sect. Nanae) distribution during the Middle and Late<br>Holocene. A comparison of received data with our previous data and published data from<br>Nordenskiöld Land shows the asynchronous of appear and distribution of shrubs on these area<br>from ~5000 to ~2500 yrs ago.</p>

scholarly journals Too Old AMS Radiocarbon Dates Obtained from Moss Remains from Lake Kwiecko Bottom Sediments (N Poland)

2008 ◽  
Vol 32 (-1) ◽  
pp. 13-19 ◽  
Author(s):  
Jacek Madeja ◽  
Dariusz Latowski
Keyword(s):  
Bottom Sediments ◽  
Pollen Analysis ◽  
Radiocarbon Dating ◽  
Radiocarbon Dates ◽  
Ams Radiocarbon Dating ◽  
Palynological Data

Too Old AMS Radiocarbon Dates Obtained from Moss Remains from Lake Kwiecko Bottom Sediments (N Poland)The paper presents the results of the AMS radiocarbon dating of moss macrofossils which seem to be too old in the context of palynological data. The lack of agreement between the obtained results of radiocarbon dating and pollen analysis has been discussed. Some possible causes of the discrepancies between the results of radiocarbon dating and palynological dating have been given.

Pollen Analysis of a Late-Glacial and Holocene Sediment Core from Mono Lake, Mono County, California

1999 ◽  
Vol 52 (2) ◽  
pp. 243-249 ◽  
Author(s):  
Owen K. Davis
Keyword(s):  
Pollen Analysis ◽  
Vegetation Change ◽  
Late Glacial ◽  
Mono Lake ◽  
Early Holocene ◽  
Summer Drought ◽  
Lake Levels ◽  
Radiocarbon Dates ◽  
Spring Runoff ◽  
Late Glacial And Holocene

Pollen analysis of a 752-cm core from Mono Lake, Mono County, California indicates generally high lake levels 11,600–7000 14C yr B.P., moderate lake levels until ca. 4000 14C yr B.P., and fluctuating levels to the present. Drying events, with lake levels near or below the historic minimum are dated ca. 8800, 4000, 2400, and 1100 14C yr B.P. Chronologic control is provided by six radiocarbon dates and six volcanic ashes. The rate of upland vegetation change is greatest 11,000, 4000, and 1130 14C yr B.P. Juniperus and Sequoaidendron pollen declines 11,000 yr B.P., marking the transition from late-glacial juniper woodland to Holocene steppe. High values (5–20%) of Sequoaidendron pollen are unique to this study and may indicate the presence of these trees east of the Sierra crest. The pollen-based reconstructions of climate are generally cooler and wetter than today, with relatively dry but cool climate during the early Holocene. The contrast between higher lake levels and more arid vegetation during the early Holocene can be explained by insolation-driven seasonality. Greater summer insolation produced summer drought, but lower winter insolation led to greater snowpack, greater spring runoff, and higher lake levels. Increased Artemisia and other Compositae pollen percentages mark the establishment of modern vegetation ca. 2000 14C yr B.P. During the late Holocene, the pollen-based reconstructions of climate generally match the Mono Lake fluctuations proposed by Stine (1990), but fewer fluctuations are recorded.

scholarly journals Vegetation change inferred from the pollen record in recent sediments from around the Lagos-East coastal environment (SW Nigeria)

2019 ◽  
Vol 59 (1) ◽  
pp. 165-175
Author(s):  
Linus Ajikah ◽  
Olusola Adekanmbi ◽  
Oluwatoyin Ogundipe
Keyword(s):  
Vegetation Change ◽  
Elaeis Guineensis ◽  
Pollen Grains ◽  
Coastal Environment ◽  
Climatic Conditions ◽  
Pollen Record ◽  
Radiocarbon Dates ◽  
The Past ◽  
Freshwater Swamp ◽  
Recent Sediments

Abstract Recent sediments from the coastal environment of Lagos East, Nigeria, were used to make a palynological reconstruction of the vegetation of the study area and to draw inferences about its palaeoclimate. A total of 8456 palynomorphs were recovered, dominated by pollen grains of Poaceae (13.96%), Cyperaceae (6.23%), Alchornea cordifolia Müll-Arg (8.36%) and Elaeis guineensis Jacq (2.41%). Others were Cyclosorus afer Ching (2.18%), Rhizophora sp. (0.45%), Nephrolepis sp. (1.03%), Celtis sp. (0.25%) and Pteris sp. (0.13%). The composition of the recovered palynomorphs suggests that the past vegetation was predominantly a mosaic of freshwater swamp, with open to dry climate, as indicated by the records of Cyperaceae, Alchornea cordifolia, Elaeis guineensis, Arecaceae, Asteraceae, Acanthaceae and Chenopodiaceae/Amaranthaceae. Radiocarbon dates obtained from two depths (surface and deepest) indicate that the sediments were deposited around the last 103.8 ± 0.4 pMC (percentage Modern Carbon) and 111.9 ± 0.4 pMC, hence in the late Holocene. The study identified fluctuations between wet and dry climatic conditions in the Holocene of this area.

Postglacial vegetation and climatic change in the upper Peace River district, Alberta

1986 ◽  
Vol 64 (10) ◽  
pp. 2305-2318 ◽  
Author(s):  
James M. White ◽  
Rolf W. Mathewes
Keyword(s):  
Climatic Change ◽  
Pollen Analysis ◽  
Sediment Cores ◽  
Growing Season ◽  
Radiometric Dating ◽  
Glacial Meltwater ◽  
Peace River ◽  
Spruce Decline ◽  
Paper Birch ◽  
Relict Vegetation

Pollen analysis and radiometric dating of sediment cores from two lakes in the Saddle Hills, Peace River district, Alberta, were used to investigate postglacial vegetation and climatic change. A poplar – willow – sage – grass – sedge zone began about 11 700 ± 260 years BP. A distinct pine and spruce rise indicates the local presence of conifers. Peace River spruce could have served as a source for spruce in the Yukon, transported by glacial meltwater conceivably as early as about 11 100 years BP. A paper birch rise and spruce decline between about 8700 and 8200 years BP is likely due to fires during a period of enhanced seasonality. It is suggested that subsequent weakening of the anticyclone associated with the Laurentide ice lengthened the growing season, permitting pine to be the major fire successor to spruce. During the pine peak ca. 7400 years BP there was no grassland over the Saddle Hills, so the Peace River grasslands cannot be explained as Hypsithermal relict vegetation. Conditions similar to the present were apparently reached by about 5000 years BP.

Early Man in Arizona: The Pollen Evidence

1963 ◽  
Vol 29 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Paul S. Martin
Keyword(s):  
Pollen Analysis ◽  
High Plains ◽  
Pollen Record ◽  
Desert Grassland ◽  
Alluvial Deposits ◽  
Radiocarbon Dates ◽  
Radiocarbon Age ◽  
Pollen Content ◽  
History Of ◽  
Sulphur Spring

AbstractUnder the classic Bryan-Antevs model the climatic history of the Southwest has been divided into (1) pluvial, (2) early postpluvial or Anathermal, (3) mid-postpluvial or Altithermal, (4) late postpluvial or Medithermal. Pollen analysis of radiocarbon-dated pluvial deposits shows that the desert grassland of southern Arizona and the short grassland of the Texas High Plains were invaded by a pine forest or pine savanna during the last pluvial period. Sulphur Spring-age alluvial deposits at Double Adobe, dated as pluvial in age by Sayles and Antevs, do not contain the pine-pollen record associated with pluvial conditions elsewhere; six radiocarbon dates from deep alluvial deposits at Double Adobe range from 7756 to 9350 years B.P. On the basis of pollen content and radiocarbon-age estimates, the beds are of early postpluvial rather than pluvial age, and thus the Sulphur Spring-stage artifacts found there are also early postpluvial in age.Under the Bryan-Antevs model the Altithermal, 7500-4000 B.P., is considered an especially hot, dry period. Sediments associated with three radiocarbon dates within this interval contain slightly more pollen of mesic and hygric indicators than do sediments postdating the Altithermal. Interpreting the results literally, the Altithermal was wetter, not hotter and drier, than at present. The limitations of pollen analysis are not fully understood. But the traditional view of a hot, dry Altithermal in southern Arizona cannot be verified from fossil pollen evidence available to date.

A Prehistoric Ford near Rough Castle, Falkirk

2001 ◽  
Vol 23 (2) ◽  
pp. 91-103
Author(s):  
JAMIE HAMILTON ◽  
CIARA CLARKE ◽  
ANDREW DUNWELL ◽  
RICHARD TIPPING
Keyword(s):  
Coal Mining ◽  
Pollen Analysis ◽  
Site Formation ◽  
Site Formation Processes ◽  
Formation Processes ◽  
Radiocarbon Dates ◽  
Small Stream ◽  
Mining Project ◽  
First Millennium

This report presents the results of the excavation of a stone ford laid across the base of a small stream valley near Rough Castle, Falkirk. It was discovered during an opencast coal mining project. Radiocarbon dates and pollen analysis of deposits overlying the ford combine to indicate a date for its construction no later than the early first millennium cal BC. Interpreting this evidence was not straightforward and the report raises significant issues about site formation processes and the interpretation of radiocarbon and pollen evidence. The importance of these issues extends beyond the rarely investigated features such as fords and deserve a larger place in the archaeological literature.

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.

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