Stratigraphic relationships and paleoecology of a late-glacial peat bed from the Queen Charlotte Islands, British Columbia

1982 ◽  
Vol 19 (6) ◽  
pp. 1185-1195 ◽  
Author(s):  
Rolf W. Mathewes ◽  
John J. Clague
Keyword(s):  
Late Pleistocene ◽  
Pinus Contorta ◽  
Vegetation History ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Radiocarbon Dates ◽  
Queen Charlotte Islands ◽  
Modern Analogue ◽  
Armeria Maritima ◽  
Late Glacial And Holocene

The stratigraphic relationships of late-glacial and Holocene sediments exposed in sea cliffs at Cape Ball on the Queen Charlotte Islands are summarized, based on section descriptions and 13 radiocarbon dates on wood, peat, and marine pelecypod shells. One peat bed dated at 12 400 ± 100 years BP (GSC-3112) to 10 200 ± 90 BP (GSC-3159) was investigated for pollen and plant macrofossils. This study extends the late Pleistocene vegetation history of the Queen Charlotte Islands by about 1550 years, and suggests that the record will date back to before 13 700 ± 100 BP (GSC-3222).Four local pollen zones are described from the 70 cm thick peat, beginning with a 7 cm thick herb-dominated zone (CB-1), characterized by up to 60% grass pollen, and including a unique assemblage with abundant Apiaceae, Cyperaceae, Empetrum/Ericaceae, Polemonium, Plantago macrocarpa, Fritillaria, and Ranunculus. A high diversity of other herbs, including subalpine/alpine species and two taxa presently absent from the Charlottes (Armeria maritima and Polemonium caeruleum type), suggests that this zone represents an open floodplain vegetation with no modern analogue. Zone CB-2 (63–45 cm) is dominated by Pinus conforta type pollen (65–70%) and moderate values for fern spores. Zone CB-3 (45–30 cm) shows a rapid rise of Picea pollen from 3 to 39%, followed by a drop to about 12%. Fern spores (20–50%) and Alnus (6%) also reach maximum levels in this zone. Abundant wood fragments and sand inclusions are compatible with an interpretation of a swampy floodplain forest during this interval. The uppermost zone (30–0 cm) exhibits high Pinus contorta (40–60%) and Cyperaceae (12–38%) values, along with a moderate abundance of grasses, ferns, and Apiaceae. Estuarine and marine sediments with pelecypod shells, deposited during a marine transgression, overlie the peat bed.Implications for the controversy over the existence of late Pleistocene refugia in the Charlottes are briefly discussed.

Paleoecology of late-glacial terrestrial deposits with in situ conifers from the submerged continental shelf of western Canada

2003 ◽  
Vol 60 (2) ◽  
pp. 180-188 ◽  
Author(s):  
Terri Lacourse ◽  
Rolf W. Mathewes ◽  
Daryl W. Fedje
Keyword(s):  
Continental Shelf ◽  
Pinus Contorta ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Terrestrial Vegetation ◽  
Queen Charlotte Islands ◽  
Subaerial Exposure ◽  
Late Wisconsinan ◽  
Heracleum Lanatum

AbstractExtensive portions of the continental shelf off the coast of British Columbia were subaerially exposed during Late Wisconsinan deglaciation due to lowering of relative sea level by as much as 150 m. Paleoecological analyses were conducted at two sites on the emergent continental shelf where terrestrial surfaces with in situ conifers are preserved. The woody plant remains confirm that, during the latest period of subaerial exposure, terrestrial vegetation was established on the continental shelf. Microscopic identification of fossil wood, and analyses of pollen and plant macrofossils from the associated paleosols and overlying shallow pond sediments indicate that productive Pinus contorta-dominated communities with abundant Alnus crispa and ferns grew on the shelf adjacent to and on the Queen Charlotte Islands around 12,200 14C yr B.P. Dwarf shrubs including Salix and Empetrum, and herbaceous plants such as Heracleum lanatum and Hippuris vulgaris, were also important components of the shelf vegetation. Near northern Vancouver Island, mixed coniferous forests dominated by Pinus contorta with Picea, Tsuga spp., Alnus spp., and ferns occupied the shelf at 10,500 14C yr B.P.

scholarly journals Radiocarbon Chronology of the Late Pleistocene–Holocene Paleogeographic Events in Lake Baikal Region (Siberia)

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 745-754 ◽  
Author(s):  
Sergey K Krivonogov ◽  
Hikaru Takahara ◽  
Yaroslav V Kuzmin ◽  
Lyobov A Orlova ◽  
A J Timothy Jull ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Lake Baikal ◽  
Baikal Region ◽  
Late Glacial ◽  
Vegetation Changes ◽  
Radiocarbon Dates ◽  
Lake Baikal Region ◽  
Cold Events ◽  
Late Glacial And Holocene ◽  
Radiocarbon Chronology

New radiocarbon dates obtained from Late Pleistocene and Holocene deposits of the southern, eastern, and northern shores of Lake Baikal in 1995–2001 are presented, and the most important results of paleoenvironmental studies based on C data are discussed. The following paleogeographic events were verified with the help of C dating: 1) first Late Pleistocene glaciation (Early Zyryan); 2) Middle Zyryan interstadial; 3) loess formation during the Late Zyryan (Sartan) deglaciation; 4) warm and cold events in the Late Glacial; and 5) vegetation changes and forest successions during the Late Glacial and Holocene.

A late Pleistocene Steller sea lion (Eumetopias jubatus) from Courtenay, British Columbia: its death, associated biota, and paleoenvironment

2004 ◽  
Vol 41 (11) ◽  
pp. 1285-1297 ◽  
Author(s):  
C R Harington ◽  
R LM Ross ◽  
R W Mathewes ◽  
K M Stewart ◽  
O Beattie
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Sea Lion ◽  
Radiocarbon Dates ◽  
Sea Lions ◽  
Regional Sea Level

A partial juvenile Steller sea lion (Eumetopias jubatus) skeleton from nearshore marine sands at Courtenay, Vancouver Island, British Columbia has been radiocarbon dated to 12 570 ± 70 BP. This date is supported by both stratigraphic and regional sea-level emergence data and is similar to radiocarbon dates on a Steller sea lion humerus from Bowen Island, just north of Vancouver. The juvenile apparently died from a blow to the braincase, most likely caused by a Steller sea lion bull. The Courtenay specimen is significant since very few Pleistocene otariid fossils are complete enough to be assigned to modern taxa. Associated mollusk remains indicate that the marine paleoclimate of the fossil locality was considerably colder than now — close to that along the northern reaches of Cook Inlet and Prince William Sound, Alaska. Pollen and plant macrofossils collected from the Courtenay site clearly demonstrate the presence of lodgepole pine (Pinus contorta) forests nearby during this early late-glacial interval. Fish remains (mainly Pacific cod and walleye pollock, with some salmon) from this site probably reflect selection by adult sea lions at a rookery.

scholarly journals Transformation of Lake Ecosystem into Peat Bog and Vegetation History Based on Durne Bagno Mire (Lublin Polesie, E Poland)

2007 ◽  
Vol 29 (-1) ◽  
pp. 23-43 ◽  
Author(s):  
Krystyna Bałaga
Keyword(s):  
Vegetation History ◽  
Chemical Elements ◽  
Late Glacial ◽  
Unique Element ◽  
Peat Bogs ◽  
Lake Ecosystem ◽  
Peat Bog ◽  
Mineral Material ◽  
Late Glacial And Holocene ◽  
Almost All

Transformation of Lake Ecosystem into Peat Bog and Vegetation History Based on Durne Bagno Mire (Lublin Polesie, E Poland)In this paper, the history of Durne Bagno, i.e. the largest peat bog in the Lublin Polesie, is shown. Peat bogs are a unique element of the Polesie landscape. They occur mostly in the subregion of the Łęczna-Włodawa Lake District occupying 1.07% of its area. They fill basin-shaped depressions without outflow, often in the immediate vicinity of dystrophic lakes. Based on interdisciplinary research, the changes of vegetation cover and the Durne Bagno lake-mire ecosystem in the Late Glacial and Holocene are presented. The environmental conditions are reconstructed from pollen analysis, detailed identification of algae ofPediastrumgenus and chemical composition of deposits, together with the results of Cladocera analysis. The distribution of archaeological artefacts in the surroundings of Durne Bagno peat bog gives the view on the intensity of settlement in this area. The duration of the limnic and mire stages during the development of the ecosystem was different in different parts of the examined depression. In its central part the limnic stage lasted about 8000 years and included the period from the Late Glacial to the middle Holocene (to about 6000 BP). It is represented by 7 pollen zones and 6 chemical zones. The mire stage contained a part the Atlantic period and on the Subboreal and Subatlantic periods. It is represented by 4 pollen zones and 5 chemical zones. Limnic and mire deposits differ widely in the concentrations of chemical elements. The contents of mineral material and almost all analyzed elements in limnic deposits are high. These deposits are characterized by positive correlation between the contents of Zn and Cr and the frequency of Cladocera fauna. Peat contains very low amount of mineral material. The contents of Ca, Sr and Ba are rather high in sedgemoss peat. The concentrations of these elements decrease upwards due to oligotrophic processes and sedentation of sedge-Eriophorum-Sphagnumpeat. Peat succession was modified by pastoral economy of prehistoric man.

scholarly journals Vegetation history and palaeoclimate at Lake Dojran (FYROM/Greece) during the Late Glacial and Holocene

2017 ◽  
Author(s):  
Alessia Masi ◽  
Alexander Francke ◽  
Caterina Pepe ◽  
Matthias Thienemann ◽  
Bernd Wagner ◽  
...  
Keyword(s):  
Roman Empire ◽  
Vegetation History ◽  
Late Glacial ◽  
Mediterranean Area ◽  
Human Presence ◽  
The Past ◽  
Age Model ◽  
Late Glacial And Holocene ◽  
Yugoslavian Republic ◽  
Southern Balkans

Abstract. A new high-resolution pollen and NPPs (Non-Pollen Palynomorphs) analysis has been performed on the sediments of Lake Dojran, a transboundary lake located at the border between Greece and Former Yugoslavian Republic of Macedonia (FYROM). The sequence covers the last 12 500 years and provides information on vegetational dynamics of the Late Glacial and Holocene for southern Balkans. A robust age-model, sedimentological, diatom, and biomarker analyses published previously have been the base 5 for a multi-perspective interpretation of the new palynological data. Pollen analysis revealed that the Late Glacial is characterized by steppic taxa with prevailing Amaranthaceae, Artemisia and Poaceae. The arboreal vegetation starts to rise after 11 500 yr BP, taking a couple of millennia to be definitively attested. Holocene vegetation is characterized by the dominance of mesophilous plants. Quercus robur type and Pinus are the most abundant taxa followed by Quercus cerris type, Quercus ilex type and Ostrya/Carpinus orientalis. The first attestation of human presence can be presumed at 5000 yr BP for the 10 contemporary presence of cereals, Juglans and Rumex. A drop of both pollen concentration and influx together with a δ18Ocarb shift indicates increasing aridity and precedes clear and continuous human signs since 4000 yr BP. Also a correlation between Pediastrum boryanum and fecal stanol suggests that the increase of nutrient in the water is related to human presence and pasture. An undoubted expansion of human-related plants occurs since 2600 yr BP when cereals, arboreal cultivated and other synanthropic non-cultivated taxa are found. A strong reduction in arboreal vegetation occurred at 2000 yr BP, when the strong 15 Roman Empire impacted on a landscape undergoing climate dryness in the whole Mediterranean area. In recent centuries the human impact still remains high but spots of natural vegetation are preserved. The Lake Dojran multi-proxy analysis including pollen data provide a valuable contribution to the palaeoenvironmental reconstruction and the comprehension of the past vegetation dynamics of southern Balkans.

scholarly journals Late Glacial and Holocene changes in vegetation cover and climate in southern Siberia derived from a 15 kyr long pollen record from Lake Kotokel

2009 ◽  
Vol 5 (1) ◽  
pp. 127-151 ◽  
Author(s):  
P. E. Tarasov ◽  
E. V. Bezrukova ◽  
S. K. Krivonogov
Keyword(s):  
Late Glacial ◽  
Time Interval ◽  
Pollen Record ◽  
Time Intervals ◽  
Southern Siberia ◽  
Noticeable Increase ◽  
Modern Analogue ◽  
Quantitative Characteristics ◽  
Late Glacial And Holocene ◽  
Vegetation And Climate

Abstract. In this study a radiocarbon-dated pollen record from Lake Kotokel (52°47´ N, 108°07´ E, 458 m a.s.l.) located in southern Siberia east of Lake Baikal was used to derive quantitative characteristics of regional vegetation and climate since about 15 kyr BP (1 kyr=1000 cal. yr) until today. Quantitative reconstruction of the late glacial vegetation and climate dynamics suggests that open steppe and tundra communities predominated in the study area prior to ca. 13.5 kyr BP and again during the Younger Dryas interval, between 12.8 and 11.6 kyr BP. The pollen-based climate reconstruction suggests lower-than-present mean January (~–38°C) and July (~12°C) temperatures and annual precipitation (~270–300 mm) values during these time intervals. Boreal woodland replaced the primarily open landscape around Kotokel three times at about 14.8–14.7 kyr BP, during the Allerød Interstadial between 13.3–12.8 kyr BP and with the onset of the Holocene interglacial between 11.5 and 10.5 kyr BP, presumably in response to a noticeable increase in precipitation, and in July and January temperatures. The maximal spread of the boreal forest (taiga) communities in the region is associated with a warmer and wetter-than-present climate (Tw~17–18°C, Tc~–19°C, Pann~500–550 mm) occurred ca.\\ 10.8–7.3 kyr BP. During this time interval woody vegetation covered more than 50% of the area within a 21×21 km window around the lake. The pollen-based best modern analogue reconstruction suggests a decrease in woody cover percentages and in all climatic variables about 7–6.5 kyr BP. Since that time our results demonstrate gradual decrease in precipitation and mean January temperature towards their present-day values in the region around Lake Kotokel.

scholarly journals Interdisciplinary studies of spring mire deposits from Radzików (South Podlasie Lowland, East Poland) and their significance for palaeoenvironmental reconstructions

2012 ◽  
Vol 39 (1) ◽  
pp. 10-29 ◽  
Author(s):  
Radosław Dobrowolski ◽  
Irena Pidek ◽  
Witold Alexandrowicz ◽  
Stanisław Hałas ◽  
Anna Pazdur ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Environmental Changes ◽  
Younger Dryas ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Interdisciplinary Studies ◽  
Carbon Stable Isotopes ◽  
Calcareous Tufa ◽  
Palaeoenvironmental Reconstructions ◽  
Late Glacial And Holocene

Abstract The paper presents the results of interdisciplinary (multiproxy) palaeoenvironmental studies of peat — calcareous tufa depositional sequences of spring mire from Radzików site (east Poland). Analyses of three biotic proxies (plant macrofossils, pollen, molluscs) were supplemented with sedimentological, geochemical, oxygen and carbon stable isotopes analyses and radiocarbon dating and used for reconstruction of environmental changes in Late Glacial and Holocene. The obtained results enable us to (1) reconstruct main phases of mire development and (2) determine environmental factors influencing changes of water supply. The object started to develop in Allerød. The Late Glacial and Early Holocene deposit sequence is relatively thick (about 1.0 m), with good palaeoecological record. The boundary between Younger Dryas and Preboreal is especially well confirmed by palynological and malacological analyses as well as radiocarbon dating. The Mesoholocene deposits are considerably worse preserved. Mire development was evaluated in terms of general mire ecology.

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