Les C Cwynar
Biographic Data
| ID | 10710324 |
|---|---|
| NAME | Les C Cwynar |
| GIVEN NAMES | Les C |
| FAMILY NAME | Cwynar |
| SIGNATURE | CWYNAR C |
| AFFILIATIONS | University of New Brunswick |
| VERIFIED | No |
| TOTAL WORKS | 11 |
| TOTAL CITATIONS | 0 |
| AUTHOR COUNT | 11 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1989 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 0 |
High-resolution forest and fire dynamics from Fish Lake, New Brunswick, Canada, during the last millennium
The Acadian Forest is a mixed-wood forest covering the Canadian provinces of New Brunswick and Nova Scotia. Picea rubens (red spruce) is its signature species which has been prominent for circa 2000 years. We extracted a 124 cm surface core from Fish Lake, (46° 8′ 38.32′′N, 66° 53′ 12.64′′ W), near Fredericton, New Brunswick. A rplum age-depth model, based upon 4 14 C and 15 210 Pb dates, showed that the core bottom dates to AD 890. We performed …
Formal ratification of the subdivision of the Holocene Series/Epoch (Quaternary System/Period)
Mike Walker, Martin J. Head, Max Berkelhammer, Svante Björck, Hai Cheng, Les Cwynar, David Fisher, Vasilios Gkinis, Antony Long, John Lowe, Rewi Newnham, Sune Olander Rasmussen, Harvey Weiss. Episodes 2018;41:213-23. https://doi.org/10.18814/epiiugs/2018/018016
Formal subdivision of the Holocene Series/Epoch
This discussion paper, by a Working Group of INTIMATE (Integration of ice‐core, marine and terrestrial records) and the Subcommision on Quaternary Stratigraphy (SQS) of the International Commission on Stratigraphy (ICS), considers the prospects for a formal subdivision of the Holocene Series/Epoch. Although previous attempts to subdivide the Holocene have proved inconclusive, recent developments in Quaternary stratigraphy, notably the definition …
A late Quaternary paleotemperature record from Hanging Lake, northern Yukon Territory, eastern Beringia
The late Quaternary paleoclimate of eastern Beringia has primarily been studied by drawing qualitative inferences from vegetation shifts. To quantitatively reconstruct summer temperatures, we analyzed lake sediments for fossil chironomids, and additionally we analyzed the sediments for fossil pollen and organic carbon content. A comparison with the δ 18 O record from Greenland indicates that the general climatic development of the region througho…
Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records
The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event i…
Holocene thermal maximum in the western Arctic (0–180°W)
Holocene Treeline History and Climate Change Across Northern Eurasia
Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern …
Chironomid Evidence for Late-Glacial Climatic Reversals in Maine
Previously published pollen studies from Maine have not identified any late-glacial reversals despite evidence for them from adjacent areas. The distribution and abundance of midge flies are strongly correlated with summer surface-water temperatures. We analyzed fossils of larval midge flies from the sediments of two ponds (Trout and Tilley) from Maine. Each site reveals a major and a minor oscillation during which inferred summer surface-water t…
A Multiproxy Investigation of Late-Glacial Climate and Vegetation Change at Pine Ridge Pond, Southwest New Brunswick, Canada
Pollen, plant macrofossil, chironomid, and lithological analyses of late-glacial sediment from Pine Ridge Pond all indicate that the warming following deglaciation was punctuated on two separate occasions by a return to colder climes; initially by a brief and moderate cold episode (the Killarney Oscillation), followed shortly by the Younger Dryas. The Killarney Oscillation, AMS 14 C dated at between 11,290 and 10,960 yr B.P., is characterized by …
Accelerator-Mass-Spectrometer Ages for the Younger Dryas Event in Atlantic Canada
In Atlantic Canada, bulk-sediment dates for the onset of a late-glacial cooling, widely regarded as the Younger Dryas event, are highly variable, ranging from 14,300 ± 270 to 10,800 ± 100 yr B.P. We present the first accelerator-mass-spectrometer (AMS) 14 C dates from Atlantic Canada, at or close to the boundaries of this event, from six sites in New Brunswick and Nova Scotia. The mean of five dates places the onset of this cooling at ca. 10,770 …
Accelerator-Mass Spectrometer Ages for Late-Glacial Events at Ballybetagh, Ireland
Although the character of late-glacial vegetation development in Ireland is well known, the dating is weak for a number of reasons. We report six accelerator-mass spectrometer (AMS) 14 C dates of hand-picked organic material from Ballybetagh. Several of the dates are based on terrestrial plant remains, thus eliminating the commonly encountered problem associated with Irish sites of errors due to the hard-water effect. The two most significant ind…
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Accelerator-Mass Spectrometer Ages for Late-Glacial Events at Ballybetagh, Ireland
Although the character of late-glacial vegetation development in Ireland is well known, the dating is weak for a number of reasons. We report six accelerator-mass spectrometer (AMS) 14 C dates of hand-picked organic material from Ballybetagh. Several of the dates are based on terrestrial plant remains, thus eliminating the commonly encountered problem associated with Irish sites of errors due to the hard-water effect. The two most significant ind…
Accelerator-Mass-Spectrometer Ages for the Younger Dryas Event in Atlantic Canada
In Atlantic Canada, bulk-sediment dates for the onset of a late-glacial cooling, widely regarded as the Younger Dryas event, are highly variable, ranging from 14,300 ± 270 to 10,800 ± 100 yr B.P. We present the first accelerator-mass-spectrometer (AMS) 14 C dates from Atlantic Canada, at or close to the boundaries of this event, from six sites in New Brunswick and Nova Scotia. The mean of five dates places the onset of this cooling at ca. 10,770 …
A Multiproxy Investigation of Late-Glacial Climate and Vegetation Change at Pine Ridge Pond, Southwest New Brunswick, Canada
Pollen, plant macrofossil, chironomid, and lithological analyses of late-glacial sediment from Pine Ridge Pond all indicate that the warming following deglaciation was punctuated on two separate occasions by a return to colder climes; initially by a brief and moderate cold episode (the Killarney Oscillation), followed shortly by the Younger Dryas. The Killarney Oscillation, AMS 14 C dated at between 11,290 and 10,960 yr B.P., is characterized by …
Chironomid Evidence for Late-Glacial Climatic Reversals in Maine
Previously published pollen studies from Maine have not identified any late-glacial reversals despite evidence for them from adjacent areas. The distribution and abundance of midge flies are strongly correlated with summer surface-water temperatures. We analyzed fossils of larval midge flies from the sediments of two ponds (Trout and Tilley) from Maine. Each site reveals a major and a minor oscillation during which inferred summer surface-water t…
Holocene Treeline History and Climate Change Across Northern Eurasia
Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern …
Holocene thermal maximum in the western Arctic (0–180°W)
A late Quaternary paleotemperature record from Hanging Lake, northern Yukon Territory, eastern Beringia
The late Quaternary paleoclimate of eastern Beringia has primarily been studied by drawing qualitative inferences from vegetation shifts. To quantitatively reconstruct summer temperatures, we analyzed lake sediments for fossil chironomids, and additionally we analyzed the sediments for fossil pollen and organic carbon content. A comparison with the δ 18 O record from Greenland indicates that the general climatic development of the region througho…
Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records
The Greenland ice core from NorthGRIP (NGRIP) contains a proxy climate record across the Pleistocene–Holocene boundary of unprecedented clarity and resolution. Analysis of an array of physical and chemical parameters within the ice enables the base of the Holocene, as reflected in the first signs of climatic warming at the end of the Younger Dryas/Greenland Stadial 1 cold phase, to be located with a high degree of precision. This climatic event i…
Formal subdivision of the Holocene Series/Epoch
This discussion paper, by a Working Group of INTIMATE (Integration of ice‐core, marine and terrestrial records) and the Subcommision on Quaternary Stratigraphy (SQS) of the International Commission on Stratigraphy (ICS), considers the prospects for a formal subdivision of the Holocene Series/Epoch. Although previous attempts to subdivide the Holocene have proved inconclusive, recent developments in Quaternary stratigraphy, notably the definition …
Formal ratification of the subdivision of the Holocene Series/Epoch (Quaternary System/Period)
Mike Walker, Martin J. Head, Max Berkelhammer, Svante Björck, Hai Cheng, Les Cwynar, David Fisher, Vasilios Gkinis, Antony Long, John Lowe, Rewi Newnham, Sune Olander Rasmussen, Harvey Weiss. Episodes 2018;41:213-23. https://doi.org/10.18814/epiiugs/2018/018016
High-resolution forest and fire dynamics from Fish Lake, New Brunswick, Canada, during the last millennium
The Acadian Forest is a mixed-wood forest covering the Canadian provinces of New Brunswick and Nova Scotia. Picea rubens (red spruce) is its signature species which has been prominent for circa 2000 years. We extracted a 124 cm surface core from Fish Lake, (46° 8′ 38.32′′N, 66° 53′ 12.64′′ W), near Fredericton, New Brunswick. A rplum age-depth model, based upon 4 14 C and 15 210 Pb dates, showed that the core bottom dates to AD 890. We performed …
Geology and Paleoclimatology Research (11 works) · Geology (10 works) · Paleontology (10 works) · Geography (8 works) · Holocene (8 works) · Physical geography (8 works) · Oceanography (7 works) · Younger Dryas (7 works) · Glacial period (6 works) · Climate change (4 works)