A multi-proxy reconstruction of climate during the late-Pleistocene to early Holocene transition in the northeastern, USA

2021 ◽  
pp. 1-17
Author(s):  
Laurie D. Grigg ◽  
Kevin J. Engle ◽  
Alison J. Smith ◽  
Bryan N. Shuman ◽  
Maximilian B. Mandl
Keyword(s):  
Late Pleistocene ◽  
Climatic Variability ◽  
Warming Trend ◽  
Early Holocene ◽  
Individual Species ◽  
Environmental Preferences ◽  
The North ◽  
Show Evidence ◽  
Dry Conditions ◽  
Components Analysis

Abstract A multiproxy record from Twin Ponds, VT, is used to reconstruct climatic variability during the late Pleistocene to early Holocene transition. Pollen, ostracodes, δ18O, and lithologic records from 13.5 to 9.0 cal ka BP are presented. Pollen- and ostracode-inferred climatic reconstructions are based on individual species’ environmental preferences and the modern analog technique. Principal components analysis of all proxies highlights the overall warming trend and centennial-scale climatic variability. During the Younger Dryas cooling event (YD), multiple proxies show evidence for cold winter conditions and increasing seasonality after 12.5 cal ka BP. The early Holocene shows an initial phase of rapid warming with a brief cold interval at 11.5 cal ka BP, followed by a more gradual warming; a cool, wet period from 11.2 to 10.8 cal ka BP; and cool, dry conditions from 10.8 to 10.2 cal ka BP. The record ends with steady warming and increasing moisture. Post-YD climatic variability has been observed at other sites in the northeastern United States and points to continued instability in the North Atlantic during the final phases of deglaciation.

Variability of Monsoon Climate in East Asia at the End of the Last Glaciation

1996 ◽  
Vol 46 (3) ◽  
pp. 219-229 ◽  
Author(s):  
Zhou Weijian ◽  
Douglas J. Donahue ◽  
Stephen C. Porter ◽  
Timothy A. Jull ◽  
Li Xiaoqiang ◽  
...  
Keyword(s):  
North Atlantic ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Climatic Variability ◽  
Late Glacial ◽  
Proxy Records ◽  
The North ◽  
Last Glaciation ◽  
Eolian Sand ◽  
Dry Conditions

High-resolution paleomonsoon proxy records from peat and eolian sand–paleosol sequences at the desert–loess transition zone in China denote a rapid oscillation from cold–dry conditions (11,200–10,600 14C yr B.P.) to cool–humid conditions (10,600–10,200 14C yr B.P.), followed by a return to cold–dry climate (10,200–10,000 14C yr B.P.). Variations in precipitation proxies suggest that significant climatic variability occurred in monsoonal eastern Asia during the Younger Dryas interval. Late-glacial climate in the Chinese desert–loess belt that lies downwind from Europe was strongly influenced by cold air from high latitudes and from the North Atlantic via the westerlies. The inferred precipitation variations were likely caused by variations in the strength of the Siberian high, which influenced the pressure gradient between land and ocean and therefore influenced the position of the East Asian monsoon front.

scholarly journals Spatial distribution of benthic foraminiferal stable isotopes and dinocyst assemblages in surface sediments of the Trondheimsfjord, central Norway

2013 ◽  
Vol 10 (7) ◽  
pp. 4433-4448 ◽  
Author(s):  
G. Milzer ◽  
J. Giraudeau ◽  
J. Faust ◽  
J. Knies ◽  
F. Eynaud ◽  
...  
Keyword(s):  
Organic Matter ◽  
Climatic Variability ◽  
Intermediate Water ◽  
North Atlantic Current ◽  
Local Conditions ◽  
Bottom Water Temperature ◽  
The North ◽  
Show Evidence ◽  
Matter Flux ◽  
Instrumental Records

Abstract. Instrumental records from the Norwegian Sea and the Trondheimsfjord show evidence that changes of bottom water temperature and salinity in the fjord are linked to the salinity and temperature variability of the North Atlantic Current (NAC). Changes in primary productivity and salinity in the surface and intermediate water masses in the Trondheimsfjord as well as the fjord sedimentary budget are mainly driven by changes in riverine input. In this study we use 59 surface sediment samples that are evenly distributed in the fjord to examine whether dinocyst assemblages and stable isotope ratios of benthic foraminifera reflect the present-day hydrology and can be used as palaeoceanographic proxies. In general, modern benthic δ18O and δ13C values decrease from the fjord entrance towards the fjord head with lowest values close to river inlets. This is essentially explained by gradients in the amounts of fresh water and terrigenous organic matter delivered from the hinterland. The distribution of benthic δ13C ratios across the fjord is controlled by the origin (terrigenous vs. marine) of organic matter, local topography-induced variability in organic matter flux at the water–sediment interface, and organic matter degradation. The dinocyst assemblages display the variations in hydrography with respect to the prevailing currents, the topography, and the freshwater and nutrient supply from rivers. The strength and depth of the pycnocline in the fjord strongly vary seasonally and thereby affect water mass characteristics as well as nutrient availability, temporally creating local conditions that explain the observed species distribution. Our results prove that dinocyst assemblages and benthic foraminiferal isotopes reliably mirror the complex fjord hydrology and can be used as proxies of Holocene climatic variability.

scholarly journals Late Pleistocene and Early Holocene Vertebrates and Paleoenvironments on the Southern High Plains, U.S.A.

2007 ◽  
Vol 40 (3) ◽  
pp. 249-261 ◽  
Author(s):  
Eileen Johnson
Keyword(s):  
Late Pleistocene ◽  
Temperature Fluctuation ◽  
Drainage System ◽  
Warming Trend ◽  
Early Holocene ◽  
Archaeological Sites ◽  
High Plains ◽  
Moisture Regime ◽  
Local Fauna ◽  
Southern High Plains

ABSTRACT Only a few vertebrate faunas are known for the Southern High Plains from the late Pleistocene and early Holocene. This review focuses on vertebrate local faunas from two major localities on opposite sides of the region but in the same drainage system that provide proxy data for paleoenvironmental reconstructions from ca. 11,600 to 8600 yr BP. Both localities are archaeological sites within deeply stratified, radiocarbon-dated deposits. Four distinct, successive vertebrate local faunas are known for Lubbock Lake covering the period 11,100 to 8600 yr BP. Two distinct, successive vertebrate local faunas come from Blackwater Draw Locality # 1 for the period 11,600 to 10,500 yr BP. All of the local faunas are disharmonious but the extent of disharmony and diversity varies. Faunal elements from the Northern Plains and Southeast are the most notable. The late Pleistocene local faunas indicate mild winters which did not maintain freezing conditions and cool summers with a more effective moisture regime, reduced annual temperature fluctuation, and less seasonality. The beginnings of a warming trend, greater seasonality, and increased annual temperature fluctuation denote the early Holocene. The latest local fauna marks the last of the pluvial-related ones and heralds the end of pluvial conditions beginning around 8500 yr BP. The successive local faunas illustrate the complexity of disharmony occurring in unglaciated regimes during déglaciation of North America.

Evidence for geographic variation in the diets of late Pleistocene and early Holocene Bison in North America, and differences from the diets of recent Bison

2007 ◽  
Vol 68 (3) ◽  
pp. 338-346 ◽  
Author(s):  
Florent Rivals ◽  
Nikos Solounias ◽  
Matthew C. Mihlbachler
Keyword(s):  
North America ◽  
Late Pleistocene ◽  
Statistical Tests ◽  
Early Holocene ◽  
Central Plains ◽  
Dietary Breadth ◽  
The North ◽  
Microwear Analysis ◽  
Dietary Study ◽  
Ecological Versatility

AbstractDuring the late Pleistocene and early Holocene, Bison was widely dispersed across North America and occupied most regions not covered by ice sheets. A dietary study on Bison paleopopulations from Alaska, New Mexico, Florida, and Texas was performed using two methods that relate dental wear patterns to diet, mesowear analysis and microwear analysis. These data were compared to a mixed sample of extant Bison from the North American central plains, extant wood Bison from Alberta (Canada) and a variety of other modern ungulates. Mesowear relates macroscopic molar facet shape to levels of dietary abrasion. The mesowear signature observed on fossil Bison differs significantly from the hyper-abrasive grazing diet of extant Bison. Tooth microwear examines wear on the surface of enamel at a microscopic scale. The microwear signal of fossil samples resembles to modern Bison, but the fossil samples show a greater diversity of features, suggesting that fossil Bison populations regularly consumed food items that are texturally inconsistent with the short-grass diet typical of modern plains Bison. Mesowear and microwear signals of fossil Bison samples most closely resemble a variety of typical mixed feeding ungulates, all with diets that are substantially less abrasive than what is typical for modern plains Bison. Furthermore, statistical tests suggest significant differences between the microwear signatures of the fossil samples, thus revealing geographic variability in Pleistocene Bison diets. This study reveals that fossils are of value in developing an understanding of the dietary breadth and ecological versatility of species that, in recent times, are rare, endangered, and occupy only a small remnant of their former ranges.

Localization and possible social aggregation in the Late Pleistocene and Early Holocene on the north coast of Perú

2003 ◽  
Vol 109-110 ◽  
pp. 3-11 ◽  
Author(s):  
Tom D. Dillehay ◽  
Jack Rossen ◽  
Greg Maggard ◽  
Kary Stackelbeck ◽  
Patricia Netherly
Keyword(s):  
Late Pleistocene ◽  
Early Holocene ◽  
North Coast ◽  
Social Aggregation ◽  
The North ◽  
North Coast Of Peru

scholarly journals Anomalous glacier responses to 20th century climatic changes in Darwin Cordillera, southern Chile

1995 ◽  
Vol 41 (139) ◽  
pp. 465-473 ◽  
Author(s):  
Per Holmlund ◽  
Humberto Fuenzalida
Keyword(s):  
20Th Century ◽  
General Trend ◽  
Warming Trend ◽  
Turn Of The Century ◽  
Aerial Photographs ◽  
The North ◽  
Asymmetric Pattern ◽  
Dry Conditions ◽  
Northern Side ◽  
Wind Activity

AbstractThere is an asymmetric pattern response of glaciers in Darwin Cordillera (54–55° S, 69–71° W) to the climate of the 20th century. This asymmetry is suggested here as a cause of an increased wind activity which has a pronounced orographic effect. Although climatic records for the last 50 years show a warming trend, as well as no trend in precipitation in the area, some glaciers are advancing. The area is characterized by strong climatic gradients, with high rates of precipitation on the southwestern side of the range and dry conditions on the northern side. Glaciers on the northern and eastern sides show a general trend of receding fronts. With a few exceptions, these glaciers have gradually and uninterruptedly been shrinking since the turn of the century. On the southern rim, the present extents of some glaciers are similar to their 20th century maximum extents. These are, in turn, similar or close to the Holocene maximum. The most extreme sites are the glaciers on either side of Mount Darwin, which is 2469 m high. The north-facing glacier Ventisquero Marinelli has retreated several hundred metres per year over the last two decades, while the south-facing glaciers in the Pahia Pia basin have advanced during the same period.In this study, the frontal changes over the last 50 years of 20 glaciers have been analysed. Aerial photographs (verticals) from 1943 and 1984 have been used, as well as oblique aerial photographs from 1993. The general result is that glaciers with accumulation areas facing south and west show somewhat stable fronts, while glaciers facing east and north show receding fronts.

scholarly journals Spatial distribution of benthic foraminiferal stable isotopes and dinocyst assemblages in surface sediments of the Trondheimsfjord, central Norway

2013 ◽  
Vol 10 (3) ◽  
pp. 5889-5921 ◽  
Author(s):  
G. Milzer ◽  
J. Giraudeau ◽  
J. Faust ◽  
J. Knies ◽  
F. Eynaud ◽  
...  
Keyword(s):  
Organic Matter ◽  
Climatic Variability ◽  
Intermediate Water ◽  
North Atlantic Current ◽  
Local Conditions ◽  
Bottom Water Temperature ◽  
The North ◽  
Show Evidence ◽  
Matter Flux ◽  
Instrumental Records

Abstract. Instrumental records from the Norwegian Sea and the Trondheimsfjord show evidence that changes of bottom water temperature and salinity in the fjord are linked to the salinity and temperature variability of the North Atlantic Current (NAC). Changes in primary productivity and salinity in the surface and intermediate water masses in the Trondheimsfjord as well as the fjord sedimentary budget are mainly driven by changes in riverine input. In this study we use 59 surface sediment samples that are evenly distributed in the fjord to examine whether dinocyst assemblages and stable isotope ratios of benthic foraminifera reflect the present-day hydrology and can be used as paleoceanographic proxies. In general, modern benthic δ18O and δ13C values decrease from the fjord entrance towards the fjord head with lowest values close to river inlets. This is essentially explained by gradients in the amounts of freshwater and terrigenous organic matter delivered from the hinterland. The distribution of benthic δ13C ratios across the fjord is controlled by both the origin (terrigenous vs. marine) of organic matter and local topography-induced variability in organic matter flux at the water-sediment interface. The dinocyst assemblages display the variations in hydrography with respect to the prevailing currents, the topography, and the freshwater and nutrient supply from rivers. The strength and depth of the pycnocline in the fjord strongly varies seasonally and thereby affects water mass characteristics as well as nutrient availability, temporally creating local conditions that explain the observed species distribution. Our results prove that dinocyst assemblages and benthic foraminiferal isotopes reliably mirror the complex fjord hydrology and can therefore be used as proxies of Holocene climatic variability.

scholarly journals Anomalous glacier responses to 20th century climatic changes in Darwin Cordillera, southern Chile

1995 ◽  
Vol 41 (139) ◽  
pp. 465-473 ◽  
Author(s):  
Per Holmlund ◽  
Humberto Fuenzalida
Keyword(s):  
20Th Century ◽  
General Trend ◽  
Warming Trend ◽  
Turn Of The Century ◽  
Aerial Photographs ◽  
The North ◽  
Asymmetric Pattern ◽  
Dry Conditions ◽  
Northern Side ◽  
Wind Activity

AbstractThere is an asymmetric pattern response of glaciers in Darwin Cordillera (54–55° S, 69–71° W) to the climate of the 20th century. This asymmetry is suggested here as a cause of an increased wind activity which has a pronounced orographic effect. Although climatic records for the last 50 years show a warming trend, as well as no trend in precipitation in the area, some glaciers are advancing. The area is characterized by strong climatic gradients, with high rates of precipitation on the southwestern side of the range and dry conditions on the northern side. Glaciers on the northern and eastern sides show a general trend of receding fronts. With a few exceptions, these glaciers have gradually and uninterruptedly been shrinking since the turn of the century. On the southern rim, the present extents of some glaciers are similar to their 20th century maximum extents. These are, in turn, similar or close to the Holocene maximum. The most extreme sites are the glaciers on either side of Mount Darwin, which is 2469 m high. The north-facing glacier Ventisquero Marinelli has retreated several hundred metres per year over the last two decades, while the south-facing glaciers in the Pahia Pia basin have advanced during the same period.In this study, the frontal changes over the last 50 years of 20 glaciers have been analysed. Aerial photographs (verticals) from 1943 and 1984 have been used, as well as oblique aerial photographs from 1993. The general result is that glaciers with accumulation areas facing south and west show somewhat stable fronts, while glaciers facing east and north show receding fronts.

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