Late Pleistocene and early Holocene environmental history of southwestern Washington State, U.S.A.

1984 ◽  
Vol 21 (6) ◽  
pp. 619-629 ◽  
Author(s):  
Cathy W. Barnosky
Keyword(s):  
Environmental History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Cascade Range ◽  
Early Holocene ◽  
Olympic Mountains ◽  
Tundra Vegetation ◽  
Plant Remains ◽  
History Of ◽  
Glacial Time

A comparison of pollen records and associated plant remains from sites along a major precipitation gradient in southwestern Washington enables reconstruction of the late Quaternary environment during glacial and early Holocene time. During the Evans Creek Stade (25 000 – 17 000 years BP) little moisture reached lowlands east of the Olympic Mountains and as a result both the Puget Trough and the Columbia Basin featured a cold dry climate and parkland–tundra vegetation In glacial time, greatest aridity seems to have occurred between 19 000 and 17 000 years BP. After 17 000 years BP the development of mesophytic subalpine parkland suggests that maritime conditions extended farther east into the Puget Trough, and the Cascade Range became an important precipitation divide. Conditions warmer and (or) drier than today developed throughout western Washington between 10 000 and 8000–6000 years BP. Vegetation on opposite sides of the Cascade Range became dissimilar as early as 17 000 years BP, but this trend was accentuated in late glacial and early Holocene time.

Late Weichselian Environmental History in Southeastern Sweden during the Deglaciation of the Scandinavian Ice Sheet

1987 ◽  
Vol 28 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Svante Björck ◽  
Per Möller
Keyword(s):  
Environmental History ◽  
Vegetation Change ◽  
Time Lag ◽  
Ice Sheet ◽  
Late Glacial ◽  
Climatic Data ◽  
Basal Ice ◽  
Tundra Vegetation ◽  
History Of ◽  
Late Weichselian

AbstractLate Weichselian litho-, bio-, and chronostratigraphy (14C and varves) in southeastern Sweden provide a detailed picture of the deglaciation pattern and dynamics, shore displacement, late-glacial sedimentation, and history of the landscape, vegetation, and climate. Two plausible glacial models were tested against lithologic, chronologic, and climatic data. Permafrost at and outside the ice margin and topographic conditions beneath the ice apparently caused inward spread of frozen glacier-bed conditions. This led to a buildup of a large zone of debris-rich basal ice. A climatic amelioration about 12,700 yr B.P. changed the temperature profile in the ice sheet. Deposition of basal melt-out till began at the previously frozen glacier bed, and a rapid recession of the clean ice set in; thin exposed debris-rich basal ice which was separated from the active ice margin about 150 yr later. In this zone of stagnant ice there followed a 200– 300-yr period marked by subglacial and supraglacial melt-out and resedimentation, forming a large hummocky/transverse moraine. The mild climate favored rapid plant immigration, and a park-tundra was established. The gradual closing of the landscape was interrupted by a 100- to 150-yr period of tundra vegetation and a cool, dry climate, with local vegetational differences caused by differences in soil moisture. About 12,000 yr B.P. a second climatic amelioration set in, and during the next 1000 yr a birch (and pine) woodland gradually developed. Soils stabilized and Empetrum heaths became abundant as the climate gradually deteriorated at the end of this period. By 11,000 yr B.P. the area had become a tundra again with scattered birch stands, dominated by herbs such as Artemisia, Chenopodiaceae, grasses, and sedges. Some 500 yr later a birch/pine woodland again succeeded, and within about 500 yr the vegetation changed to a rather closed woodland as the climate ameliorated further. However, the time lag between climatic and vegetation change was considerable.

Late Quaternary vegetational history of the Howard Pass Area, northwestern Alaska

1999 ◽  
Vol 77 (4) ◽  
pp. 570-581 ◽  
Author(s):  
W Wyatt Oswald ◽  
Linda B Brubaker ◽  
Patricia M Anderson
Keyword(s):  
Late Quaternary ◽  
Local Variation ◽  
Late Glacial ◽  
Early Holocene ◽  
Pollen Accumulation Rates ◽  
Rubus Chamaemorus ◽  
History Of Vegetation ◽  
History Of ◽  
Western Arctic ◽  
Northern Alaska

Palynological records from Tukuto and Etivlik Lakes contribute to an improved understanding of the late Quaternary history of vegetation in the Howard Pass area of northern Alaska. During the Itkillik II glaciation (24-14 ka BP), the vegetation of the western Arctic Foothills was sparse, xeric tundra, as evidenced by taxa indicative of dry, rocky substrates (e.g., Selaginella rupestris (L.) Spring, Chenopodiaceae, and Encalypta cf. rhaptocarpa) and very low pollen accumulation rates in this interval of the 30-ka-old Tukuto Lake record. Mesic tundra dominated by non-Sphagnum (Bryidae) mosses, Cyperaceae, and Salix species expanded near Tukuto Lake during the late-glacial period, followed by the establishment of Sphagnum moss and increased shrub cover at ca. 10 ka BP. Landscapes around both lakes supported stands of Populus cf. balsamifera during the early Holocene, and Alnus crispa expanded in the Howard Pass area during the middle Holocene. Local variation in plant communities is illustrated by the comparison of the Tukuto and Etivlik pollen records. During the early Holocene, Populus cf. balsamifera was more common near Etivlik Lake than Tukuto Lake, and Juniperus cf. communis was present only in the vicinity of Etivlik Lake. Throughout the middle to late Holocene, Sphagnum, mesic tundra shrubs (Betula nana L., Salix, and Ericaceae species), and minor herbaceous taxa (e.g., Rubus chamaemorus L., Thalictrum, and Caryophyllaceae) were more prevalent at Tukuto Lake than at Etivlik Lake. These differences are likely related to the influence of local landform and soil characteristics near the two sites.Key words: Alaska, Arctic Foothills, Brooks Range, pollen analysis, Quaternary.

Postglacial vegetation and fire history of the southern Cascade Range, Oregon

2015 ◽  
Vol 84 (3) ◽  
pp. 348-357 ◽  
Author(s):  
Alicia White ◽  
Christy Briles ◽  
Cathy Whitlock
Keyword(s):  
Late Holocene ◽  
Large Scale ◽  
Fire History ◽  
Late Glacial ◽  
Fire Frequency ◽  
Cascade Range ◽  
Early Holocene ◽  
Glacial Period ◽  
Holocene Thermal Maximum ◽  
History Of

The Cascade Range of southwestern Oregon contains some of North America's most diverse forests, but the ecological history of this area is poorly understood. A 7900-yr-long pollen and charcoal record was examined to better understand past changes in vegetation and fire activity in relation to large-scale climate variability. From 7900 to 3500 cal yr BP, the dominance of xerophytic species and the frequent fires are consistent with a climate that was warmer and drier than at present. The period from 3500 cal yr BP to present experienced an abundance of mesophytic taxa and reduced fire frequency, suggesting cooler and wetter conditions. The regional history of Abies indicates that it was most widespread during the late-glacial period; its range contracted during the early Holocene thermal maximum, and it steadily expanded during the middle and late Holocene. In contrast, Pseudotsuga was restricted in range during the glacial period, became abundant at low-elevation sites in the Coast and northern Cascade ranges during the early Holocene, and was more prevalent in southern mid-elevation sites as the climate became cooler and wetter in the late Holocene. The sensitivity of these species to past climate change suggests that biogeographic responses to future conditions will be highly variable in this region.

scholarly journals Late Quaternary history of Lammefjorden, north-west Sjælland, Denmark

2020 ◽  
Author(s):  
Ole Bennike ◽  
Peter Roll Jakobsen ◽  
Jakob Walløe Hansen
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
Late Glacial ◽  
Early Holocene ◽  
Last Deglaciation ◽  
North West ◽  
Najas Marina ◽  
Marine Deposits ◽  
Minimum Age ◽  
History Of

Lammefjorden is a reclaimed fjord in north-west Sjælland, Denmark. Sediment cores from the area were collected to study its development after the last deglaciation, in particular the sea-level history. Late glacial and Early Holocene lake and bog deposits occur below marine deposits. Sparse late glacial fossil assemblages indicate tree-less environments with dwarf-shrub heaths. Early Holocene deposits contain remains of Betula sec. Albae sp. and Pinus sylvestris, which indicate open forests. The wetland flora comprised the calciphilous reed plant Cladium mariscus and the water plant Najas marina. Marine gyttja from basins is characterised by sparse benthic faunas, probably due to high sedimentation rates. In some areas, shell-rich deposits were found, with large shells of Ostrea edulis, indicative of high summer temperatures, high salinity and strong tidal currents. A marine shell dated to 6.7 cal. ka provides a minimum age for the marine transgression of Lammefjorden.

A revised late-Quaternary vegetation history of the unglaciated southwestern Yukon Territory, Canada, from Antifreeze and Eikland ponds

2010 ◽  
Vol 47 (1) ◽  
pp. 75-88 ◽  
Author(s):  
Jesse C. Vermaire ◽  
Les C. Cwynar
Keyword(s):  
Vegetation Change ◽  
Vegetation History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Yukon Territory ◽  
Early Holocene ◽  
Glacial Period ◽  
Vegetation Shifts ◽  
History Of ◽  
New Interpretation

Antifreeze Pond was thought to contain the oldest record of continuous environmental change in the southwestern Yukon. We have revised the original interpretation of the vegetation history of Antifreeze Pond and this region based on new pollen, stomate, and macrofossil analysis, along with 38 new accelerator mass spectrometry (AMS) 14C dates from Antifreeze Pond and nearby Eikland Pond. Although the overall pattern of vegetation change is similar to the previously published Antifreeze Pond record, our new analysis indicates that the timing of the major vegetation shifts is substantially different, particularly during the late-glacial and early Holocene periods (from ∼17 000 – 9000 cal years BP). The original Antifreeze Pond record was thought to span a mid-Wisconsinan interstadial (>30 000 cal years BP) and the full-glacial period. Our results, however, indicate that the material of mid-Wisconsinan age was likely deposited by slumping around the pond making interpretation of the paleoenvironment difficult. Furthermore, our AMS 14C dates show that what was thought to be a full-glacial vegetation record is actually the vegetation history of the late-glacial period (ca. 17 000 – 11 000 cal years BP), which was a time of rapid sediment deposition into the ponds. The Eikland Pond record has an early Holocene Populus rise between ca. 11 000 – 8000 cal years BP that is not present in either the new or original Antifreeze Pond records. This new interpretation of the vegetation history should aid comparisons to other regional paleoenvironmental records.

scholarly journals XIX.—The Bone-Cave in the Valley of Allt nan Uamh (Burn of the Caves), near Inchnadamff, Assynt, Sutherlandshire

1918 ◽  
Vol 37 ◽  
pp. 327-349 ◽  
Author(s):  
B. N. Peach ◽  
J. Horne ◽  
E. T. Newton
Keyword(s):  
Characteristic Feature ◽  
Late Glacial ◽  
Early History ◽  
The Arctic ◽  
Geological History ◽  
Collateral Evidence ◽  
History Of ◽  
Glacial Time

A characteristic feature of the plateau of Cambrian Limestone in the neighbourhood of Inchnadamff is the occurrence in it of swallow-holes, caves, and subterranean channels which are intimately associated with the geological history of the region. The valley of Allt nan Uamh (Burn of the Caves), locally known as the Coldstream Burn, furnishes striking examples of these phenomena. One of the caves in this valley yielded an interesting succession of deposits, from which were collected abundant remains of mammals and birds. The discovery of bones of the Northern Lynx, the Arctic Lemming, and the Northern Vole among these relics, and the collateral evidence of the materials forming some of these layers, seem to link the early history of this bone-cave with late glacial time, or at least with a period before the final disappearance of local glaciers in that region.

Late Quaternary glacial and interglacial environments of the Nechako River - Cheslatta Lake area, central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A Plouffe ◽  
V M Levson
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Late Glacial ◽  
Lake Area ◽  
Glacial Lakes ◽  
Ice Flow ◽  
Coast Mountains ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Quaternary History

The Quaternary stratigraphy of the Nechako River – Cheslatta Lake area of central British Columbia is described and interpreted to reconstruct the late Quaternary history of the region. Exposures of glacial and nonglacial sediments deposited prior to the last glaciation (Fraser) are limited to three sites. Pollen assemblages from pre-Fraser nonglacial sediments at two of these sites reveal forested conditions around 39 000 BP. During the advance phase of the Fraser Glaciation, glacial lakes were ponded when trunk glaciers blocked some tributary valleys. Early in the glaciation, the drainage was free in easterly draining valleys. Subsequently, the easterly drainage was blocked either locally by sediments and ice or as a result of impoundment of the Fraser River and its tributaries east of the study area. Ice generally moved east and northeast from accumulation zones in the Coast Mountains. Ice flow was influenced by topography. Major late-glacial lakes developed in the Nechako River valley and the Knewstubb Lake region because potential drainage routes were blocked by ice.

Late Quaternary vegetation, climate, and fire history of the Southeast Atlantic Coastal Plain based on a 30,000-yr multi-proxy record from White Pond, South Carolina, USA

2019 ◽  
Vol 91 (2) ◽  
pp. 861-880 ◽  
Author(s):  
Teresa R. Krause ◽  
James M. Russell ◽  
Rui Zhang ◽  
John W. Williams ◽  
Stephen T. Jackson
Keyword(s):  
South Carolina ◽  
Vegetation Change ◽  
Fire History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Atlantic Coastal Plain ◽  
Proxy Records ◽  
Dry Conditions ◽  
History Of ◽  
Mississippian Culture

AbstractThe patterns and drivers of late Quaternary vegetation dynamics in the southeastern United States are poorly understood due to low site density, problematic chronologies, and a paucity of independent paleoclimate proxy records. We present a well-dated (15 accelerator mass spectrometry14C dates) 30,000-yr record from White Pond, South Carolina that consists of high-resolution analyses of fossil pollen, macroscopic charcoal, andSporormiellaspores, and an independent paleotemperature reconstruction based on branched glycerol dialkyl tetraethers. Between 30,000 and 20,000 cal yr BP, openPinus-Piceaforest grew under cold and dry conditions; elevatedQuercusbefore 26,000 cal yr BP, however, suggest warmer conditions in the Southeast before the last glacial maximum, possibly corresponding to regionally warmer conditions associated with Heinrich event H2. Warming between 19,700 and 10,400 cal yr BP was accompanied by a transition from conifer-dominated to mesic hardwood forest.Sporormiellaspores were not detected and charcoal was low during the late glacial period, suggesting megaherbivore grazers and fire were not locally important agents of vegetation change.Pinusreturned to dominance during the Holocene, with step-like increases inPinusat 10,400 and 6400 cal yr BP, while charcoal abundance increased tenfold, likely due to increased biomass burning associated with warmer conditions. Low-intensity surface fires increased after 1200 cal yr BP, possibly related to the establishment of the Mississippian culture in the Southeast.

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