Quaternary stratigraphy and history of the Ootsa Lake - Cheslatta River area, Nechako Plateau, central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 751-765 ◽  
Author(s):  
D J Mate ◽  
V M Levson
Keyword(s):  
Late Quaternary ◽  
Lacustrine Sediments ◽  
Late Glacial ◽  
Stratigraphic Correlation ◽  
Study Region ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Holocene Stratigraphy ◽  
Plateau Central ◽  
Late Wisconsinan

Erosion along the Nechako Reservoir and Cheslatta River Spillway has resulted in unusually well-exposed late Quaternary and Holocene stratigraphy. Surficial sediments in the study area are mostly products of Late Wisconsinan glaciation. However, evidence for pre-Late Wisconsinan sedimentation has been found along the shores of the Nechako Reservoir, including till of an older glaciation and organic-bearing, blue-grey, lacustrine sediments of probable Middle Wisconsinan age. Stratigraphic correlation of the lake sediments suggests that an extensive lake system occurred in the region during the Olympia Nonglacial Interval. Late Wisconsinan ice initially moved along major valleys, with glaciofluvial outwash deposited in front of the advancing ice. Advance-phase glaciolacustrine sediments are rare but significant, as slope failures are spatially associated with areas where they are preserved. The distribution of these sediments and associated deltaic deposits indicates that advance-phase glacial lakes occurred up to approximately 855 m asl, at least several metres above the modern reservoir level. Sediments deposited in front of the ice margin were overridden during ice advance and are best preserved in large valleys. At the glacial maximum, ice flowed northeasterly throughout the study region. Crag and tails, flutings, and drumlinoid ridges with a generally consistent northeast trend are the dominant landforms. Till is the most common Pleistocene surficial sediment, covering approximately 80% of the area; large areas of exposed bedrock are rare. Late-glacial glaciofluvial and Holocene fluvial deposits are uncommon and occur mainly along the Cheslatta River valley.

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 sediments and geomorphic history of north-central Vancouver Island

1981 ◽  
Vol 18 (1) ◽  
pp. 1-12 ◽  
Author(s):  
D. E. Howes
Keyword(s):  
Late Quaternary ◽  
Lacustrine Sediments ◽  
Late Glacial ◽  
Vancouver Island ◽  
Time Span ◽  
Quaternary Sediments ◽  
Single Exposure ◽  
North Central ◽  
Sedimentary Environments ◽  
History Of

Materials from two glacial and two nonglacial intervals are identified on north-central Vancouver Island, British Columbia. The oldest Pleistocene unit, Muchalat River drift, consists of till and overlying glaciolacustrine silt. It has been tentatively correlated with Dashwood drift of the Semiahmoo Glaciation. An overlying single exposure of mudflow sediment in the Gold River valley contains wood dated at 40 900 ± 2000 years BP within the time span of the Olympia nonglacial interval. The Olympia nonglacial interval was characterized by a period of degradation in which Olympia-age sediments were deposited in transient sedimentary environments and subsequently eroded. Gold River drift includes Gold River advance deposits, Gold River till, and Gold River late glacial deposits, and was deposited during the Fraser Glaciation. The Fraser Glaciation was well underway on north-central Vancouver Island by 25 200 ± 330 years BP. During the Fraser Glaciation maximum, which occurred after 20 600 ± 330 years BP, Coast Mountain ice flowed in a southwesterly direction across north-central Vancouver Island overtopping all but the highest peaks of the Vancouver Island Mountains. Deglaciation commenced prior to 12 930 ± 160 years BP and the ice had probably disappeared before 9500 years ago. During postglacial times rivers have dissected older Quaternary sediments and bedrock up to at least 40 m. Macroflora data recorded in postglacial lacustrine sediments suggest that the Hypsithermal Interval commenced before 8300 ± 70 years BP.

scholarly journals Quaternary Stratigraphy and History, Quesnel, British Columbia

2007 ◽  
Vol 42 (3) ◽  
pp. 279-288 ◽  
Author(s):  
John J. Clague
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Drainage System ◽  
Glacial Lakes ◽  
Quaternary Stratigraphy ◽  
Valley Fills ◽  
History Of ◽  
Late Wisconsinan ◽  
Sand And Gravel

ABSTRACT Thick Quaternary sediments at Quesnel, British Columbia, provide a record of the late Quaternary history of an area near the centre of the former Cordilieran Ice Sheet. These sediments, in part, fill stream valleys that were cut sometime prior to the Late Wisconsinan Fraser Glaciation. Of special note are (1) fluvial or glaciofluvial sand and gravel deposited by aggrading streams, perhaps in part during early Fraser time; (2) thick glaciolacustrine mud, sand, and diamicton laid down later as glaciers advanced across central British Columbia; and (3) glaciolacustrine sediments similar to (2), but deposited in an ice-dammed lake at the end of the Fraser Glaciation. The stratigraphy is punctuated by colluvial deposits that are products of landslides from valley walls at various times during the late Quaternary; this process continues to the present. During the Fraser Glaciation, glaciers from the Coast and Cariboo Mountains coalesced and flowed north over central British Columbia. Fraser Glaciation advance sediments and older Pleistocene deposits were partially removed by this ice sheet and the eroded remnants mantled with till. At the end of this glaciation, the Cordilieran Ice Sheet downwasted and receded southward along an irregular front across the study area. Large amounts of sediment were deposited in glacial lakes dammed by the southward-retreating ice. With complete déglaciation of the interior, glacial lakes drained and the present drainage system was established. At first, valleys were partially aggraded with sand and gravel, but later, streams dissected valley fills to produce a series of terraces at successively lower levels.

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.

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.

scholarly journals Late-Glacial and Postglacial Vegetation and Climate of Jackson Hole and the Pinyon Peak Highlands, Wyoming

1985 ◽  
Vol 9 ◽  
pp. 44-49
Author(s):  
Cathy Barnosky
Keyword(s):  
Rocky Mountains ◽  
National Park ◽  
Vegetation History ◽  
Late Quaternary ◽  
Late Glacial ◽  
Glacial Refugia ◽  
Northern Rocky Mountains ◽  
Jackson Hole ◽  
History Of ◽  
Vegetation And Climate

The late-Quaternary vegetation history of the northern Rocky Mountains has thus far been inferred largely from isolated records. These data suggest that conifer forests were established early in postglacial time and were little modified thereafter. The similarity of early postglacial vegetation to modern communities over broad areas gives rise to two hypotheses: (1) that glacial refugia were close to the ice margin, and (2) that vegetation soon colonized the deglaciated areas and has been only subtly affected by climatic perturbations since that time. It is the goal of this project to test these two hypotheses in the region of Grand Teton National Park.

LATE QUATERNARY HISTORY OF THE NORTHERN BEETLE FAUNA OF NORTH AMERICA: A SYNTHESIS OF FOSSIL AND DISTRIBUTIONAL EVIDENCE

1988 ◽  
Vol 120 (S144) ◽  
pp. 93-107 ◽  
Author(s):  
Donald P. Schwert ◽  
Allan C. Ashworth
Keyword(s):  
North America ◽  
Boreal Forest ◽  
Late Quaternary ◽  
Ground Beetle ◽  
The Arctic ◽  
Beetle Species ◽  
Centre Of Origin ◽  
Tangible Evidence ◽  
History Of ◽  
Late Wisconsinan

AbstractFossils from sites of Late Quaternary age in North America provide tangible evidence of temporal changes in the character of the northern beetle fauna. Based on a synthesis of the fossil data with analyses of the present distributions for northern species, a rudimentary model is proposed to explain the recent history of the fauna of the arctic and the boreal forest.An open-ground beetle fauna of arctic–subarctic affinities had become established along the southern margin of the Laurentide ice sheet in the midcontinent by 20 500 years before present (yr B.P.). Climatic warming decimated this fauna throughout lowland areas at some time between 16 700 and 15 300 yr B.P.; small populations of some arctic–subarctic species, however, survived within either alpine habitats of the Cordillera and Appalachians or specialized environments associated with stagnant ice.Populations of the same arctic–subarctic beetle species existed within the ice-free Alaska–Yukon refugium throughout the late Wisconsinan. During the Holocene, this region served as the principal centre-of-origin for the dispersal of the arctic–subarctic beetle fauna.The beetle fauna of the boreal forest was also displaced southward by Late Wisconsinan glaciation. By 15 300 yr B.P., however, this fauna had largely replaced the arctic–subarctic beetle fauna along the ice margin of the midcontinent. Evidence provided by fossils from a series of sites demonstrates that beetle species of the boreal forest dispersed northward into Canada as the ice front receded.

Quaternary stratigraphy and glacial history of the Peace River valley, northeast British ColumbiaThis article is one of a selection of papers published in this Special Issue on the theme Geology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

2008 ◽  
Vol 45 (5) ◽  
pp. 549-564 ◽  
Author(s):  
Gregory M.D. Hartman ◽  
John J. Clague
Keyword(s):  
British Columbia ◽  
River Valley ◽  
Quaternary Sediments ◽  
Shallow Gas ◽  
Peace River ◽  
Last Glaciation ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Late Wisconsinan ◽  
Selection Of

Two Cordilleran and three Laurentide glacial advances are recorded in Quaternary sediments and landforms in the Peace River valley, northeast British Columbia. The advances are inferred from fluvial gravels, glaciolacustrine sediments, and tills within nested paleovalleys excavated during three interglaciations and from the distribution of granitoid clasts derived from the Canadian Shield. Till of the last (Late Wisconsinan) Laurentide glaciation occurs at the surface, except where it is overlain by postglacial sediments. The advance that deposited this till was the most extensive in the study area, and the only advance definitively recognized in western Alberta south of the study area. Late Wisconsinan Cordilleran till has not been found in the study area, but Cordilleran and Laurentide ice may have coalesced briefly during the last glaciation. Support for this supposition is provided by the inferred deflection of Laurentide flutings to the southeast by Cordilleran ice. The earliest Laurentide advance may have been the least extensive of the three Laurentide events recognized in the study area. Erratics attributed to this advance occur only east of the Halfway River – Beatton River drainage divide.

Quaternary stratigraphy of the Prophet River, northeastern British ColumbiaThis article is one of a selection of papers published in this Special Issue on the theme Geology of northeastern British Columbia and northwestern Alberta: diamonds, shallow gas, gravel, and glaciers.

2008 ◽  
Vol 45 (5) ◽  
pp. 565-575 ◽  
Author(s):  
Michelle Trommelen ◽  
Vic Levson
Keyword(s):  
British Columbia ◽  
Oxbow Lake ◽  
Laurentide Ice Sheet ◽  
Glacial Sediments ◽  
Boreal Plains ◽  
Fluvial Terraces ◽  
Quaternary Stratigraphy ◽  
History Of ◽  
Late Wisconsinan ◽  
Floodplain Sediments

Exposures in the Prophet River valley in northeast British Columbia provide a unique glimpse into the Quaternary history of the northwest Canadian Boreal Plains. The region shows evidence of Late Wisconsinan Laurentide glaciation in the form of widespread till, containing abundant erratic clasts derived from the Canadian Shield. Vertical sections along the Prophet River expose non-glacial and advance glacial sediments below this till. Pre-Late Wisconsinan non-glacial or interglacial floodplain sediments are interbedded with fluvial gravels at many sites. Macrofossils within horizontally laminated organic-rich black clay and silt indicate deposition on the floodplain of the paleo-Prophet River within an oxbow lake. The climate during deposition is interpreted to be similar to present, supporting a dominantly spruce forest. Wood obtained from eight sites provided non-finite radiocarbon ages, and one sample provided an age of 49 300 ± 2000 BP, which is also considered non-finite. Glaciolacustrine clays and silts, deposited during impoundment of eastward-flowing drainage by the advance of the Laurentide Ice Sheet (LIS) in the Late Wisconsinan, overlie the non-glacial sediments throughout the valley. A blanket of clast-poor, clay-rich till up to 20 m thick, and deposited by the LIS, drapes the glaciolacustrine sediments. Since deglaciation, the Prophet River has incised the valley and formed fluvial terraces at different levels above the modern river.

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