Tertiary-quaternary drainage of the Pre-glacial Mackenzie basin

Duk-Rodkin, A; Hughes, O L

doi:10.1016/1040-6182(94)90015-9

Cited by 79 publications

(27 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of fl uvially eroded landforms such as cuestas and mesas on the Scotian Shelf are also evidence for a subaerial landscape during the Paleogene (King et al, 1974). Ancient fl uvial valleys observed in Ontario upstream St. Lawrence River (Flint and Lolcama, 1986) and in the Hudson Bay drainage basin (Bell River system: e.g., Bell, 1895;MacMillan, 1973;Duk-Rodkin and Hughes, 1994) were probably also eroded during such a phase of low base level.…”

Section: Preserved Preglacial Fluvial Gorges and Valleysmentioning

confidence: 94%

Buried preglacial fluvial gorges and valleys preserved through Quaternary glaciations beneath the eastern Laurentide Ice Sheet

Lajeunesse¹

2014

Geological Society of America Bulletin

View full text Add to dashboard Cite

The geomorphology, geometry, and sedimentary infi ll of buried gorges and V-shaped valleys observed at the base of major river valleys in the formerly glaciated southeastern Canadian Shield region have been revealed from excavation and drilling data acquired during the construction of hydroelectric dams and seismic data collected on lakes and offshore. Compilation of these previously published and unpublished data provided an exceptional opportunity to examine the morphology and spatial distribution of buried bedrock gorges and the mechanical processes responsible for their erosion. In some valleys, detailed observations of deep gorges have been allowed by their exhumation over large areas. Archive photographs show deep and large potholes, natural pillars, furrows, fl utes, and scallops on the wellpolished bedrock walls of the gorges. They also reveal that gorges and valleys have a sharp-ending V shape and very narrow base and are superimposed by a U-shaped valley, forming a buried valley-within-valley topography. The narrow and deep cross-profi le of these gorges, their well-polished slopes, and the type of bedforms observed within them are typical features of fl uvial bedrock channels. Drilling operations at many sites have also provided data on bedrock topography of these gorges within valleys and on the nature of their sedimentary infi ll. The different lines of evidence presented in this paper indicate that gorges and V-shaped valleys of the region were not eroded by the Laurentide Ice Sheet during Quaternary glaciations but are relics of a preserved preglacial fl uvial system eroded during a lower base level. This paleofl uvial system is interpreted to be linked to fl uvially cut channels observed on the seafl oor of the Estuary and Gulf of St. Lawrence.

show abstract

Section: Preserved Preglacial Fluvial Gorges and Valleysmentioning

confidence: 94%

Buried preglacial fluvial gorges and valleys preserved through Quaternary glaciations beneath the eastern Laurentide Ice Sheet

Lajeunesse¹

2014

Geological Society of America Bulletin

View full text Add to dashboard Cite

show abstract

“…The LIS most likely blocked direct northern drainage into the Beaufort Sea, resulting in a drainage diversion that forced LIS meltwater and local drainage southward up the Babbage River and its confluences. Similarly, in the central Yukon, the LIS impounded the eastward drainage of the paleo-Porcupine River at McDougal Pass (e.g., Duk-Rodkin and Hughes, 1994) and caused westward drainage diversion into the Yukon River (e.g., Duk-Rodkin et al, 2004). The southern slopes of the British Mountains all belonged to the paleo-Porcupine watershed (Duk-Rodkin and Hughes, 1995); therefore, the Babbage River and its tributaries likely served as the major proglacial drainage path to the north along the oscillating LIS margin during the latest part of the full glacial.…”

Section: Late Glacial Drainage Diversion-initial Sedimentationmentioning

confidence: 99%

Late glacial and Holocene sedimentation, vegetation, and climate history from easternmost Beringia (northern Yukon Territory, Canada)

et al. 2012

View full text Add to dashboard Cite

Beringian climate and environmental history are poorly characterized at its easternmost edge. Lake sediments from the northern Yukon Territory have recorded sedimentation, vegetation, summer temperature and precipitation changes since ~ 16 cal ka BP. Herb-dominated tundra persisted until ~ 14.7 cal ka BP with mean July air temperatures ≤ 5°C colder and annual precipitation 50 to 120 mm lower than today. Temperatures rapidly increased during the Bølling/Allerød interstadial towards modern conditions, favoring establishment ofBetula-Salixshrub tundra. Pollen-inferred temperature reconstructions recorded a pronounced Younger Dryas stadial in east Beringia with a temperature drop of ~ 1.5°C (~ 2.5 to 3.0°C below modern conditions) and low net precipitation (90 to 170 mm) but show little evidence of an early Holocene thermal maximum in the pollen record. Sustained low net precipitation and increased evaporation during early Holocene warming suggest a moisture-limited spread of vegetation and an obscured summer temperature maximum. Northern Yukon Holocene moisture availability increased in response to a retreating Laurentide Ice Sheet, postglacial sea level rise, and decreasing summer insolation that in turn led to establishment ofAlnus-Betulashrub tundra from ~ 5 cal ka BP until present, and conversion of a continental climate into a coastal-maritime climate near the Beaufort Sea.

show abstract

“…In this context, a single date from the Cape Dalhousie Sands beneath the Kittigazuit Fm at section 2.13 on the Tuktoyaktuk Peninsula provided the oldest date (Shfd02060; 62.6 ± 3.4 ka) obtained in the present study. Additionally, we cannot discount the possibility that fluvial activity associated with the pre$Last Glacial Maximum (LGM) Porcupine and Anderson river basins (Duk$Rodkin and Hughes, 1994) and the post$LGM Mackenzie and Anderson systems (Lemmen ., 1994;Duk$Rodkin and Lemmen, 2000) delivered sand to the Tuktoyaktuk Coastlands or their fringes, where it was reworked by wind. As discussed below, there is evidence from northeast Richards Island for deglacial meltwater activity interrupting aeolian sedimentation.…”

mentioning

confidence: 99%

The chronostratigraphy of Late Pleistocene glacial and periglacial aeolian activity in the Tuktoyaktuk Coastlands, NWT, Canada

Bateman

Murton

2006

Quaternary Science Reviews

View full text Add to dashboard Cite

Aeolian periglacial sand deposits are common in the Tuktoyaktuk Coastlands of Western Arctic Canada. Regionally extensive and thick aeolian sand$sheet deposits have been observed in two major stratigraphic settings: within a sand unit characterized by large aeolian dune deposits; and interbedded with glaciofluvial outwash from the Laurentide Ice Sheet (LIS). Small, localized sand sheets have also been observed along the tops of sandy bluffs, within sequences of drained thermokarst lakes deposits and as an involuted veneer above buried basal ice of the LIS.On the basis of radiocarbon and optically stimulated luminescence (OSL) dates from preserved periglacial aeolian sand sheets and dunes a regional chronostratigraphy is presented which indicates that both extensive dunes and sand sheets accumulated mainly between . 30 and 13 ka. A switch to dominantly sand$sheet aggradation at c. 14-13 ka, with sand sheets forming widely until . 8 ka, is attributed to (a) surface armouring by glacial deposits associated with the advance of the LIS; and (b) amelioration of the climate from cold aridity. An absence of OSL dates between . 8 and 1 ka suggests that sand sheets stabilized during much of the Holocene. Local sand$sheet aggradation during recent centuries has occurred near sandy bluffs and on the floors of drained thermokarst lakes. The OSL dates constrain the maximum extent of the LIS in the Tuktoyaktuk Coastlands to Marine Isotope Stage 2.

show abstract

Tertiary-quaternary drainage of the Pre-glacial Mackenzie basin

Cited by 79 publications

References 8 publications

Buried preglacial fluvial gorges and valleys preserved through Quaternary glaciations beneath the eastern Laurentide Ice Sheet

Buried preglacial fluvial gorges and valleys preserved through Quaternary glaciations beneath the eastern Laurentide Ice Sheet

Late glacial and Holocene sedimentation, vegetation, and climate history from easternmost Beringia (northern Yukon Territory, Canada)

The chronostratigraphy of Late Pleistocene glacial and periglacial aeolian activity in the Tuktoyaktuk Coastlands, NWT, Canada

Contact Info

Product

Resources

About