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

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.

2008 ◽  
Vol 45 (5) ◽  
pp. 611-618 ◽  
Author(s):  
Richard J. Hebda ◽  
James A. Burns ◽  
Marten Geertsema ◽  
A. J. Timothy Jull

Dissected colluvial sediments on a Peace River terrace at Bear Flat, northeast British Columbia enclosed a late Pleistocene micromammalian faunule. The fossil remains, including a few loosely articulated skulls and mandibles, were dominated by taiga voles ( Microtus xanthognathus ). The Bear Flat site constitutes the second fossil occurrence in the region of this elusive species, which is unknown in British Columbia in historic times. The late Pleistocene age, determined by accelerator mass spectrometry directly on taiga vole bone collagen, is consistent with the ages of widespread taiga vole records peripheral to the Laurentide ice sheet in western, mid-western, and eastern North America. The presence of allo-chronous remains within a comprehensively dated sedimentary sequence provides a cautionary note about straightforward acceptance of relative stratigraphic dating.


2008 ◽  
Vol 45 (5) ◽  
pp. 565-575 ◽  
Author(s):  
Michelle Trommelen ◽  
Vic Levson

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.


2008 ◽  
Vol 45 (5) ◽  
pp. 577-591 ◽  
Author(s):  
Adrian S. Hickin ◽  
Ben Kerr ◽  
Derek G. Turner ◽  
Tom E. Barchyn

The relatively subdued topography of British Columbia’s northern interior plains does not reflect the irregular, buried bedrock surface. Many areas have been deeply incised by preglacial rivers that have subsequently filled with a succession of Quaternary sediments. In this study, oil and gas petrophysical logs, drill chip samples, water well logs, and surficial and bedrock outcrop maps were used to model the bedrock topography of the Fontas map sheet (NTS 94I). The modelled data produced several depressions that are interpreted to be paleovalleys incised into the soft Cretaceous shale of the Fort St. John Group. Understanding the geometry, thickness, and stratigraphy of the drift has considerable safety and resource management implications as artesian aquifers and natural gas were encountered in the drift during oil and gas well drilling. Four major paleovalleys are suggested. The most dominant paleovalley (Kotcho–Hoffard Paleovalley) is located south of the Etsho Plateau and trends west-southwest across the map area. A second depression occurs within the loop of the Hay River and may be a tributary of the Kotcho–Hoffard Paleovalley that links with the Rainbow Paleovalley in Alberta. A third paleovalley is mapped south of the Sahtaneh River (Kyklo Creek Paleovalley) and is either a tributary to, or crosscuts the Kotcho–Hoffard Paleovalley. The Niteal Creek Paleovalley is located between the Fontas and Sikanni Chief rivers. Its geometry is speculative as there are sparse data, but it may be a tributary of the Kotcho–Hoffard Paleovalley.


2007 ◽  
Vol 42 (3) ◽  
pp. 279-288 ◽  
Author(s):  
John J. Clague

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.


2001 ◽  
Vol 38 (4) ◽  
pp. 719-731 ◽  
Author(s):  
A Plouffe ◽  
V M Levson

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.


Author(s):  
Andriy Bogucki ◽  
Olena Tomeniuk ◽  
Andriy Yatsyshyn ◽  
Roman Dmytruk

The Department of Geomorphology and Palaeogeography of the Faculty of Geography at the Ivan Franko National University of Lviv employs a group of palaeogeographers (A. Bogucki, O. Tomeniuk, A. Yatsyshyn, R. Dmytruk), which comprehensively studies Quaternary sediments in Western Ukraine and other territories of the country. The thematic focus of palaeogeographic research is very diversified: the study of key sections of Quaternary sediments; conditions of formation and structure of periglacial loess-palaeosol sequences; research of the deposits of the glacial complex; periglacial processes and forms; the role of tectonics in the formation of Quaternary sediments; interdisciplinary research of the Palaeolithic; engineering and geological investigations; geophysical research; mineralogical research; weathering of anhydrite; study of the Holocene stage of the formation of the Dnister River valley; river terraces; lithology of alluvium; study of the Vyshnia River valley; malacological research; research of travertines, history of geography, etc. The selected issues are a priority research topic of the palaeogeographic group of the Department of Geomorphology and Palaeogeography. On the occasion of the 70th anniversary of the department, an attempt to summarize the scientific achievements of palaeogeographers over the past twenty years, particularly in thematic directions of research, was made. A large amount of new original factual material has been received, a significant number of international and Ukrainian scientific grants have been implemented, ten PhD students have defended their theses and received a PhD degree, more than 500 scientific papers have been published, more than half of which are in European Union languages. Due to the limited scope of this article, the greatest attention among all of the publications is paid to selected monographic works, collections of scientific papers prepared by researchers, papers in the journals from Scopus and Web of Science databases, and some others. It is worth mentioning the close cooperation of palaeogeographers of the Faculty of Geography with researchers from Ukraine, Poland, Belarus, Lithuania, France, Belgium and other countries. Without doubts, there are all the reasons to talk about a progressive palaeogeographic school at the Faculty of Geography, whose work is gaining momentum. Key words: palaeogeography; key sections; loess-palaeosol sequence; Quaternary period; periglacial processes; Palaeolithic.


2008 ◽  
Vol 45 (9) ◽  
pp. 1189-1209 ◽  
Author(s):  
Arash Eshraghian ◽  
C. Derek Martin ◽  
Norbert R. Morgenstern

Since the construction of the Canadian Pacific Railway and Canadian National Railway main rail lines in western Canada in 1885 and 1905, respectively, both companies have had to contend with 11 large, translational, retrogressive earth slides in the Thompson River Valley south of Ashcroft, British Columbia. The initiation of these slides is associated with the down cutting by the Thompson River through the Quaternary sediments in its valley. The slides move on two subhorizontal weak layers in a glaciolacustrine clay–silt unit within this Quaternary sediment sequence. Transient seepage and stability analyses were conducted for two sample slides, and the results were in agreement with inclinometer and piezometric data. It is concluded that the Thompson River triggers the movements in a drawdown mechanism and (or) erosion mechanism. The Thompson River affects the stability of these slides in three ways: (i) by changing the pore pressure on the rupture surface, (ii) by changing the supporting force on the toe of the slide, and (iii) by changing the geometry of the slides as a result of river erosion. The relative importance of each of these effects depends on the river erosion protection, the depth of the rupture surface, and the amount of river level fluctuation.


1980 ◽  
Vol 60 (2) ◽  
pp. 185-197 ◽  
Author(s):  
K. W. G. VALENTINE ◽  
K. R. FLADMARK ◽  
B. E. SPURLING

A terrace section in the Peace River Valley of British Columbia contained seven buried paleosols developed in eolian material. Chemical, physical and micromorpholgical data showed the soils to be Chernozemic. The main soil-forming processes have been the leaching and reprecipitation of carbonates, the formation of mull aggregates, the weathering of primary minerals and the weak physical translocation of soil fabric. Five cultural components or levels had been identified in nearby archaeological excavations and these were correlated with the Ah horizons of five of the paleosols. However, none of these Ah horizons contained large amounts of organic P as have been found in cultural layers of other archaeological sections. The cultural components contained tools, flakes, shell beads, bones and projectile points. Radiocarbon dates from charcoal ranged from 5830 ± 80 yr B.P. in the second lowest paleosol to 1530 ± 70 yr B.P. in the second highest paleosol. They showed that most of the eolian material had been deposited on the terrace by about 4500 yr B.P.; that is, by the end of the Hypsithermal. The chronology of soil development and eolian deposition are discussed by applying a previously published system of horizon designations that combines and describes the gradational and pedomorphic features in soils.


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