Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A

Total Page:16

File Type:pdf, Size:1020Kb

Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A Document généré le 4 oct. 2021 19:12 Géographie physique et Quaternaire Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A. Avancée et recul des inlandsis de la Cordillère dans l’État de Washington (É.-U.) Vorstoß und Rückzug der Kordilleren-Eisdecke in Washington State. U.S.A. Don J. Easterbrook Volume 46, numéro 1, 1992 Résumé de l'article Dans la Cordillère, les glaciations se sont produites selon des modes URI : https://id.erudit.org/iderudit/032888ar caractéristiques d'avancée et de recul : 1) dépôts fluvioglaciaires d'avancée; 2) DOI : https://doi.org/10.7202/032888ar poli glaciaire; 3) till; 4) dépôts fluvio-glaciaires de retrait au sud de Seattle, dans le sud des basses-terres de Puget, dépôts glacio-marins dans les basses-terres Aller au sommaire du numéro du nord, et eskers, terrasses fluvioglaciaires et petites moraines sur le plateau de Columbia. La datation au radiocarbone indique que les lobes de Puget et de Juan de Fuca ont avancé et reculé synchroniquement. Parmi les preuves qui Éditeur(s) nous contraignent à rejeter l'hypothèse selon laquelle un front en fusion, qui vêlait, serait à l'origine des dépôts glacio-marins, citons : 1) les nombreuses Les Presses de l'Université de Montréal datations au radiocarbone qui révèlent la mise en place simultanée de dépôts glacio-marins sur tout le territoire; 2) les dépôts issus de la fusion de la glace ISSN stagnante, intimement associés aux dépôts glacio-marins; 3) les preuves irréfutables d'une origine autre que marine des sables de Deming qui révèlent 0705-7199 (imprimé) que la Cordillère était libre de glace immédiatement avant la mise en place des 1492-143X (numérique) dépôts glacio-marins. Dans le nord des basses-terres de Puget le déroulement des événements comprend les étapes suivantes : 1) au cours du maximum de Découvrir la revue Vashon, charge glaciaire sous 1800 m de glace; 2) 12-13 ka BP, amincissement rapide du glacier et dérive de la glace contribuant à la mise en place des dépôts glacio-marins de Kulshan; 3) vers 11 500 ans BP, emersion et dépôt des sables Citer cet article de Deming d'origine fluviale; 4) nouvelle submersion et mise en place des dépôts glacio-marins de Bellingham jusqu'à une hauteur d'environ 200 m, bien Easterbrook, D. J. (1992). Advance and Retreat of Cordilleran Ice Sheets in supérieure à l'élévation eustatique du niveau de la mer; 5) vers 10 500-11 500 Washington, U.S.A. Géographie physique et Quaternaire, 46(1), 51–68. ans BP, emersion et mise en place des dépôts fluvio-glaciaires de Sumas sur les https://doi.org/10.7202/032888ar dépôts glacio-marins de Bellingham; 6) à l'Holocène, élévation eustatique du niveau de la mer au même rythme que le relèvement isostatique. Tous droits réservés © Les Presses de l'Université de Montréal, 1992 Ce document est protégé par la loi sur le droit d’auteur. L’utilisation des services d’Érudit (y compris la reproduction) est assujettie à sa politique d’utilisation que vous pouvez consulter en ligne. https://apropos.erudit.org/fr/usagers/politique-dutilisation/ Cet article est diffusé et préservé par Érudit. Érudit est un consortium interuniversitaire sans but lucratif composé de l’Université de Montréal, l’Université Laval et l’Université du Québec à Montréal. Il a pour mission la promotion et la valorisation de la recherche. https://www.erudit.org/fr/ Géographie physique et Quaternaire, 1992, vol. 46, n° 1, p. 51-68, 22 fig., 1 tabl. ADVANCE AND RETREAT OF CORDILLERAN ICE SHEETS IN WASHINGTON, U.S.A.* Don J. EASTERBROOK, Department of Geology, Western Washington University, Bellingham, Washington 98225, U.S.A. ABSTRACT Cordilleran Ice Sheet glacia­ RÉSUMÉ Avancée et recul des inlandsis de ZUSAMMENFASSUNG VorstoB und tions show characteristic patterns of advance la Cordillère dans l'État de Washington (É.-U). Rùckzug der Kordilleren-Eisdecke in and retreat, consisting of (1) advance out- Dans la Cordillère, les glaciations se sont pro­ Washington State. U.S.A. Die Vereisung der wash, (2) glacial scouring, (3) deposition of till, duites selon des modes caractéristiques Kordilleren-Eisdecke zeigt charakteristische (4) deposition of recessional outwash south of d'avancée et de recul: 1) dépôts fluvio­ VorstoB- und Rùckzugsmuster, bestehend Seattle in the southern Puget Lowland, glacio­ glaciaires d'avancée; 2) poli glaciaire; 3) till; aus (1) glazialem SchwemmvorstoB, (2) gla- marine drift in the northern lowland, and 4) dépôts fluvio-glaciaires de retrait au sud de zialem Scheuern, (3) Ablagerung der eskers, kames, and small moraines on the Seattle, dans le sud des basses-terres de Grundmoràne, (4) Ablagerung von Rùck- Columbia Plateau. Radiocarbon dates show Puget, dépôts glacio-marins dans les basses- zugsschwemm-Material sùdlich von Seattle that the Puget and Juan de Fuca lobes terres du nord, et eskers, terrasses fluvio­ im sûdlichen Puget-Lowland, glaziomarines advanced and retreated synchronously. The glaciaires et petites moraines sur le plateau Material im nôrdlichen Tiefland und Esker, Puget lobe backwasted to Seattle by de Columbia. La datation au radiocarbone Kames und kleine Morànen auf dem 13.4-14 kayrs BP, where the thinning ice indique que les lobes de Puget et de Juan de Columbia-Plateau. Radiokarbondaten zeigen, floated in seawater northward to Canada by Fuca ont avancé et reculé synchroniquement. daf3 die Puget — und Juan de Fuca-Loben 13 kayrs BP depositing glaciomarine drift Parmi les preuves qui nous contraignent à gleichzeitig vorstieBen und sich zurûckzogen. contemporaneously over 18,000 km2. Com­ rejeter l'hypothèse selon laquelle un front en Gegen das rùcklàufige, kalbende Terminus- pelling evidence against the backwasting, fusion, qui vêlait, serait à l'origine des dépôts Modell fur den Ursprung des glaziomarinen calving, terminus model for the origin of the glacio-marins, citons: 1) les nombreuses data­ Materials sprechen die folgenden Tatsachen glaciomarine drift includes: 1) abundant 14C tions au radiocarbone qui révèlent la mise en in zwingender Weise: 1) zahlreiche '"C-Daten dates demonstrate simultaneous deposition of place simultanée de dépôts glacio-marins sur beweisen die gleichzeitige Ablagerung von glaciomarine drift over the entire area; tout le territoire; 2) les dépôts issus de la glaziomarinem Material ùber das gesamte 2) stagnant-ice deposits closely related to gla­ fusion de la glace stagnante, intimement asso­ Gebiet; 2) Ablagerungen von stagnierendem ciomarine drift are not consistent with an ciés aux dépôts glacio-marins; 3) les preuves Eis, die in enger Verbindung zu glaziomari­ actively-calving, backwasting terminus; irréfutables d'une origine autre que marine des nem Material stehen, stimmen nicht mit einem 3) irrefutable evidence for the nonmarine ori­ sables de Deming qui révèlent que la aktiv kalbenden rùcklàufigen Terminus gin of Deming sand shows that Cordilleran ice Cordillère était libre de glace immédiatement ùberein; 3) unwiderlegbares Beweismaterial was absent immediately prior to deposition of avant la mise en place des dépôts glacio- fur den nichtmarinen Ursprung des Sands von the overlying glaciomarine drift. The pattern marins. Dans le nord des basses-terres de Deming zeigt, daB es kein Kordilleren-Eis gab of events in the northern Puget Lowland Puget le déroulement des événements com­ unmittelbar vor der Ablagerung darùberliegen- includes: 1) glacial loading under 1800 m of prend les étapes suivantes: 1) au cours du den glaziomarinen Materials. Die Abfolge der ice during the Vashon maximum; 2) rapid gla­ maximum de Vashon, charge glaciaire sous Ereignisse im nôrdlichen Puget Lowland bein- cial thinning and floating of the ice deposited 1800 m de glace; 2) 12-13 ka BP, amincisse­ haltet: 1)glaziale Fracht unter 1800 m Eis Kulshan glaciomarine drift 12-13 ka yrs BP; ment rapide du glacier et dérive de la glace wàhrend des Vashon Maximums; 2) schnelles 3) emergence and deposition of fluvial contribuant à la mise en place des dépôts glaziales Ausdùnnen und treibendes Eis Deming sand -11.5 ka yrs BP; 4) resubmer- glacio-marins de Kulshan; 3) vers 11 500 ans lagerte 12-13 ka Jahre v.u.Z. das glazioma- gence and deposition of Bellingham glacioma­ BP, emersion et dépôt des sables de Deming rine Material von Kulshan ab; 3) Auftauchen rine drift up to -200 m, well beyond global d'origine fluviale; 4) nouvelle submersion et und Ablagerung von Deming-FluBsand eustatic sea level rise; 5) emergence mise en place des dépôts glacio-marins de -11.5ka Jahre v.u.Z.; 4) Wieder- -10.5-11.5 ka yrs BP and deposition of Bellingham jusqu'à une hauteur d'environ untertauchen und Ablagerung von glazioma­ Sumas outwash on Bellingham glaciomarine 200 m, bien supérieure à l'élévation eusta- rinem Belligham-Material bis zu - 200 m, weit drift; 6) Holocene eustatic sea level rise kept tique du niveau de la mer; 5) vers 10 500- ùber die globale eustatische Meeresan- pace with isostatic rebound, thus, post-Sumas 11 500 ans BP, emersion et mise en place hebung hinaus; 5) Auftauchen - 10.5-11.5 ka marine terraces are absent. des dépôts fluvio-glaciaires de Sumas sur les Jahre v.u.Z. und Ablagerung von Sumas- dépôts glacio-marins de Bellingham; 6) à l'Ho- Schwemm-Material auf dem glaziomarinen locène, élévation eustatique du niveau de la Bellingham-Material; 6) die eustatische mer au même rythme que le relèvement Anhebung des Meeresspiegels im Holozàn isostatique. hielt Schritt mit dem isostatischen Ruckprall. * The present article is a follow up to the special issue dedicated to the Cordilleran Ice Sheet (Vol. 45, No. 3) / Cet article constitue la suite du numéro spécial consacré à l'Inlandsis de la Cordillère (vol. 45, n° 3). Manuscrit reçu le 11 mars 1991; manuscrit révisé accepté le 22 octobre 1991 52 D. J. EASTERBROOK INTRODUCTION in accord with one another.
Recommended publications
  • Self-Guiding Geology Tour of Stanley Park
    Page 1 of 30 Self-guiding geology tour of Stanley Park Points of geological interest along the sea-wall between Ferguson Point & Prospect Point, Stanley Park, a distance of approximately 2km. (Terms in bold are defined in the glossary) David L. Cook P.Eng; FGAC. Introduction:- Geomorphologically Stanley Park is a type of hill called a cuesta (Figure 1), one of many in the Fraser Valley which would have formed islands when the sea level was higher e.g. 7000 years ago. The surfaces of the cuestas in the Fraser valley slope up to the north 10° to 15° but approximately 40 Mya (which is the convention for “million years ago” not to be confused with Ma which is the convention for “million years”) were part of a flat, eroded peneplain now raised on its north side because of uplift of the Coast Range due to plate tectonics (Eisbacher 1977) (Figure 2). Cuestas form because they have some feature which resists erosion such as a bastion of resistant rock (e.g. volcanic rock in the case of Stanley Park, Sentinel Hill, Little Mountain at Queen Elizabeth Park, Silverdale Hill and Grant Hill or a bed of conglomerate such as Burnaby Mountain). Figure 1: Stanley Park showing its cuesta form with Burnaby Mountain, also a cuesta, in the background. Page 2 of 30 Figure 2: About 40 million years ago the Coast Mountains began to rise from a flat plain (peneplain). The peneplain is now elevated, although somewhat eroded, to about 900 metres above sea level. The average annual rate of uplift over the 40 million years has therefore been approximately 0.02 mm.
    [Show full text]
  • The Cordilleran Ice Sheet 3 4 Derek B
    1 2 The cordilleran ice sheet 3 4 Derek B. Booth1, Kathy Goetz Troost1, John J. Clague2 and Richard B. Waitt3 5 6 1 Departments of Civil & Environmental Engineering and Earth & Space Sciences, University of Washington, 7 Box 352700, Seattle, WA 98195, USA (206)543-7923 Fax (206)685-3836. 8 2 Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia, Canada 9 3 U.S. Geological Survey, Cascade Volcano Observatory, Vancouver, WA, USA 10 11 12 Introduction techniques yield crude but consistent chronologies of local 13 and regional sequences of alternating glacial and nonglacial 14 The Cordilleran ice sheet, the smaller of two great continental deposits. These dates secure correlations of many widely 15 ice sheets that covered North America during Quaternary scattered exposures of lithologically similar deposits and 16 glacial periods, extended from the mountains of coastal south show clear differences among others. 17 and southeast Alaska, along the Coast Mountains of British Besides improvements in geochronology and paleoenvi- 18 Columbia, and into northern Washington and northwestern ronmental reconstruction (i.e. glacial geology), glaciology 19 Montana (Fig. 1). To the west its extent would have been provides quantitative tools for reconstructing and analyzing 20 limited by declining topography and the Pacific Ocean; to the any ice sheet with geologic data to constrain its physical form 21 east, it likely coalesced at times with the western margin of and history. Parts of the Cordilleran ice sheet, especially 22 the Laurentide ice sheet to form a continuous ice sheet over its southwestern margin during the last glaciation, are well 23 4,000 km wide.
    [Show full text]
  • Land Ice, Paleoclimate and Polar Climate Working Groups
    2019 WG Meetings Land Ice, Paleoclimate and Polar Climate Working Groups Simulating the Northern Hemisphere climate and ice sheets during the last deglaciation with CESM2.1/CISM2.1 Petrini M. & Bradley S.L February 4, 2019 Study area and scientific motivations Study area: • At Last Glacial Maximum, ~21 ka, three large ice sheets: CIS Greenland, North American, Eurasian; LIS IIS GIS BSIS FIS BIIS Ice sheet reconstruction for initial LGM boundary conditions, from BRITICE-CHRONO + Lecavalier et al., 2014. Eurasian Ice Sheet complex: Fennoscandian Ice Sheet (FIS), Barents Sea Ice Sheet (BSIS), British-Irish Ice Sheet (BIIS). North American Ice Sheet complex: Laurentide Ice Sheet (LIS), Cordilleran Ice Sheet (CIS), Innuitian Ice Sheet (IIS). Study area and scientific motivations Study area: • At Last Glacial Maximum, ~21 ka, three continental ice sheets: CIS Greenland, North American, Eurasian; • Sea level ~132±2 m lower: 76.0±6.7 Eurasian: 18.4±4.9 m SLE North American: 76.0±6.7 m SLE LIS IIS Greenland: 4.1±1.0 m SLE. f (Simms et al., 2019 QSR) GIS BSIS 4.1±1.0 FIS BIIS 18.4±4.9 Ice sheet reconstruction for initial LGM boundary conditions, from BRITICE-CHRONO + Lecavalier et al., 2014. Eurasian Ice Sheet complex: Fennoscandian Ice Sheet (FIS), Barents Sea Ice Sheet (BSIS), British-Irish Ice Sheet (BIIS). North American Ice Sheet complex: Laurentide Ice Sheet (LIS), Cordilleran Ice Sheet (CIS), Innuitian Ice Sheet (IIS). Study area and scientific motivations Study area: • At Last Glacial Maximum, ~21 ka, three continental ice sheets: CIS Greenland, North American, Eurasian; • Sea level ~132±2 m lower: Eurasian: 18.4±4.9 m SLE North American: 76.0±6.7 m SLE LIS IIS Greenland: 4.1±1.0 m SLE.
    [Show full text]
  • Post-Glacial Sea-Level Change Along the Pacific Coast of North America Dan H
    University of Washington Tacoma UW Tacoma Digital Commons SIAS Faculty Publications School of Interdisciplinary Arts and Sciences 8-1-2014 Post-glacial sea-level change along the Pacific coast of North America Dan H. Shugar University of Washington Tacoma, [email protected] Ian J. Walker Olav B. Lian Jordan BR Eamer Christina Neudorf See next page for additional authors Follow this and additional works at: https://digitalcommons.tacoma.uw.edu/ias_pub Recommended Citation Shugar, Dan H.; Walker, Ian J.; Lian, Olav B.; Eamer, Jordan BR; Neudorf, Christina; McLaren, Duncan; and Fedje, Daryl, "Post-glacial sea-level change along the Pacific oc ast of North America" (2014). SIAS Faculty Publications. 339. https://digitalcommons.tacoma.uw.edu/ias_pub/339 This Article is brought to you for free and open access by the School of Interdisciplinary Arts and Sciences at UW Tacoma Digital Commons. It has been accepted for inclusion in SIAS Faculty Publications by an authorized administrator of UW Tacoma Digital Commons. Authors Dan H. Shugar, Ian J. Walker, Olav B. Lian, Jordan BR Eamer, Christina Neudorf, Duncan McLaren, and Daryl Fedje This article is available at UW Tacoma Digital Commons: https://digitalcommons.tacoma.uw.edu/ias_pub/339 1 Post-glacial sea-level change along the Pacific coast of North 2 America 3 Dan H. Shugar1,*, Ian J. Walker1, Olav B. Lian2, Jordan B.R. Eamer1, Christina 4 Neudorf2,4, Duncan McLaren3,4, Daryl Fedje3,4 5 6 1Coastal Erosion & Dune Dynamics Laboratory, Department of Geography, 7 University of Victoria, Victoria, BC,
    [Show full text]
  • Animating the Temporal Progression of Cordilleran Deglaciation and Vegetation Succession in the Pacific Northwest During the Late Quaternary Period
    Western Washington University Western CEDAR Scholars Week 2017 - Poster Presentations May 17th, 9:00 AM - 12:00 PM Animating the Temporal Progression of Cordilleran Deglaciation and Vegetation Succession in the Pacific Northwest during the late Quaternary Period Henry Haro Western Washington University Follow this and additional works at: https://cedar.wwu.edu/scholwk Part of the Environmental Studies Commons, and the Higher Education Commons Haro, Henry, "Animating the Temporal Progression of Cordilleran Deglaciation and Vegetation Succession in the Pacific Northwest during the late Quaternary Period" (2017). Scholars Week. 20. https://cedar.wwu.edu/scholwk/2017/Day_one/20 This Event is brought to you for free and open access by the Conferences and Events at Western CEDAR. It has been accepted for inclusion in Scholars Week by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. Animating the Temporal Progression of Cordilleran Deglaciation in the Pacific Northwest during the late Quaternary Period Henry Haro – 2017 The Cordilleran Ice Sheet Sequential Progression of Cordilleran Retreat The topography of the Pacific Northwest, its fjords, inland waterways and islands, are a result of an extended period of glaciation and glacial retreat. This retreat influenced the physical features and the resulting succession of vegetation that led to the landscape we see today. Despite this importance of the Cordilleran ice sheet and the large volume of research on the topic, there lacks a good detailed animation of the movement of the entire ice sheet from the last glacial maximum to the present day. In this study, I used spatial data of the glacial extent at different periods of time during the Quaternary period to model and animate the movement of the Cordilleran ice sheet as it retreated from 18,000 BCE to 10,000 BCE.
    [Show full text]
  • Climate Investigations Using Ice Sheet and Mass Balance Models with Emphasis on North American Glaciation Sean David Birkel
    The University of Maine DigitalCommons@UMaine Electronic Theses and Dissertations Fogler Library 2010 Climate Investigations Using Ice Sheet and Mass Balance Models with Emphasis on North American Glaciation Sean David Birkel Follow this and additional works at: http://digitalcommons.library.umaine.edu/etd Part of the Glaciology Commons Recommended Citation Birkel, Sean David, "Climate Investigations Using Ice Sheet and Mass Balance Models with Emphasis on North American Glaciation" (2010). Electronic Theses and Dissertations. 97. http://digitalcommons.library.umaine.edu/etd/97 This Open-Access Dissertation is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of DigitalCommons@UMaine. CLIMATE INVESTIGATIONS USING ICE SHEET AND MASS BALANCE MODELS WITH EMPHASIS ON NORTH AMERICAN GLACIATION By Sean David Birkel B.S. University of Maine, 2002 M.S. University of Maine, 2004 A THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (in Earth Sciences) The Graduate School The University of Maine December, 2010 Advisory Committee: Peter O. Koons, Professor of Earth Sciences, Advisor George H. Denton, Libra Professor of Earth Sciences, Co-advisor Fei Chai, Professor of Oceanography James L. Fastook, Professor of Computer Science Brenda L. Hall, Professor of Earth Science Terrence J. Hughes, Professor Emeritus of Earth Science ©2010 Sean David Birkel All Rights Reserved iii CLIMATE INVESTIGATIONS USING ICE SHEET AND MASS BALANCE MODELS WITH EMPHASIS ON NORTH AMERICAN GLACIATION By Sean D. Birkel Thesis Advisor: Dr. Peter O. Koons An Abstract of the Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (in Earth Sciences) December, 2010 This dissertation describes the application of the University of Maine Ice Sheet Model (UM-ISM) and Environmental Change Model (UM-ECM) to understanding mechanisms of ice-sheet/climate integration during ice ages.
    [Show full text]
  • Introduction
    INTRODUCTION This is the fourth and final volume on the avifauna of British Columbia; it completes a discussion of the passerine birds of the province that began in Volume 3. Coming some 10 years following the publication of Volumes 1 and 2 (the non- passerine birds), it is the culmination of over 25 years of effort by the authors and significant contributions from col- leagues around the world and thousands of volunteers (Fig. 1) throughout British Columbia. The methodologies used in the preparation of this work have previously been described (Volume 1, page 146, and Volume 3, page 13) and will not be repeated here. Because of the length of time between the publication of Volumes 1 and 2 (1990) and this final volume, we have in- cluded a chapter called “Additions to the Avifauna of British Figure 2. Adult Black-legged Kittiwake with chick at nest ledge (Gjelpruvaer, Columbia, 1987 through 1999.” There we list 28 species new Norway, 11 July 1994; R. Wayne Campbell). to the province that were reported over that period. Some species, such as Manx Shearwater, Crested Caracara, Xantus’s Hummingbird, and Least Tern are new occurrence additions to the avifauna of the province. Others, such as Northern Ful- mar, Baird’s Sandpiper, Franklin’s Gull, and Black-legged Kit- tiwake (Fig. 2), now breed in the province. One species, Pa- cific Golden-Plover, has been elevated from subspecies to full species status due to taxonomic changes. Beyond the scope of the chapter are the many new changes in numbers, distribution, and results of research that contribute to our current knowledge and status of birds in the province.
    [Show full text]
  • Three Dimensional Hydrostratigraphic Model of the Nanoose – Deep Bay Area, Nanaimo Lowland, British Columbia
    GEOLOGICAL SURVEY OF CANADA OPEN FILE 7796 Three dimensional hydrostratigraphic model of the Nanoose – Deep Bay Area, Nanaimo Lowland, British Columbia N. Benoit, D. Paradis, J.M. Bednarski, T. Hamblin, and H.A.J. Russell 2015 GEOLOGICAL SURVEY OF CANADA OPEN FILE 7796 Three dimensional hydrostratigraphic model of the Nanoose – Deep Bay Area, Nanaimo Lowland, British Columbia N. Benoit, D. Paradis, J.M. Bednarski, T. Hamblin, and H.A.J. Russell 2015 © Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources Canada, 2015 doi:10.4095/296302 This publication is available for free download through GEOSCAN (http://geoscan.nrcan.gc.ca/). Recommended citation Benoit, N., Paradis, D., Bednarski, J.M., Hamblin, T., and Russell, H.A.J., 2015. Three dimensional hydrostratigraphic model of the Nanoose-Deep Bay area, Nanaimo Lowland, British Columbia; Geological Survey of Canada, Open File 7796, 1 .zip file. doi:10.4095/296302 Publications in this series have not been edited; they are released as submitted by the author. Table of Contents ABSTRACT ........................................................................................................................................................................... 1 1 INTRODUCTION ........................................................................................................................................................ 2 2 STUDY AREA .............................................................................................................................................................
    [Show full text]
  • 1 a Geologic and Oceanographic Journey
    Open Access e-Journal Earth Science India- www.earthscienceindia.info Popular Issue, 12 (IV), October, 2019, 1-31 A GEOLOGIC AND OCEANOGRAPHIC JOURNEY ACROSS THE SALISH SEA (SOUTHWESTERN CANADA AND NORTHWESTERN USA) Alice S. Chang and Arun Kumar The Salish Sea is also an active waterway for fisheries, industry, transportation, and recreation….. The year 2020 marks the tenth anniversary of the official naming of the Salish Sea….. The rocks of Wrangellia are mainly represented by the Karmutsen Formation, a 6,000- meter thick pile of flood basalts (flows and pillow lavas) and volcanic tuffs that were part of an oceanic plateau some 230 million years ago (late Triassic)….. Several hypotheses have been proposed to explain the origin of the Georgia Depression. These include Cretaceous–Tertiary (66 million-year-old) downwarping or down faulting of the crust, eastward tilting of the Vancouver Island block, and crustal weakening between the Insular and Coast belts. The Strait of Georgia, the Strait of Juan de Fuca, Puget Sound, and the surrounding waterways of southwestern British Columbia (BC), Canada, and northwestern Washington State, USA, are collectively called the Salish Sea (Figure 1). As one of the world’s most productive ecosystems, the Salish Sea is also an active waterway for fisheries, industry, transportation, and recreation. Scenic port cities (Vancouver and Seattle) and provincial and state capitals (Victoria and Olympia, respectively) call the shores of the Salish Sea home, as do 70% of BC’s and 60% of Washington’s populations. We decided to write this popular science article because as earth scientists, we have a long association with this region through recreation, as well as research at the universities of BC (Vancouver) and Victoria (Vancouver Island), and at Carleton University (Ottawa, Canada), where one or both of us were involved.
    [Show full text]
  • Behavior of the James Lobe, South Dakota During Termination I
    Behavior of the James Lobe, South Dakota during Termination I A dissertation submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in the Department of Geology of the McMicken College of Arts and Sciences by Stephanie L. Heath MSc., University of Maine BSc., University of Maine July 18, 2019 Dissertation Committee: Dr. Thomas V. Lowell Dr. Aaron Diefendorf Dr. Aaron Putnam Dr. Dylan Ward i ABSTRACT The Laurentide Ice Sheet was the largest ice sheet of the last glacial period that terminated in an extensive terrestrial margin. This dissertation aims to assess the possible linkages between the behavior of the southern Laurentide margin and sea surface temperature in the adjacent North Atlantic Ocean. Toward this end, a new chronology for the westernmost lobe of the Southern Laurentide is developed and compared to the existing paradigm of southern Laurentide behavior during the last glacial period. Heath et al., (2018) address the question of whether the terrestrial lobes of the southern Laurentide Ice Sheet margin advanced during periods of decreased sea surface temperature in the North Atlantic. This study establishes the pattern of asynchronous behavior between eastern and western sectors of the southern Laurentide margin and identifies a chronologic gap in the western sector. This is the first comprehensive review of the southern Laurentide margin since Denton and Hughes (1981) and Mickelson and Colgan (2003). The results of Heath et al., (2018) also revealed the lack of chronologic data from the Lobe, South Dakota, the westernmost lobe of the southern Laurentide margin.
    [Show full text]
  • Geologic Map of the Suquamish 7.5' Quadrangle and Part of the Seattle
    Geologic Map of the Suquamish 7.5’ Quadrangle and Part of the Seattle North 7.5’ x 15’ Quadrangle, Kitsap County, Washington By Ralph A. Haugerud and Kathy Goetz Troost Pamphlet to accompany Scientific Investigations Map 3181 2011 U.S. Department of the Interior U.S. Geological Survey This page intentionally left blank Contents Introduction.....................................................................................................................................................1 Geologic framework .............................................................................................................................1 About this report ...................................................................................................................................2 Stratigraphy ....................................................................................................................................................3 Glacial and nonglacial deposits .........................................................................................................3 Deposits older than Olympia interglaciation of Armstrong and others (1965) ...................3 Deposits older than Vashon stade of Fraser glaciation of Armstrong and others (1965)..............................................................................................................................4 Vashon Drift ..................................................................................................................................4 Late-glacial deposits
    [Show full text]
  • Article Is Available Online USA, 2004
    The Cryosphere, 10, 639–664, 2016 www.the-cryosphere.net/10/639/2016/ doi:10.5194/tc-10-639-2016 © Author(s) 2016. CC Attribution 3.0 License. Numerical simulations of the Cordilleran ice sheet through the last glacial cycle Julien Seguinot1,2,3, Irina Rogozhina3,4, Arjen P. Stroeven2, Martin Margold2, and Johan Kleman2 1Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Zürich, Switzerland 2Department of Physical Geography and the Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden 3Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany 4Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany Correspondence to: Julien Seguinot ([email protected]) Received: 21 June 2015 – Published in The Cryosphere Discuss.: 7 August 2015 Revised: 2 February 2016 – Accepted: 19 February 2016 – Published: 16 March 2016 Abstract. After more than a century of geological research, 1 Introduction the Cordilleran ice sheet of North America remains among the least understood in terms of its former extent, volume, and dynamics. Because of the mountainous topography on During the last glacial cycle, glaciers and ice caps of the which the ice sheet formed, geological studies have often had North American Cordillera have been more extensive than only local or regional relevance and shown such a complexity today. At the Last Glacial Maximum (LGM), a continuous that ice-sheet-wide spatial reconstructions of advance and re- blanket of ice, the Cordilleran ice sheet (Dawson, 1888), treat patterns are lacking. Here we use a numerical ice sheet stretched from the Alaska Range in the north to the North model calibrated against field-based evidence to attempt a Cascades in the south (Fig.1).
    [Show full text]