Durham E-Theses Glacial Geomorphology of southern Alberta, Canada YOUNG, NATHANIEL,JOSEPH,PETER How to cite: YOUNG, NATHANIEL,JOSEPH,PETER (2009) Glacial Geomorphology of southern Alberta, Canada, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/60/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk Glacial Geomorphology of southern Alberta, Canada Nathaniel Joseph Peter Young A thesis submitted for the degree of Master of Science Department of Geography University of Durham April 2009 i Declaration of Copyright I confirm that no part of the material presented in this thesis has previously been submitted by me or any other person for a degree in this or any other university. In all cases, where it is relevant, material from the work of others has been acknowledged. The copyright of this thesis rests with the author. No quotation from it should be published without prior written consent and information derived from it should be acknowledged. Nathaniel Joseph Peter Young Department of Geography University of Durham April 2009 ii Abstract During deglaciation from the Last Glacial Maximum three terrestrial ice streams within the south western sector of the Laurentide Ice Sheet competed and coalesced in southern Alberta; the High Plains Ice Stream (HPIS), Central Alberta Ice Stream (CAIS) and the east lobe. The ice streams are characterised by smoothed corridors along which lie lineations that identify multiple flow events, transverse ridges of thrust and push origin, esker networks and large sequences of parallel and transverse meltwater channels. The CAIS and HPIS were dynamic and transitory in nature creating a ‘time‐transgressive’ imprint. The CAIS terminated within southern Alberta creating a wealth of landforms composed of controlled, hummocky, push and thrust block moraines, along with doughnut hummocks, ice walled lake plains, recessional meltwater, tunnel and large spillway channels. The CAIS margin is interpreted to have been polythermal in nature, creating a continuum of landforms that is dominated by active marginal recession. The methodologies used were placed within an overarching ‘scale approach’, whereby the research initially focused on a small, regional scale and gradually moved to large scale, local investigations. Firstly, Shuttle Radar Topography Mission (SRTM) and Landsat 7 Enhanced Thematic Mapper (Landsat ETM+) data sets were used to map the regional picture. Then, Aerial Photo Investigation (API), ground truthing and sedimentary analyses were employed to provide a detailed, localised focus into the landform sediment assemblages in southern Alberta. iii Contents Page Abstract iii List of figures vii List of Tables viii Acknowledgements ix 1 Introduction 1 1.1 Rationale 2 1.2 Aims and Objectives 4 1.3 Ice Streams 4 1.4 Ice Stream life cycle 5 1.4.1 Onset 5 1.4.2 Ice Streaming 6 1.4.3 Temporal behaviour and shutdown 8 1.5 Palaeo‐ice streams 9 1.5.1 Categories and criteria 9 1.5.2 Dynamics 10 1.6 The Geomorphic Imprint 11 1.6.1 Mega‐scale glacial lineations 11 1.6.2 Ribbed 'Rogen' moraines 13 1.6.3 Meltwater Hypothesis 14 1.7 Ice marginal features 14 1.7.1 Transverse ridges 15 1.7.2 Hummocky Terrain 16 1.8 Alberta 18 1.8.1 Alberta geology 21 1.9 Summary 22 2 Methods 23 2.1 Scale Dependent Model 24 2.2 Mapping 24 2.2.1 SRTM 25 2.2.1.1 Method 1 26 2.2.1.2 Method 2 28 2.2.2 Landsat ETM+ 30 2.2.3 Aerial Photo Investigation (API) 32 2.3 Sedimentary Analysis 33 2.4 Summary 34 iv 3 Results 35 3.1 Regional results 36 3.1.1 High Plains Ice Stream 36 3.1.2 Central Alberta Ice Stream 40 3.1.3 Flow‐sets and lineations 40 3.1.4 Transverse ridges 42 3.1.5 Hummocky terrain 46 3.1.6 Crevasse squeeze ridges 48 3.1.7 Esker networks 48 3.1.8 Meltwater Channels 49 3.2 Ice marginal landscape 51 3.2.1 Transverse Ridges 51 3.2.2 Hummocky terrain 57 3.2.3 Lineations 60 3.2.4 Glaciofluvial activity 60 3.3 Sedimentary results 62 3.3.1 Etzikom Coulée 62 3.3.2 Milk River 62 3.3.3 Writing on Stone 65 3.3.4 Ketchem Creek 65 3.3.5 Milk River Ridge Reservoir 68 3.3.6 Red Creek a 68 3.3.7 Red Creek b 68 3.3.8 Bow Island 69 3.3.9 Pendant d’Oreille 69 3.3.10 Cherry Coulée 71 3.3.11 Wolf Island 72 4 Interpretations 73 4.1 Glacial sedimentology 74 4.1.1 Till production 74 4.1.2 Glaciotectonics and sedimentary structures 74 4.2 Transverse ridges 76 4.2.1 Thrust ridges 76 4.2.1.1 CAIS marginal area 76 4.2.1.2 Southern Alberta 77 4.2.2 Push ridges 79 4.2.3 Push ridges and linear hummocks 80 4.2.4 Crevasse squeeze ridges 81 4.3 Hummocky Terrain 82 4.3.1 Hummocks (type1) 82 4.3.1.1 CAIS marginal area 82 v 4.3.1.2 Southern Alberta 83 4.3.2 Doughnut hummocks (type 2) 85 4.3.3 Ice walled lake plains (type 3) 85 4.4 Glaciofluvial and glaciolacustrine evidence 86 4.4.1 CAIS marginal area 86 4.4.2 Southern Alberta 88 4.5 Lineations and MSGLs 89 4.5.1 Southern Alberta 89 4.5.2 CAIS marginal area 91 4.6 Deglacial style of the CAIS 92 5 Discussion 96 5.1 Methods and data sources 97 5.1.1 Scale Dependent Model (SDM) 97 5.1.2 Mapping and Sedimentology 97 5.2 Terrestrial ice stream margin 98 5.3 Ice stream dynamics 101 5.3.1 Onset and location 102 5.3.2 Ice streaming ‐ temporal and spatial behaviour 103 5.3.3 Shutdown 104 5.3.3.1 Why did the CAIS shutdown? 104 5.3.3.2 What caused the CAIS to re‐advance? 106 6 Conclusions 108 6.1 Recommended further research 109 References 111 vi List of Figures Page Figure 1 Terrestrial and marine based ice streams (Stokes and Clark, 2001) 11 Figure 2 Terrestrial ice stream landsystem: time‐transgressive vs. Rubber 12 stamped (Evans et al., 2008, adapted from Clark and Stokes, 2003). Figure 3 Location maps of the study area 20 Figure 4 Large scale location map of the field site. 21 Figure 5 Digital Elevation Model created from Canadian Digital Elevation Data 26 Figure 6 Rendered Digital Elevation Model, created in Global Mapper 27 Figure 7 3D image of Global Mapper Digital Elevation Model 28 Figure 8 Grey scale image of SRTM data 29 Figure 9 Relief shaded profiles created from exported ENVI image files 30 Figure 10 Glacial geomorphology map of southern Alberta 37 Figure 11 Location map of Figures 13‐19 and transverse ridge sets 38 Figure 12 Reconstructed flow‐set map 39 Figure 13 Cross and long profiles of the study area 41 Figure 14 Example lineations and flowsets 43 Figure 15 Transverse ridge set examples 45 Figure 16 Transverse ridge set examples 46 Figure 17 Hummocky terrain examples 47 Figure 18 Crevasse squeeze ridges 48 Figure 19 Meltwater channels 50 Figure 20 Glacial geomorphology map of the CAIS marginal area Insert Figure 21 Location map of Figures 13E, 18‐36 and transverse ridge sets 52 Figure 22 Transverse ridge sets 1 and 2, located in the SE corner of the CAIS 53 marginal area Figure 23 Morphological characteristics of transverse ridge sets, types 1‐3 54 Figure 24 Type 2 transverse ridges located SE of Pakowki Lake and field work 55 photos of individual type 3 ridges Figure 25 Type 3 ridges sets within the CAIS marginal area 56 Figure 26 Hummocky terrain examples 58 Figure 27 Morphological characteristic of hummocky terrain types 1‐3 58 Figure 28 Hummocky terrain and ridges east of Del Bonita and field work photos of 59 type 1 hummocks. Figure 29 Field work photo of a lineation within CAfs_3 60 Figure 30 Spillway and meltwater channels within the CAIS marginal area 61 vii Figure 31 Etzikom Coulée cross section and stratigraphic log 63 Figure 32 Milk River cross section and stratigraphic log 64 Figure 33 Writing on Stone cross section and stratigraphic log, and Ketchem Creek 66 stratigraphic log Figure 34 Milk River Ridge Reservoir stratigraphic log 67 Figure 35 Red Creek cross section a 69 Figure 36 Red Creek cross section b 69 Figure 37 Bow Island stratigraphic log and grain size analysis 70 Figure 38 Pendant d’Oreille cross section and grain size analysis 71 Figure 39 Cherry Coulée and Wolf Island stratigraphic logs and grain size analysis 72 Figure 40 Deglacial timeline within southern Alberta 95 Figure 41 Terrestrial Ice marginal landform continuum and basal thermal regimes 100 List of Tables Page Table 1 List of Landsat ETM+ scenes 30 Table 2 Flowset data 42 Table 3 Ice stream geomorphological criteria 90 viii Acknowledgements I would firstly like to thank my parents for all of their support and generosity during the unexpectedly long time it has taken to complete this thesis.