University of Alberta Dmmlinized Terrain of North-Centrai British Columbia: Reading Between the Li~eations Brian Sawyer O A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science. Department of Earth and Atmospheric Sciences University of Am- Spring, 2000 uisitions and Acquisitions et aiographicServices servicas bibliographiques The author has granted a non- L'ama accordé une licence non exclusive licence ailowing the exclusive permettant à la National Licbrary of Canada to Biôliotheque nationale du Canada de reproduce, loan, distribute or seil reproduire, prêter, distribuer ou copies of this thesis in microfonn, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/füm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial exûacts hmit Ni la thèse ni des extraits substantiels may be printed or otherwise de celie-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. High-resolution Global Positioning System meysdelineate the morphology of more than twenty dnunlins and related glacial landforms near Prince George, B.C. Closeiy- spaced transects of sub-meter- resolution elevations are interpolated as digital elevation models. Raster and vector Geographic Information Systems m used for 3D imaging and analysis of suffixe dope, aspect and microrelief. Regional dnimllli and fluting orientations are remarkably consistent ovex varying elevations and physiograpbic regions, implying a contempomeous landform genesis. The variety of drumlin composition and scale, the sinuousity of dacemicrofeatures, and the regional distriiution of a cobble/boulder lag indicate a turbulent erosional agent of limited cornpetence. Oblique till fabrics and tmcated ci& stratigraphy indicate a complex genesis of intemal materials involving multiple sediment dcposition/erotion cycles. Fraser Glaciation gravels were rapidiy deposited in a northeasterly flow, and are overlain by a regional unconforrnity. Glaciolacustrine rhythmites, previously interpreted as proglacial deposits, were deposited at higher elevations than previously thought, and were subsequently eroded by a northeasterly flow event. The drwnlinized rhythmites that remain, distorted at th& daceand overlain by eskm and ice-contact deposits, provide evidence for the infiIlhg and catastrophic drainage of a subglacial lake. The results of this study have far- reaching implications for reconstructions of Late Wisconsinan ice sheet evolution based on 'glacial' d&celineations. 1want to nrSt express rny appreciation to my supervisor, Dr. John Shaw. He inspired me to undertake this project, encouraged me to seek my own answers, provided me with patient and mobtrusive support, and taught me the necessity for clarity of purpose and expression. Research funding was genmusly provided through Dr. Shaw's NSERC grmt* 1thank Dr. Bruce Rains for sharing his knowledge and enthusiasrn for the research topic, and for his thoughtfid editing. Dn.Ben Rivard and Ted Evans made numerous suggestions that significantly impmved the thesis. Jeff O'Keefe and Craig Sherba provided valuable field support and cheerful companionship, through good weather and bad. David Chesterman was always available for essistance and advice in the sediment lab. Mandy Mm-Staziuk shared some valuable iasights earIy in the project, when 1 most aeeded them. Dr. Alan Gottesfeld (University of Northem British Columbia) introduced me to the landscape of Prince George, provided valuable feedback on my ideas and, together with Dr. Roger Wheate (UNBC), provided access to the GPS equipment on which this project depended. 1 am indebted to Dr. Howard Tipper for his pioneering work in the area, and was honoured to think that 1 may have occasionally walked in his footsteps. 1 am grateful to my wife, Arlene Collins, who convinced me I was capable of succeedllig and showed me that good work is its own reward. Finally, 1thank my parents for their unconditional support, even whai my path diverges far hmtheir expectatiom. TABLE OF CONTENTS Page C~LAPTER1. ~ODUCTION 1 O 1.1 Rationale 1 O 12 Objectives 4 O 1.3 Importance of this study 5 O 1.3.1 Relationships beiween fonn and process 5 O 1.3.2 Ice-sheet reconstruction 6 O 1.3.3 CIimate change srudies 6 O 1.3.4 Minerai exploration 6 O 1.4 Thestudyarea 7 O 1.5 Previous work 9 CHAPTER2. METEODOLOCY O 2.1 Site selection O 2.2 Global Positioning System (GPS)data collection O 2.3 GPS differential correction O 2.4 Interpolation of digital elevation models O 2.5 Surficial sediment and fabric analysis O 2.6 Stratigraphie analysis O 2.7 Diamict consolidation o 2.8 Regional observations CEIAPTER3. BEDROCKDRUMLINS O 3.1 Siimmit Lake (locaiity A) O 3.2 Willow Road shale ndge (locality B) O 3.3 Purden Lake (locality C) O 3.4 Bowron Road (locality D) O 3.5 Stoner dump (locaiity E) O 3.6 Tabor Mountah (locality K) O 3.7 Interpretations of bedrock dnimlins CFIAPTER~.DIAMICT DRUMUNS O 4.1 Stone Creek Dnimlins (locality F) O 4.1.1 Central Stone Creek Sector O 4.1.2 Western Stone Creek Sector O 4.1.3 Eastern Stone Creek Sec for O 4.1.4 Northern Stone Creek Sector O 4.2 Channel dnimlin (locality G) O 4.3 Right-angle Channel Dnimlin (locality H) O 4.4 Split Dnmiüns (Idty1) O 4.5 Montagne dnrmlin (locality J) O 4.6 Merdiamict sampIe sites O 4.7 Interpretations TABLE OF CONTENTS (continued) C~APTER5. GRAVELAND SILTDRUMLINS O 5.1 Fraser Grave1 Exposures O 5.1. l College Heights (locality ü) O 5.1.2 BC Rail right-of-way, Prince George O 5.1.3 Hàon Creek (Iocality O 5.1.4 Ncrver Creek O 5.2 SiltRhythmites O 5.2.l 'White Silts ' of McMillm B-f/s (locality T) O 5.2.2 College Heights (locality LI) O 5.2.3 Cale Creek (Iocality Y) O 5.2.4 Naver Fores@ Road (local@ 4 O 5.3 Powerline dnimlins (locality P) O 5.4 Strathnever dnmilins (locaiity Q) O 5.4.1 Strathnever highway exposures O 5.5 Chubb Lake Road flutings (locality R) O 5.6 Vanderhoof dnimlin (locaiity S) O 5.7 Eskers and Ice-Contact Deposits O 5.7.1 North Nechako (localiîy YY) O 5.7.2 Hmt Highlands (loculiity 0 O 5.7.3 Kolling Road (locolity Z) O 5.7.4 Chubb Lake Road (locaIity 223 O 5.7.5 Uhn Townsite O 5.7.6 Bednesti Compound Esk O 5.8 Interpretation of silt and grave1 deposits and drurnîins CIIAPTER6. DISCUSSION,CONCLUSIONS AND IMPLICATIONS O 6.1 General discussion of findings O 6.1.1 Bedrockhmlins O 6.1.2 BeCaock striations undjrutings O 6.1.3 Till hmlins O 6.1.1 High elevation dianikt O 6.1.5 Regional diamict O 6.1.5 Fraser grauel O 6.1.6 Glaciolawtrtines sediments O 6.2 Conclusions O 6.3 Impiicatiotls Figure 1-1 Drumiin formation by deposition (a, b), deformation (c, d) and erosion (e). Figure 1-2 Physiographic regions of central British Columbia (after Tipper, 1971). Figure 1-3 Regional dnimlios and glacial lake deposits. Figure 1-4 Quatemary geology studies in centrai British Columbia Figure 1-5 Typical drumiin fonns (schematic, a£ter Armstrong and Tipper, 1948) Figure 1-6 Regionai eskers and glacial striae. Figure 2-1 GPS ûansect grid for a two-rover system. Figure 2-2 Example of correcte& amalgamated GPS transect data prior to DEM interpolation. Figure 2-3 Effects of DEM mean filtering. Figure 3-1 Bedrock lodties of the study area. Figure 3-2 Contour map and profiles of quarried rock dnimlin, locality A Figure 3-3 Fabric orientations hmwithin Summit Lake dnimlin (a, b), and sites 5 km to the northwest (c), and 5 km to the north (d, e). Arrow indicates long-axis orientations of local dnimlùis. Figure 3-4 Quarried stoss end of a mal1 rock dnimlin, locality A. Figure 3-5 Photogmph, lee side of dnimlinized shale ridge, locality B. Flow was hmright to left. Figure 3-6 Contour maps of bedrock ndge (lefi) and dnmilins (right), locality B. Figure 3-7 Modeled oblique view of drumlins on shale ridge, looking West, locality B. Figure 3-8 Contour maps of dnimlinized bedrock Ml, locaiity C. Figure 3-9 Oblique views of dnmrlins, looking north, locality C. Figure 3-10 Contour mps of limestone ridge, locality D, (flow was left to right). Figure 3-1 1 Flutings in lhestone (compass is 5 cm wide), locality D. Figure 3-12 Contour map and profdes of rock dnmilin, locality E. Figure 3- 13 Tabor Mountain dnimlinized ndges, locality K (flow was northeast). Figure 3-14 Profiles and schematic of dnimlinized ridge, locality K. Figure 3-15 Small fluting, oriented southwest-northeast, locaiity K Figure 3-16 Bedrock striations, locaüty K (penny for de). Figure 3-17 Dnrmiins, flutings and suggested flow paths, bedrock ridge, locality D. Figure 3-18 Fluting atop Sinliut Mountain, oriented east-W. Figure 3-19 Sinkut Mountain, looking south kmVanderhoof area Figure 4-1 Diamict drumlin localities. Figure 4-2 Grain size of diamict hmbon (south) to Wdliston Lake (noah). LIST OF FIGURES (continueà) page Figure 4-3 Grain size of a) total sediment and b) matrix components of regionai 45 diamict. Figure 4-4 Cobbles extracted hma diamict dig pit, Stone Creek (3'kS" card for 46 scale). Figure 4-5 Grain size of a) total sediment and b) matrix components of Stone 48 Creek diamict. Figure 4-6 The four surveyed sectors of the Stone Creek dnunlins ('Jocality F).