CBO EzIA Le THE CANADIAN ROCKIES AND SELKIRKS LS WILLLAIL ‘HITTELL SHERZER Cornell Aniversity Library THE GIFT OF Hm. A.D, White . Ac220b18. 0 | alae 678-2 Cornell University Library laciers of the Canadian Rockies and Sel SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE PART OF VOLUME NNNIV GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS (SmirHsoniAN EXPEDITION OF 1904) BY WILLIAM HITTELL SHERZER, Ph.D. (No. 1692) CITY OF WASHINGTON PUBLISHED BY TITE SMITHSONIAN INSTITUTION 1907 Commission to whom this Memoir has been referred . THOMAS CHROWDER CHAMBERLIN HARRY FIELDING REID GEORGE PERKINS MERRILL The Knickerbocker Press, Hew Work ADVERTISEMENT. Doctor Wititam H. SHEeRzeER, Professor of Natural Science at Michigan State Normal College, has brought together in the present memoir the results of an expedition undertaken by the Smithsonian Institution among the glaciers of the Canadian Rockies and Selkirks in the year tg04. The general objects of the research were to render available a description of some of the most access- ible glaciers upon the American continent, to investigate to what extent the known glacial features of other portions of the world are reproduced in these American representatives, and to ascertain what additional light a study of similar features here might shed upon glacier formation and upon some of the unsettled problems of Pleistocene geology. A systematic survey was made of the Victoria and Wenkchemna glaciers in Alberta and of the Yoho, Asulkan, and Illecillewaet glaciers in British Columbia, located about two hundred miles north of the boundary of the United States. The largest of these is the Yoho Glacier, extending more than three miles below the névé field, and a mile in width for two-thirds of its length. Doctor Sherzer investigated various surface features of each of these glaciers, the nature and cause of ice flow, the temperature of the ice at various depths and its relation to air temperature, the amount of surface melting and the possible transference of material from the surface to the lower portion; their forward movement and the recession and advance of their extremities, and the general structure of glacial ice. In summarizing the most important results Doctor Sherzer discusses the indicated physiographic changes in the region during the Mesozoic and Pleis- tocene periods; the question of precipitation of snow and rain, and the effect of climatic cycles on glacial movements, the structure of the ice as to stratification, shearing, blue bands, ice dykes, glacial granules, and the possible methods of their development. In discussing the theories of glacial motion the author expresses his conviction that the nature of the ice movement can be “‘satis- factorily explained only upon the theory that under certain circumstances and within certain limits ice is capable of behaving as a plastic body, that is, capable of yielding continuously to stress, without rupture,” but “‘the plasticity of ice, a crystalline substance, must be thought of as essentially different from that manifested by such amorphous substances as wax or asphaltum.”’ Doctor Sherzer also discusses the cause of the richness and variety of coloring of glaciers and glacial lakes. In accordance with the rule of the Institution this paper has been referred to a commission consisting of Professor T. C. Chamberlin, of the University of Chicago; Professor Harry F. Reid, of Johns Hopkins University, and Doctor George P. Merrill, of the United States National Museum, and upon their favorable recommendation is published in the series of ‘‘Smithsonian Contribu- tions to Knowledge.” RicHarD RATHBUN, Acting Secretary. SMITHSONIAN INSTITUTION, WasuinctTon, D.C., January, 1907. il PREFACE. THE five glaciers selected for investigation are located in Alberta and British Columbia, along the line of the Canadian Pacific Railway. They repre- sent the great snow-ice masses which accumulate, season after season, upon the higher slopes and within the amphitheaters of the Selkirks and Canadian Rockies, the slow downward movements of which prevent indefinite accumulation and bring these great ice bodies to a level where complete melting may occur and the waters again be put into circulation. The observations here described were begun by the writer in the summer of 1902 and continued through the seasons of 1903, 1904, and 1905; the entire field season of 1904 being devoted to the surveys and more detailed studies.1. Camps were established in the immediate vicinity of the glaciers selected and they were kept under almost continuous observation during the hours of daylight. Beginning with the nose of each glacier, surveys around either side to the névé field were made with plane-table, transit, or compass; the measurements being with a steel tape. It was found impracticable and unnecessary to traverse the névé areas and those portions mapped were drawn from field observations and original photo- graphs together with maps and illustrations from the Canadian Topographic Survey, and other sources. The writer was ably assisted by Mr. DeForrest Ross and Mr. Frederick Larmour, to whom he desires to make grateful acknowl- edgment for intelligent and faithtul service, rendered often under trying cir- cumstances. During the latter part of the season of 1905 very efficient assistance was rendered by Messrs. E. W. Moseley and O. K. Todd. Being the most accessible glaciers upon the American continent it was desired to render available as complete a description as time and facilities would permit and to ascertain to what extent the known glacial features of other portions of the world are reproduced in these American representatives. It was hoped that a study of the same features, produced under somewhat different conditions, might shed additional light upon their method of formation and upon some of the unsettled problems of Pleistocene geology. A dispro- portionate amount of time was devoted to the Victoria Glacier, at the head of the superbly beautiful Lake Louise Valley, since this glacier is geologically the most interesting and may well be taken as a type bv students of glaciology. A delightful camp site lies under the lee of the outer massive block moraine and a still more picturesque one farther up, on a low shoulder of Mt. Whyte, over- 1A preliminary report upon the expedition appeared in May, 1905, in the ‘‘ Smithsonian Miscellaneous Collections,”’ vol. 47, Quarterly Issue, pp. 453 to 496. v vi PREFACE. looking the small lakelets. Students who may carry this report into the field generally desire an explanation which they can put to the test, wpon the spect, and so an attempt has been made at interpretation of the various phenomena described. The value of such interpretation will be known only after others have passed judgment upon the same features and more extended observations are available. Numerous forest fires in the season of 1904 prevented distant photography, on account of the smoke or haze, but through the courtesy of the Dominion Topographic Survey and of the Detroit Publishing Company we are permitted to reproduce some of their general views. obtained under favorable conditions. In addition to the views so used the writer is indebted to Captain Eduard Deville, Surveyor General of Dominion Lands, and his Chief Topographer, Arthur O. Wheeler, for a series of maps and photographs and much information concerning the regions under study. To the Director, R. F. Stupart, of the Canadian Meteorological Service, to the Assistant Director, B. C. Webber, and to Mr. N. B. Sanson, very grateful acknowledgment is made for meteorological data relating to British Columbia and Alberta and for the use of instruments kindly placed at the disposal of the expedition. Very sincere thanks are hereby ten- dered also to Prof. Joseph B. Davis, of the University of Michigan, and to Prof. Elmer A. Lyman, of the Michigan State Normal College, for the use of surveying instruments. The writer further desires to express his deep gratitude to the officials and employees of the Canadian Pacific Railway, who permitted the use of their Swiss guides for the necessary higher climbing and in many ways rendered very substantial assistance to the expedition. Finally to the packers and outfitters, Messrs. Robert W. Campbell and George W. Taylor, with their indis- pensable though often unwilling cayeuses, the writer desires to gratefully acknowledge the most generous and courteous treatment. W. H. SHERZER. Tue Micuican State Norma CoLvece, YPSILANTI, Micu., December, 1906. TABLE OP CONTENTS. Advertisement Preface . : List of Illustrations CHAPTER I, INTRODUCTION. Geographical Data a. Physiographic features b. Streams ‘ ‘ ‘ c. Glaciers selected for study . Historical Data Geological Data a. Stratigraphy ‘ b. Physiographic changes c. Lakes : d. Alterations in drainage Climatic Data : d j a. Geographic distribution of moisture b. Chinook winds c. Oscillations in climate CHAPTER IT. ViIcTORIA GLACIER. General Characteristics Nourishment Double Tributary : a. Mitre Glacier; the host b. Lefroy Glacier; the parasite Drainage ; a. Surface ablation b. Surface drainage Marginal drainage d. General drainage brook e. Water temperatures . °C Forward Movement a. Measurements . b. Frontal changes c. Shearing d. Crevasses PAGE H w w Now ST ann 10 12 5 19 20 22 22 22 24 25 27 28 29 2: 29 2 34 Vill I. Le) ~ CONTENTS. CHAPTER III. Victoria GLACIER (continued). Glacial Structure Stratification Dirt zones Granular structure Capillary structure Melting features Blue bands Ice dykes mmHOAA SA Surface Features a. Superficial débris b. Lateral moraines c. Medial moraine d. Terminal moraine e. Dirt bands ; /. Dirt stripes. : g. Dust and pebble wells h. Débris cones : i. Glacial tables . 7. Surface lakelets k. Rock reflection Former Activity a. Terminal moraines b. Lake Louise basin c. Lake Louise delta d. Lake Louise Valley e. Ancient till sheet CHAPTER IV. WENKCHEMNA GLACIER. General Characteristics Piedmont Type Nourishment Drainage Moraines Crevasses Movement about the Front Former Activity a. Bear-den moraines b. Moraine Lake . ; c. Valley of Ten Peaks . 63 64 64 65 67 67 68 68 69 7° is) CONTENTS. CHAPTER V. Youo GLacigErR. General Characteristics Nourishment Distributary Moraines Crevasses Ice Structure Drainage : : ‘ ‘ : : % Frontal Changes Former Activity a. Moraines b. Plucking action c. Yoho Valley CHAPTER VI. ILLECILLEWAET GLACIER. General Characteristics Nourishment Moraines : a. Surface débris . b. Left lateral moraine . Terminal moraines Right lateral moraine Boulder pavement 2 Ao Crevasses Ice Structure . Drainage : ; : a. Surface and marginal drainage b. Terminal drainage c. Temperatures . Forward Movement Frontal Changes : s : : . ; a. Recession data b. Ice waves Former Activity. ; : : ; 3 a. Rock scorings b. Bear-den moraines 78 79 80 mn wo wo bo a nmom nk wW Ww Ww oC oo nN OL 93 95 95 96 CONTENTS. CHAPTER VII. ASULKAN GLACIER. General Characteristics Piedmont Characteristics . Nourishment Moraines Crevasses Ice Structure . Drainage Frontal Changes Former Activity . : a. Development and decadence b. Bear-den moraines c. Rate of retreat CHAPTER VIII. SUMMARY AND CONCLUSIONS. Physiographic Changes in the Region a. Mesozoic peneplain b. Pre-pleistocene erosion c. Pleistocene erosion d. Pleistocene deposition Precipitation a. Geographic distribution b. Climatic cycles c. Ice waves ‘ > Piedmont Type of Glaciers Parasitic Glacier Bear-den Moraines Surface Features. ; ; a. Dirt bands, zones, and stripes b. Differential melting effects Ice Structure Stratification a. b. Shearing c. Blue bands d. Ice dykes e. Glacial granules Theories of Glacial Motion Color of Ice and Glacial Water . PAGE 97 98 99 IOOo 102 103 105 106 107 107 107 108 109 109 Ilo I10 Ill I12 II2 Iil2 113 II4 114 ILS 118 118 119 120 120 121 122 123 125 129 131 LIST OF ILLUSTRATIONS. PLate I.—Mt. Victoria and Lake Louise : Frontispiece Puate I].—General view of Canadian Rockies from Mt. Balfour Prate III.—Map of Victoria Glacier Piate IV.—r. General view of Victoria Glacier, looking southward. 2. Lefroy tribu- tary and Victoria Glacier Piate V.—1. Débris-covered nose of Victoria Glacier. 2. Neévé field of Victoria Glacier Piate VI.—1. Path of avalanche along Victoria névé. 2. Hanging glacier upon Mt. Victoria Pirate VII.—r. Hanging glacier upon Mt. Lefroy. 2. Double névé field of Mitre Glacier . Pirate VIII.—1. Parasitic Lefroy Glacier being carried by Mitre Glacier. 2. Western face of Mt. Aberdeen. 3. Surface drainage stream upon Victoria Glacier. 4. Ob- lique front of Victoria Glacier Pirate [X.—1. First stage in formation of a moulin, Lefroy Glacier. 2. Marginal lakelet on west side of Victoria Glacier. 3. Inner end of abandoned drainage tunnel, Victoria Glacier. 4. Mouth of abandoned drainage tunnel, looking outward; Victoria Glacier Pirate X.—1. Drainage from Victoria Glacier after a day of much melting. 2. Refer- ence boulder A, Victoria Glacier. 3. Stratifiedice front, Victoria Glacier. 4. Front of Victoria Glacier, showing irregular stratification and shearing Pirate XI.—Time of contact between two dirt zones, Lefroy Glacier. 2. Dirt zones upon Lefroy Glacier Pirate XII.—1z. Glacier capillaries, Yoho Glacier. 2. Glacier capillaries, Ilecillewaet Glacier. 3. Stratification on wall of ice tunnel, Victoria Glacier. 4. Blue bands in Lefroy Glacier Pirate NIII.—1. Blue bands near nose of [llecillewaet Glacier. 2. Contorted blue bands, Yoho Glacier. 3. Ice dyke filled with horizontal ice prisms. 4. Crevasse in Victoria Glacier Pirate XIV —r. Stony till, left lateral moraine, Victoria Glacier. 2. Sharply crested left lateral moraine, Victoria Glacier Pirate XV.—1. Ground moraine, Lefroy Glacier. 2. Right lateral and medial mo- raines of Victoria Glacier Pirate XVI.—1. Formation of Forbes’s dirt bands, Deville Glacier. 2. Forbes’s dirt bands, Victoria Glacier Pirate XVII.—1. Forbes’s dirt bands, Asulkan Glacier. 2. Dust wells, Victoria Glacier. 3. Small dirt cone, Victoria Glacier. 4. Same cone, dirt veneering removed x1 FACING PAGE x TO 20 is) to 23 27 28 39 41 42 47 48 590 Xl LIST OF ILLUSTRATIONS. Pirate XVIII.—r. Glacial table, Victoria Glacier. 2. Dethroned glacial table, Vic- toria Glacier . : Pirate XIX.—1. Boulder mound, Wenkchemna Glacier. 2. Surface lakelet, Vic- toria Glacier Pirate XX.—Map of delta, head of Lake Louise Pirate XXI.—The Continental Divide, Canadian Rockies Pirate NNII.—Map of Wenkchemna Glacier Pirate NNITI. 1.—Drainage brook from Wenkchemna Glacier. 2. General view of eastern end of Wenkchemna Glacier PLate XXIV.—1. Front of Wenkchemna Glacier. 2. Front of glacier showing forest invasion. 3. Disintegrated blocks of bear-den moraine. 4. Melted area on north side of surface block of quartzite, Victoria Glacier PLATE XXV —General view of Moraine Lake and eastern end of Wenkchemna Glacier Pirate XXVI.— Map of Yoho Glacier Pirate XXVII.—1. Ice distributary from Yoho Glacier. 2. Ice plucking upon a mountain peak, head of Yoho Valley. 3. Yoho Glacier, head of Yoho Valley. 4. Three-hundred-foot ice arch, Yoho Glacier ; ; : : Pirate XXVIII.—1. Knoll and ridges of ground morainic material in front of Yoho Glacier. 2. Yoho Valley, showing Wapta and Waputik snowfields Pirate XXIX.—1. Formation of Forbes’s dirt bands from crevasses, Yoho Glacier. 2. Hanging Valley, head of Yoho Glacier . Prate XX X.—Map of Illecillewaet Glacier PLratE XX XI.—Tongue and moraines of the Ilecillewaet Glacier, August, 1899 Pirate XXXII.—1. General view from Roger’s Peak. 2. General view of Ilecillewaet Glacier Pirate XX XIII.—Map of the Selkirk snowfields and glaciers Pirate XXXIV.—1r. Beginning of subglacial fluting by pressure melting, lecillewaet Glacier. 2. Subglacial fluting, Illecillewaet Glacier. 3. Roches moutonnées near nose of Illecillewaet Glacier Prate XXXV.—r. Regelation of ice blocks at foot of ice cascade, Ilecillewaet Glacier. 2. Stratification in upper part of Ilecillewaet Glacier Pirate XXXVI.—1. Mllecillewaet Glacier in 1888. 2. Tllecillewaet Glacier in 1905 Pirate XXXVII.—1. Bear-den moraine made conjointly by the Illecillewaet and Asulkan Glaciers. 2. Illecillewaet Glacier in 1897 PLate XX XVIII.—Map of Asulkan Glacier Pirate XX XIX.—1. General view of Asulkan Glacier in 1902. 2. The Asulkan glaciers and snowfields from Mt. Avalanche Pirate XL.—r. Left Asulkan moraine. 2. Nose of Asulkan Glacier, 1904 Piate XLI.—1. Stratification of Asulkan Glacier. 2. General view of Asulkan Glacier in 1808. Pirate XLIL--1. Development of seracs from glacial blocks, Asulkan Glacier. 2. Dis- rupted quartzite blocks illustrating plucking power of glaciers FACING PAGE 56 57 61 62 63 64 68 7O 71 74 78 80 81 82 84 85 86 88 92 96 97 98 Ioo 102 108 \ WN WAN “Sodje 7a AHS—ADAATMONY OL SNOLLATIN.LNOD NVINOSHLINS osu AY UV ‘TaALWId GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS (Report of the Smithsonian Expedition of 1904.) By Wiii1amM HItTELL SHERZER, Ph.D. CHAPTER I. INTRODUCTION. 1. GEOGRAPHICAL DaTA. a. Physiographic features—The Canadian Pacific Railway crosses the Rockies and Selkirks between north latitude 51° and 51° 30’, working its way up the left bank of the Bow River and its small tributary Bath Creek, to the Kicking Horse Pass, attaining an altitude of 5,329 feet above sea-level. Upon the more abrupt western slope of the Rockies the road follows the left bank of the Kicking Horse River to its junction with the Columbia, crosses this great waterway of the mountains, and slowly ascends the eastern slope of the Selkirks along the left bank of the Beaver. The summit of the Selkirks, Rogers’ Pass, is crossed at an elevation of 4,351 feet, whence there is rapid descent along the swift-flowing Ilecillewaet to the Columbia again, which has encircled the system to the north, forming the “Big Bend.’’ These transverse mountain valleys are lined with most majestic peaks, many of them rising a mile above the valley floor and furnishing some of the grandest of mountain scenery wpon the American continent. The highest peak in the Rockies, seen from the railway, is Mt. Temple, with an elevation of 11,627 feet, and in the Selkirks, Mt. Sir Donald, 10,808 feet. Numerous peaks range from 10,000 to 11,000 feet and are believed to culminate to the northward in latitude 52° to 53°. The Rockies and Selkirks, together with the Gold and Coast ranges to the west, make up the Great Cordillera in this part of Canada. North of the inter- national boundary this great system is much narrower than in the United States, pr 2 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. having a total width of about four hundred miles, and the component ranges are straighter and more regular. The systems are progressively higher from the coast eastward, culminating in the Rockies proper, which stand as a lofty buttress along the western margin of the great central plains. Between the Coast and the Gold ranges there lies an interior plateau a hundred miles wide with an average elevation of about 3,500 feet above sea-level. The Gold, Selkirk, and Rocky systems are separated by the Columbia and the Columbia- Kootenay valleys, made by the action of water and ice along the strike of the geological formations, assisted probably by some dislocations of the strata. The Rocky Mountains, or as formerly called, the Stony Mountains, consist of an imposing array of parallel ranges with a general trend in this region of north- northwest to south-southeast, separated by longitudinal valleys and attaining a total breadth of 40 to so miles. Compared with the systems to the west they are strikingly rugged in character and free from vegetation. Skirting the eastern border, and a part of them both geologically and structurally, are the ‘‘foot-hills,’’ consisting of folded parallel ridges, reaching out 15 to 20 miles and merging into the ‘‘plains”’ at an elevation of about 3,300 feet. b. Streams.—The main streams occupy the longitudinal valleys for a portion of their course, leaving the mountains by the transverse valleys, which extend into the foot-hills. According to Dawson the base-level of the streams upon leaving the mountains to the eastward is about 4,360 feet, while to the west it is about 2,450 feet above sea-level. Upon the eastern slope of the Great Continental Divide the waters are gathered into the Saskatchewan and reach the Atlantic Ocean by way of Hudson Bay; while those to the west drain into the Columbia River and work their way to the Pacific Ocean. As pointed out by Dawson, the actual water parting does not correspond entirely with the highest crest line of the mountains, but lies to the eastward, in which direction it seems to be moving. Between the international boundary of north latitude 49° and 52°, the Rocky Mountains are sharply separated from the Selkirks to the west by the Columbia-Kootenay Valley, which maintains a considerable breadth and a remarkably straight course through more than three degrees of latitude. This valley is filled with drift materials to a considerable depth and is undergoing but little erosion, the river simply cutting tortuous channels through the loose deposits. The eastern side of the valley is generally steep and escarpment-like, while the western is rounded and wooded. The Columbia starts within a mile and a half of its southward-flowing tributary, the Kootenay, and moves northwestward in a great sweep as though intent upon capturing the drainage of the region before starting for the sea. In this great fold it en- closes and sharply limits the less rugged, but picturesque, Selkirk System, with its subdued outlines and forested slopes. Some of the eastern ranges are continuous and have the same general trend as those of the Rockies, but, in general, there is less regularity and continuity in the arrangement of crests and peaks, and they do not attain as great a height. The drainage is all into the Columbia River, and the streams are unable to develop any considerable GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 3 size. Being so largely glacier fed here, as well as in the Rockies, the streams maintain themselves during the summer months, but reach their highest stage in the late spring, or early summer, from the melting of the snows, when the Columbia may rise 30 to 40 feet ahove its usual level. The streams are generally turbid with glacial sediment that gives them a milky, or yellowish, appearance, changing to green and, upon the loss of the sediment, to a blue color wherever the water is of considerable depth. The lakes of the region owe their origin mainly to former glacial action, consisting either of rock-basins, or of depressions in the glacial or fluvio-glacial deposits. Certain ones have been dammed back by morainic material deposited either beneath or at the extremities of glaciers of greater extent than at present. Those lakes which receive glacial sediment, or which are shallow, have a greenish cast, while those free from sediment and of moderate to considerable depth are rich blue. c. Glaciers selected for study.—The glaciers selected for study lie close to the main crests of the systems above described, between north latitude 51° and 52°, and west longitude 116° and 117° 30’, from 160 to 200 miles north of the inter- national boundary between the United States and Canada. They are but a few of a series available for study, those being selected which are most easily reached by well established trails. They are at such low altitudes that one may comfortably ride almost to the nose of each and none require climbing except to reach the névé regions. The two most easterly of the glaciers here discussed, the Victoria and Wenkchemna, lie east of the Great Divide in Alberta, the other three are west in British Columbia. 2. HistoricaALt Data. The establishment of the international boundary to the south, along the 4gth parallel, and the opening of the railway in 1885 called for geographic, geologic, and topographic work which was started by the various Dominion departments concerned and is still in progress. Dr. George M. Dawson began his work in 1874 along the boundary and extended it northward to include the region pierced by the railway, where he was assisted by R. G. McConnell. Topographic work of a preliminarv nature, along the line otf the railway, was begun in 1886 by J. J. McArthur. Photographic methods were introduced into the survey in 1889 by Director Deville and the accompanying triangulation of the ‘‘railwav belt” placed in charge of W. S. Drewry, D. L. S. The same year Mr. St. Cyr made a survey along the upper Columbia, between the Selkirks and Rockies, and in 1896 he and McArthur continued the work from Revelstoke down the Columbia and Arrow Lakes, with the view of connecting the surveys of the railway belt with those of the boundary commission.!. Two topographic maps, upon a scale of two miles to the inch, were issued in 1902 by the Depart- ment of the Interior, under the direction of James White. geographer. These are the Banff and Lake Louise sheets and are issued by the department at 1 The reports of the work of McArthur, Drewry, and St. Cyr will be found in the Annual Reports of the Canadian Dept. of the Interior for 1886, 1888 1889, 1890 1891, 1892, and 1893. 4 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. Ottawa. The topographic work of the mountains is now in the hands of Mr. Arthur O. Wheeler and there is being issued an enlarged map (scale 5,000 feet to an inch) of a section of the mountains lying between the railway and the Great Divide and extending from the Kicking Horse to the Vermilion Pass. This map includes completely the regions surrounding the Victoria, Horseshoe, and Wenkchemna glaciers, with corrected elevations, essentially the same territory covered by Wilcox’s map, 1896, on the scale of an inch and a half to the mile. Based upon work done during the seasons of 1901 and 1902, there will be issued with vol. 1 of Wheeler’s Selkirk Range an admirable piece of mountain mapping, extending from the Columbia to the Columbia, across the Selkirks along the line of the railway. The opening of the railway and the wonderful attractions of the region brought in a body of non-professional explorers and mountaineers, among the first of whom was the Rev. W. S. Green, Carrigaline, Ireland. He spent the working season of 1888 in the Selkirks, using Glacier House as a base, and gathered material for an interesting volume, Among the Selkirk Glaciers, Macmillan & Co., 1890. The map accompanying the volume, originally published in the Proceedings of the Royal Geographical Society, vol. x1, 1889, was the first attempt at detailed mapping in the Selkirks. One year earlier than Green, in 1887, Messrs. George and William Vaux, Jr., of Philadelphia, visited Glacier House, secured a valuable collection of photographs and began a series of observations upon the glaciers to which frequent reference will be made in the later chapters of this report. During the closing decade of the last century, and the opening decade of the new, there has been much work done in the region of an exploratory and mountaineering character. There should be mentioned especially the names of Wilcox, Fay, Parker, Collie, Stutfield, Allen, Habel, Topham, Thompson, Huber, Sulzer, Noyes, and the English ladies Benham, Tuzo, and Berens. Besides three superbly illustrated and attractively written volumes by Wilcox, Wheeler, and, conjointly, by Stutfield and Collie,| there have been prepared a number of descriptive papers for the scientific societies and magazines. A bibliography of the region, full but not complete, will be found in Appalachia, vol. x, 1903, pp. 179 to 186. The Canadian artist, F. M. Bell-Smith, of Toronto, has spent many seasons in the mountains and, based upon the various maps, photographs, and original sketches, has prepared relief maps of the best known areas of the Rockies and Selkirks. Copies of these maps are placed in the hotels operated by the railroad. It is not likely that these mountain valleys ever supported anything more than a scant Indian population, owing to the scarcity of fish, game, and available pasture. Providing food, en route, has always been a precarious matter for exploring parties. Aside from the marmot and rock-rabbit and an occasional porcupine, there is a strange and impressive feeling of desertion. The few 1 Camping in the Canadian Rockies, Wilcox. G. P. Putnam’s Sons, N. Y., 1896. The Rockies of Canada, Wilcox. Putnams, 1903. Climbs and Explorations in the Canadian Rockies, Stutfield and Collie. Longmans, Green & Co., N. Y., 1903. The Selkirk Range, Wheeler. Government Printing Bureau, Ottawa, 1905. GLACIERS OF THE_CANADIAN ROCKIES AND SELKIRKS. 5 birds that one meets seem awed into silence by the grandeur of their surround- ings. The mountain Crees had possession of the region at the coming of the white traders and trappers, but within rather recent time have been assimilated by the Stoneys, a tribe of Assiniboines, from the plains to the east. 3. GEOLOGICAL Data. a. Stratigraphy. The first work of a geological nature in this region was by Dr. Hector in 1858 to 1860, as a member of the Palliser expedition, his observa- tions being confined mainly to the Rockies and the region to the east. A geological map and numerous sections were prepared to accompany a paper presented to the Geological Society of London, in advance of the publication of the results of the expedition.! For detailed knowledge of the geology of the Rockies and Selkirks we are indebted mainly to Dr. George M. Dawson and his assistant R. G. McConnell, the former of whom began his work in 1874, as geol- ogist of the boundary commission. The Bow River region was entered in 1881 and in the Annual Report of the Geological Survey for 1885 there was published a preliminary report upon the geology of the Rockies lying between the boundary and north latitude 51° 30’. The report was accompanied by a large scale geological map, which was followed the next year with a geological section by McConnell, approximately along the line of the 51st parallel of latitude. Work was extended westward into the Selkirks and, at the Washington meeting of the Geological Society of America, Dr. Dawson, in 1890, presented the results of his observations amongst these ranges.2 The present Geological Survey, under the directorship of Robert Bell, is still at work upon the detailed study of portions of the region. The Selkirks and Rockies consist of an enormous complex of sedimentary strata, 50,000 to 60,000 feet in thickness, underlain by crystalline rock. In age they range from the Archzan to the Laramie, at the close of which the final stages of upheaval were accomplished. The rock strata graduate in age from the west, eastward, and were folded and faulted by pressure from the west, by which they were forced against the resistant layers underlying the “‘oreat plains.”’ The crystalline rocks of the series, of presumable Archean age, consist of gray gneisses, passing into schists, and occur only along the western margin of the Selkirks, where they constitute the Shuswap series. No trace of them has yet been discovered in the Rockies. Overlying the series occurs the Nisconlith, with an estimated thickness of 15,000 feet, consisting of dark colored argillite-schists and phyllites, showing various stages of alteration from true argillites to micaceous schists. Interbedded layers of dark limestone and quartzite are seen in certain sections. Although the beds yielded no fossils they were referred to the Cambrian by Dawson, because of their relation to the 1“QOn the Geology of the Country between Lake Superior and the Pacitic Ocean,” James Hector, M.D., 1861, Quart. Journal Geol. Society, vol. xvil, pp. 388 to 445. 2“ Note on the Geological Structure of the Selkirk Range,’ Geol. Soc. of Amer., vol. 2, 1891, pp. 165 to 176. Anextract from this paper is given in Wheeler’s Selkirk Range, vol. 1, pp. 405 to 409. 6 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. crystallines and their supposed equivalency with strata of known Cambrian age in the Rockies to the eastward. The crest of the Selkirks, the region in which occur our snowfields and glaciers, consists of the folded Selkirk series, with an estimated thickness of 25,000 feet and believed to be of Cambro-Silurian age. The strata have been forced into a synclinal fold, which terminates to the eastward by a thrust fault, produced by the western half of a sharp anticline being thrust upward with reference to the eastern half. The rocks consist of gray schists and quartzites, passing into grits and conglomerates which weather to pale vellowish or brownish colors. The latter are often more or less schistose from pressure and other metamorphic agencies, silvery mica, or sericite, being developed. At times the strata are wrinkled and contorted. Passing into the Rockies, to the eastward, we find them made up very largely of the representatives of the Nisconlith and Selkirk series just described, but known in the report of Dawson as the Bow River and Castle Mountain series. In the western part of the Rockies, adjacent to the Columbia, the upper and younger of the two is continued from the Selkirks, showing crumpling and folding, with metamorphism, but without faulting. The rocks are dipping eastward and have their ‘‘ strike’ parallel with the mountain ranges. Along the center of the range the folds are broad and sweeping, while eastward, for about 25 miles, there is a succession of thrust faults, running parallel with the ranges, the maximum vertical displacement being estimated at 15,000 feet. McConnell made out seven of these faults, giving rise to a series of massive mountain blocks resting in succession upon one another and forming escarpments to the east and relatively gentle slopes to the west. It was to this type of mountain that Leslie Stephen applied the suggestive term ‘‘ writing-desk.”’ The ranges making up the central portion of the Rockies are of the Castle Mountain series (Selkirk series) and of Cambro-Silurian age. They are more regular and depart less from the horizontal than the strata to the east and west. Mt. Stephen, on the line of the railway, gives a 5,000-foot section of the series, one shaly band being remarkably rich in Cambrian trilobites. The total thickness of the series is estimated at 10,000 feet, as compared with 25,000 feet in the Selkirks, and consists of limestone and dolomite, with calcareous schists and shales. These rocks give the steep-sided, massive, block-like cliffs, typically shown in Castle Mountain, which has furnished the name for the series. These rocks extend lengthwise of the central ranges to the Yoho Glacier at the north and the Victoria and Wenkchemna glaciers to the south. At the base of Mt. Stephen. at the head of Lake Louise, and in the Bow River, there has been brought up from below by an anticlinal fold the “Bow River Group,” or Nisconlith series of the Selkirks. This is of Cambrian age, estimated at 10,000 feet in thickness, and consists of quartzites and conglomerates, with dark gray, purplish, and greenish argillites. b. Physiographic changes. When viewed from a high elevation the rough ridges and jagged peaks appear to blend, as far as the eye can reach, into a great plateau with a notably even sky-line (pl. 1), giving the appearance of an ‘uypdauad pajsassip pue paytdn uv sayiusis aury- 63 | —5 o 70 | = | | 5 | 78.01 | +15.99) 126 g 1895 , 16.00 —o.64} 96 Ra | graphed, 1903, by Arthur O, Wheeler, GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 2I blowing, or in the lee of Lefroy with an east wind. Thus because of its shape, position, and depth the upper valley is able to capture much more snow than it would ordinarily be entitled to. c. Upon the opposing faces of Victoria (elevation 11,355 feet) and Lefroy (11,220 feet) large beds of snow accumulate during the fall, winter, and early spring. During the late spring and early summer much of this snow is pre- cipitated into the valley as avalanches, with the roar of thunder and the blast of a tornado. It is the danger from this source that has suggested the name “Death-Trap,”’ for the narrower portion of the valley, although no fatalities have yet occurred here. These avalanches mav shoot directly across the valley, or they may turn and move along it lengthwise as shown in plate v1, figure 1. They must bring down numerous rock fragments, which are distributed completely across this portion of the glacier and incorporated into its névé. d. Aconsiderable portion of the snow which clings to the eastern shoulder of Mt. Victoria is compacted into stratified ice, and over an area of about one square mile there arises a true glacier perched up on the mountainside, with a slope that appears too steep to give it a foothold. Such a glacier is known as a ‘‘cliff glacier,”’ or ‘“‘hanging glacier” (plate v1, figure 2). It moves down the slope, probably with considerable velocity, and is avalanched into the valley upon the back of the Victoria Glacier, filling the air with ice dust. At the crest of the precipice the ice has an estimated thickness of 200 to 300 feet, from which great blocks, sometimes as large as a city square of buildings, are detached and fall vertically 1,200 to 1,500 feet. At certain places where the falls are more frequent there are built up débris cones of coarse granules upon the western margin of the glacier. This avalanched ice spreads over the glacier and is incorporated into its body along with more or less ground-morainic material which has been manufactured between the hanging glacier and its bed. When the weather is cool and cloudy these ice avalanches are infrequent, but upon a warm bright day, with much melting and more rapid forward movement of the ice, they occur every few minutes from some portion of the long front. On August 25, 1903, during the mid-portion of the day avalanches were noted as follows: 10:39 A.M. moderate. 12:29 P.M. moderate. 10:43 slight. TEt4AG moderate. TES shght. io752 slight. Tii2y slight. aoa moderate. 11:28 heavy. 1:18 moderate to heavy. 11:40 shght. ris moderate. 12:20 P.M. _ slight. 12127 moderate. ise moderate. Boe moderate. Owing to its western and southern exposure the opposite face of Lefroy does not support a hanging glacier, although there is a suitable collecting area 22 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. for the snow. That which is not precipitated into the valley as avalanches melts away in the course of the summer and this water, along with that from Mt. Victoria, forms slender cascades, which are partially absorbed by the névé and, in part, work their way to the bed of the valley and are incorporated into the subglacial drainage. In these various wavs the upper Victoria receives the precipitation from about two square miles of collecting area. Through pressure, rain, and surface melting, due to the intense solar action, as well as the chinook winds, this mass of granular snow is compacted into a very fine granular ice. Powerful winds sweep over the bare peaks and ridges and spread over the névé more or less fine matter, organic as well as inorganic. This material is concentrated at the surface, when sufficient melting has taken place, and gives a rather sharp line of demarcation between the older snow and that which falls freshly upon it. In consequence of the melting and the presence of the foreign matter, the névé acquires a characteristic stratification, which in the case of the Victoria persists to its nose. Owing to the avalanches of snow and ice from Mts. Victoria and Lefroy these strata are rendered more or less irregular. The great weight of this snow and underlying ice forces the entire mass valleyward and thus prevents indefinite accumulation. 3. DousLe TRIBUTARY. a. Mutre Glacier; the host. Upon either side of the small peak known as the Mitre (elevation 9,470 feet), there descend two steep snow slopes, which give rise to two névé-covered streams of ice (see plate vu, figure 2). That to the right is intersected by a great crevasse, caused by the glacier drawing away from the snow and ice which adhere to the rocky slope, and forming what is known as the ‘‘bergschrund.’”’ This schrund renders this stream impracticable, but the other may be safely ascended with a guide, to the Mitre Pass leading over into Paradise Valley. Here from an elevation of 8,480 feet the descent is very rapid for about 1,200 feet, when the two streams unite into a single glacier, for which the name Mitre, first proposed by Allen for the entire tributary, may best be retained. For a very short distance the glacier is permanently covered with névé, but in midsummer this soon disappears and discloses a very weak and poorly defined medial moraine (plate vu, figure 2). It flows lazily down the straight valley, one and one-third miles, between Mts. Lefroy and Aberdeen, attains an average width of one-third to one-half a mile, and joins the Victoria with a breadth of 3,200 feet. b. Lefroy Glacier; the parasite. Upon the eastern and northern slope of Mt. Lefroy, because of its exposure and other favorable conditions, there has arisen another hanging glacier similar to although smaller than that just de- scribed upon Mt. Victoria. Plate 1v and plate vu, figure 1, give views of this elevated glacier, clinging to the steep mountain slope, the latter view being taken from the summit of Mt. Aberdeen, looking westward and from an elevation of 10.340 feet. From the steep, vertical ice face great blocks are avalanched 2,000 feet into the valley, much of the ice being ground into dust and shot SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE—SHERZER. PLATE VII. Fic, 1.—Hanging glacier upon Mt, Lefroy as seen from summit of Mt. Aberdeen (elevation 10,340 feet), Vhoto- graphed, 1903, by Arthur O. Wheeler. Aberdeen, Mitre Pass. Mitre. Little Mitre. Letroy. Fic, 2.—Double névé field of Mitre Glacier, July, t904. Faulted neve strata are seen in left tributary In foreground a snow-filled crevasse ; beyond which lies the névyé line, dbo w GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. out beyond the base of the cliff. Upon the western or Lefroy side of the upper half of the Mitre Glacier, there is thus heaped up a mass of pulverized ice, which is compacted by freezing into strata. This mass constitutes a new glacier, since the structure of the original one must have been destroyed by the plunge, with the exception of the granules and their fragments. Such a glacier is said to be ‘‘reconstructed,’”’ or ‘‘regenerated.’”’ Furthermore, this new glacier rests upon the back of the Mitre; is nourished differently; is of a different form; has its own distinct set of strata, unconformable with those of the Mitre; moves across the valley instead of lengthwise of it, and is accomplishing a totally different geological work. This glacier, for which the term Lefroy is appro- priate, is one of the best known examples of what Forbes termed a “‘ parasitic glacier,”’! far better, indeed, than the type itself. It is parasitic in the sense that it is carried by its host, the Mitre, and in that it is nourished entirely by snow and ice which would be otherwise available for the host. Just what is the structural relation of the Lefroy to the Mitre, the parasite to its host, can only be conjectured, since the contact was not observed and the plane of separation may not be at all distinct. There is, however, a very evident, deep-seated motion down the valley and an equally evident superficial motion across from the base of Lefroy to the foot of Aber- deen. The result of the latter motion is to carry most of the ground-morainic material, such as clay, sand, bruised and scratched pebbles and boulders, which has been manufactured beneath the hanging glacier of Lefroy, entirely across the valley and dump it in a great heap upon the eastern or Aberdeen side of the Mitre (plate vii, figure 1, and plate xv, figure 1). The front of the parasitic Lefroy being parallel with the side of the Mitre, some of the ground- morainic deposit is arranged in ridges parallel with the side of the latter, in which form it is being dealt out to the Victoria. Until the above stated relations were discovered it was a serious puzzle to ascertain how a glacier could get its ground moraine upon its own back and arrange it in ridges parallel with its side (see plate xv, figure 1). That the material could not have come from Mt. Aberdeen was evident from the fact that it does not support a hanging glacier upon its western face, as shown in plate vii, figure 2, although there is a buried mass of stagnant ice upon the northern shoulder. Avalanches of snow and the ordinary processes of weathering have brought down considerable angular material from Aberdeen which covers most of the ground-morainic deposit from the opposite side of the valley. While this ground-morainic material is being moved east- northeast by the Lefroy for a distance of 1,800 to 1,900 feet, it is also being carried north-northwest for a distance of about 3,800 feet by the underlying Mitre and the resultant motion is somewhat east of north. This will be made clear from an inspection of the map, plate 111. Opposite the large débris cone seen in plate Iv, figure 2, upon the western side of the Lefroy Glacier, there is a marked depression in the surface of the ice and also across the entire tributary where it joins the Victoria, giving good ! Travels through the Alps of Savoy, James D. Forbes, Edinburgh, 1845, p. 201. 24 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. exposures of the outcropping edges of the strata, to be noted later. These depressions furnish confirmatory evidence that the general movement of the superficial layers is across and not parallel with the valley. The position of the left lateral moraine from the débris cone, above noted, to the Victoria, shows, however, that along the base of the Lefroy cliff the movement is normal and due to the Mitre, although the strata belong to the Lefroy. In consequence of this a relatively small amount of morainic material is captured from the Lefroy and delivered to the medial moraine of the Victoria at the nose of Mt. Lefroy. This double tributary joins the Victoria at an elevation of about 6,670 feet, having an average surface slope of 1,360 feet to the mile, and is at once compressed to about 600 feet, as compared with 3,200, or as 54 is to 1. There being no corresponding increase in the height of the ice, the inference is that the tributary delivers relatively little ice to the Victoria and that its movement is correspondingly slow. 4. DRAINAGE. a. Surface ablation. The drainage supply of the glacier originates from the rainfall over the glacier and adjacent mountain slopes, from the melting of the snow and ice in the region of the hanging glaciers, and from the general melting of the glacier itself and its tributaries. No definite data are available concerning the rainfall over the glacier and adjacent slopes. Owing to its greater altitude it would be much less than at Field and Banff and would practically all fall during June, July, August, and September. After heavy showers the streams from the mountain slopes are in many cases highly charged with sediment, those originating from the melting of snow being generally clear. The temperature of the ice during the summer was found to be either just at the freezing point, or so near it that any addition of heat was sufficient to start the process of melting. In the abandoned drainage tunnel, to which reference will be made later, holes were bored into the ice wall, 140 feet back from the entrance, and a standard minimum thermometer inserted its full length. Owing to the course of the tunnel the point of observation was estimated to be 70 feet from the foot of the oblique ice wall and about 17 feet from the actual ice face (plate vii, figure 4). During the week from july 3240 August 4%, sooq, thereadines were 31,6" I, 90.0", 31.8", 290°) 31.9%, and 32°. The maximum temperature of the air in the tunnel during the week ranged from 31.4° to 33.0° F. Owing to the warmth of the body and that of the candle used, it was found impracticable to get the temperature of the air at the same time that the temperature of the ice was taken. In the rarified atmosphere at these high altitudes the midsummer sun strikes with surprising force and the surface ice, so near its melting point, is at once converted into water without changing its temperature. In the case of scores of observations made upon the surface streams of the series of glaciers the temperature was almost uniformly 32° F. In rare cases it was found to be a small fraction of a degree above. In order to secure some data for an estimate bobr ‘<{nf *yauuny asvuleip pauopurqe SuLwoys ‘WaLOVPH) BUIOJIA Jo Juosz anbyqog—"t ‘oy "BLIOJILA AY JO aoRjNs WoL] Jaie[s) ora] ssoioe Suryoor ‘uaapray Vy “TY JO aovyj Utlaisayy—"t OIA “WaLavTH) viojotA UOdN Wealjs asvulvIpP advjANG—'E “OT lOU[H) BI A I S TA ALWTd ‘Aoljay ayy Aq, aaqtyy Ay} Ssotow parses puv sora] “VJ UO Aa1ov[s Sursuvy ayy yyeauaq pasnjovynuvw ‘AULEIOM pu720.L9 JO ATUILU S}SISUOD UDapIaqy “]]Y JO aseq yw uorepnu “nose uUIeIOpy —“Aalovyy) aaqtyy Aq pattivos Butaq savy AosjaT oisesre~qg—'l ‘ory AorjaT ‘INI “udapseqy “NaAZAAHS—AOTATMONM OL SNOILNGIYLNOO NVINOSHLINS GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 25 of the rate at which surface ablation was taking place over the lower portion of the Victoria, accurate elevations were taken upon the series of steel plates used in determining the forward movement. The results are shown in table V, page 31, giving the total melting from July 13 to August 4, 1904, for a period of 22 days of midsummer. The maximum lowering of the ice surface occurred at plate No. 13, nearly two-thirds of the way across when measured from the west side, and amounted to 3.8 feet, or a daily average of 2.076 inches. This plate was located on a portion of the glacier least protected by rock débris. Although this lowering of the surface is due, in the main, to the sun's action and general effect of the atmosphere, usually above the freezing point in summer, there are other’minor agencies which would tend to give the same result. One of these is the rain, 1.506 inches of which fell during the period of the observations. Other agencies are subglacial melting and subglacial erosion, longitudinal stretching, or a lateral spreading of the ice, all of which would tend to lower the upper surface. It should be noted, further, that in the 22 days this plate moved forward 60 inches and with the average surface slope ot 7° to 8°, the plate would be lowered by this agency alone about one-third of an inch daily. Making this correction the actual ablation, from sun, atmosphere, and rain, would amount to about 1.74 inches daily and for the two main months of July and August would give a total of about 9 feet. Observations upon the lower Lefroy showed that the ice surrounding certain morainic heaps had been lowered during the season by about this amount. No glacial tables of this height can be found, however, because of the undercutting effect of the sun’s rays and the consequent destruction of their pedestals. The broad medial depression lying just west of the medial moraine (see plate Iv, figure 2, and cross section page 30) has been produced by the greater surface melting and this has been permitted by the thinner covering of rock débris, the ice of this portion of the glacier coming from the Lefroy side of the upper Victoria. This depres- sion continues down the glacier for 2,200 feet, where it thins out, apparently from surface melting. With a forward motion here of about 64.5 feet annually, it would require 34 years for the ice to move from the line of plates to the oblique ice face, during which time some 306 feet of ice might be melted away. If the rate of melting and rate of forward movement remained constant, this number would represent the approximate thickness of the ice beneath plate 13. It is very probable that the rate of melting becomes less, owing to the concen- tration of rock débris at the surface, but it is also very probable that the rate of forward movement becomes also less as the ice diminishes in thickness. The work with the spirit level indicated that this plate was originally 393 feet above the lower margin of the ice in this depression, the difference of 87 feet representing the rise of the valley floor in this distance. If this latter figure is approximately correct the inclination of the bed is much less than that of the surface of the ice itself b. Surface drainage. Over the entire névé area the water from the melting snow, as well as that from the rainfall, is absorbed into the body of the glacier 26 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. and refrozen, binding the granules together into an ice conglomerate. Where the ice itself is exposed and crevasses absent, the melted ice and rainfall are concentrated into more or less well defined channels, which persist from season to season. In the early morning the glacier is impressively quiet, the ice is dry, and many of the small pools are frozen over with a thin layer of ice. When the summer sun enters the valley the exposed ice becomes moist, small trickles of water unite into rills, that grow larger and larger from the union of innumerable others, and these form still larger brooks which empty their clear, ice-cold waters into the main drainage channels and, after a day of rapid melting, we have here roaring torrents. These streams slowly cut their way into the solid ice by mechanical erosion, assisted by the rock fragments which the water is able to move along, and by melting. The water being apparently at the melting point of the ice, 32° F., it is incapable of imparting heat to that over which it flows and the melting must arise from the conversion of its kinetic energy into heat. Such heat would be imparted to the ice, rendered latent in the process of lique- faction and the temperature of the water would not be sensibly raised. The question arose in the mind of the writer while studying these ice streams whether water at 32° is capable of dissolving ice at the same temperature, as it might dissolve rock salt over which it was flowing. So far as he has been able to learn the question has not been investigated, but if water does have any such effect upon ice under these conditions, it would help to explain the formation of these ice channels. In the upper part of their courses these stream beds are generally free from débris and quite straight, but as the bed is broadened, boulders, too large for the stream to handle, slide in from the surface and the stream is compelled to go around. In this way a system of meanders is formed, as shown in plate vill, figure 3, and the ice banks are rendered steep and, here and there, undercut by the rushing water. In the lower portions of the course the bed may contain considerable rock débris, but this has simply shd down from the surface and nowhere suggests an agerading action of the stream. When the stream channel is contracted for any reason, the level of the water is raised, its velocity increased in consequence, and an ice basin cut out upon the down-stream side, filled with more quiet water. This is suggestive of the manner in which the Lake Louise rock basin, to be later described, may have originated when the entire valley was ice-filled. In portions of the glacier intersected by crevasses it 1s obvious that surface streams, of any considerable size, cannot develop. The water escapes by an englacial or subglacial tunnel, to reappear at or near the nose. Whena stream encounters such a crevasse, from which there is drainage beneath, it forms a small cascade and begins to cut a channel in the vertical face of the crevasse wall. If the velocity and volume of the water are sufficient, a corresponding channel may be produced in the opposite wall. As the lips of the crevasse are subsequently brought together by movements of the ice body, and the crevasse is healed, this small vertical channel persists and still furnishes an SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE—SHERZER. PLATE. 1X. Tic, 2.—Marginal lakelet west side Victoria Glacier. Fic. 3.—Inner end abandoned drainage tunnel, Victoria Glacier, July, 1904, Fic, 4.—Mouth abandoned drainage tunnel, Victoria Glacier, looking outward. — July, 1904. GLACIERS OF THE CANADIAN ROCKIES AND, SELKIRKS. 27 escape for the surface stream. This is well shown in plate 1x, figure rt, the small stream entering the nearly healed crevasse from the right. As the ice moves valleyward the drainage area of the stream may be enlarged, the amount of water correspondingly increased, and our glacial well, or ‘“‘moulin,’” may be indefinitely enlarged both in diameter and depth. Since the water is introduced from above and escapes below, they are more like wells, turned wrong-side up. They may be found in various stages of development, the younger in the region of the open crevasses, the mature examples in the lower course of the glacier, where they have been carried by the general forward movement of the ice, and into which the surface torrent plunges with a sullen roar to unseen depths. The main drainage stream of the Victoria Glacier starts near the nose of Mt. Lefroy, to the west of the medial moraine, and passes somewhat obliquely downward to a moulin, opposite the oblique ice face (plate Iv, figure 1, and plate 11). This stream drains that portion of the glacier over which the surface melting is the greatest? A second drainage stream originates near the above, but in the depression between the medial moraine and the Lefroy tribu- tary. This stream collects the surface waters from the tributary and extends for one-quarter mile down the deep depression between the medial and right lateral moraines and disappears in a system of crevasses that cut this portion of the glacier. Two short, but rather deep, drainage channels occur upon the western side of the glacier, lying upon the inner side of the left lateral moraine. One of these has incised the ice to a depth of 18 to 20 feet. Since these streams have probably occupied their present sites for many years it is rather remarkable that they have not completely cut through the ice to the rocky bed beneath. From the fact that they have not done so we are forced to conclude, either that the rate of cutting is surprisingly slow, or else that the glacier thickens in such a way that the bottoms of the streams are elevated with reference to the base of the glacier. It is possible that the longitudinal compression to which the glacier is subjected in its lower half mav be sufficient to secure this result. c. iAlarginal drainage. Upon the eastern side of the lower Victoria, along the base of Mt. Aberdeen and Castle Crags, there is no visible marginal drainage at present, but water may be heard trickling amongst the rocky débris. Just at the head of this depression, however, where the tributary joins the main Victoria, there is evidence of earlier drainage here, in the form of an abandoned lake bed, with a length of 500 to 600 feet. «A small gravel delta was formed at the head, while the rest of the bed is filled with silt. s--57 feet "Ne: §<3e27 No. 14-2227 “Tossa113 feet ~Tr=--81 feet No 6007 No. 15-2227 ___-- 109 feet == 66 feet NO). “7sse52 7 No. 16-222 Disset00 feet “7 r2=>83 feet No. 8 Nowrpesoo ues Ta 83 feet "lo ze= 83 feet No. g-s2277 No. 18-s2277 ie ~75 feet _los= 45 feet No to---77" “No. 19-7 7777 For reasons to be given later the writer believes that the intervals between these bands mark the annual progress of the ice down the slope, as conjectured by Tyndall, and offers the following explanation of the phenomenon. As the ice of the glacier is pushed over the crest of the ridge in its bed, which is responsible for its change in surface slope, there is formed successively a series of transverse crevasses, aS explained upon page 36 of this report. The distance between these crevasses will be determined mainly by the thickness of the ice and the change in its angle of slope. Since the glacier is moving forward in winter as well as summer, although at a less rate, these crevasses must originate at all seasons of the vear. Those which have been formed in the late fall, or winter, upon passing down the slope will be perfectly healed, since their lips have ex- perienced practically no melting from the sun’s action. The opposite crevasse walls come slowly together, refreeze, and leave no visible scar in the ice. Those crevasses, however, which have formed in the late spring and summer have their lips much rounded by the sun’s rays. If the glacier is moving northward as in the case of the Victoria and Lefroy, the northern, or down-stream lip of the crevasse will receive the maximum effect, the southern comparatively little. Should the glacier be moving southward, the northern lip of the crevasse would still be the one most strongly acted upon by the sun, but in this case it would be the up-stream side. Glaciers flowing east or west, and having their transverse crevasses in an approximately north-south position, would have their crevasse 52 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. walls affected more evenly, unless surrounding mountain cliffs interfered. In the healing of such crevasses there would be left a depression, representing the sun’s action upon the lips of the crevasse, not simply for one season but through a series, and in this depression the wind-blown dust would collect and the fine débris would be washed by rain and melting ice from the adjacent portions of the glacier, rendering it lighter by contrast. Owing to the more rapid central movement of the ice the bands, at first nearly straight, will begin to curve down- stream and become more and more sharply bent, their apices marking the locus of maximum surface motion. Between them will lie swellings, or ridges, having the same general form of the depressions, from which much of the finer dirt has been removed. These ridges and intervening depressions may be very inconspicu- ous, as upon the Victoria, or they may become very prominent, as shown upon the Deville Glacier in the Selkirks, forming what Forbes termed ‘“‘ wrinkles” (plate xv1, figure 1). They mark that portion of the ice which passed the crest of the slope in the late fall and winter and appear as ridges, partly because of the severe compression to which the ice is subjected and mainly because the adjacent ice has been lowered by melting. Owing to the more rapid movement of the ice down the slope the bands will be farther apart and less well defined, than after the more gentle slope below has been reached and the ice is subjected to longitudinal compression. Upon this more gentle slope they have a better chance to catch and retain the fine débris. Since the sun’s action was more powerful at the center of the crevasse, the depression is greater at the apex of the band and persists after that of the extremities has been finally lost by surface melting. In consequence the bands become shorter and shorter and lastly disappear, when ablation has reduced the surface to a general slope and the fine débris is redistributed. Very often it must happen that instead of a single crevasse being formed during the season of melting there would be formed a series of them. Upon a steep slope of the Asulkan they seem to be formed in pairs as shown in plate xvul, figure 1, in which it is seen that the ridge of ice separating two adjacent crevasses is acted upon from either side and lowered, assisting in the formation of the depression. The crevasses that are forming the depres- sions, preparatory to the reception of the dirt, may be traced around to the almost healed crevasses at the left, while between them are seen traces of crevasses that have healed with practically no marginal melting. These are presumably those which opened and closed soon enough to escape the rounding action. If the surface slope is too great the depression produced in the ice may not be sufficient to retain enough dust to bring out the series distinctly, as is the case with the Asulkan just noted. Study figure 1, plate xxix, from the Yoho Glacier. That the method of formation of these dirt bands is essentially as outlined above admits of no doubt. The question as to whether they are produced annually, or at irregular intervals, needs to be investigated. The average inter- val of those bands originally described by Forbes upon the Mer-de-Glace was 711 feet. Opposite his station D the interval was 667 feet (Travels through the Alps of Savoy, p.165). Ina postscript to his volume, p. 420, he gives the move- "2109 “BuTpeur aovyins BIT MOYS OF Apts GUO WOTP paaotiar SuuAaura Wip YI € oanSg ur uaoys auoo awueg—'‘t “oy spivjar stiqgap Aysor ayy Ayuenb yuaiyyns up czawxpy vuoqwry ‘aaod yp jpeug—'f ‘oy “Bunpau sayeqplowy yp sayuuenb [[vws uy “BUN[IUI [PNUaLaHIp JO 1fMsar ayy ‘Watavpy CUO ‘s_faw asm ~—"s “OLY ‘roOr ‘ysusny purq WIp §saqioy Jo uonRWIOy—"1 ‘Oly TAS aad “MAZMAHS—AITAT MONA OL SNOTLAPINLNOO NVINOSHLINS GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 53 ment of one of the lateral points opposite station D as 483 feet for the year and suggests that ‘‘the movement of the center is probably, at least, two-fifths greater, corresponding closely with the intervals of the ‘dirt bands’ of the glacier.” Although the size of the intervals in this series differs plainly to the eye, still Forbes states that the difference for any one interval is probably not a tenth of the mean. From the same point of view as that used by Forbes in 1842, Tyndall counted upon the Mer-de-Glace, 17 years later, exactly the same number of bands and remarked: ‘‘The entire series of bands which I observed with the exception of one or two, must have been the successors of those observed by Professor Forbes; and my finding the same number after an interval of somany years proves that the bands must be due to some regularly recurrent cause.”’ In Chapter xxxitof his Glaciers of the Alps, Tyndall has described his ‘“white ice-seams,”’ the ‘‘bandes lactées’’ of the French and “ weissen Blatter”’ of the Germans. These are due, in part, to the filling of transverse crevasses, left open during the fall, with snow and then its later compression into a white vesicular ice. Since, in general, these crevasses would be those which had been acted upon by the summer sun, they would be the counterpart of the dirt bands under discussion. Sévé found the average interval for these white seams upon the Béium Glacier, in Norway, to be 218 feet and that this represented also the average forward annual movement.' So far as the Victoria Glacier is concerned we have not sufficient data at hand to settle the question of the annual character of the dirt bands. At the line of plates, about a third of a mile below, the maximum annual movement of the ice was found to be 65.85 feet. The average annual interval for the lower half of the series is 76.56 feet, which is about what would be expected in the way of annual ice movement, when compared with the above. We should also expect the movement to increase as we approached the crest of the ice slope. So that the actual and relative spacing of the bands very strongly suggests their annual character. If due to some “regularly recurrent cause,” as Tyndall suggests, this cause must recur with the seasons. We are, however, not entirely without evidence that the intervals between the dirt bands indicate approximately the annual movement of the ice. As pointed out upon page 30, the Messrs. Vaux marked the location of a large boulder upon this portion of the glacier July 26, 1899. From range lines, one year later, they determined that the boulder had moved forward 147 feet. In September, 1905, this boulder was found opposite the gth band of the series given upon page 51. In 1899 it should have lain opposite the 3rd band and, if the motion there had been the same as it was in 1904~5, it should have moved in 1899-1900 the distance of 126 feet. The previous year it should have moved 174 feet. My field notes say that the second and third bands were indistinct, so that there is strong probability that the three intervals between one and four may not have been properly distributed. The average for the three is 153 feet, which agrees very well with the actual observed motion of the boulder. If the dirt band intervals are an approximate indication of the annual ice movement 1 Quoted from Heim’s Gletscherkunde, p. 140. 54 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. the Vaux boulder had moved downward in 1905 from its original position some 676 feet, or at an average rate of about 113 feet per annum. fj. Dirt stripes. Somewhat closely related to the dirt bands just described, so far as their method of formation is concerned, are the fine streaks of dirt seen along the margins of most glaciers, sufficiently free from surface débris. They may be found, however, anywhere upon the glacier that the blue bands are well developed, reach the surface at a fairly steep angle and are being subjected to surface melting. The blue bands, being composed of relatively firm, compact ice, are more resistant of the sun’s action, than the vesicular ice in which they are embedded and project as delicate ridges, separated by narrow furrows. Into these furrows the wind-blown dust settles and is washed from the adjoining ridges, forming narrow, parallel dirt streaks, or stripes. When well developed, as upon the Lefroy, the glacier has the appearance of having been swept with a coarse wire broom; the strokes having all been long, regular and parallel. The dirt stripes mark the position of the vesicular bands in the ice and the lighter streaks between the position of the blue bands them- selves. In this way the banding is clearly shown at the surface, whereas, other- wise, it might be obscure. Views of these stripes have already been shown in plate xil, figure 4 and plate xin, figures 1,2. Sometimes they run down the face of a crevasse wall (plate xm, figure 4), as though they might be something more than a superficial feature, but a little chipping of the ice shows plainly that they are not. After they have once been formed the dirt stripes will absorb the sun’s heat and still further emphasize the small furrows. Running, in general, lengthwise of the glacier these furrows become the sites of minute rills which have a tendency to clear away the fine dirt, as fast is it collects. For this reason, as well as because of the nature of the banding itself, the individual stripes are not continuous for any considerable distance. They are sometimes so closely placed that 10 stripes may be counted within the distance of an inch, but are usually considerably coarser. g. Dust and pebble wells. Where small pebbles, or patches of fine dirt, often black from the presence of organic matter, are thinly distributed over the surface of the ice, heat is absorbed and the ice immediately beneath is melted more rapidly than the surrounding ice. Cavities are thus formed with vertical walls, which for a time retain the water. They sink into the ice for a few inches, until protected from the direct rays of the sun by their own walls, when further melting would be delayed until the general surface was lowered sufficiently to allow the sun to again reach the foreign matter at the bottom. Such wells are shown in plate xvu, figure 2. Although their depth at any one time is seldom greater than a finger’s length, still in the course of the season their total length would be 9 to 10 feet upon the Victoria and Lefroy. A thin film of water often freezes at night over the surface and then thaws out promptly when again exposed to the sun. After thus freezing the water is at times drawn into the 1A sample collected from the Ilecillewaet in 1903 contained 14 per cent. of organic matter, enough so that when set away moist in a warm room it soon became offensive. GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 55 glacier, by means of the capillaries developed between the granules, leaving the well free from water, but with its ice cover. Where pebbles, or small dirt patches, are abundant, as shown in the last figure, the ice between the adjoining wells is melted more rapidly by the sun than it would ordinarily be, forms minute pinnacles and appears whitish and spongy. In this way the lower- ing of the general surface of the glacier by ablation is accelerated. By keeping itself thus at the bottom of a small well the dirt of these small patches is pre- vented from being blown away, or washed away, and thus it is possible that the same well may persist through, not only a season, but a succession of seasons. Should the well, however, collect additional dirt, beyond a certain limit, this excess would then protect the bottom of the well from further melting, the adjoining ice would soon be lowered below the bottom of the well and the well would be literally turned wrong-side-out. Where one has a few days to spare about the same glacier an interesting experiment would be to sift dirt into a group of typical wells, filling them to varying depths, and observing the result. Such an experiment may easily be performed upon a snow bank of sufficient depth, when it is being strongly acted upon by the spring sun. It would prepare the way for a clear understanding of the next three surface features to be described. h. Débris cones. When the amount of dirt, sand, gravel, or rock débris, is sufficient to protect the surface of the ice from melting, or to even partially protect it, over a limited area, the surrounding ice surface will be lowered more rapidly than that beneath the protecting material and the débris will begin to be elevated, with reference to the neighboring surface. The loose débris will slide, or roll down about the side, exposing the edges and corners to the melting action of the sun, allowing still more sliding of the débris and still further melting. The ice core will finally assume the form of a ridge, cone, or mound, with its thin veneering of foreign matter, as in the case of the lateral and medial moraines already described. The companion figures 3 and 4, plate xv1, show the structure of a small gravel cone, only 15 to 16 inches in height; figure 3, as it was found upon the ice, figure 4, after the gravel upon one side had been washed off to show the ice core. It is seen what a thin covering will suffice to bring about the result. Depending upon the nature of the covering they are known as dirt, sand and gravel cones, and boulder mounds, and they may vary in height from a few inches to many feet. In plate xix, figure 1 is shown a mound upon the Wenkchemna Glacier, estimated to be 80 feet high. This pile of rock rubbish was either dumped in a heap by an avalanche, or collected in the bottom of a lakelet, as described by Russell for the Malaspina in Alaska.1 Cones of all types, varying in height, from a few inches to 12 or 15 feet are to be found upon the Victoria in the region of maximum melting. They may persist from one season to another, but there is a limit to the height to which any particular cone may attain. As the height of the cone grows the lateral surface is increased, over which the débris must be spread in order to suffi- : Glaciers of North America, p. 115. 56 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. ciently protect the ice. When this covering becomes too thin, or when it is blown off, or washed down the steep slopes by heavy rains, the ice core becomes exposed and rapid melting ensues, resulting in the destruction of the feature. In case the surface covering is distributed about the base and the pure ice core exposed, the melting does not cease when the general level is reached but con- tinues more rapidly than the surrounding ice to which has been transferred the débris. Instead of a cone, we may now get a basin-shaped depression, which is gradually extended laterally by melting, and into this depression the original material may again slide and be collected at the centre until there is sufficient to prevent further melting. An interesting and instructive experiment, in connection with that suggested upon the dirt wells, is to wash down the gravel, sand or dirt, from a collection of small cones, mark the location, and watch the changes from day to day. t. Glacial tables. In the case of a single rock fragment, of sufficient size, resting upon the ice over which surface melting occurs, protection is afforded the ice immediately beneath. As the result of the more rapid melting of the surrounding ice the rock is relatively elevated upon a pedestal of ice and there results what is termed a ‘‘glacial table’; as seen in plate xvi, figure 1. As the rock is elevated a short and narrow ridge of ice lying to the north of the pedestal (observe the shadow in the figure) is protected from the noonday sun, so that viewed from the east or west the pedestal is unsymmetrical. This lack of symmetry is further emphasized by the undercutting action of the rays of the noonday sun upon the southern side. Some observations were made with a view of discovering the lower limit of the rock fragments that were capable of furnishing the protection necessary to form tables. The following were found forming low tables, or starting to form them. It is obvious that the color and nature of the rock would both have their influence in determining the effect upon the ice. Dark gray limestone, 12x 12% 4.5 inches. 6c cs oe ce I3X 9X 3 Light ™ zs tre 6x4a¢ “ Reddish quartzite, 10x8 x2.5 “ Rusted limestone, QX4.5X1 - Dark limestone, 8x4xX 2.5 to 3 inches. In the case of the last specimen the thicker end was found to be protecting, while the thinner was inducing melting. Owing to the undercutting action of the sun’s rays blocks of this size can form only low tables. Larger blocks may rise to a height of three to five or six feet upon the Victoria, the latter heights being unusual. They may persist from one season to another but there is a limit to the height which any particular table may attain, determined mainly by the size and shape of the rock. As the rays undercut, mainly upon the southern side, the block begins to lean to the south and finally topples off in that direction (plate xvitl, figure 2). The remnant of the pedestal is removed by SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE—SHERZER. PLATE, XWITI, Fic, 1.—Glacial table, Victoria Glacier, looking southwest. Observe undercutting action of rays upon south side and shadow cast by the rock upon north side, with resultant ridge of ice. bic. 2.—Dethroned glacial table, Victoria Glacier, looking northeast. The boulder fallen to the south by undercutting action of sun’s ray SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE—SHERZER. PLATE NIX. Fic, 1.—Boulder mound, Wenkchemna Glacier, illustrating the protective effect of rocky debris, | Estimated to be eighty feet in height. Whyte. Devil’s Thumb, Bow Valley. Fairview. Fic, 2.—Surface lakelet, Victoria Glacier, resulting from lack of debris protection, Enlargement towards right is still in progress by melting, but has practically ceased towards the left, owing to the rocky cover, GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 57 melting, the block settles into its position of equilibrium and the making of a glacial table begins anew. In exceptional cases the undercutting of the pedestal may be done by a surface stream. In the case of 25 tables selected at random, it was found that the longer of the horizontal axes of the pedestals had an average magnetic bearing of N. 36° W., or 11° W. of true north. With a larger, or a different, series, the average would probably be more nearly the true north. j. Surjace lakelets. Upon the middle portion of the Victoria, western side, where the ice is presumably quite stagnant, there occurs a series of surface lakelets, the crater-like basins of which have been hollowed in the ice. The largest of this series is somewhat elliptical in form, 200 feet long by 100 feet broad (plate x1x, figure 2), and filled with deep blue water in which miniature ice-bergs may be seen floating about. The southern and eastern banks of the lakelet are from 12 to 20 feet high and under cut, apparently by the melting action of the lake water. The northern and western banks have been acted upon more strongly by the sun, causing them to recede and the débris to slide down until the margins of the lake are filled and the ice banks veneered sufficiently to retard melting (plate x1x, figure 2). These banks are as steep as the débris can stand and from 25 to 30 feet in height. From the still steeper ice walls the gravel and small boulders are splashing into the water with a sound suggestive of considerable depth. The lake has no visible outlet and persists from season to season. Several similar lakelets, but smaller, occur in the same vicinity, some having their sides completely veneered with rock débris, which has checked melting and allowed the lakelet to become almost dry. These lakelets may have originated in marginal crevasses and been enlarged and shaped by melting, or they may have originated by surface melting over certain limited areas less well protected by débris covering. In the preceding discussion of débris cones it was shown how miniature basins might originate. In a stagnant portion of the glacier it is possible that the basins of such lakelets might arise in a similar manner from such a mound as that figured from the Wenkchemna Glacier (plate x1x, figure 1). The rock débris rolling or sliding to the base would leave the cone sufficiently bare to permit rapid melting to a depth at which the marginal débris would begin to slide back again. The accumula- tion of the débris in the basin would check further melting at the center, while the surrounding ice has lost, in proportion, a part of its débris. As observed by Russell upon the Malaspina, the surrounding ice would be lowered until the basin disappeared and what had been the centre of the basin would become the crest of a boulder mound. If conditions remained favorable, 7.e., sufficient thickness of stagnant ice and continuous surface ablation, the sides of the mound would become more and more steep, as it gained in height and the time would come when the bulk of the débris would slide or roll to the base, the ice core would be removed to the general level and a new basin would be started. For the larger lakelets the complete cycle would probably have to be reckoned in decades and centuries. k. Rock reflection (?). A final surface feature remains to be described, al- 58 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. though a satisfactory explanation has not been found. Observations were begun upon the Victoria in 1904 before the winter snow had disappeared from the lower half of the glacier, which is ordinarily bare in the summer. It was noted that as the surface boulders protruded through the snow a larger percentage of them showed melted areas upon their northern sides, the shape and size of which sus- tained a certain relation to the breadth, height, shape, and possibly position of the boulders themselves. Over the melted area the snow was removed, in whole or part, to the soiled surface of the glacier, so that the feature shows with much clearness in the photographs secured. The phenomenon was seen upon the Lefroy, as well as the Victoria, and sparingly upon the Wenkchemna in midsummer, near the névé lines. The same thing was also seen upon the snow of an avalanche which had descended from Mt. Whyte and carried along some small rock fragments, which were scattered over the surface. The block shown in plate xx1v, figure 4 is a gray quartzite standing 10 inches high and is 29 inches broad. The melted area has the same length as the rock and has a corre- spondence in outline. The farther right hand corner of the rock is somewhat lower than the general surface and the corresponding corner of the melted area is seen to be rounded and incompletely melted. Boulders showing the phenom- enon were not hard to find upon the Victoria, but were very abundant. The north-south axes of ten of the areas, selected at random, gave an average magnetic reading of N. 25.5° W., with less range than was shown in the case of the glacial tables. The magnetic declination of the region, as obtained by the Canadian Topographic Survey, is N. 25°5’ E., so that these areas are oriented with reference to the noonday sun, and might have been used for determining approximately the meridian and the magnetic declination. The natural infer- ence is that the phenomenon is due to the reflection of heat from the surface of the boulders, this action being at a maximum when the sun is upon the meridian. 3. Former ACTIVITY. a. Terminal moraines. Between the present poorly defined terminal moraine, described upon page 49, and Lake Louise there occurs a series of ancient terminal moraines which furnish evidence of the glacier’s former extent and greater activity. The first two of these moraines are remarkable in that they consist of massive blocks of quartzite and sandrock, tumultuously heaped together and without the usual filling of gravel, sand, and clay. The position of these is shown upon the map, plate 11. The spaces between the great blocks enable man, or animals, to creep in between and under them and they form an ideal home for the marmots. For moraines of a somewhat similar appear- ance, although probably different history, in the Mount Ktaadn region Prof. R. S. Tarr has used the expressive term “‘bear-den moraine.” ! The inner of these two moraines extends obliquely across the valley from the present nose, being partially overridden by the glacier and along the side of the valley nearly parallel with the oblique front. It consists of what were originally massive 1 Glaciation of Mount Ktaadn, Maine. Bulletin Geol. Soc. of Amer., vol. X1, 1900, plate 37. GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 59 blocks of quartzite, sandstone, and schist tumultuously heaped into a ridge 30 to 40 feet high. The sandstone and schist have undergone considerable disintegration, in place, forming more or less soil which supports a growth of moss, shrubs, spruce, and fir. The rings of growth, in the spruce and fir of the Lake Louise Valley, were found to average 0.884 mm., and, in the case of the averages for individual trees, to range fromo.s1mm.to1.26mm. As the tree matures the new rings are excessively thin; owing to the reduction in the relative amount of leaf surface, the scant precipitation, the short growing season, and the lack of direct sun light in a deep valley with a north-south trend. The largest tree found upon this moraine gave a circumference of 221 cm., at a distance of 50 cm. from the base, and should be approximately 400 years old. The material of this moraine is arranged in two main heaps, between which the glacial brook passes, that upon the eastern side having come from Mt. Lefroy and that upon the west from Victoria. After the formation of the moraine the glacier retreated up the valley to a point greater than that occupied by the present nose. From 300 to 800 feet farther down the valley there occurs the second of this type of moraines, the blocks consisting very largely of quartzite, lichen-covered and moss-grown, but not disintegrated. As in the case of the preceding moraine the blocks are disposed in two heaps, upon either side of the glacial brook, the bulk of it lying to the west, where it forms an oblique ridge 700 to 800 feet long, with a maximum breadth of 300 feet and a height of 70 to 80 feet. Made up of such coarse blocks and with no filling of sand, gravel, or clay the whole presents a very imposing mass and impresses one with the possible importance of glaciers as geological agents. The largest block seen had split in falling, measured 31X25 x15 feet, and was estimated to weigh 970 tons. The blocks are generally sharp and angular and have not been subjected to stream oriceaction. They were carried either upon the ice or within it and show almost no signs of ice abrasion. An occasional single face is glaciated but in such a way as to show that this was done when, in its original position, it formed the face of the cliff. Owing to the lack of soil the growth of shrubs and trees is scant. The largest spruce seen upon the moraine itself was estimated to be 450 years old, while another just beyond the outer edge was estimated at 580 years. Upon the side of Mt. Whyte just at the line of plates, there is a large collection of similar blocks, and appar- ently of equal age, which appear to have become stranded here while the others were undergoing transportation. It should be noted that the present Victoria is entirely incapable of making such a moraine now, no matter how prolonged the halt. The present terminal moraine, and the oldest of the series to be described, are essentially alike but very different from these great block, or bear-den moraines. The cliffs which contributed the bulk of the material, so far as we may judge from their favorable situation and the location of the blocks, have a north-northwest trend and the blocks fell from them to the eastward. Down the valley, a distance of one-quarter of a mile, there occurs a double detrital cone, derived from the opposite mountain slopes of Mt. Whyte and Castle 60 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. Crags. The slide from the latter slope is still in process of formation and consists of freshly broken angular fragments. That from Mt. Whyte is older and covered with spruce, fir, and willow. This material overlies, and almost conceals, a triple moraine, composed of boulders, gravel, and clay. The inner and higher ridge of the three curves regularly across the valley and in one place about 60 feet of it have been cut away by the drainage brook. It here has a breadth of too feet, a height of about 20 feet, and consists largely of a yellowish, stony till. Between it and the outer bear-den moraine the drainage stream has filled in with sand and gravel; forming a nearly level flat. Lower down the slope and 4oo feet distant, there is another morainic ridge, approximately parallel with the first, but made up more largely of boulders while 350 feet farther on there is a third ridge containing a higher percentage of yellowish clay. b. Lake Louise basin. This lake is roughly elliptical, with a major axis of 1} miles and a width of 1 to 2 of a mile, placed with its longer axis parallel with the valley (see plate 1 and plate xiv, figure 2). The chief irregularity in the outline is due to the presence of a rock slide from Mt. Fairview and to the delta deposits at the head. The level of the lake is given by the Topographic Survey as 5,670 feet above sea level. This level, however, fluctuates in the course of the season and from year to year, being some 15 inches higher in the spring, as a result of the rapid melting of the snow. Four determinations upon the inflow at the head gave an average of 80 cubic feet per second. Two measurements upon the outflow, through a rectangular orifice at the dam, gave an average of 88 cubic feet per second, the lake receiving a small additional flow from Mirror Lake and Lake Agnes. In midsummer, owing to the presence of the glacial sediment, the lake has a superb green color, but during the winter this has a chance to settle to the bottom and in the spring the color is more of a blue, the natural color of pure water. From the studies of Mr. W. D. Wilcox, reported in the paper previously cited (page 7), the basin of the lake is seen to be a U-shaped trough, with a maxi- mum depth of 230 feet just beyond the centre. This shows that the valley was excavated by ice and that, in all probability, the bottom of the lake is a glacially excavated rock-basin, similar to that of Lake Agnes, just west but at a higher level. Bedrock is found upon all sides of the lake, except about the foot, where there is the ground-morainic dam previously described (page 8) filling the valley to an unknown depth. At the head of the lake the valley walls are much contracted, being but 570 feet apart. They consist of a very firm quartzite, in the main, with a little slaty schist, dipping up the valley at an angle of ro° to 15°. This feature of the valley must have greatly contracted the ancient glacier passing through the gateway, caused it to thicken correspondingly and to vigorously gouge out its bed until it had a chance to again expand laterally. In this way we may account for the presence of the rock-basin, but should expect the deepest part of it to be somewhat nearer the head of the lake than is shown in Wilcox’s contour map. It is not at all improbable, however, that the deepest part of the rock-basin is really so located and that there has been a SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE SHERZER. PLATE XX. Scale 200 ! O 50 100 bite 300 400 ft. Map of delta, head of Lake Louise, by W. LL, Sherzer. Plane-table survey, July, T9094. Forrest Ross and Frederick Larmour, Field assistants De GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 61 filling of the lake bed here with glacial sediment and débris from the Mt. Fair- view slide, to the extent, at least, of 50 to 60 feet. c. Lake Louise delta. After the ancient Victoria permanently retreated from the head of the lake, there began the formation, at the head of Lake Louise, of a gravel, sand, and silt delta, which is a minimum measure of the amount of glacial erosion that has since been taking place in the upper part of the valley. This delta extends into the lake 400 feet, with an average breadth of about 300 feet, as shown upon the map, plate xx, that was prepared with a plane-table in July, t904. A shelf of fine sediment borders that portion above water and then drops off rapidly, forming a layer of unknown thickness over the bottom of the lake. Much of the delta is elevated but 10 to 12 inches above the lake level and is under water during high water stages of the lake. Portions of it are flooded during midsummer after periods of excessive melting. In this way the delta is gradually growing in height. Low, broad levees line the main stream. This comparatively small portion, which projects into the lake, is simply part of a very much more extensive deposit of glacial silt, sand, and gravel, which reaches up the valley for a distance of } to + of a mile and has a breadth of 500 to 600 feet. Over this very gradual slope the glacial drainage courses in three rapid, turbid streams, which unite into a single channel, 40 to 50 feet broad and one to two feet deep. Grasses and moss cover the lower, flat portion of the deposit, close set willow and spruce the central part, and isolated willows the upper gravelly region. The rock-slide from Mt. Fairview has encroached upon the lake as well as the morainic dam at the foot of the lake, upon which stands the chalet. Between this dam and the range of moun- tains in the background les the Bow River Valley, which supported a great trunk glacier, leading eastward from the mountains (plate xrv, figure 2). d. Lake Louise Valley. When the mountains were in process of making it is very probable that this valley began as a structural feature either as a trough between mountain folds, or from the opening of a joint in the rock strata. Before the coming of the glaciers it is probable that ages of stream action, aided by atmospheric weathering, deepened and broadened the original feature into a V-shaped valley. With the advent of the perennial snowfields a new geological agent entered, deepening the bed and broadening out the base so that the cross- section of the valley, particularly the lower half, assumed the characteristic U-shape of glacially excavated, or glacially modified valleys. An inspection of the general views of the valley, such as plate 1, shows a lower portion with steeply inclined, nearly vertical walls, while the upper portion has more flaring walls, the arms of a truncated v. This upper portion was glaciated to a height of about 9,000 feet above sea level, or some 3,000 feet above the valley floor, the walls being smoothed and fluted and the spurs evenly truncated; see the shoulder of Mt. Fairview at the right in plate xix, figure 2. It is not improbable that these more gentle, higher slopes represent portions of the original pre-glacial valley, produced mainly by the action of weather and running water, and not very materially modified by the ice. These slopes produced until they intersect may 62 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. be assumed to represent approximately the original valley before the ice invasion. The lower portion, with the very steep walls and broad base, probably represents that portion of the valley which was profoundly affected by the great ice stream that so nearly filled the valley. The destruction of the strata necessary to secure such a result was very probably accomplished by the disrupting power of the ice, known as ‘‘plucking.”’ e. Ancient till sheet. The rock débris was, in great part, delivered to the Bow Glacier and carried beyond the mountains. The finer portions, consisting of gravel, sand, and clay, with some cobbles and boulders, secured lodgment in certain favorable places, particularly near the mouth of the valley, and com- pacted by the great weight of ice formed the ground moraine, or sheet of till. From 75 feet to roo feet of this deposit have been exposed between the foot of the lake and the Bow River, but the maximum thickness was very probably much greater. It forms an irregular sheet, of unknown extent and thickness, reaching up to and under the modern glacier, mantling the actual rock bottom of the valley. It is entirely without stratification and the rock fragments are largely bruised and scratched. The color, as seen in the exposed sections, is a brownish-yellow, as the iron of the clay is being slowly oxydized. The more deeply buried beds would, undoubtedly, show more of the bluish-gray, which characterizes this material when it is fresh. CHAPTER IV. WENKCHEMNA GLACIER. 1. GENERAL CHARACTERISTICS. NESTLING close in behind the northern base of that grand array of peaks for which the Canadian Geographic Board has recently adopted the name Wenk- chemna Group lies the Wenkchemna Glacier. The name is of Sioux origin, w7k- chemna signifying ten, and was given the glacier by Mr. S. E.S. Allen, in allusion to its relation to the series of ten peaks upon which he bestowed the Indian numerals. These peaks, the highest of which has been rechristened Mt. Deltaform, with their high connecting ridges constitute here the great Continental Divide (plate xxi). Between them and Mt. Temple lies a broad valley originally called “* Deso- lation Valley”? by Wilcox, but now known as the Valley of the Ten Peaks. The glacier occupies the southern half of the upper third of this valley, and faces north, while the valley itself slopes eastward and then northeastward. In a direct line it lies only about six miles south-southeast from the Victoria, and may be reached by crossing the Mitre Pass, encircling the Horseshoe Glacier at the head of Paradise Valley and entering the Valley of the Ten Peaks by the Wastach Pass. The ordinary way of reaching the glacier, however, is from the chalet at the foot of Lake Louise, over a good trail to Moraine Lake, where a Summer camp is maintained by the Canadian Pacific Railway. From “Aaains peorydeisodo 7 uvipvursy ‘wopasy Ay “ey anyiay Aq “(qaez gzg't1) ajdway ayy yo quuams mor ‘Co6r ur paydeasojoyg "Syvag uay ay) Jo AaypeA ‘sabpoy, uBrpeuwy ‘aprary [eyuauqjuoy ayy, +) PUY YUDd | tuony advurvs cayeryp au ey LAL S Uva eal “yenqdan Wmsoyepa¢y “LON "9 °ON “SON “EON °Z ON, “AE IXN GAL VW1Id “UWAZAAHS—AVAAIMONN OL SNOILAGIALNOO NVINOSHLINS “XOOTEAN “AL “CT pur dapaay Ay ‘CG “y jo sdevut uodn paseq uorsar qusse[py “Mowse] xuUapery PUL ssoy ysa1t0.T aq syuvysisse pat ‘tobr ‘ysnsny ‘1azZIIYS “TT “Ay Sq uavrp puv pakaamg ‘saryooyy uvipeues ‘syvay vay jo Aaper ‘apr vutiayoyuaay jo dvyy syead 40 dnoids euUle4 4 Ua qq ats - : : cn . : “94S22'1| ; aS Wi40Jl1)aq “4 2928 yenidan 33.879'0! 8 2 e ~ & ° 9 =z x = + A aanaan 001 0 oos 0001 9ye9Ss : IMAXXN GLW Td “TAZ AHS AOU A LAOSN OL SNOLMMISLNOD. NVINUSH TICS GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. O7 to support a growth of raspberries, blueberries, etc., and also a few spruce 8 to 12 inches in diameter. The bulk of the material lies to the west of the glacial brook and was derived from the eastern side of Glacier Crest and Mt. Lookout, the cliffs of which have a northwest-southeast trend. The shape of the moraine and the way in which the blocks have been deposited indicate, as noted by Prof. Penck at the time of his visit, that the moraine was built conjointly by the former Ilecillewaet and Asulkan glaciers. The blocks contributed by the Asulkan came from the western side of Glacier Crest and the Asulkan Ridge, and are much less in amount than those derived from the eastern side and transported by the Illecillewaet. The largest tree found growing inside of this moraine was calculated to have been 520 years old when it died and from the condition of its wood and bark to have been dead about 30 years. CHAPTER, VII. ASULKAN GLACIER. 1. GENERAL CHARACTERISTICS. LyinG at the head of the Asulkan Valley, upon the opposite side of Glacier Crest from the Hlecillewaet Glacier (see plates Xxx and xxwxtt), is located the Asulkan Glacier. Its broad expanse of snowfield extends in a semicircle from Asulkan Ridge, past Leda, Pollux, and Castor to the northern extremity of the Dome, faces to the northward, and under the sunlight is of dazzling whiteness. The name is of Cree Indian origin and is generally said to mean ‘‘goat,”” but Iam assured that it really means ‘“‘bridge.’’ The nose of the glacier lies about three miles from the station, reached by a picturesque and easy trail, except in the upper part, where the trail becomes steep. The glacier itself may be safely visited and studied without a guide, but no one should venture upon the névé unattended, as it 1s very treacherously crevassed. This glacier is the smallest and the most southern and western of the series here reported upon, its nose lying in longitude 117° 28’, west and latitude 51° 13’, north. The glacier consists of three streams, two of which are closely united and the third separated from the other two except in the névé region where they are allunited. The length of this third stream, measured from the Asulkan Pass, is about two miles, of which the first mile is névé and the lower mile is ordinarily free from snow during the summer season (plate xxx1x, figure 1). The breadth of the dissipator is about 1,800 feet in the upper part, but about the middle of its course it makes an abrupt bend from the north to the northeast and tapers gradually to a sharp nose. The eastern margin curves around gradually to the nose, while the western side is curiously straight, cutting diagonally across what appears to be the natural course of the glacier. There seems no apparent reason for this abrupt bend in the glacier and for the remarkably straight western margin of the ice, but the explanation will appear in what follows. This peculiar contouring of this stream gives it the general form of a bear’s paw—a polar bear 98 GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. —in which the straight margin represents the sole. From near the heel of this foot there extends southward a long, slender ridge of glaciated rock, carrying more or less morainic matter, which separates this eastern ice stream from the double ice mass immediately to the west (plate xxx1x, figure 1). Judging from the line of crevasses and faulting across the névé, there lies another similar ridge, parallel with the first and about one-quarter mile to one-half mile to the west, which separates this mass into two streams, each having its own separate nose, as shown upon the map. This ridge is apparently the continuation of the line of bedrock exposed along the right-hand margin of the westernmost ice stream. The névé line upon this glacier is about 7,000 feet above sea-level and the main portion of the névé lies between this altitude and 8,000 feet. From the Asulkan Pass (7,710 feet) to the nose of the easternmost stream the descent is 2,110 feet, or at the rate of 1,055 feet to the mile. The altitude of the nose is 5,600 feet, or some 800 feet higher than that of the Ilecillewaet, due apparently to the smaller volume of ice in the Asulkan and its dissipation at three separate points. The altitudes of the two higher noses to the west are about 6,000 feet, or the same as the Victoria. So far as may be judged from the crevasses and faultings, the ice responds fully to the irregularities in its bed which indicates that it is relatively thin. The surface slope of the western and middle streams is very steep; that of the easternmost, or main, stream is much more gentle, amounting in places to not more than 6°. Toward the nose the inclhnation becomes 25° and then drops off to but a few degrees, so that it may be readily ascended. Upon either side of the stream the marginal slopes are steep for a few hundred feet back from the nose. 2. PIEDMONT CHARACTERISTICS. If the reader has covered Chapter IV of this report he will have recognized already the piedmont character of the Asulkan, which consists of three com- mensal streams. The glacier is of peculiar interest because it is an illustration of a piedmont glacier in its senile condition. It has reached its second childhood and now illustrates the disintegration of a piedmont glacier into the component streams, the union of which in its youth gave rise to the glacier itself. Every glacier of this type begins with the independent development of a system of Alpine glaciers, coérdinate in importance, which coalesce laterally into a single ice mass. The length of the glacier is determined by the length of the separate streams composing it and its breadth by the number of streams and their com- bined breadth. In the final stages of dissolution, which must come sooner or later in its life history, the piedmont glacier shrivels back into the original Alpine components. The eastern tributary has already separated sufficiently so that it may be regarded as an independent glacier. The other two have separated for a distance of about one-fourth of a mile, but the separation will not be com- plete until the ridge of rock above noted has appeared at the surface of the ice. The middle stream covered the ridge of rock, now exposed between it and the eastern stream, and sent its nose down the valley as far as the drainage brook SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE—SHERZER, PLATE XXXIX. Mt. Donkin and Asulkan Pass. Leda. Pollux, Castor. Fic. 1.—General view of Asulkan Glacier in 1902. Copyrighted, 1902, by the Detroit Photographic Co. Donkin, Castor and Pollux. Dome. Ronney. Fic, 2,.—The Asulkan glaciers and snowfields from Avalanche Mt. (elevation 9,387 feet), showing a decadent piedmont glacier. Photographed in got by Arthur O, Wheeler. GLACIERS OF THE CANADIAN ROCKIES AND SELKIRKS. 99 shown upon the map. There it formed a series of terminal moraines upon its eastern side, the eastern component standing at about the same level and forming a similar series. The sudden bend noted in the eastern component, one-half mile back from the nose, resulted from its pressure against the side of the middle stream which it was unable to force aside. Conjointly they formed a straight medial moraine from the bend to the nose. Upon the more rapid retreat of the middle stream and its disappearance from this part of its bed, this moraine became the left lateral of the easternmost stream (plate xxx1x, figure 1), and was of such a massive character that it has continued to deflect the ice from its natural course. Inplate xxx1x, figure 1, we have shown nearly the entire eastern and middle streams of the Asulkan, and a portion of the névé of the western.