Popular Science Monthly/Volume 68/January 1906/The Geologic Survey of Alaska

From Wikisource
Jump to: navigation, search
THE GEOLOGIC SURVEY OF ALASKA[1]

By ALFRED H. BROOKS

U. S. GEOLOGICAL SURVEY

A DECADE[2] ago the United States Geological Survey began its work in Alaska by sending a party of only three men to the territory, whereas in the past summer twelve parties, with an aggregate membership of fifty odd men, were there engaged in geologic surveys. Even this rapid expansion is hardly commensurate with the size of the territory and the importance of the mineral resources, the development of which the geologic investigations aim to aid. Alaska's 600,000 square miles are much spread out, stretching to a width of 2,400[3] miles and to a north and south length of 1,100 miles. Were this vast area, which is equal to two and a half times that of Texas, the cold, barren waste so often pictured it would be of small practical import as to when it should be surveyed. But Alaska has large and constantly growing mining interests, and it is the demand of these which has influenced congress to increase the appropriation for geologic surveys from $5,000 in 1895 to $80,000 in 1905.

Even the present appropriation is less than one per cent, of the annual gold production, which has increased from $1,866,645 in 1895 to $9,300,000 in 1904, and is far from having reached its maximum. Nor does the gold production tell the whole story; the value of the copper and silver annually mined now exceeds half a million dollars, and the output of the former is rapidly increasing. There is in Alaska also some coal mining, though this industry has not yet attained its rightful importance. The territory contains some very valuable bituminous coal fields. Prospective mineral wealth also lies in Alaska's tin ores, oil fields and gypsum beds, which have all been sufficiently exploited to indicate their probable commercial importance. The time will come when iron and zinc ores are mined in Alaska, and its immense granite areas will yield building stone to the Pacific coast.

Applied geology touches the activities of mankind at many places, but primarily, of course, in the vocation of mining. It is on the basis of geologic knowledge that soils must be classified, and this, in turn, together with the topography, determines the distribution of animal and vegetable life. In the Alaskan work of the geological survey, practically only the needs of the miner have to be considered. The agricultural and allied interests of the territory are being investigated by other governmental bureaus.

The attitude of the public towards the science of applied geology has so materially changed during the last decade that its practical value is now generally recognized, though a few still remain skeptical as to the commercial importance of the results. This attitude exists partly because geology (not being an exact science) has often been brought into disrepute by dilettantism, if not downright charlatanism. Among technicians, however, it has become generally accepted that with the increase of geologic knowledge of a given region comes a decrease of the element of chance in the discovery of ore bodies. Intelligent prospecting should and can be based upon scientific principles, for a properly executed geologic map will define the areas within which there is a probability of finding a given kind of mineral deposit. The veriest tyro need hardly be told not to seek coal in a granite, nor would he ordinarily prospect for gold in a region of coal-bearing rocks. The geologist carries this classification of the rocks still farther, and may thereby prophesy the occurrence of ore deposits in a region which he has mapped. The actual discovery of ore is no part of the work of the geologist; this demands detailed examinations and often excavation, such as only individual property-owners can make. This point is emphasized because, even among the well-informed, the question is often raised why the geologist does not more often discover mineral deposits. Lack of appreciation of the relation of applied geology to mining is traceable in part to the stories current of the bonanzas discovered by an accident to a mule, the luck of a tenderfoot or the appetite of birds, which are in the popular mind so interpreted as to throw discredit upon geologic science.

The intelligent prospector has learned that even at best his chance of success is small; but is much increased by a knowledge of the geology of a region he intends to explore. With a better understanding of the laws which govern the occurrence, origin and distribution of mineral deposits the old-fashioned, picturesque haphazard prospector, to whom it must be admitted we owe the discovery of most of our mineral wealth, will disappear, and the technician will take his place. This is probably the last field where the specialist will crowd out the man of purely practical training; but it is a substitution bound to take place in time.

A geologic survey has two objects: first, the increase of scientific knowledge, and, second, the application of this knowledge to the mining industry. The purely scientific investigations include many subdivisions and ramifications that can not here be considered, but it will be evident, even to the layman, that, while any part of the earth's surface remains geologically unmapped, there will be a hiatus in our knowledge, which may prevent broad generalizations.

In Alaska special attention has been given to the second field of activity, namely, the application of geology to the needs of the miner. This is in part the influence of the growth of economic work in both state and federal surveys during the last decade, but more specially because the appropriation is specifically made for the investigation of the mineral resources of Alaska. With this end in view, a score of publications dealing with the occurrence and distribution of the mineral deposits of the territory have been issued. It has been the policy to make public the results attained while yet the investigation is in progress, in the belief that even an incomplete knowledge of the geology would be of value to the miner. With this end in view, bulletins treating of the occurrence of coal, petroleum, tin and copper have been issued, as well as many which are devoted to the gold deposits. These preliminary reports have found favor with the mining public because of their timely appearance, and have forestalled criticism of delay in issuing the more elaborate treatises.

The danger in issuing such reports is that the less intelligent miner may accept tentative statements as final conclusions, and this may lead to losses. It is impossible to escape this danger entirely, for to avoid all opinions which are not definitely established by the facts in hand, shears a geologic report of much of its usefulness to the practical man, who wants the expert who has visited the field to prophesy what the conditions of occurrence of the ore bodies are likely to be.

While applied geology has been kept constantly to the front in the Alaskan investigations, the study of the broader problems, be they stratigraphic, physiographic or paleontologic, has by no means been lost sight of. The purpose of every geologist sent to the north has been twofold: first, the gathering of information which will directly advance the mining interests, and, secondly, the study of the purely geologic problems. It has been the policy to defer the publication of purely scientific results until a larger number of facts have been accumulated, and the theoretic discussion can be supported by the knowledge of a wider field. Thus only the salient outline of the stratigraphic succession has been put in print, but meanwhile a number of specialists have been carrying on paleontologic and stratigraphic studies to determine definitely certain geologic horizons to which all future work can be referred. In the same way, though a large petrographic collection has been amassed, its detailed study has been deferred until a broader knowledge of the field relations can be secured. Other branches of geologic science have been treated in a similar way. It is hoped that in this way a basal knowledge of the larger problems will be available in a few years, on which to found detailed studies with more assurance.

A geologic map can not be constructed without an adequate base map. As in the west there were practically no adequate and systematic topographic surveys of the interior before the organization of state and federal geologic bureaus, it naturally fell to these organizations to construct base maps for their work. The same holds true of Alaska, where the conditions have been even less favorable because of the many large areas which have been practically unexplored. It is no exaggeration to state that, at the inception of this work, there was not a single area, large or small, except at the actual coast line, of which there was a map of even approximate accuracy. A few explorations had, to be sure, been made; but the resulting maps were absolutely worthless for geologic mapping and of little use for anything else. Thus the survey of one of the largest rivers of the territory proved to be thirty to forty miles out in location, near-by mountains, whose altitude had been indicated at seventeen to nineteen thousand feet, proved to be less than fifteen thousand feet in altitude. It is evident, then, that an investigation of the mineral wealth had to be preceded or accompanied by accurate geographic surveys. Maps were needed not only by the geologist, but also by the prospector and miner. The mining interests demanded that watercourses should be surveyed and passes and watersheds explored. During the Klondike excitement of 1898 there were at least 10,000 people in Alaska who were attempting to follow unexplored routes and to navigate unmapped rivers. It is no exaggeration to state that the cost of these fruitless efforts aggregated several million dollars, many times the cost of a survey of the entire territory. In view of these conditions, much of the money, therefore, appropriated for the investigation of Alaska's mineral wealth was necessarily used for explorations and for topographic surveys.


Older Explorations and Surveys.

It will be well to review briefly the progress of Alaskan explorations previous to the time when the Geological Survey entered this field. When, in 1867, Russia ceded all her North American possessions to the United States, so little was known of this province that it is hard to understand what was the basis for the purchase price of $7,200,000. To Russia Alaska had been a field for private speculation rather than an integral part of the empire. First, ravaged by the itinerant and half savage fur trader, and then, for two thirds of a century, in the complete control of an incorporated company, the territory was probably not regarded as a valuable asset by the Czar and his advisers. To be sure, during the last two decades of the Russian dominion, naval officers had been been sent from St. Petersburg to govern the colony, and a semblance of imperial authority was thereby kept up; but this control was limited to but a fraction of the coast line and to the lower courses of some of the larger rivers. The Russian posts were all stockaded, and the powers of the governor were practically limited to the range of his crude artillery. The Russians made some coastal surveys, a few inland explorations, and one abortive attempt to find gold, and this was as far as they went in the study of the resources of their distant colony.

William H. Dall and his associates of the Western Union Telegraph expeditions, in 1865-7, did much toward gaining a knowledge of the vast interior. The navigators of various nationalities, who had explored and charted the coast line, had gathered fragmentary data of the natural history and geology, and these, together with the specimens collected by them, had found their way to European museums, where they were examined and described by scientists. One of these, by name Carl Greywingk, a German, with infinite pains and thoroughness, compiled all the notes on the geology and geography of Alaska, then known as Russian America. He went so far as to publish a geologic map of a part of the territory—a very remarkable piece of work, considering the fragmentary character of his data.

It appears that the people of the United States were even more indifferent to Alaska than the government at St. Petersburg. There had been strong opposition to its acquisition, both by those adverse to any territorial expansion, and also by a much larger number, who believed that we were purchasing a barren waste of ice and snow, whose only resource was furs. After the treaty had been signed and military occupation had been taken, the general opinion seemed to be, even among the annexationists, that we had fulfilled our duties toward the new possession. A policy of neglect of this northern province has been consistently followed almost to the present day. It was sixteen years after its annexation that Alaska was given a civil government, it was thirty-three years before it was given a complete civil code, and over a quarter of a century elapsed before systematic steps were taken toward investigating its resources.

In the meantime, individual enterprise did much toward opening the province to civilization. A strong corporation had succeeded to the interests of the old Russian American Fur Company, and, though it inherited most of the prejudices of its predecessors against the introduction of any new enterprises, nevertheless its agents, bent only on the acquisition of furs, did not a little to find new fields for the prospector.

The real exploration began with the advent of the restless gold seeker. The search for gold on the west coast of our continent, begun by the discovery of the California placers in 1848, gradually moved northward into British Columbia, and by 1870 had reached the Cassiar district, close to the Yukon watershed. It was the men trained in the placer fields of British Columbia who first prospected in Alaska, and who by 1880 were mining in the Juneau region, and a few years later in the Yukon basin itself. These facts are here set forth because it was the prospector who made almost the first observations on the geology of the interior.

There were, to be sure, a number of exploring expeditions which, considering the resources at their command, had achieved important results, but they were geographic rather than geologic. Thus Frederick Schwatka, U.S.A., following the route blazed out by early prospectors, crossed the Chilkoot Pass in 1883 and made his way down stream to the mouth of the Yukon. In 1885 H. T. Allen, U.S.A., explored the Copper, Tanana and Koyukuk rivers, while about the same time G. M. Stoney, U.S.N., and J. C. Cantwell, U.S.R.C.S., led expeditions which penetrated the Arctic watershed of Alaska. The Canadian geologists, George M. Dawson and E. G. McConnell, had meanwhile explored the Canadian part of the Yukon basin. In 1890 I. C. Russell, of the Geological Survey, reconnoitered the geology of the Yukon, while attached to a coast survey party whose aim was to determine the position of the international boundary. Schwatka made a second trip into the interior in 1891 and this time was fortunately accompanied by C. W. Hayes of the U. S. Geological Survey, who made important additions to both geographic and geologic knowledge. Since the acquisition of the territory, the coast survey has been steadily at work charting the shore line, and much was learned of the geology of the littoral province by Wm. H. Dall, long attached to that organization. John Muir's fascinating accounts of the glaciers of Alaska attracted widespread attention, and a number of expeditions were sent north to study them.

By all these means considerable geologic data were accumulated, though actual surveys were entirely lacking. A few official publications made reference to the mineral deposits, but these statements were unreliable because based purely on compiled information, and were taken at their true value by the public, which paid small heed to reports of valuable ore bodies in this northern field.


Systematic Surveys.

As year after year placer gold continued to be brought from the Yukon region and mining along the coast continued to expand, there arose a demand for more exact information. This led to a small appropriation which enabled the United States Geological Survey to send G. F. Becker and Wm H. Dall north to study the coal and gold deposits along the Pacific coast in 1895, while the following year J. E. Spurr, with two others, visited the gold placers of the Yukon. These two expeditions represent practically the beginnings of geologic surveying in this province.

Public attention was focused on Alaska by the discovery of the rich placers of the Klondike in 1896. Though these deposits lay in the Canadian-Yukon, it was close to the boundary, and the public generally regarded all of Alaska as lying within the gold field. Congress in 1898 increased the appropriation for Alaskan surveys and has since that time been liberal in supplying funds for this purpose.

There was an urgent demand for immediate information about routes, conditions of travel and occurrence of mineral wealth, on the part of the thousands who had started, or were about to start, north. Plans had to be formulated and parties organized in great haste, for the money did not become available until about the end of February. The task which confronted the Geological Survey was far from being easy. But little was known of this vast region which stretched toward the pole, much of which was locked in the ice over half the year. The field of operations could be reached only by long journeys by sea and land, and there was little in the way of experience to base the plans upon. Thanks to Spurr's journey into the Yukon, something was known of the conditions of travel, and the first season's plans were largely formulated by him. It appeared that the most important work was to make explorations to determine the geographic features and, as far as possible, to establish the distribution of the placer gold. Detailed surveys were out of the question; with the funds available they could not be made rapidly enough to meet the public demand. Moreover, so little was known of the region, that it was impossible to make choice as to which were the more important districts. It was, therefore, necessary to precede areal surveys by a system of explorations. Such had been the procedure in the western part of the United States during the preceding half century. The explorer was the first in the field, and it was only after the unknown regions had been honeycombed by many explorations that areal surveys were undertaken.

The routes leading inland from the coast appeared of first importance, and hence received the first attention. A bold mountain barrier stretches along the entire shore line of Alaska, as far west as Cook Inlet, and, previous to 1898, inland travel had crossed the barrier only at Chilkoot Pass, which leads to. the Yukon through northern British Columbia. To the west two large rivers, the Alsek and the Copper, empty into the Pacific. Both had been traversed by white men and reported as unnavigable. Of a third, the Sushitna River, emptying into Cook Inlet, little was known. The problem was to seek a feasible route which should avoid traversing Canadian territory, and an important part of the first year's plan was explorations looking to this end.

In cooperation with the War Department, one geologist explored inland from Prince William Sound, while another mapped a route from the head of Cook Inlet. A Geological Survey party carried on an exploratory survey up the Sushitna River and discovered a low pass into the Yukon basin. The Alaskan Range, which lies west of Cook Inlet, was traversed by another party, which found a broad pass into the Kuskokwim, which it descended, and, making a broad circuit, reached the Pacific coast again after traversing the Alaskan Peninsula. Two parties crossed to White Pass, then being used by thousands of gold seekers, and descended the Lewes and Yukon rivers in canoes. One of these ascended the White River, portaged to the Tanana, and continued down that stream to the Yukon. The other surveyed an area of about 2,000 square miles adjacent to the International Boundary and lying close to the Klondike gold fields.

The personnel of the four expeditions last mentioned included a geologist and a topographer, the senior of the two being in command. These officers were selected from the staff of the survey, among those who had had from five to twenty years of training and who were believed to have special aptness for exploratory work. From four to six canoeists, cooks, etc., completed each party, and these were picked among those who had rendered faithful services to the Geological Survey in other fields. It was important that they should be such men as could be relied upon in emergency, and particularly such as would not desert the party during a gold excitement.

As most of the surveys were to be along rivers, canoes were determined upon as means of transportation, and careful consideration led to the choice of those of the voyageur type, built in Canada. These boats, which were propelled with paddles and poles, combined the quality of staunchness with lightness and durability. A canoe from eighteen to nineteen feet long, weighing about one hundred and twenty five pounds, was provided for every two men. It would carry a load of half a ton, and could be transported across a portage by its crew. The camp equipment, of the simplest character, included a sleeping bag for each man, a small mosquito-proof tent for every two men, a light cooking outfit, axes and a few tools. Not the least important part of the equipment was the repairing outfit, including some strips of cedar which were carried in each canoe, for the boats were so light that it was impossible to escape occasional injuries when running rapids. A light carbine with a hundred rounds of ammunition was carried in each canoe. The topographer was provided with a light theodolite and plane-table, while the geologist carried only a few hand instruments and cameras. Each member of the party was obliged to limit his personal baggage to the barest necessities; but was provided with mosquito-proof head-dress and gloves. The equipment of six men, aside from eatables, on a journey of four to five months, did not exceed 400 pounds in weight.

For the first season's work the provisions were limited to a very simple ration, consisting of little more than bacon, beans, flour and coffee, with a little butter, sugar, dried fruit and some farinaceous foods. The simplicity of the rations made it possible to reduce its weight to less than three pounds per man a day. Experience has shown, however, that there is economy in carrying more variety of food, as it keeps the party in better health and spirits. All perishable supplies were double-sacked and made absolutely water-proof. The wisdom of this precaution was many times made evident when the canoes were overturned or injured.

The methods of travel were practically the same for all the parties.

PSM V68 D054 Map of alaska illustrating progress of exploration up to 1904.png
1. Map of Alaska, illustrating progress of exploration up to 1904.

Up-stream journeys were made by dragging the canoes with ropes, called 'tracking,' by which from two to ten miles a day could be accomplished, depending on the swiftness of the current and the character of the banks. If conditions were favorable, recourse was had to poling, by which much better time can be made. When the head of canoe navigation was reached, explorations into another watershed were made and a portage route determined upon. Then, if necessary, a trail was chopped and bridges built. Finally, the whole outfit was carried over by the members of the party. The longest portage made by a survey party was eighteen miles; but the work of transporting half a ton of supplies for such a distance is almost heart-breaking.

The methods of survey were determined more or less by the means and rapidity of travel. In most cases it was possible to make a fairly
PSM V68 D055 Map of alaska showing unexplored areas in 1895.png
2A. Map of Alaska, showing unexplored areas in 1895.

accurate reconnaissance map, with elevations indicated by contours; but where time pressed, a canoe traverse, with estimated distances, was substituted. Fortunately it proved possible to carry a rough triangulation, checked by latitude and azimuth observations, throughout much of the explored regions. The topography was sketched, on a field scale of about three miles to the inch, with the aid of a plane-table. Altitudes were determined as far as possible by vertical angles, but in many instances depended solely on the readings of aneroid barometers. Contours were sketched at intervals of 200 feet, or, if the topography was very rugged, 500 feet. In some cases it was possible to run stadia lines along the rivers, and salient topographic points were located by intersections. Though some of the journeys were accomplished under exceeding difficulties, in no instance were the surveys entirely interrupted.

The movements of the party were guided more by the requirements of the topographic than of the geologic surveys, and the geologist was perforce required to get such information as he could. Continuous series of notes were kept and specimens were assiduously collected. Special attention was given to the occurrence of placer gold and other metalliferous deposits, but all phases of geologic problems were studied as far as circumstances would permit. Probably the most important scientific results were those that had to do with the general physiographic problems. In most cases only the broader features of the stratigraphic succession could be determined, but even these results, bearing as they did on the geology of an important part of the American continent, proved of value. The work that has since been done has shown that it is in Alaska that we must seek the meeting-point of the stratigraphy of the old world and the new.

The methods and plans for the first season's work have been presented in some detail, as they afford an insight into the difficulties encountered and the character of the work. During the following winter the more important economic results were thrown into popular form for immediate publication. It is no exaggeration to state that, had it been possible to give to the public a year earlier the information obtained during this first season, i. e., before the Klondike rush began, hundreds of thousands of dollars might have been saved: first, by directing the inland travel along the best routes, and, second, by furnishing a clew to the general distribution of the placer gold.

Thanks to the increased knowledge of the conditions of travel, and of the general geography, it was possible to direct the second season's work much more intelligently. It was discovered that horses could be used, which gave the parties far more mobility. During this season the explorations of the Yukon basin continued, and an examination of the newly discovered Nome placers was made. The latter, then thought to be a mere incident in what was considered more important work, proved to be of first interest to the public. A brief account of this gold field was published and placed in the hands of a large percentage of the thousands who started for Nome in the spring of 1900.

PSM V68 D056 Map of alaska showing unexplored areas in 1905.png
2B. Map of Alaska, showing unexplored areas in 1905.
 

At the opening of the third year, explorations had been carried over so large an area that it seemed wise to defer their continuance until some areal surveys could be executed. These were so vigorously pushed that at the end of the summer nearly 15,000 square miles had been mapped. Since that time the areal work, both geologic and topographic, has held first place, though explorations have not been entirely neglected. The most notable of the explorations was made in 1902, when a small party, under the leadership of W. J. Peters and F. C. Schrader, starting in the dead of winter, made a 1,400-mile journey with dog teams. When the ice broke they continued their explorations in canoes, reached the arctic divide, portaged across and descended the Colville River to the Polar Sea. There thev skirted the coast westward, rounded Point Barrow, the northernmost cape of Alaska, and finally reached Nome.


Results.

A comparison of the two maps here reproduced will indicate the progress of the areal surveys, and this matter is summarized in greater detail in the following table.

Sq.Miles
Explorations by U. S. Geological Survey 80,000
Geologic and topographic reconnaissance surveys 60,000
Explorations by other departments 50,000
Coastal province, shore line surveyed by coast survey and some geological surveys made by geological survey
120,000
Unmapped and practically unexplored 310,000
Total area of Alaska 620,000


Besides this about one thousand square miles have been surveyed in great detail. The above statement does not include the extensive special investigations of mineral resources which have been made, for which about twenty per cent, of the total appropriations has been used.

It is difficult now to realize how little was known of Alaska previous to 1896. The general courses of the larger drainage features were laid down on maps, but only in a very crude way. The coastal mountains were known, but the two great inland ranges, one of which contains the highest peaks on the continent, were hardly indicated on any map. Only a few of the passes were known and the altitude of not a single point away from the coast had been established. Now all but two of the larger rivers have been surveyed, and contour maps have been made of over 150,000 square miles. All of the larger geographic features have been outlined by the network of explorations which have been extended over the entire territory. There are no new mountain ranges to be discovered, though there are several which are but imperfectly known.

In the purely geologic work the results are still more striking. While a decade ago only a few facts about the geology of the coast province was known, it has been possible now to prepare a preliminary map of the geologic features of over half the territory. The stratigraphic studies are of still greater interest, for they have shown the presence of many horizons in northwestern America that were previously unsuspected.

The economic results have been touched upon in the previous pages. The proof of their comprehensiveness lies in the fact that there is not a single mining district in Alaska which has not been reported upon. An inquiry in regard to the mineral resources of any part of Alaska, coming to the office of the survey, is now met with a printed report containing the latest and most authentic information.

While much has been accomplished, much remains to be done. Over half the territory has not been covered by even reconnaissance maps. Even these will not suffice in regions of important mineral production, where often hundreds of thousands of dollars are being invested, and detailed surveys, comparable to those made in the states, are demanded. Railways are in construction, involving expenditures of millions of dollars, and, though these are being built without any direct governmental aid, such as is being extended in the Philippines, the capitalists who are financing them have a right to expect that the government will at least explore routes and furnish reliable information regarding the resources of the region to be traversed. It was this liberal policy which hurried the construction of the transcontinental lines a generation ago. There are parts of the territory which have considerable prospective agricultural value, and their settlement will be hastened, if their topography and resources are made known. Roads must be constructed, and this can only be properly done on the basis of a full knowledge of the geology and topography.

In its relation to the federal government, Alaska differs from any other possession of the United States. Though heavily taxed, the 30,000 white residents have no voice in the making of their laws. Porto Ricans and Hawaiians have territorial government, the Filipinos have their commission, but Alaska must depend entirely on the benevolent paternalism of a legislative body 5,000 miles away. In this northland there are thousands who have been struggling with adverse conditions to open up a new land, who have thereby benefited the whole country. These people have a right to expect that the people of the United States will come to their aid in the development of Alaska.

  1. Published by permission of the Director U. S. Geological Survey.
  2. It will be shown below that members of the Geological Survey were sent to Alaska before 1895, but these were either detailed to other government bureaus, or were attached to private expeditions.
  3. This is about the distance from Savannah to Los Angeles.