An Expedition to Mount St. Elias, Alaska

The surface of the névé is white, except near its lower limit in late summer, where it frequently becomes covered with dust blown from neighboring cliffs. It is almost entirely free from moraines, but at the bases of steep slopes small areas of débris sometimes appear at the surface when the yearly melting has reached its maximum. The absence of moraines is accompanied by an absence of glacial tables, sand-cones and other details of glacial surfaces due to differential melting. Streams seldom appear at the surface, for the reason that usually the water produced by surface melting is quickly absorbed by the porous strata beneath; yet the crevasses are frequently filled with water, and sometimes shallow lakes of deep blue occur at the bottoms of the amphitheatres and form a marked contrast to the even white of the general surface. Crevasses are present or absent according to the slope of the surface on which the névé rests. In the crevasses the edges of horizontal layers of granular ice are exhibited, showing that the névé down to a depth of at least one or two hundred feet is horizontally stratified. In the St. Elias region the strata are most frequently from ten to fifteen feet thick, but in a few instances layers without partings over fifty feet thick were seen. The surface is always of white, granular ice, but in the crevasses the layers near the bottom appear more compact and bluer in color than those near the surface.

Some of the most striking features of the névé are due to the crevasses that break their surfaces. The orderly arrangement of marginal crevasses and of the interior crevasses at the rapids in the Seward glacier have already been referred to; but there are still other crevasses, especially in the broad, gently sloping portions of the snow-fields where the motion is slight, which, although less regular in their arrangement, are fully as interesting. The crevasses on such slopes generally run at right angles to the direction in which the snow is moving. On looking down on such a surface, the breaks look like long clear-cut gashes which have stretched open in the center, but taper to a sharp point at each end. The ability of the névé ice to stretch to a limited extent is thus clearly shown. The initiation of the crevasses seems to be due to the movement of the névé ice over a surface in which there are inequalities of such magnitude that the ice cannot stretch sufficiently to allow it to accommodate itself to them, so that strains are produced which result in fractures at right angles to the line of general movement. Crevasses found where the grade is gentle vary from a fraction of an inch to 10 or 15 feet in width, and are sometimes two or three thousand feet long. Broader gulfs are seldom formed unless the slope has an inclination of 15° or 20°.

The grandest crevasses are in the higher portions of the névé, and occur especially on the borders of the great amphitheatres. In such situations the crevasses are usually fewer in number but are of greater size than in equal areas lower down. A length of three or four thousand feet and a breadth of fifty feet or more is not uncommon. The finest and most characteristic glacial scenery is found among these great cañon-like breaks. Standing on the border of one of the gulfs, as near the brink as one cares to venture, their full depth cannot usually be seen. In some instances they are partially filled with water of the deepest blue, in which the ice-walls are reflected with such wonderful distinctness that it is impossible to tell where the ice ends and its counterfeit begins. The walls of the crevasses are most frequently sheer cliffs of stratified ice, with occasional ornamentations, formed of ice-crystals or a pendent icicle. After a storm they are frequently decorated in the most beautiful manner with fretwork and cornice of snow. The bridges spanning the crevasses are usually diagonal slivers of ice left where the clefts overlap; but at times, especially in the case of the larger crevasses, there are true arches resembling the Natural Bridge of Virginia, but on a larger scale, spanning the blue cañons and adding greatly to their strange, fairy-like beauty. The most striking feature of these cracks is their wonderful color. All tints, from the pure white of their crystal lips down to the deepest blue of their innermost recesses, are revealed in each gash and rent in the hardened snow.

Above the snow-line all of the mountain tops that are not precipitous are heavily loaded with snow. Where the snow breaks off at the verge of a precipice and descends in avalanches a depth of more than a hundred feet is frequently revealed, but in the valleys and amphitheatres the snow has far greater thickness. Pinnacles and crests of rock, rising through the icy covering, indicate that the thickness of the névé must be many hundreds of feet.

There are no evidences of former glaciation on the mountain crests which project above the névé fields. There are no polished and striated rock surfaces or glaciated domes to indicate that the mountains were ever covered by a general capping of ice, as has been postulated for similar mountains elsewhere. When the glaciers had their greatest expansion the higher mountains were in about their present condition. The increase in the volume of the glaciers was felt almost entirely in their lower courses.

The first feature that attracts attention on descending from the névé region to the more icy portion of the glaciers is the rapid melting everywhere taking place. Every day during the summer the murmur and roar of rills, brooks and rivers are to be heard in all of the ice-fields. The surface streams are usually short, on account of the crevasses which intercept them. They plunge into the gulfs, which are many times widened out by the flowing waters so as to form wells, or moulins, and join the general drainage beneath. The streams then flow either through caverns in the glaciers or in tunnels at the bottoms. While traversing the glacier one may frequently hear the subdued roar of rivers coursing along in the dark chambers beneath when no other indication of their existence appears at the surface. When these subglacial streams emerge, usually near the margin of the ice, they issue from archways forming the ends of tunnels, and perhaps flow for a mile or two in the sunlight before plunging into another tunnel to continue their way as before.

The best example of a glacial river seen during our exploration was near the western border of the Lucia glacier. It is shown in the illustration forming plate 12, which is reproduced mechanically from a photograph. This Styx of the ice-world has been described on an earlier page. The lakes formed at the southern end of nearly every mountain spur projecting into the Malaspina glacier discharge through tunnels in the ice, which are similar in every way to those formed by the stream already mentioned.

In the beds of the glacial streams there are deposits of sand and gravel, and when the streams expand into lakes these deposits are spread over their bottoms in more or less regular sheets. When streams from the mountains empty into the lakes, deltas are formed. While these deltas have the same characteristics as those built in more stable water bodies, many changes in detail occur, owing to the fluctuation of the water level.

One of the tunnels leading to a dry lake-bed at the end of the Hitchcock range was explored for several rods and found to be a high, arching cavern following a tortuous course, and large enough to allow one to drive a coach and four through it without danger of collision. Its floor was formed of gravel and bowlders, and its arching roof was clear ice. Here and there the courses of crevasses could be traced by the stones and finer débris that had fallen in from above, giving the appearance of veins in a mine. The deposit on the floor of the tunnel rested upon ice, and would certainly be greatly disturbed and broken up before reaching a final resting place in case the glacier should melt. In the lake basins, also, the sand and gravel forming their bottoms frequently rested upon substrata of ice, and are greatly disturbed when the ice melts.

At the ends of the glaciers the subglacial and intraglacial drainage issues from tunnels and forms muddy streams. These usually flow out from the foot of a precipice of ice, down which rills are continually trickling. The streams flowing away from the glaciers are usually rapid, owing to the high grade of their built-up channels, and sweep away large quantities of débris which is deposited along their courses. The streams widen and bifurcate as they flow seaward, and spread vast quantities of bowlders, sand, and gravel over the country to the right and left, not infrequently invading the forests and burying the still upright trees. The deposits formed by the streams are of the nature of alluvial fans, over which the waters meander in a thousand channels. Where this action has taken place long enough the alluvial fans end in deltas; but should there be a current in the sea, the débris is carried away and formed into beaches and bars along adjacent shores. Should these glaciers disappear, it is evident that these great bowlder washes would form peculiar topographic features, unsupported at the apexes, and it might be perplexing to determine from whence came the waters that deposited them. I am not aware that similar washes have been recognized along the southern border of the Laurentide glaciers, but they should certainly be expected to occur there.

Another very striking difference in the appearance of the glaciers above and below the snow-line is due to the prevalence of débris on the lower portion. The melting that takes place below the snow-line removes the ice and leaves the rocks. In this manner the stones previously concealed in the névé are concentrated at the surface, and finally form sheets of débris many miles in extent. So far as my observations go, there is nothing to indicate that stones are brought to the surface by any other means than the one here suggested. Upward currents in the ice that would bring stones to the surface have been postulated by certain writers, but nothing sustaining such an hypothesis has been found in Alaska.

The moraines on the lower extremities of the Alpine glaciers may frequently be separated into individual ridges, which in many instances would furnish instructive studies; but in no case has the history of these accumulations been worked out in detail.

With the appearance of moraines at the surface come a great variety of phenomena due to unequal melting. Ridges of ice sheathed with débris, glacial tables, sand cones, etc., everywhere attract the attention; but these features are very similar on all glaciers where the summer's waste exceeds the winter's increase, and have been many times described.

The general distribution of the moraines of the lower portion of the Alpine glaciers of the St. Elias region merits attention. The moraines themselves exhibit features not yet observed in other regions. From Disenchantment bay westward to the Seward glacier the lower portions of the ice-streams are covered and concealed by sheets of débris. About their margins the débris fields support luxuriant vegetation, and not infrequently are so densely clothed with flowers that a tint is given to their rugged surfaces. On the extreme outer margins of the moraines there are sometimes thickets and forests so dense as to be almost impenetrable. The best example of forest-covered moraines resting on living glaciers, however, is found along the borders of the Malaspina ice-field.

This type is represented in the region explored by the Malaspina glacier. This is a plateau of ice having an area of between 500 and 600 square miles, and a surface elevation in the central part of between 1,500 and 1,600 feet. It is fed by the Agassiz, Seward, Marvine, and Hayden glaciers, and is of such volume that it has apparently displaced the sea and holds it back by a wall of débris deposited about its margin. All of its central portion is of clear white ice, and around all its margins, excepting where the Agassiz and Seward glaciers come in, it is bounded by a fringe of débris and by moraines resting on the ice. Along the seaward border the belt of fringing moraines is about five miles broad. The inner margin of the moraine belt is composed of rocks and dirt, without vegetation, and separated more or less completely into belts by strips of clear ice. On going from the clear ice toward the margin of the glacier one finds shrubs and flowers scattered here and there over the surface. Farther seaward the vegetation becomes more dense and the flowers cover the whole surface, giving it the appearance of a luxuriant meadow. Still farther toward the margin dense clumps of alder, with scattered spruce trees, become conspicuous, while on the outer margin spruce trees of larger size form a veritable forest. That this vegetation actually grows on the moraines above a living glacier is proved beyond all question by holes and crevasses which reveal the ice beneath. The curious lakes scattered abundantly over the moraine-covered areas, and occupying hour-glass-shaped depressions in the ice, have already been described.

From the southern end of the Samovar hills, where the Seward and Agassiz glaciers unite, there is a compound moraine stretching southward, which divides at its distal extremity and forms great curves and swirl-like figures indicating currents in the glacier.

All the central part of the plateau is, as already stated, of clear white ice, free from moraines; at a distance it has the appearance of a broad snow surface. This is due to the fact that the ice is melted and honey-combed during the warm summer and the surface becomes vesicular and loses its banded structure. A rough, coral-like crust, due to the freezing of the portions melted during the day, frequently covers large areas and resembles a thick hoar-frost. Crevasses are numerous, but seldom more than a few feet deep. They appear to be the lower portions of deep crevasses in the tributary streams which have partially closed, or else not completely removed by the melting and evaporation of the surface.

Many of the crevasses are filled with water, but there are no surface streams and no lakes. Melting is rapid during the warm summer days, but the water finds its way down into the glacier and joins the general subglacial drainage. It is evident that the streams beneath the surface must be of large size, as they furnish the only means of escape for the waters flowing beneath the Agassiz, Seward and Marvine glaciers, as well as for the waters formed by the melting of the great Malaspina glacier.

The outer borders of the Malaspina glacier are practically stationary, but there are currents in its central part. Like the expanded ends of some of the Alpine glaciers, as the Galiano and Lucia glaciers, for example, this glacier is of the nature of a delta of ice, analogous in many of its features to river deltas. As a stream in meandering over its delta builds up one portion after another, so the currents in an expanded ice-foot may now follow one direction and deposit loads of débris, and then slowly change so as to occupy other positions. This action tends to destroy the individuality of morainal belts and to form general sheets of débris. The presence of such currents as here suggested has not been proved by measurements, but the great swirls in the Malaspina glacier and the tongues of clear ice in the upper portions of the débris fields on the smaller glaciers strongly suggest their existence.

The Malaspina glacier is evidently not eroding its bed; any records that it is making must be by deposition. Should the glacier melt away completely, it is evident that a surface formed of glacial débris, and very similar to that now existing in the forested plateau east of Yakutat bay, would be revealed.

The former extent of the Malaspina glacier cannot be determined, but it is probable that during its greatest expansion it extended seaward until deep water was reached, and broke off in bergs in the same manner as do the Greenland glaciers at the present day. Soundings in the adjacent waters might possibly determine approximately the former position of the ice-front, and it is possible that submarine moraines might be discovered in this way. The Pimpluna reefs, reported by Russian navigators and indicated on many maps, may possibly be a remnant of the moraine left by the Piedmont glacier from the adjacent coast.

The glaciers west of Icy bay were seen from the top of Pinnacle pass cliffs, and are evidently of the same character as the Malaspina glacier and fully as extensive. A study of these Piedmont glaciers will certainly throw much light on the interpretations of the glacial records over northeastern North America. Their value in this connection is enhanced by the fact that they are now retreating and making deposits rather than removing previous geological records.

The expedition of last summer was a hasty reconnoissance, during which but little detail work could be undertaken. The actual study of the ice-fields of the St. Elias region remains for those who come later.

PART V.

HEIGHT AND POSITION OF MOUNT ST. ELIAS.

The height and position of Mount St. Elias have been measured several times during the past century with varying results. The measurements made prior to the expedition of 1890 have been summarized and discussed by W. H. Dall, of the United States Coast and Geodetic Survey, and little more can be done at present than give an abstract of his report.

The various determinations are shown in the table below. The data from which these results were obtained have not been published, with the exception of the surveys made by the United States Coast Survey in 1874, printed in report of the superintendent for 1875.

All of the figures given in the table have been copied from Dall's report, with the exception of the position determined by Malaspina; this is from a report of astronomical observations made during Malaspina's voyage, which places the mountain in latitude 60° 17' 35" and longitude 134° 33' 10" west of Cadiz.³⁶ Taking the longitude of Cadiz as 6° 19' 07" west of Greenwich, the figures tabulated above are obtained.

³⁶ Ante, p. 65.

It was intended that Mr. Kerr's report, forming Appendix B, should contain a detailed record of the triangulation executed last summer, but a careful revision of his work by a committee of the National Geographic Society led to the conclusion that the results were not of sufficient accuracy to set at rest the questions raised by the discrepancies in earlier measurements of the height of Mount St. Elias; and as the work will probably be revised and extended during the summer of 1891, only the map forming plate 8 will be published at this time. Some preliminary publications of elevations have been made, but these must be taken as approximations merely.³⁷

³⁷ The shore-line of the map, plate 8, and the positions of the initial points or base-line of the triangulation are from the work of the United States Coast Survey. The extreme western portion is from maps published by the New York Times and Topham expeditions. All the topographic data are by Mr. Kerr, and all credit for the work and all responsibility for its accuracy rest with him. The nomenclature is principally my own, and has been approved by a committee of the National Geographic Society.

By consulting the map forming plate 8 it will be seen that Mounts Cook, Vancouver, Irving, Owen, etc., are not in the St. Elias range. Neither do they form a distinct range either topographically or geologically. Each of these mountains is an independent uplift, although they may have some structural connection, and are of about the same geological age. Mount Cook and the peaks most intimately associated with it are composed mainly of sandstone and shale belonging to the Yakutat system. Mounts Vancouver and Irving are probably of the same character, but definite proof that this is the case has not been obtained.

The St. Elias uplift is distinct and well marked, both geologically and topographically, and deserves to be considered as a mountain range. The limits of the range have not been determined, but, so far as known, its maximum elevation is at Mount St. Elias. The range stretches away from this culminating point both northeastward and northwestward, and has a well-marked V-shape. The angle formed by the two branches of the range where they unite at Mount St. Elias is, by estimate, about 140°. Each arm of the V is determined by a fault, or perhaps more accurately by a series of faults having the same general course, along which the orographic blocks forming the range have been upheaved. The structure of the range is monoclinal, and resembles the type of mountain structure characteristic of the great basin. The dip of the tilted blocks is northward.

The crest of the St. Elias range, as already stated, is composed of schists which rest on sandstone, supposed to belong to the Yakutat system. The geological age of the uplift is, therefore, very recent. The secondary topographic forms on the crest of the range have resulted from the weathering of the upturned edges of orographic blocks in which the bedding planes are crossed by joints. The resulting forms are mainly pyramids and roof-like ridges with triangular gables. Extreme ruggedness and angularity characterize the range throughout. There are no rounded domes or smoothed and polished surfaces to suggest that the higher summits have ever been subjected to general glacial action; neither is there any evidence of marked rock decay. Disintegration of all the higher peaks and crests is rapid, owing principally to great changes of temperature and the freezing of water in the interstices of the rock; but the débris resulting from this action is rapidly carried away by avalanches and glaciers, so that the crests as well as the subordinate features in the sculpture of the cliffs and pyramids are all angular. The subdued and rounded contour, due to the accumulation of the products of disintegration and decay, the indications of the advancing age of mountains, are nowhere to be seen. The St. Elias range is young; probably the very youngest of the important mountain ranges on this continent. No evidences of erosion previous to the formation of the ice-sheets that now clothe it have been observed. Glaciers apparently took immediate possession of the lines of depression as the mountain range grew in height, and furnish a living example from which to determine the part that ice streams play in mountain sculpture.

APPENDIX A.

OFFICIAL INSTRUCTIONS GOVERNING THE EXPEDITION.

In order to make the records of the St. Elias expedition complete, copies of the instructions under which the work was carried out are appended:

Mr. I. C. RUSSELL, Geologist.

SIR: You are hereby detailed to visit the St. Elias range of Alaska for work of exploration, under the joint auspices of the National Geographic Society and the United States Geological Survey. The Geological Survey furnishes instruments and contributes the sum of $1,000 towards the expenses of the expedition. The money devoted to this purpose is taken from the appropriation for the fiscal year ending June 30, 1890, and the manner of its expenditure must conform to that fact.

The Survey expects that you will give special attention to glaciers, to their distribution, to the associated topographic types, to indications of the former extent of glaciation, and to types of subaërial sculpture under special conditions of erosion, and that you will also bring back information with reference to the age of the formations seen and the type of structure of the range.

With the aid of Mr. Kerr, it is expected that you will secure definite geographic information as to the belt of country traversed by you.

    Approved,
             J. W. POWELL, Director.

Mr. I. C. RUSSELL, Geologist.

SIR: You will proceed at the earliest practicable date to Tacoma, Washington Territory, and thence by water to Sitka, Alaska, at which point you will make special arrangements to visit the St. Elias range of mountains and make geological examinations as per instructions otherwise communicated. Mr. Mark B. Kerr, Disbursing Agent, will report to you at Victoria, B. C., and accompany you on the expedition, assisting you in the capacities of Disbursing Agent and Topographer. On the completion of your work you will return to Washington, the route being left to your discretion, to be determined by considerations which cannot now be foreseen.

    Approved,
             J. W. POWELL, Director.

Mr. MARK B. KERR, Disbursing Agent.

SIR: You are hereby detailed to assist Mr. I. C. Russell, Geologist, who starts at once on an expedition to Alaska, under the joint auspices of the National Geographic Society and the United States Geological Survey. It is expected that you will immediately aid him in disbursement, and that you will act during the exploratory part of the expedition as topographer. Your duties will, however, not be limited to these special functions, but you will be expected to perform any other duties he may assign to you, and to labor in every way for the success of the expedition.

It is expected that you will be reappointed to the grade of topographer on the United States Geological Survey on the 1st of July, 1890, and you will please take the required oath of office before your departure.

The money remaining in your possession as Disbursing Agent includes that needed to meet Mr. Russell's salary and your own, and also the sum of $1,000, allotted from the funds of the Geographic Branch for expenses of the expedition prior to June 30. This amount you will expend as directed by Mr. Russell, and his authority and certificate will need to accompany your vouchers in rendering account of the same.

    Approved,
             J. W. POWELL, Director.

Mr. MARK B. KERR, Disbursing Agent.

SIR: You will proceed at once to San Francisco, California, and thence by steamer or by rail and steamer to Sitka, Alaska. It is expected that you will join Mr. I. C. Russell, Geologist, at Victoria, B. C., or at Sitka; and you will report to him for further orders.

    Approved,
             J. W. POWELL, Director.

Mr. MARK B. KERR, Topographer.

SIR: You are hereby assigned to field-work in the vicinity of Mount St. Elias, Alaska, in the party under charge of Mr. I. C. Russell. Upon the receipt of these instructions you will please proceed without delay to the field, and map upon a scale of four miles to an inch such territory in the vicinity of Mount St. Elias, including that mountain, as the field season will permit. The work should, if practicable, be controlled by triangulation. Special attention in the course of your work should be given to measuring the altitude of Mount St. Elias, and it should be determined by triangulation and also, if practicable, by barometer in such manner as to be conclusive.

The topographic work should be controlled by triangulation. As many positions on this coast are approximately known, including a number of the prominent peaks, astronomical determinations of position will not be necessary unless needed to supplement the triangulation.

The details of your outfitting and the management of the work will be left to your own judgment.

Memorandum of Instructions to the Party sent out under the Direction of Mr. I. C. Russell, assisted by Mr. Mark B. Kerr, to explore the Mount St. Elias Region, Alaska, 1890.

The general object of the expedition is to make a geographic reconnoissance of as large an area as practicable in the St. Elias range, Alaska, including a study of its glacial phenomena, the preparation of a map of the region explored, and the measurement of the height of Mount St. Elias and other neighboring mountains. Observations should also be made and information collected on other subjects of general scientific interest as far as practicable.

The purpose of these instructions is mainly to suggest the lines of investigation that give promise of valuable results, but it is not intended that they shall limit the director of the expedition in the exercise of his own discretion.

    Washington, D. C., May 29, 1890.

APPENDIX B.

REPORT ON TOPOGRAPHIC WORK.

In addition to the ascent of Mount St. Elias, it was part of the original plan of the expedition to make an accurate topographic map of the region explored. It was not, however, for this purpose proposed to divide the party or to deviate much from the most direct route to Mount St. Elias from Yakutat bay. Triangulation of fair precision was provided for. Details were to be filled in by approximate methods.

Field-work began June 20 by the careful measurement of a base-line, 3,850 feet in length, near the point of landing, on the northern shore of Yakutat bay. Expansion was readily carried to the foot-hills, and several horizontal angles were taken to an astronomical station of the United States Coast and Geodetic Survey at Port Mulgrave. In the region of these initial triangles, work was done from a central camp; and topographic details were fixed with considerable precision by intersection and vertical angles.

After the departure of the expedition from the Base Line camp, an accident to the transit made resort to an inferior instrument necessary, and, furthermore, as the region traversed proved to be ill-adapted to, and the line of travel too direct for, the proper development of a narrow belt of triangles, the anticipation of a degree of precision in the triangulation which would give high value to the determinations of position and altitude of the several peaks was not realized; but topographic map work, showing the general features, altitudes and location of the mountain ranges, valleys and glaciers, was extended over about 600 square miles.

Within the approximate geometric control, stations were interpolated by the three-point method, and minor locations were multiplied by intersection and connected by sketch. The best meander possible under the circumstances was carried forward on the line of travel by compass directions and estimates of distance from time intervals. The work ceased August 22 with the abandonment of the instruments in a snow-storm of four days' duration on the eastern slope of Mount St. Elias.

The accompanying map (a reduction of which forms plate 8, page 75) shows the ice-streams and peculiar mountain topography of a region heretofore unvisited, and constitutes a considerable addition to the geography of Alaska.

APPENDIX C.

REPORT ON AURIFEROUS SANDS FROM YAKUTAT BAY.

Among the specimens obtained by Mr. I. C. Russell during the course of his explorations on and about Mount St. Elias is a bottle of sand procured from the beach on the extreme southern end of Khantaak island, Yakutat bay, and characteristic of the shore material over a large area. This sand was turned over to me for examination, and additional interest was given to its study by the fact that it is from a comparatively uninvestigated region and possesses, perhaps, economic value; for the sample is gold-bearing, and it is said that a "color" can readily be obtained by "panning" at many points on the bay shore.

Macroscopically, the sand has the appearance of ordinary finely comminuted beach material; but it differs in the uniformity of the size of its particles from beach sand from Fort Monroe and Sullivan island, South Carolina, with which it was compared. Its mineralogic constituents greatly surpass in variety those of the sands referred to, but are markedly similar to those of gold-bearing sand from New Zealand. At least twelve minerals are present, with an unusual predominance of one, as will be noted later. Through the mixture of white, green, and black grains, a dull greenish-black color is given to the mass. The roundness of fragments is such as usually results from water action, but it is less than that which results from transportation by wind.

When put into a heavy liquid (Thoulet solution of a density of 3.1) in order to determine the specific gravity of the constituents, it was found that the sand is made up largely of the heavier materials, for the amount that floated was trifling compared with that which quickly sank. Even the abundant quartz was largely carried down by the weightier ingredients bound up within it, and only a few water-clear fragments were left behind. This would seem to suggest that the lighter minerals are lacking in the neighboring rocks, or else have been carried to greater distances by the sorting power of the water.

Among the minerals recognized, gold is the most important, though relatively not abundant. It occurs in flakes or flattened grains from a quarter to a half of a millimeter in size. The particles are sufficiently numerous to be readily selected from their associates by the aid of "panning" and a hand lens of good magnifying power, and if distributed throughout the beach as plentifully as in the sample would, under favorable conditions, pay for working. The flakes in their rounded character show the effect of the agency which separated them from their matrix; a separation so complete that no rock is found adhering to the grains.