A Report On Washington Territory Part 9

This great pile of basalt was built up by a succession of overflows of lava, the joints of which are plainly visible. The basaltic area, though perhaps thickest here, continues with a thickness of 1,000 to 1,500 feet up the Columbia for hundreds of miles; indeed the whole plateau, or prairie country of East Was.h.i.+ngton, which is a quadrilateral of some 200 miles in diameter, is but a continuation of the great lava-sheet seen at the Cascades and the Dalles. Through it the Columbia and Snake rivers have cut deep channels; and other, though shallower channels, have been cut across the surface of the plateau by departed streams.

[Sidenote: Origin of the rich soil of East Was.h.i.+ngton.]

Whether the extremely fertile soil which overlies the basalt in East Was.h.i.+ngton is a top-dressing of volcanic ashes, or is decomposed basalt, cannot readily be determined. It cannot be referred to the Glacial period, as I observed no appearance of drift anywhere except in the valley of Spokane River. Such a wide spread of lava is not unexampled in view of somewhat similar overflows now occurring at intervals in the Sandwich Islands, where lava runs and spreads itself like water. These Hawaiian flows are mentioned by Captain C. F. Dutton in his report of the Zuni Plateau.

A ledge of sandstone belonging to the Meiocene Tertiary is visible under the basalt at the lower cascade in the Columbia River; and a stratum of iron ore and vegetable matter is found on the Willamette at Oswego, lying horizontally between great ma.s.ses of basalt, showing a long interval between overflows.

[Sidenote: The volcanoes not wholly extinct.]

These eruptions probably continued with diminis.h.i.+ng force until near the present time. It is reported that Mount Hood has sent out smoke or steam since the settlement of Oregon. The crater of Mount Ranier was visited by two gentlemen within a few years, and a night spent in its bottom by the side of a jet of steam. Such, at least, is the account given by one of them, Mr. Stevens.

[Sidenote: Glacial drift.]

The Quaternary or Drift Period has left abundant, though by no means universal, traces of its presence. As before intimated, I saw no relics of it in East Was.h.i.+ngton, except a deposit of rather small, generally very small, and well-rounded quartz gravel, thickly strewing, and really forming, the flats bordering Spokane River. This gravel macadamizes the streets of the City of Spokane Falls, and the neighboring roads, so as to make them firm at all seasons. These gravelly bottoms are not tillable except in a few spots.

The undulating country north and east of Puget Sound is in many places deeply covered with drift material which shows the effect of both ice and water. Blocks of partially rounded granite several feet in diameter are found on the hills around Seattle. This gravel deposit is not often found on high points, but there is a ridge in the Cascade Mountains, near Salal Prairie, which is thickly bestrewed at an elevation of 1,000 feet. This, however, was quite exceptional, and may be the lateral moraine of a local glacier. The deposit around Seattle is not only easy to cultivate (its soil being a light blue loam), but seems fertile. The bottom lands are free from gravel.

So much for the general geology.

ECONOMIC GEOLOGY.

NOTE.--The location of the coal-fields and collieries mentioned in the following pages may be seen on an accompanying map.

Under the head of Economic Geology, I shall describe with more detail the mineral beds which have a commercial value, and in the following order:--I. Coal; II. Iron Ore; III. Granite, Limestone, and Marble; IV.

Precious and Base Metals.

[Sidenote: Thickness of the Coal Measures.]

I. COAL.--The thickness of the Coal Measures of the Puget Sound basin is estimated by Bailey Willis at something like 14,000 feet, though he admits the obvious possibility of error in the calculation by reason of undiscovered faults. We may fairly expect them, however, to be thicker than the same group in the Rocky Mountains, which measure about 9,000 feet. As heretofore remarked, the sediments become thinner from west to east. Of course, the maximum thickness is not to be expected in every locality. Mr. Willis's estimate was made in the Wilkeson and Green River fields, and really did not reach the limit of the coal-bearing rocks.

The coal rocks of the Cedar River and Snoqualmie basin have never, so far as I know, been estimated, but probably this group is equal in thickness to that of any other part of the field. The difficulty of measurement arises from the numerous fractures and changes of strike which exist.

[Sidenote: Fifteen workable seams.]

The number of distinct workable seams of coal of three feet and upwards, belonging to the measures, may safely be put down at not less than fifteen.

[Sidenote: Different kinds of coal described.]

Before considering the quality of these coals, I will, for better understanding, make some prefatory statements in regard to the character of coals generally. Charcoal has greater purity than mineral coals usually have, because there is nothing in the charcoal except what naturally belongs to the woody matter. Mineral coal, however, having been buried in water, mud, and sand, must, almost of necessity, have some mixture of foreign matter, either slate, which is simply hardened mud; silica, which may have been derived from sand; iron and sulphur, some of which may have been in the wood, but most of it, probably, introduced in solutions; to which should be added, unexpelled oxygen, which is not only useless as fuel, but which combines with a portion of the contained hydrogen, and forms water in the substance of the coal.

The proportion of ash in coals of the same cla.s.s is usually determined by the amount of slate in the coal, in addition to the mineral matter which belonged originally to the vegetable material from which the coal was formed. In the pure state, the proportion of ash increases as the transformation of woody fibre goes on from peat to anthracite.

[Sidenote: The chemical changes in coal beds.]

It is worth while to note what are the changes which take place in the vegetable matter during the process. It may be described in a word as a progressive loss of oxygen, and by this loss the coal becomes richer, for the reason just given. The deoxidizing process is carried on by means of chemical changes in the substance of the coaly matter. The oxygen combining with a certain proportion of the carbon, forms carbon di-oxide, or carbonic acid gas; and a certain other portion, combining with hydrogen, forms water. Both of these are volatile in their character, and gradually escape. Another loss is effected by the combination of hydrogen and carbon, forming marsh gas. We have deadly proof that these combinations are in progress in all coal mines by the occurrence of "choke-damp" and "fire-damp," which are the miners' names for these gases.

[Sidenote: Deficient nomenclature.]

Unfortunately, we have no settled nomenclature for the varieties of coal, excepting the broad names lignite or brown coal, bituminous coal, and anthracite. Even the term "bituminous" is scientifically inaccurate, there being, in fact, no bitumen in any coal. But it is applied to such coals as contain more oxygen and volatile combustible matter and water than anthracite, and less of these elements than lignite. The term lignite is made to include a great variety of substances, covering the lignites of the Juro-Trias of James River (Dutch Gap), which retain not only the structure, but the appearance of decaying wood; the lignites of the State of Mississippi, which are of the same geologic age as those of the Rocky Mountains, but which, owing to their watery and crumbly character, are unfit for market; the lignites of the Grand and Moreau rivers of Dakota, which are reported to have no commercial value; the lignites of Bozeman, Montana, which are really valuable, but soon break down into chips and grits; the lignites of Green River, Wyoming, which are firm, bright, lump coals; and the lignites of King County, Was.h.i.+ngton Territory, many of which are hard, bright, steam and s.h.i.+pping coals. And when brought to the laboratory, it is found that chemically these lignites vary even more than they do optically.

[Sidenote: Lignite an unsuitable name for the coals of Was.h.i.+ngton Territory.]

This want of a varied nomenclature is to be regretted, because it sometimes handicaps a good coal with an inferior name. It is only of late that the Laramie or Cretaceous coals of Was.h.i.+ngton Territory have been divided into lignites, bituminous coals, and anthracites. These grade into each other so insensibly that it would be impossible to cla.s.sify them sharply. None of the lignites which I saw were as low in grade as the typical lignite. The woody structure was quite discernible in some samples of the Franklin coal, and less in the Newcastle and Green River; but in respect to the two latter, I could not with the naked eye discern more of the woody structure than I have seen in some of the West Virginia coals, which belong to the Carboniferous period. I sat by fires of Newcastle and neighboring coals for a month, and observed no unusual amount of smoke, and no peculiar odor. By a.n.a.lysis, these coals show a larger percentage of oxygen than the typical bituminous coal, but decidedly less than is found in the brown coal of Germany, or in some of the lignites of Montana. They need a new name.

Their heating power is not so great as that of the bituminous coals of the same region. Their streak and powder are less black, and their fracture more conchoidal, but not decidedly so.

The bituminous coals have the usual cubical fracture. The Wilkeson readily breaks down into small cubes. The lignites are black and l.u.s.trous. They come out as lumpy as ordinary coal, and, when exposed to weather, do not break up into powder and grits like ordinary lignite.

This is true, at least, of the Newcastle coal.

[Sidenote: The c.o.king quality not general in these coals, but found in some.]

The c.o.king quality of these coals cannot be determined by calculating the proportion between the fixed carbon and the volatile, combustible matter. I am not sure that Professor Fraser's fuel ratio tables are a safe guide in any case. So far as now known, only a few of the Was.h.i.+ngton Territory coals can be made into good c.o.ke. On this point, however, we have only laboratory and rough field tests, excepting at the Wilkeson mines, where twenty-five ovens were turning out a superior quality of c.o.ke, as proved by every test save the use of it in high furnace stacks, in which there had been no opportunity for trial. It is claimed by many persons that seams on Green River, Skagit, Yakima, and Snoqualmie will furnish good c.o.king coal. The coal on Snoqualmie Mountain, near Hop Ranch, has not been studied, but it certainly has the external characteristics of good c.o.king coal, and Mr. Peter Kirke made a rough trial of it in an earth-pit with decidedly encouraging results.

Somewhat similar coal is found on Raging River, but where opened, so much slate was interleaved with the coal that was.h.i.+ng would be necessary before use. More will be said hereafter with regard to these coals; but the remark may be repeated here in respect to the entire Puget Sound basin, that much additional examination is necessary before its coals will be fully understood. The variations in character of these are not owing entirely, or even chiefly, to their relative ages, but also to the conditions to which they have been subjected, especially in respect to heat. This metamorphic agency has acted not only in the body of the Cascade Mountains, but all through the coal-fields, where faults, flexures, and intrusive rocks have occasioned changes in the original condition of the coal-beds, giving results along the whole scale of metamorphism from lignite to anthracite.

[Sidenote: a.n.a.lyses of Was.h.i.+ngton Territory coals.]

I here introduce (on the opposite page) a table of a.n.a.lyses made in Was.h.i.+ngton City from representative samples of Was.h.i.+ngton Territory coals and lignites selected by Mr. Bailey Willis during the examination which he made of this field for the Census Bureau, and found in Vol. XV.

of the Census Reports.

THE COLLIERIES.

I will now give some account of the princ.i.p.al coal seams which have been worked in Was.h.i.+ngton Territory, namely, those in the field lying east and southeast of Puget Sound; and in so doing I shall add to my own knowledge all information from any reliable sources. Unfortunately, the sources of information are few.

[Ill.u.s.tration: ENTRANCE TO GILMAN COAL MINE ON THE LINE OF THE SEATTLE, LAKE Sh.o.r.e AND EASTERN RAILWAY.]

[Sidenote: Authorities.]

In the Report of Bailey Willis to Professor Pumpelly for the Census Bureau, we have the best account extant of the Carbon River and Green River basins. Mr. Willis spent three years in his examination, a.s.sisted by topographical engineers. He made numerous trial-pits and borings with diamond drill, and forwarded samples to Was.h.i.+ngton City for a.n.a.lysis.

Mr. F. H. Whitworth, of Seattle, accompanied me in my excursions, and prepared maps which are filed herewith. Mr. Whitworth has probably more practical knowledge of the Puget Sound coal basin than any one else. A small volume on the Pacific coal field was prepared some years ago by Mr. W. A. Goodyear. And Governor Squire's lucid and intelligent reports contain valuable information upon the coal, and all the other interests of Was.h.i.+ngton Territory. Governor Semple has also, in his Report for 1887, given us the latest official information.

a.n.a.lYSES OF REPRESENTATIVE SAMPLES OF WAs.h.i.+NGTON TERRITORY COALS AND LIGNITES.

Key for Sites: A Miles City, Dakota.

B Newcastle, Was.h.i.+ngton Territory.

C Vein (?) G. R. C.

D Vein 33, G. R. C.

E Vein (?), G. R. C.

F Vein xviii. G. R. C.

G Vein ix. G. R. C.

H Vein vi. G. R. C.

I Vein iii. G. R. C.

J Upper Yakima River, Wash'n Ter.

K Carbon Station, Wyoming Territory.

L Rock Springs, Wyoming Territory.

M Wingate Vein, Carbonado.