Slike strani
[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

Seven million seven hundred and sixty-four thousand seven hundred and eighty-seven pounds altogether, or nearly four thousand tons.

In September, 1865, the company sold the mine to Martin & Co., dealers in ores, of San Francisco. Since it has been in the hands of this firm, for reasons explained above, the yield of ore has nearly ceased. The total shipments from the mine since the purchase have not exceeded 150 tons, of which about onehalf has been second class, and the other concentrated ore.

With reference to the classification of the ores in the above table, as the same method for that purpose is followed in all mines producing the same description of ores, it may be as well to explain that method in this part of the report.

The heavy costs for labɔr, bags, transportation, commissions, &c., causing all ores below 10 per cent. to be valueless on this coast, none are shipped below that grade; but as there is a considerable advantage gained by separating the ores which vary more than 5 per cent. in richness, the plan generally followed is to class all above 15 per cent. as first, and from 10 per cent. to 15 per cent. as second. There is some difference in the grade of the ores from the various

The Union ores are the lowest. The owners of that mine, being extersive shipping agents, have facilities for shipping ores of less value than will pay to ship from any other mine. The average of all the ores shipped from the Union does not exceed 15 per cent. From the Napoleon they were above 16 per cent., causing a difference in value of nearly $5 per ton. The Keystone ores are about 1 per cent. higher than the Union.

The concentrated ores above referred to were prepared by the following very economical process : A pit of about two feet deep was cut in the soft soil, about twenty feet square, in which was laid as evenly as possible about four cords of dry pine wood; over this was piled, in the form of a truncated cone, one hundred tons of ore. There was nothing more done, except to ignite the wood, which soon set the sulphur in the ore on fire, and it continued to burn for six or seven weeks, when the greater portion of the sulphur having been evaporated, the fire went out and the ore was concentrated about 6 per cent, or 10 per cent.; poor second class was converted into 16 per cent., or first class.

The machinery used on this mine consists of a small six-horse power steamengine, for hoisting and pumping. There are usually about thirty hands employed on this mine, about one-third of whom are Chinese.

Quail Hill, No. 1, where Hughes made the first discovery of copper, is about three miles east from the Napoleon mine, and about seven miles west from Copperopolis. Quite a town, called Telegraph City, has sprang up between these two discoveries of Hughes's.


Forest Hill district.—The most important mines in Amador county are the Cosumnes, in the Forest Hill district, near Jackson, the county seat, and the Newton, on the same lode, about three miles to the west, near Ione valley, a beautiful and fertile valley, separated from the great valley of the Sacramento by low, irregular hills, as Salt Spring valley is divided from the valley of the San Joaquin. The Cosumnes was located in January, 1862. A company to work it was incorporated in February, 1863. It contains 5,000 feet on the main lode and the same quantity on the Oriental lode, which runs parallel and close to it. This Oriental lode, which is quite extensive, was discovered by the Rev. J. B. Fish, in January, 1863. It appears that the reverend gentleman was returning from a trip to Copperopolis, when he observed the croppings of the lode as he was riding past, the location being near the road. Getting off his horse, he satisfied himself that what he saw was copper ore, and located the claim for himself and friends. The parson's mine has produced nearly one hundred tons of good ore.

The Newton was located early in 1863, by Dr. J. Newton, of Jackson, in the names of himself and six members of his own family, who at present control it. Dr. Newton was the first person in this county who worked a copper mine in it.

Quite a town, called Copper Centre, has sprung up between these two districts. Two years ago it was one of the most active copper mining camps in the State-hundreds of claims having been located on the two copper belts, which can be traced for miles on both sides of the original claims. One of these belts is about six miles northeast of the other, and follows the same course as the parallel lodes at Copperopolis-north about 50° east. These lodes also dip from 10° to 200 to the east, as do those at Copperopolis; are in the same geological formation, and the ores are so much alike in appearance and composition that the best judges cannot tell one from the other. There is no doubt but that the Amador county mines are located on the same lodes as the mines at Copperopolis. There are many valuable copper mines in this vicinity, but though the great distance from a market, and the want of capital and experience of those who own them, work on all except the Cosumnes and Newton has ceased. Probably these would also have remained undeveloped had not Meader & Co., copper merchants of San Francisco, become interested in them.

[ocr errors]

A great deal of work has been done on the Newton, which has been sufficiently tested by shafts and drifts to prove that it is of great value, and this value would be fourfuld greater if there were proper means for bringing the ore to tide-water. The lode on this mine is not so large as it is at Copperopolis, but the ore is less divided by the containing slate than it is in the Keystone. At one hundred feet deep the lode here was only three and half feet wide. It increased considerably as the depth of the shafts increased. Most of the ore from this mine will average 15 per cent. In 1864 it shipped about one hundred tons per month, averaging 16 per cent.

On the Cosumnes ground the lode is about ten feet wide at one hundred and twenty-five feet deep, and averages about 16 per cent. This company shipped about two hundred and fifty tons per month during 1864, averaging 12 per cent.

Hope valley.--The Rodger's mine, in Hope valley in this county, is located a few miles west of Carson cañon, on the borders of the State of Nevada, only a few miles from some of the highest peaks of the Sierra Nevadas. It was discovered in 1855, but has never been worked to any extent, though the ore is very valuable and of great beauty. It is not a regular lode, but a sort of chimney, which makes its appearance, about two feet wide and nearly perpendicular, in the face of a lofty bluff of solid, hard, white granite, at the eastern end of the valley. The only sign of this body of ore is confined to its exposure in the face of the bluff, and for about thirty feet on the top of it. A great deal of prospecting has been done in the vicinity, in the hope of finding a continuation of it, but in vain. The ore is accompanied on the south side by a body of hard, grayish, crystaline limestone, the only sign of that mineral for many miles around-the whole country being composed of bare, rugged cliffs and peaks of felspathic granite. On the north side of the ore there is a seam, of about a foot wide, of dark brown quartz, of a peculiar cellular structure. There is a great abundance of brilliant lime garnets in this ore, which, together with the peculiar combination of sulphurets, oxides, and carbonates of which it is formed, render it exceedingly interesting for cabinet specimens ; though it is very doubtful whether it will ever pay to extract it for commercial purposes.

Mariposa county mines.—The existence of important lodes or deposits of copper ores of considerable commercial value in Mariposa county was known for several years before any attempt was made to turn them to profitable account. The croppings of a series of large bodies of the ore are seen protruding through the surface all through the county, from where it unites to Merced county on the one side to where it joins Fresno county on the other. It was not until the summer of 1863 that any attention was paid to copper mining in this county. The distance from a market and want of roads, as well as the broken and disturbed condition of the geological formation in which the ore is contained, prevented men of experience and capital investing time or money in their development.

There are two extensive districts in which copper mining is carried on in this county. One is on the south side of it, on the Chowchilla river, near the dividing line between this county and Merced. This is called the Hamilton district. It embraces mines in both these counties. The other is the Hunters' Valley district. This is located west of the Bear Valley mountains and south of the Merced river. The La Victoire, the most important copper mine in Mariposa county, is in this district.

A good many companies are working in the Hamilton district; but thus far the developments have not been of much importance, as no shaft of any considerable depth has been sunk, and no permanent lode has been discovered. There is but little doubt that the mines in this county are located on portions of the great cupriferous belt referred to in the introductory remarks to this report as passing through the State; but the shifting and dislocation to which it has been subjected since its formation have so broken it up that it is exceedingly

doubtful whether any permanent mine will be discovered in the southern district of this .county. Some activity has been imparted to this district during the past year by the erection of several smelting furnaces on a small scale, which, operating on the silicates, oxides, and carbonates of the metal, which are found in great abundance for miles around, make large quantities of regulus and black copper from 60 per cent. to 96 per cent. of fineness. The owners of these furnaces pay a fair price of all the ores of a suitable character the miners can bring. This will account for the activity in the district and for the shallowness of the explorations, as the ores cease to be of the class required at a few feet below the surface.

One of these furnaces has been erected on James's ranch, and another, about six miles distant, on the border of Fresno county, at Buchanan Hollow. From this latter place about one hundred and fifty tons of copper, in bars ranging from 80 per cent. to 96 per cent. of metal, have been exported from San Francisco to New York by Coffee & Risdon, the proprietors of the works.

The furnaces at James's ranch are constructed on the French plan, introduced on this coast, on the Queen of Bronze mine, in Oregon, by M. De Hierry, a French metallurgist of considerable ability. They are capable of operating on about eight tons of ore in twenty-four hours. The class of ores operated on have averaged about 12 per cent., the greater portion of which has been obtained from the Green Mountain and Lone Tree mines, near the works.

The company obtain plenty of pine wood charcoal at $70 to $80 per ton. All the smelting is done with this description of fuel. About a ton of this charcoal is required to produce a ton of marketable regulus. There are about a dozeu men employed at each of these works.

The furnaces used at Buchanan Hollow are what are known as Haskell's water-lined, a brief description of which will be found under the head of “Processes,” &c. They are of about the same capacity as those mentioned above, and consume about the same quantity of the same description of fuel. There are several of this latter description of furnaces in use in this State; one on the Cosumnes mine, in Amador county; another on the La Victoire mine, in Mariposa county, and several others are in an advanced state of construction in various localities.

About six miles south of these smelting works at Buchanan Hollow there are several of the best mines in this county ; among them is the Bachman. In the shaft on this mine, at a depth of sixty feet, the lode is ten feet wide, composed of yellow sulphurets, identical in appearance and composition with those found at Copperopolis and Campo Seco, and accompanied with all the characteristics of the lodes in those districts, and affording many facts to prove a connection in the origin of all of them.

Near the smelting works on James's ranch there is a series of lodes, traceable for about ten miles, and ranging N. 24° W., corresponding very closely with those already noticed in Salt Spring valley. In a shaft sunk on the Dozer lode, one of this series, at a depth of eighty feet it was found to be six feet wide, composed of nearly solid yellow sulphuret. But, as was explained above, the disturbance of the containing rock does not hold out a reasonable hope of the permanence of any body of ore in the district.

Mr. Haskell, the proprietor of the Buchanan lode, has recently sold it and the smelting works above described to a firm at Stockton for $22,000. This will afford à basis on which to estimate the value of the best mines in the district.

The "La Victoire” mine, in Hunter's valley, is a most valuable property, being second in importance to scarcely any copper mine in the State. It is located in a section of this county which has not been affected by those disturbing causes which have broken up the lodes in all the other sections. It also possesses the very great advantage of having an immense body of very good ore above the level of the surrounding country, which enables the company to extract it without the use of expensive hoisting and pumping machinery. The lode runs through a hill several hundred feet in length and nearly three hundred feet high, cropping out on the very summit of it, and traceable, unbroken, through its entire length, at an average width of nearly five feet. The proprietors, who are mostly Frenchmen, have sunk shafts on the lode at both ends of the base of this hill to the depth of nearly two hundred feet, without discovering any material difference in its appearance, the only important change being that, while the lode dips to the east at an angle of 450 at twenty-five feet below the surface, at the base of the hill, at one hundred feet lower, it dips at an angle of 680; but, as it increases nearly a foot in thickness at the point where the dip changes, it is evident that the change has not been the effect of dislocation. A great deal of very rich ore has been taken out of this mine, much of it containing sufficient gold to pay for working it for that metal only:

It may be proper in this connection to state that the copper bars made in this county by the furnaces described above contain a very large per cent. of gold. Some of it, assayed by Kellogg & Hueston, of San Francisco, was found to contain as high as $450 to the ton. Much of this copper contains $50 in gold to the ton; none of it less than $20.

There is a small smelting furnace on this mine, but it is not in use. For the past year but little work of any kind has been done on the mine in consequence of disagreements among the owners, one portion of whom are playing the game of “freeze out

upon the others. There are several other good copper mines in this district, but those who own them do not appear to have either the means or disposition to develop them, and capitalists from abroad are afraid to invest very extensively in such mines in this county till they have been better examined.

San Luis Obispo county mines.—The Osos mines in San Luis Obispo county were discovered in the spring of 1864. They are situate about eight miles west of the Old Mission of San Luis Obispo, on the Osos ranch, near the south end of a wide belt of cupriferous ores that is traceable for more than twenty miles to the north, among the range of mountains which lay between the town of San Luis Obispo and the Old Mission of Santa Marguerita. This belt of ore, on which there are a great number of mines, presents very much the same peculiarities as are mentioned in the description of the Hamilton district, in Mariposa county. 'The disturbance of the lode by subterranean causes has broken

up to such an extent as to render it unprofitable to mine. The Osos district, as is the case with Hunter's valley, in Mariposa, appears to have been less affected by these disturbing causes. A shaft one hundred and ten feet deep has been sunk on the Osos lode, which was from four feet to twelve feet wide. One hundred tons of ore, averaging eighteen per cent., have been shipped from this mine direct to Boston and Swansea, and there are several hundred tons more ready for shipment. Ex-congressman Phelps is extensively interested in these mines.

Los Angeles county mines.—The Solidad district, in Los Angeles county, is located about thirty miles due north from Los Angeles. The knowledge of the existence of copper in this locality was published by M. Duflot de Mofras nearly twenty years ago, as it was somewhere in the neighborhood that placer mining for gold was carried on as far back as 1840. Mr. Bidwell, member of Congress for California, saw these early gold miners at work, and probably saw the croppings of the copper lode, which are quite extensive and conspicuous for a long distånce. In 1854 a Frenchman named Maris discovered the mines in what is now known as the Solidad district, but the discovery attracted no attention till the excitement about copper, which followed the discovery of the mines at Salt Springs valley, in 1861 and 1862, when great activity in prospecting raged in this locality, and a great amount of work was


« PrejšnjaNaprej »