Chapter V: Part 5

Doubtless it at one time extended some distance upward, but that portion has been eroded. Along the plane of the fault the line of demarkation between ore and porphyry is very distinct, as the two bear not the slightest resemblance, but at the outer edges of the deposit no such line can be discovered. The mineral gradually disappears, leaving only a brecciated mass of whitish rock, which graduates into the normal porphyry. The brecciated condition of the mass is made more plain by the variety of color assumed by the angular fragments. They are various shades of green, red, white, and brown, or yellow, caused by copper carbonates and iron oxides.

Though the original condition of the ore was doubtless sulphide, it now contains, as the result of oxidation, hematite, limonite, magnetite, malachite, azurite, chrysocolla, cerussite, wulfenite, chloride of silver, manganese oxide, and metallic gold. The value of the ore lies principally in the gold contained, though in one portion of the ore body, near its eastern end, rich chloride of silver ore is found, with but little gold. The physical appearance of the ore is no criterion of its gold contents, as two pieces, with identically the same characteristics, will differ widely in value. One may contain $2 or $3 in gold, the other several hundred. Should ever a mill be erected in the district, this ore can be worked to a profit, though this single ore body will alone scarcely justify the construction of a mill.

On the south side of this fissure or slip is a vein which runs nearly parallel with the chambered vein above described. This vein can be traced for several thousand feet. In character the ore is similar to that found in the Imperial lode. Assays running over $200 in gold have been obtained from this ore, and $50 assays are not uncommon. The vein is quite small, ranging from a mere seam to 2 feet. Scarcely any development has been done on this vein, though it promises better results than the large “vein chamber.”

The developments on the Gladstone consist of a shaft 60 feet deep. The first level is cut at a depth of 30 feet from the surface, where drifts have been run for a distance of 30 feet each way from the shaft, on the course of the vein, and a crosscut, 28 feet north. East of this, a 15-foot shaft has been sunk in a good sized cut. A large open cut, 100 feet long, has exposed the upper portion of the ore deposit perfectly. Other superficial work has been done at various points along the vein. A tramway of 1,700 feet has been constructed from the mine to the bottom of an adjacent cañon.

OTHER CLAIMS.

In the vicinity of the mines described in this district are numerous other claims, some of them having considerable development, but all lying idle at the time of my visit. One claim has an 80-foot tunnel, and shows some lead and silver ore of good grade. This claim is patented.

THE ALVORD MINES.

Twenty-three miles northeast from Daggett are the Alvord Mines. The property has changed hands several times, but is now owned by a party of Pasadena capitalists, who have under consideration the reconstruction of their mill, which was burned in September, 1891.

The property consists of six full claims located on one mineral-bearing zone. The strike of the belt is a few degrees south of west. The mine is well equipped. The company also owns a millsite at Camp Cady, on the Mojave River, 9 miles distant from the mines, and valuable water rights at Paradise Springs, 11 miles northwest from the mines, and a spring about 1½ miles east of the camp, which is used for camp purposes only.

The mines lie along a broad zone or belt of crystallized carbonate of lime (calcite), which may be seen for many miles traversing the dark-colored inclosing rocks. A huge dike of porphyritic rock cuts across this belt at an angle approaching 90°. The principal mineralization of the lode occurs east of this dike.

The country rock is described by F. R. Burnham, E.M., formerly the Superintendent, in his report on the property to the company, as rock more or less schistose in character, through which, at frequent intervals, are intruded eruptive dikes. At the east end of the belt is an accumulation of tufa and basalt. The belt dips south at an angle of 75°. The mineralized portion of this lode extends from the porphyry dike east through three full claims, disappearing finally beneath the eruptive rock and desert wash. The dominant point on the lode is 550 feet above the base of the hill.

The entire lode is gold-bearing, some of the iron rock being extremely rich; gold also occurs in the calcite, though it is usually of a lower grade than where accompanied by the iron. Iron sulphide containing gold has been discovered, indicating plainly the origin of the slag-like iron ores and limonite found on the surface.

To Mr. Burnham’s report I am also indebted for information concerning the value of the rock, tonnage, and bullion output to date. He has given arbitrary figures for shipments aggregating $37,000, and an estimate on $13,000 more, making a total of $50,000. This ore was milled mostly at the Camp Cady mill and at Hawley’s mill.

An arrastra was used in the early history of the mine. The average assays made on a ten days’ mill run just prior to the burning of the mill returned $12 75 per ton. Tailings, during the same period, averaged $1 25. Bullion produced, $1,430. It was found very difficult to sort the ore, though it varied constantly in value from $2 to $20 per ton. About 90 per cent of the assay value, it is claimed, was saved in the mill. In looking through a daily record of assays made in July and August, 1891, I find them to range from a trace to as high as $1,750, most of them running from $6 to $18. Mr. Burnham figures 184,000 tons of mill rock in sight, including all grades, besides large amounts presumed to be available, but not blocked out for stoping. The value of the ore is placed at $5 to $6 throughout.

The cost of milling this ore is placed at $2 50, and mining at 50 cents in large stopes. Should the company now controlling the Alvord Mines determine to rebuild their mill it will doubtless again become a bullion producer.

ORO GRANDE DISTRICT.

The Oro Grande Mining District is located immediately east of the Southern California Railroad, at the town of Oro Grande. It is commonly supposed to embrace all the mines for some miles around, though, in fact each group of mines or hills has been given a separate name, but as these so-called districts are mostly without organization, all the claims and mines will be considered under one head.

The geology of the district about Oro Grande is complex, the formations being uplifted, greatly faulted, and broken, besides the intrusion of dikes of felsitic rock, diorite, and quartz porphyry. I had not sufficient time at my disposal when at Oro Grande to study out the somewhat intricate geological problem, and will describe the region in general terms.

Commencing at the town of Oro Grande, which stands on the bank of the Mojave River, the country rises in a gentle slope toward the hill half a mile distant; gently rolling hills are reached, which in turn give place to more rugged masses, and finally to a rough mountainous area, the hillsides being almost precipitous. The lowlying country about the base of the hills is mostly made up of schistose micaceous rocks, a quartzose mica schist predominating. The first hills of any consequence are eruptive, mostly a light-greenish felsite and a coarse-grained porphyritic rock. Beyond are prominent hills of a dense, hard quartzite resting upon a crystalline limestone, the highest hills being made up of practically the same materials (quartzite and limestone), in part schistose with some mica schist, jasper, and many intrusive dikes of all the previously mentioned eruptives, prominent among them being diorite of dark-green color.

THE EMBODY MINE.

Within half a mile of the town, and on a lower spur or ridge that makes down from the hills, is located the Embody Mine, which, during the excitement at this locality in 1890, attracted considerable attention. The gold-bearing material is quartzose, micaceous rock of somewhat friable character. The deposit, as I may term it, has the appearance of being an impregnation without definite form.

Were it not for the fact that the shoot of gold rock makes across the strike of the schists, it would resemble some bedded deposits found at the Homestake, Black Hills, South Dakota, where micaceous schists have been silicified and hornblende schists metamorphosed to chloritic schists, the whole carrying gold across a broad zone 1,600 feet in width and 6,000 feet in length. The gold occurs in shoots or vein-like zones, without defining lines of any character. At the Embody Mine, too, little development has been done to make any positive prediction as to the future of the mine. The formation strikes northeast and southwest, and dips 70° southeast.

The country is somewhat broken up, but no considerable masses of shattered rock were observed. The croppings are quite heavily stained with iron oxides of brown and red shades, and this mineralization can be traced some distance. Two shafts, one nearly 100 feet deep, the other about 30 feet, have been sunk on the deposit, exposing rocks of uniform character, all carrying some gold. The width of the gold-bearing zone is undetermined, but it is thought to be from 6 to 20 feet.

As far as I learned, a “mill-run” had never been made on the rock from this mine. Mining operations had been stopped and the property involved in some sort of dispute. The value of the rock was given to me as $8 or $10 per ton.

THE CARBONATE MINE.

The principal mine of this district, and the one which gave the camp its fame, is the Carbonate Mine. It was discovered by a man named Collins, who was working in a lime quarry near by. Collins found croppings of ore—limonite and manganese—containing silver. He developed the property somewhat, but it finally passed into other hands, and is now owned by a Los Angeles company, which has opened the mine quite extensively.

The formation which incloses the vein has a general trend northeast and southwest, the dip at the main workings being not over 20°. Here an inclined shaft has been sunk to a depth of 225 feet on the vein. At the bottom the shaft has attained a vertical depth of about 100 feet. Two veins of ore, consisting principally of silicious and earthy iron oxide and black oxide of manganese with carbonate of lime, sometimes crystallized, extend from the surface to the bottom of the incline. These veins are very irregular in size, varying from a mere seam to upwards of 2 feet in places.

The value lies in the lead carbonate and silver which accompany the gangue minerals. The two veins are curiously formed at contact with massive blue limestone and mica schist. The schist is from 1 to 4 feet in width, the ore lying both above and below it, the whole being inclosed between hanging and foot walls of crystalline limestone. At various points in the workings is a light-colored, much decomposed rock, resembling felsite, which has the appearance of having been injected between the strata in a thin sheet. It is a notable fact that where this buff-colored, granular appearing rock occurs in contact with the vein an enrichment of the ore is noticeable, and its absence is marked by the low value of the ore or no ore at all. In this incline, at a depth of 40 feet, a short drift has been run in on ore of good grade. At 180 feet from the collar of the shaft the discovery was made that caused this mine, and, in fact, the entire camp, to become at once the scene of excitement.

At this place a small wedge of crystalline, granular quartz and calcite appeared, and with it flakes of free gold. Just below the point of this discovery the wedge widened to several inches, and the rock was a mass of glittering sheets and shot-like pieces of gold. Assays of the material gave fabulous returns. The ore was broken down on canvas, and every ounce of it sacked on the spot. This was followed down some distance, but gradually thinned out below the 200-foot level, where drifts were run, one 50 feet northeast, the other 40 feet southwest. From these drifts considerable rich quartz was obtained.

In the southwest drift the formation is badly displaced and broken and the vein is lost, a fault having thrown it, but whether up or down could not be determined, as the adjacent rock was so badly fractured. Ore was found at the face and along the sides of some of the cuttings, and some free gold was found on the 200-foot level in the southwest drift. All work on this part of the mine had been suspended some time prior to my visit, the mine having been enjoined.

ORIGIN OF THE VEINS.

This question is one which finds its answer, it would seem, in the fact that the sheet of mica schist included between the heavy masses of limestone represents what at one time was possibly a bed of sandy clay or mud, which with the metamorphosis of the region has become a crystalline schist. The planes separating this schist and the limestone above and that below it were evidently planes of weakness, and when the forces which uplifted and fractured the strata exerted themselves these rocks slipped and ground upon each other, causing considerable crushing along these planes; possibly open crevices resulted in some portions. Ore was subsequently deposited in these interstitial spaces, partly by substitution of ore for limestone, no doubt, and partly by precipitation in the crushed mass of lime and schist. The injection of a sheet of felsite into the same plane of weakness can easily be conceived, as such intrusive bodies always follow the lines of least resistance. The extreme richness of the rock, together with its somewhat unusual association of quartz and calcite, attracted no little attention to the property at the time of its discovery.

A FISSURE VEIN.

Southwestward from the deposit just described is a vertical shaft 125 feet deep. This shaft has followed down what seems to be a fissure in the limestone, in which lead carbonate, some galena, limonite quartz, calcite, and manganese oxide occur. This ore was worth at Socorro, New Mexico, $50 per ton for the gold, silver, and lead it contained, and it was shipped there in quite large quantities.

A large stope commences on the northeast side of the shaft at a depth of 30 feet from the top and extends down to the 114-foot level. Considerable ore was standing in sight in the mine at the time of my visit, but nothing was being done. The company have had to stop work, as the owners of the lime quarry claim to have this property included in their patent.

OTHER CLAIMS.

There are scores of other claims in this interesting district, but little development has been done on them. Here and there are encouraging prospects, where carbonate of lead and oxide of iron have been found; but on the most promising of these only 10-foot holes have been sunk. The mineral zones are not well defined, and the prospectors have not the capital necessary to systematically prospect the hills.

THE SILVER MOUNTAIN DISTRICT

Is 5 miles south of Oro Grande. There are a number of claims, the principal one being the Amazon. The formation is similar to that about Oro Grande. In a large dike of diorite occur the ore bodies of the Amazon Mine, which produces copper ores of a fair grade. Several holes were sunk to various depths, ranging from 15 to 30 feet, by the Mormons who settled on the Mojave River years ago. Recently a shaft has been sunk to the depth of 61 feet, and a drift run north 40 feet. The ore is principally copper-iron sulphide (chalcopyrite).

The ore in this mine occurs along slips or fault planes. This peculiar class of deposits has been described under the head of the Tiptop Mine, Lava Beds District, in this county, and as the essential features of this mine are similar to those of the Tiptop, repetition here will be unnecessary. I found a greater mineralization of the limestone in this district than about the Oro Grande, though no prospecting has been done here for lead ores.

GEM MARBLE QUARRIES.

Twelve miles northeast from Victor are the Gem quarries, that produce variegated marbles of great beauty. Shades of yellow, chocolate, black, pale blue, crimson and gray, cream-colored, rose, and white. The markings are such as to produce beautiful effects. The croppings are strong, and the surface material is apparently not at all injured by the exposure of centuries to the elements in a region where nearly all rocks decay and disintegrate rapidly. The outcrop stands boldly above the adjacent country rock from 10 to 20 feet. The entire ledge or belt is made up of bands or beds ranging from 3 to 6 feet in thickness. These strata are separated by thin seams or fractures, but it is reasonable to presume that this separating line or joint will disappear as depth is attained. The rock is all susceptible of a high polish, and it withstands a tremendous crushing force. It was said by the owners that this had been determined at 28,000 pounds per square inch.

The quantity is large, the variety abundant, and the beauty approaches that of rare onyx. With these unusual conditions surrounding the deposit, its marketing should become an industry of no small importance. The difficulties of transportation are not insurmountable.

LIME AND GRANITE QUARRIES.

Near Oro Grande and Victor several lime quarries are in operation, constantly giving employment to quite a large number of men. Lime is burned in large kilns, which finds a ready market in Southern California. Granite is also extensively quarried near each of these places, and used for building material, curbing, and paving blocks in Southern California cities. This industry employs, all told, about one hundred men.

THE KENT MINE.

Three miles from Hinkley Station, on the Atlantic and Pacific Railroad, between Barstow and Mojave, is located the Kent Mine, a vein covered by two claims. A shaft 80 feet deep and some superficial development have exposed the ore, which varies from 3 to 10 feet in width. The gangue is a rather fine-grained, granular quartz, containing galena and lead carbonate. Assays in gold and silver are obtainable anywhere in the vein. The highest grade carries lead 70 per cent, gold $25, silver 24 ounces. Some of the ore assaying low in lead contains gold and silver in paying quantities.

The property is in a prospective stage only, but is promising. Water can be obtained near the mine, and fuel is but 8 miles distant. The owner bonded the property in May, 1892, and it is at this writing being developed by the prospective purchasers. The ore is of such character that by sorting a milling ore may be obtained, the high-grade lead ore making a very good smelting material.

THE BLACK HAWK DISTRICT.

Three years ago the Black Hawk District, 40 miles east of Victor, on the north side of the San Bernardino range, attracted considerable attention through the extensive operations of an English syndicate at those mines. Development was in progress at that time, and it was planned to build a sixty-stamp mill. The quantity of gold rock, however, proved to be smaller than had been anticipated, and a small experimental mill was built; but from a short time after the completion of this mill to date all operations have been suspended, and the probability of the resumption of work is not bright.

The gold occurred in a reddish oxide of iron in bunches and stringers scattered through a crushed zone of limestone, lying along the flank of the mountains. A party, who for a time was in charge of the property, informed the writer that he had worked the rock without sorting, had endeavored to sort it, and had tried screening it, but that notwithstanding every precaution was taken, he had concluded that it could not be made to pay. The gold-bearing rock was quite rich, but it occurred in too small quantity to make it profitable.

SILVER REEF DISTRICT.

Four miles northeast of the Black Hawk Mines, lying down on the desert, is a formation of limestone and quartzite, resting on a massive crystalline rock, containing quartz, feldspar, biotite-mica, and hornblende. This reef extends from the mouth of Texas Cañon out upon the plain, sloping downward at an angle of approximately 5° for a distance of 4 miles, where it terminates in a bluff 40 to 100 feet in height. Along the entire eastern edge of this deposit it drops off abruptly as though sharply eroded. At the northern end the reef is faced by a low range of hills composed of the above-mentioned hornblende rock. From this point it swings west and with irregular outline extends for 5 or 6 miles toward Rabbit Springs. The entire area, fully 25 square miles, is cut by gulches varying from 20 to 150 feet or more in depth, that have been eroded through the strata and down into the underlying crystalline rocks. These cañons seem to have resulted from natural drainage, being started by slight depressions in the rolling plateau of limestone. On the extreme northern edge at one point, hills of considerable size have been formed by the folding and tilting of the strata. The limestone has been subjected to violent compression, as the whole area is faulted and broken into millions of fragments.

I have examined not less than twenty mining claims on the reef and traveled over the greater part of its area, and am sure I never saw a single piece of limestone that would weigh 300 pounds, most of the pieces measuring under 6 or 8 inches. Considerable masses along certain zones have been granulated, and even pulverized. This fractured rock has all since been loosely cemented by the infiltration of carbonate of lime into the seams. Geologists who have examined this peculiar deposit do not agree entirely upon its mode of formation. Some believe it to be the result of chemical precipitation of carbonate of lime from calcareous springs, similar to the Formation Springs in the Yellowstone Park. There are many things about Silver Reef which would at once suggest the probability of this mode of deposit, but I am very doubtful that such a theory will stand a thorough investigation.

It was asserted that at one time a shaft sunk in the reef passed through the lime deposit and into the “wash” of the desert beneath. On investigation I found that the lime had indeed been cut through, but the underlying rock proved to be crystalline hornblende rock in place, though somewhat decomposed. At any rate it was not desert “wash.” Over considerable areas the lime is underlaid by a stratum of quartzite of variable thickness, less than a foot in some places, and again in others 10 or 12 feet. Over certain limited areas quartzite is wanting altogether. The lime is mostly crystalline, varying in color. A small portion is as white as snow, the greater part is gray or bluish, and some of it black.

THE ORE DEPOSITS.

For fully 8 miles along the irregular front of the reef silver ores are found. The ore deposits are usually discovered by the cherty masses of silicious rock, which, being harder than the limestone, stand out from its weathered surface in bunches and small, vein-like masses. Often in breaking the cherty rocks, stains of copper carbonate are found, and from such rock silver, and sometimes gold, is obtained. Numerous shafts, cuts, and tunnels have been made on these claims, twenty or more in number, and in every one ore of good grade has been found, although the quantity is usually small. A shipment from a claim called No. 1 returned 129 ounces per ton in the Oro Grande mill. On assaying, 20 ounces can be found on any of the claims, and rock of a higher grade running into the thousands of dollars is not unknown on the reef.

The ore occurs usually as bunches, sheets, or stringers, which “roll” more or less, but in a general way follow the stratification of the limestone downward. These stringers are from 4 inches to 2 feet in thickness, pinching and swelling both longitudinally and on their extension downward. The average of the ores thus far found is probably about $50 per ton. The mines have all been opened by the discoverers, who are men of limited means, and no systematic exploration for larger ore bodies has ever been made. They may exist, though there is no surface indication that such is the case. At one claim, No. 9, I took a large sample for 20 feet across the mineralized zone and found it to assay 11 ounces silver with $2 in gold. This rock was taken from a shallow cut 4 feet in width and 5 feet deep, 20 feet long.

The ore deposits occur without exception in zones of limestone that have been crushed into small fragments, together with much very fine material. In a few places I found in contact or close to the ores what appeared to be a thin intrusive sheet of rock of undoubted igneous origin. The original nature of this rock could not be determined, as it was very much decomposed and bleached. It looked like the white porphyry of Leadville more than anything else I could liken it to, and to a great extent has, doubtless, been the source from which the minerals of the ore deposits were derived. In many places the quartzite which underlies the lime rock contains galena, lead carbonate, wulfenite, zinc-blende, iron sulphide, copper, gold, and silver. Some of this rock contains sufficient lead to be classed as a smelting ore.

The ores of the limestone deposits are chiefly chloride of silver and embolite (chloro-bromide of silver), which is usually accompanied by copper carbonate, sometimes a copper-silver sulphide, wulfenite, lead, and iron in various forms, in a gangue of calcite and quartz, with occasionally manganese oxide. Hornsilver in crystals has been found in the fracture joints and in small cavities of a pure blue limestone, taken from a shaft on one of the claims at the east edge of the district. Pasadena, Riverside, Daggett, and Victor people are the principal owners of claims. Timber can be obtained in the main range 5 or 6 miles back of the mines, and abundance of water can be had from the cañons in the neighboring mountains or from Old Woman’s Springs, 2½ miles east of the principal claims on the reef.

Altogether the district is a most interesting one geologically and also financially, as the high grade of some of the ore had induced the claim owners to sink considerable money in the development of their mines.

THE GAVILAN MINES.

On the San Jacinto estate, which is owned by an English syndicate, are located the old Gavilan Mines, which years ago produced from quartz veins considerable gold, the rock being first crushed in numerous arrastras, the beds of which, to the number of fifty or more, are still scattered all about the neighborhood of the mines. In later years, under American management, the quartz was hauled to a stamp mill in the Pinacate District. At the time the rancho became the property of the English people nothing had been done in these mines for many years. During the past two years the old workings have been investigated and a local company organized at Riverside to operate them under lease. At the time of my visit some workmen were industriously engaged in taking down the gallows frame of the hoist and making preparations to vacate the premises, and this in the face of the report that had gone abroad that a good-sized vein of pay rock had been uncovered at the bottom of the mine at the depth of 180 feet. I did not see the alleged ore shoot and could get no satisfaction from the men at work other than vague hints that there was dissension among the Board of Directors.

The veins of the Gavilan Mines are not large, but of good grade, occurring in a granitoid rock. Black tourmaline in a feldspathic and quartz gangue frequently accompanies the gold-bearing rock. The Mexicans worked a large shoot down to the water-line, and judging from the size and number of the dumps these old workings must have been of great extent. The Riverside people had sunk a new shaft at the extreme south end of the mine 180 feet in depth. The entire region is cut by large feldspathic and granitic veins, which course in every direction. These veins are doubtless intrusive dikes of the variety of granite called pegmatite. White scales of muscovite occur sparingly, but tourmaline is abundant.

THE VANDERBILT DISTRICT.

Forty-five miles from Fenner, on the line of the A. & P. R. R., in the eastern part of the county, near the Nevada State line, is the Vanderbilt District. It lies between Palm District and Ivanpah, at an elevation of 6,000 feet above the sea. Numerous claims have been located on the veins of the district and considerable development done. Messrs. Patton, Taggert & Hall own eight promising claims, which it is their purpose to develop extensively. A shaft 4½ by 6½ feet has been sunk on the vein to a depth of 60 feet, besides which a number of shafts of lesser depth and numerous open cuts have been made, all exposing ore of good grade. The vein is of the branching kind. The veins vary from 5 to 30 feet in width, striking east and west, with a dip to the north of 60°. The gangue is quartz, honey-combed at the surface from the oxidation of the sulphurets it originally contained, small disseminated crystals of which (iron, lead, and copper) begin to show in the rock from the deepest parts of the workings. Some of the rock contains a high percentage of lead in the form of galena and carbonate, but it occurs mostly in bunches and is not evenly distributed through the rock. A shipment of 6,963 pounds to the sampling works at Kingman, Arizona, returned an average assay value of $173 50 per ton, most of which was gold. Another lot averaged $44.

Near the above described property Messrs. Simmons & Roberts have sunk three shafts to a depth of 40 feet each, and Campbell & Beatty put down a shaft 100 feet, all in ore of a character and value similar to that found in the other mines. Both wood and water are obtainable in the district, pine timber growing on the hills, and a good stream of water is flowing down into the desert only 1¼ miles distant from these mines. With the character and grade of the ores found in these veins, and the advantages of wood and water, it would seem that these mines might be successfully operated, particularly as some of the owners are possessed of sufficient means. It is the expressed intention, however, to sink deeper and determine more fully the extent and character of the ore in depth before placing expensive machinery on the ground.

THE IBEX MINE.

Among the mines that have attracted unusual attention in this county during the past year, the Ibex Mine stands prominently in the front rank. It is located 3½ miles from Ibex Station, on the line of the A. & P. R. R., and not over 11 miles north from The Needles. The Ibex property is in the Ibex Mining District, and consists of seven claims, which were located in 1888, now owned by residents of Riverside and San Bernardino. The principal claim is called the Ibex. The vein strikes east and west, dipping at an angle of 45°. Two shafts, one 60 feet and one 52 feet, had been sunk at the time this information was obtained. At the bottom of the 52-foot shaft a drift 38 feet in length has been run on the vein. Surface cuts and trenches are quite numerous on the several claims, and a large amount of quartz containing gold had been exposed. Free gold could be seen in considerable quantity in some of the porous quartz. The quartz is thoroughly crystalline, showing many cavities as a result of the decomposition and leaching out of the sulphuretted minerals it originally contained. These cavities are all lined with minute quartz crystals, which have been deposited evidently since the removal of the sulphides. Rock of this description is full of gold, seemingly. It is so loose in texture that careless handling shakes out the golden grains. John Anderson, of San Bernardino, one of the owners, volunteered the information that from 2 to 4 feet of this rock sampled $100 to $150 per ton. The owners had determined the latter part of April to ship this free-milling ore to The Needles, where a mill was being constructed. Some of the quartz from the lowest workings contains small crystals of pyrite and chalcopyrite, but it would still be classed as an ore susceptible of free amalgamation. The Ibex property had a promising look in the spring of 1892. Its further development will be looked to with great interest by all interested in desert mines.

MONTE NEGRAS DISTRICT.

Near the south boundary of San Bernardino County, and about 75 miles directly east of Mount San Bernardino, a new mining district has been organized within the past two years, and considerable development work accomplished by the claim owners, who, as usual, are men of limited means.

This district is 22 miles northeast of Cottonwood Springs, 16 miles north of Eagle Mountain, and about 6 miles south from Virginia Dale. The belt is about 1½ miles in width and 5 miles in length. The veins trend north and south.

This new district, which has been named the Monte Negras, or Black Mountain District, has attracted considerable attention by the discovery in one of the claims of nuggets of gold and quartz of extreme richness. At the time of this discovery some newspapers in this county published the report that the mythical “Pegleg Smith” Mine had actually been found, which only added to the excitement produced by the bringing into San Bernardino of several hundred dollars worth of specimens.

I visited this new district in the month of May, 1892, and spent several days in making an examination of the claims and adjacent country. The Monte Negras camp is on the south side of the range of hills 45 miles northeast of Walters Station, on the line of the Southern Pacific Railroad, being reached by a fair desert road. By fair I mean a heavy, but not rough or hilly road.

Walters Station is nearly 200 feet below the level of the sea. From that point every foot of the way is up hill, till a divide near Cottonwood Springs is reached, at an altitude of 3,157 feet, the distance being 27 miles; from there to the foot of the wash, which extends 2 or 3 miles from the base of the mountains, down hill 19 miles, where the altitude is 1,300 feet. The altitude of the camp is 1,520 feet. All the mines lying back in the mountains are at higher, though varying, altitudes, the greatest elevation being 3,500 feet, at the Ramona. The neighboring peaks rise from 200 to 800 feet higher.

This district is distant about 35 miles from Cadiz, on the line of the Atlantic and Pacific Railroad. I have never traveled the road, and know nothing of it, although I am told it is a good desert road. Wood is not obtainable at all in the vicinity of the mines, and water is scarce, but has been obtained by sinking a well in a basin at Virginia Dale, a few miles north of these mines. A shaft was sunk 140 feet in the wash 3 miles south of the most southerly Monte Negras mines, but no water was obtained. Bedrock was not reached at the depth mentioned, but it is not unlikely water may be secured by continuing this shaft downward.

I mention all these drawbacks to what I otherwise believe to be promising property, because I think the difficulties may be offset by the fact that the ore is high grade.

The Monte Negras uplift consists, as far as my observation extended, entirely of eruptive rocks, diorite, quartz porphyry, and fine-grained more or less porphyritic rocks, cut by later dikes of felsite and dark-green or black diorite. Epidote occurs in great quantity throughout the region, usually associated with micaceous iron ore, which is found in the form of veins and bunches everywhere. The iron ores contain no precious metals, and are of no economic importance.

The region, although entirely eruptive, and in part volcanic (large fields of basalt occurring on the western slopes) is in the immediate vicinity of a large hill called Pinto, or Painted Mountain, which is made up of metamorphic strata, chloritic and hornblende rocks, quartzite and mica schist predominating.

The mineral-bearing veins of the Monte Negras District are all of the fissure type, and are mostly quite simple in form. The gangue is quartz, carrying iron and copper sulphurets, and the secondary products of those minerals, iron oxide and copper carbonate, with gold and silver. No lead or zinc was observed. The economic value of the ore lies almost, evidently, in its gold contents, the silver occurring so sparingly as to amount to very little. The bullion obtained from these ores is worth about $17 per ounce. The ore ranges in value from $20 to over $100 per ton. Observations on the principal mines of this district, viz.: Great Eastern, Venus, Columbus, Summit, Porcupine, Schiller, Hillerman, Annie Rooney, Ethel, Republican, Ramona, McKinley Bill, and Revenue, have to be omitted in order to condense the report.

SAN DIEGO COUNTY.

By W. H. Storms, Assistant in the Field.

There has been no marked development of mines in this county since the last report was issued, excepting in some of the districts of the Colorado Desert, of which mention will be made. The general geological and topographical features of this county have been so fully described in former reports that to repeat them here is unnecessary. At various times within the past two years new discoveries have been announced, and these have been developed to a greater or less extent, and in some instances, at least, with encouraging results.

HELVETIA MINE.

This mine is located a short distance from the town of Julian, and is equipped with a steam hoist and mill combined under one roof. The new shaft, which was started nearly three years ago, was sunk on the vein for 50 feet, at an angle of 75°, at which depth the shaft left the crevice and continued vertically to a depth of 225 feet. From this point a crosscut was started back toward the vein, running at an angle with its strike, the idea being to reach a pay shoot as quickly as possible. The shoot in question was the south extension of that developed in the old workings. The vein was encountered, and the drift continued along its course. At about 30 feet from the point of intersecting the vein in this drift of the shoot was found. It was hard, blue, rather glassy-looking quartz, filled with minute black particles, and showing considerable gold, some of the rock being very high grade.

The drift was continued along the vein, and finally reached a point over the level that had been run south from the old shaft, which is 300 feet deep. This new drift was found to be 14 feet higher than the old level. The mine was completely drained at the time of my visit, and a free circulation of pure air was found throughout the workings. The ground was ready for stoping, but owing to some legal difficulties arising the property was lying idle.

The appended sketch will give an idea of the present development of the Helvetia, which is one of the most promising properties in the district, and a type of the best class of mines of its kind found there.

The Helvetia, like other mines of the district, occurs in the crystalline schists, the quartz being found as lenses inclosed in the country rock. Some of the lenses might be mistaken for fissures, but I failed to see one possessing the characteristics of a “fissure.”

Nearly all the lenses exhibit a tendency to “make” into the hanging wall side of the country rock, the lenses of quartz following each other in a general direction, but at an angle with the stratification of the schists, and are separate and distinct from each other, being separated at the ends (where they sometimes overlap) by the “leaves,” as they may be termed, of the schistose country rock. These lenses were doubtless caused by a compressive stress on the schists, which had a tendency to split them, but was not powerful enough to cause an abrupt fracture. The accompanying sketch may convey an idea of the occurrence of these quartz lenses.

By the above sketch it will be observed that there is a tendency on the part of the quartz lenses to follow a given direction, which lies at a small angle across the strike of the schists, and that these lenses are not connected, but occur independently, though all are the result of the same force which flexed and split the strata.

Other mines about Julian were idle at the time of my visit, the most of them being inaccessible, owing to water in the workings. Considerable money has been expended on the Owens Mine in an attempt to drain and recover the workings, but it was abandoned after several months of work and considerable expense.

More activity was exhibited in the mines about Banner than any other part of the district.

READY RELIEF MINE.

This is the largest and most extensively developed mine near Banner. It has earned considerable fame, not only as a producer, but for the peculiarities exhibited in the formation of its bunches of quartz, which contain disseminated grains and masses of pyrite.

The Ready Relief has several levels, all of which are connected by winzes and shafts. The huge bunches of quartz have, from their peculiar form, been denominated “rolls,” and I know of no better term which would convey a clear idea of their appearance. As a result of close observation made at numerous points in the mine and on the surface at the time of my visit, I formed the conclusion that the “rolls” of the Ready Relief Mine simply represent an exaggerated condition of the same sort of flexing of the schists that has produced the other mines of this district. The facts as observed lead me to the belief that the “rolls” or folds of the Ready Relief Mine, and its extensions, both north and south, are the result of a severe compressive stress upon the schists at right angle to a line running nearly northwest and southeast; that this force was exerted in the form of pressure and not of contraction; that as a result of this pressure there is a tendency exhibited on the part of the contorted strata to form a reverse fault and not a normal one, and that this power expended itself before the rocks were forced to yield to the strain to the extent of fracture, the result being an abrupt crumpling of the schists without disruption.

Along this line of disturbance percolating waters have deposited silica in enormous quantities. The schistose folded masses having been completely metamorphosed, massive quartz replacing the crushed and crumpled crystalline rocks, though the lines of its former schistose structure are in many places preserved.

A sketch of a characteristic section is here reproduced, and it may help the reader to form some conception of this unusual occurrence of gold-bearing quartz. The strike of the country rock is about northwest and southeast, and varies but little from this over a wide area. The rock is, generally speaking, a dark gray, rather close-grained, micaceous rock (argillite), having a dip to the east of about 80°. The succession of folds cut across the dip of the schists at an angle about 45° from the horizon.

It will be noticed that in places several of the rolls lie side by side. Where this occurs the pay shoot is very large. The thickness of the individual rolls varies from a few inches to 5 or 6 feet, and where the folds parallel each other a width of 12 to 20 feet or more is not uncommon. These rolls do not extend longitudinally a great distance, but seem to gradually diminish, being followed by others along the strike of the vein. It seems quite evident that had the stress which produced this folding or crumpling of the schists proceeded much farther an abrupt fracture must have resulted, and the Ready Relief vein would have been a fissure having a dip of about 45°.

At the time of my visit the Bailey Bros. were overhauling their mill of ten stamps and were putting in a 12-foot waterwheel of the Pelton style.

Though large amounts of quartz have been stoped from the Ready Relief there were still thousands of tons in the mine. Mr. Bailey informed the writer that the rock averaged about $15 per ton.

The other claims which occur along the same course as the Ready Relief are quite similar from a geological standpoint, though none of them exhibit the peculiarities of the folds in such a marked degree. Among the prominent mines on this belt are the Hubbard claims, which were being operated in the spring of 1892, the Redman, Antelope, Cincinnati Belle, and some others.

THE RUBY MINE.

This mine is located a short distance east of and parallel with the Ready Relief. It occurs at the contact of mica schist and syenite. A new five-stamp mill was in course of construction at the time of my visit, in which it was intended to crush quartz from the Ruby and Wilcox, an adjoining location. A small force was employed at the mine.

THE KENTUCK S.

Since the last report was published the Kentuck S came into prominence once more under the ownership of a St. Louis syndicate. A vigorous policy was inaugurated, and for a time all seemingly went well. The shoot of quartz, which had been opened to some depth, crops out along the flank of the steep mountain side. The vein pitches into the hill at a high angle. The manager selected a place to start a new vertical, three-compartment shaft at a point up the hill about 100 feet above the croppings. The shaft was started and was fully equipped. Massive timbers were placed in the most approved style. At a depth of 100 feet the work has reached the level of the croppings, and had cost, it is said, $10,000, and it was still about 125 feet down to a connection with the vein. Here the work was stopped, and has never since been resumed, standing an excellent example of how not to open a mine. The money expended in this shaft would have driven a crosscut tunnel from the base of the hill to the vein, giving at least 500 feet of backs, affording a cheap means of draining, ventilating, and exploiting the mine.

CINCINNATI BELLE.

Among the most promising properties I saw about Banner is the Cincinnati Belle, which has made quite a record as a producer of rock of high grade. This mine, together with several other claims, was purchased by a Pomona company in 1890, for the purpose of operating these mines, among them being the Gold King and Gold Queen Mines, of which mention will be made hereafter. The Cincinnati Belle is situated about 3,000 feet northwest from the town of Banner, and is in charge of D. C. Lane.

The shoots or lenses of quartz which constitute the so-called ore bodies of this mine occur in a general course along the strike of the schists, though each succeeding lens to the northeast “makes” into the hanging wall, as indicated in the cut under the head of Helvetia Mine.

The mine was developed by a tunnel of 168 feet in length, of which the first 40 feet required timbering. Near the mouth of the tunnel a shaft has been sunk on the pitch of the quartz lenses, to a depth of 200 feet. Levels were opened at intervals of 50 feet. The first level at the top had been cut 168 feet along the course of the lead; the second 68 feet; the third 120 feet; the fourth, fifth, and sixth each 50 feet. Each level exposed a bluish quartz rock, which returns in the mill from $18 to $40 per ton. It is free milling, and is treated by a simple amalgamation process.

Though this quartz contains some pyrite, which is auriferous, carrying $8 to $10 per ton, no attempt is made to save the sulphide. The mine makes but little water, and all the quartz and waste are hoisted in a bucket. Pine timber is used, which grows in the neighboring mountains above the mine. It costs 11 cents per running foot at the mine. The property was only under process of development at the time of my examination, and as but little stoping has been done, the cost of mining per ton could not be arrived at. The lenses vary greatly in size, ranging from a few inches to 4 feet. The vein or mineral-bearing zone is accompanied by a fissure, which runs along nearly parallel with the quartz at a distance of a few feet on the hanging wall side. This fault has resulted in the crushing of the country rock along its course.

In this vein, as it may be called, the rock has been completely changed, clay, talcose, and chloritic mineral replacing the micaceous rock. This mineral contains some gold. The inclined shaft has two compartments and is substantially timbered throughout. From the mine the company has graded, along the mountain side, 4,000 feet of road, over which the quartz is transported to the mill in the town of Banner at an expense of 75 cents per ton. The mill contains ten stamps.

The mill is quite complete, but poor judgment was shown in the arrangement by the management under whose supervision it was built, which was before the present Superintendent was in charge. As an instance, the rock from the mine when delivered at the mill is dumped into an ore bin outside the mill. The rock is then taken inside as required and dumped on a grizzly. As usual the large pieces fall on the crusher floor, where they are fed by hand into the jaw rock-breaker, which stands above the level of the floor. This sort of management necessitates extra and unnecessary work.

THE GOLD KING AND GOLD QUEEN MINES

Are located about 4 miles west from Banner, and are owned by the Pomona company, that owns the Cincinnati Belle. Only four men were employed in these mines at the time of my visit, prospecting work only being done. The quartz raised from these workings is hauled 11 miles by road to Banner. The quartz is high grade, and pays well, but no large amount was developed.

THE STONEWALL MINE

Is located about 8 miles southwest from Banner on the Cuyamaca grant, belonging to the Waterman estate. The Superintendent, Waldo S. Waterman, informed the writer that nothing of special interest had been developed in the mine since the publication of the last report (1890).

MESA GRANDE DISTRICT.

A few miles to the northwest from Julian is located the Mesa Grande District, where lenses of a yellowish pellucid quartz of semi-granular texture have been developed somewhat. All of this quartz contains gold, and some of it is quite rich; but nothing of consequence has been done of late, further than to organize a stock company.

ESCONDIDO MINES.

Near the flourishing little town of Escondido are some old Mexican mines, which have been acquired by a San Diego company. The veins are gold-bearing, the quartz having formerly been worked in arrastras with evidently good results, as the surface workings are quite extensive. Within the past two years, however, little has been done on the property.

PINE VALLEY.

The Pine Valley Mines lie 6 miles from the Stonewall and San Diego Stage road, the nearest station being Descanso. Two mills, one of five and one of two stamps, crush the rock taken from the veins in the vicinity. This quartz, it was claimed, would mill over $50 per ton. The veins occur in a formation similar to that about Julian and Banner.

REPORTED TIN DISCOVERIES.