On the south side of the Sierra de Cubitas, in the Province of Camaguey, a distinctly marked zone of this excellent iron ore runs parallel to the main chain of the Cubitas for many miles. Gra.s.s covered hills, rising more or less abruptly from the surface, seem to be composed of solid ma.s.ses of iron ore. So great is the value of this mineral zone that the North Sh.o.r.e Road of Cuba, now under construction and practically completed from its eastern deep water terminus on Nuevitas Harbor to the Maximo River just east of the Sierra de Cubitas, was primarily intended as a means of exploiting and conveying the ore from this zone to the sea coast.

In the western portion of the Organ Mountains of Pinar del Rio, other deposits of nickeliferous iron have been denounced and registered, although the cost of building a railroad to deep water on the north coast up to the present prevented the development of the mines, located about 20 miles southeast of Arroyo de Mantua.

With the enormous amount of constructive work that will undoubtedly follow the great European War, in which iron and steel will play such an important part, there is every reason to believe that capital will be forthcoming with which to build the necessary roads and to develop the nickel bearing iron ores of Cuba.

Structural steel, today and in the future, will probably play a greater part in the world's progress and development than any other one of the products of nature. The demand for steel, of course, was greatly accentuated by the European conflict, without which modern warfare would be practically impossible. The splendid steel turned out in our mills of today would be impossible of manufacture without the addition of a certain percentage of either manganese or chrome. The alloys of these two metals with iron gives steel its elasticity, hardness and real value.

Manganese ores are found in California, Colorado, Arkansas, Georgia, Michigan, New Jersey and Virginia, but nowhere within the limits of the United States have the United States have the deposits of manganese proved to be sufficiently extensive to supply the domestic requirements of the country, even in normal times. The total output of manganese in the United States in 1901 was less than 12,000 tons. Southern Russia contains very large deposits of the metal, but up to 1919, 70% to 80% of the manganese consumed in the United States had been brought from the interior of Southern Brazil.

The immediate and imperative demand for both manganese and chrome, impelled the Government at Washington to seek other sources, closer by, in order to save the time consumed in securing shipments from Brazil.

Small amounts of manganese had been secured from Cuba during the ten years previous to the War, but the extent of these deposits remained unknown until, in the spring of 1918, the United States Geological Survey and Bureau of Mines sent two expert engineers, Messrs. Albert Burch, consulting engineer of the Bureau of Mines, and Ernest F.

Burchard, geologist of the United States Geological Survey, to Cuba in order to ascertain the quality and quant.i.ty of manganese and chrome that might be furnished by that Republic.

The party reached Havana in the latter part of February, and were there joined by Sr. E. I. Montoulieu, a Cuban mining engineer, detailed by the Treasury Department to act as an escort and a.s.sociate throughout research work in the Island. During the two months of their stay these gentlemen made a rapid survey of the more important chrome and manganese zones, the report of which was made to the United States Government in September of 1918.

The chrome deposits, which up to the time of the visit of these engineers had attracted attention in Cuba, are all located within distances varying from ten to twenty-five miles from the north coast of the Island. Some twelve groups were examined which displayed considerable diversity in quality, size and accessibility.

Manganese claims have been registered near Mantua and Vinales, in the Province of Pinar del Rio, but time did not permit an extended study of those deposits. Valuable manganese deposits of known value are found also in the districts of Cienfuegos and Trinidad in the Province of Santa Clara. By far the largest deposits of this ore, and the only ones that are being extensively worked, are located in the Province of Oriente.

The most westerly deposit of chrome visited was found in the eastern part of Havana province, and two others were located, one near Coliser, in the Province of Matanzas, another near Canasi, and a third near the automobile drive about half way between the City of Matanzas and Cardenas. In the province of Camaguey, only a few miles north of the city, valuable deposits of chrome were found quite accessible to the railroad for shipment. Other chrome deposits were found in Oriente; one near Holguin, another south of Nipe Bay, and three groups in the mountains not far from the coast between Punta Corda and Baracoa.

All of the chrome deposits examined by these engineers were found in serpentinized basic rocks. The ore lies in lenticular and tabular ma.s.ses, ranging in thickness from one to more than fifty feet. The ore is generally fine grained to medium coa.r.s.e, and runs from spotted material, consisting of black grains of chromite ranging in diameter from 1/30 to 1/4 of an inch, embedded in light green serpentine, to a solid black material containing little or no visible serpentine.

Most of the ma.s.ses of ore are highly inclined and certain of them are exposed in ravines, on steep hillsides and in mountainous or hilly regions. The deposits west of Nipe Bay are in areas of moderate relief, and those near Camaguey are in an area of very low relief. The deposits in the eastern part of Oriente, which are the largest visited, are in a mountainous country and very difficult of access.

In Havana Province small pockets of chrome ore have been found about two miles south of Canasi, ten miles from the railroad. A little mining has been done and about 600 tons of ore shipped.

In Matanzas Province small deposits of chrome were visited on the "Jack"

claim, seven miles northwest of the railroad station on Mocha, and on the Anna Maria claim ten miles west of Cardenas. The latter is only two miles from the railroad but no ore had been shipped from it.

Considerable development work has been done on the "Jack" claim and about 450 tons of ore were on hand in February of 1918.

Another promising claim was located in a group of several serpentine hills that rise from the comparatively level surface about a mile north of kilometer 36, on the automobile drive between Cardenas and Matanzas.

The outcropping chrome and loose lumps of float, found on the surface, were of high grade, exceeding probably 50%.

Since the visit of the American engineers another very promising chromite claim has been located some four kilometers from the railroad, near Coliseo, in the Province of Matanzas. The owners of this claim announce an unlimited quant.i.ty of good grade ore, and were shipping in the winter of 1918 and 1919 two carloads of ore per day to the United States by rail, using the Havana and Key West Ferry. Messrs. Burch and Burchard state in their report that the geological conditions in the areas referred to above warrant further exploration.

The deposits of chrome examined in Camaguey consist of three groups, which lie along a narrow zone, beginning nine miles north of the City of Camaguey and extending southeast to a point only two miles from Alta Gracia, on the Nuevitas Railroad. A level plain, covered with a thin mantle of clay and limonite gravel, extends from the City of Camaguey northward until its junction with the hills of the Sierra de Cubitas, rendering the country easily accessible by wagon road. Float ore is found in this zone, and broken ore caps some ten or twelve small hills that rise from five to fifty feet above the surrounding surface. In this zone there are also fifteen or more other outcroppings of chromite, most of them obscured by broken ore and rock debris. Prospecting has been done here to obtain samples of ore for a.n.a.lysis, but it has not shown either the nature or the extent of the deposits. On the surface, however, there is a considerable quant.i.ty of ore in the form of broken rocks or coa.r.s.e float, probably 20,000 tons.

Ten samples of ore from the deposits near Camaguey contain from 27% to 36% of chromic oxide. Only two produced less than 30% while a few ran above 35%. This is a low grade ore but is suitable for certain purposes.

If it should require concentration, sufficient water is available in small streams within a mile of the deposit.

Twenty miles north of Camaguey, near the eastern end of the Cubitas iron ore beds, are several other deposits of chrome that were examined by A.

C. Spencer of the United States Geological Survey in 1907. All of these denoted noteworthy quant.i.ties of chrome float, apparently of high grade, and the occurrence of tabular bodies of chrome from one to five feet in width. On one claim boulders of chrome ore are distributed over a belt of some 1700 feet, and on another, fragments of ore are found in an area 150 by 250 feet. On still another claim, five deposits lie within an area measuring 1200 by 3000 feet. One of these seems to be continuous for something over 900 feet.

Both chrome and manganese are scattered throughout various sections of Oriente and the largest deposits of these minerals as well as those of iron are located in this Province. Small deposits of chrome are located some seven miles northeast of Holguin, on the slopes of a low ridge of serpentine that lies between two higher ridges of steeply inclined limestone, about a half mile distant from each other. One pocket had yielded about 150 tons of ore, which with 25 tons of float was ready for shipment in March, 1918. a.n.a.lysis of samples showed an average of 34% of chromic oxide. The maximum content of chromium in pure chromite is 46.66% and the content of chromic oxide is 68%. Late in July of that year the company's consulting engineer reported that a large body of 40% ore had been developed, and that in all about 500 tons were ready for shipment.

One of the larger deposits of chrome that gives promise of a considerable output is located on the south slope of the Sierra de Nipe, about seven miles southeast of Woodfred, the headquarters of the Spanish American Iron Company's Mayari mines. The upper part of the ore body crops out of a steep hillside about 300 feet above a mountain stream, flowing into a small tributary of the Mayari River, and seems to be from ten to thirty feet in thickness. Where it does not crop out, it lies from 30 to 50 feet below the surface. The ore varies in quality, the better grade carrying as high as 48% of chromic oxide, with 7% to 15% of silica, and 7% to 10% of iron. The deposit was estimated to contain about 50,000 tons of chrome ore, 25,000 tons of which would carry more than 40% of chromic oxide and the remaining 25,000 tons between 34% and 40%.

The Cayojuan group of chrome ore claims are located on both sides of a small river emptying into Moa Bay, and lie at an alt.i.tude of about 750 feet above the sea level. An outcrop that extends around the hill for about 300 feet, and covers some 6,400 square feet, has been prospected.

Samples on a.n.a.lysis gave an average of 38.1% chromic oxide.

The Narciso claim, which nearly surrounds the above group, includes an ore body that crops out on a steep hillside, about 500 feet above the river. A sample of ore from this outcrop showed an a.n.a.lysis of 34.8% of chromic oxide.

The Cromita claims, one the left side of the river, contain three known ore bodies, and hundreds of tons of boulder float ore, in an arroyo or gulch. The ore bodies are exposed on the side of a bluff at a height of 150 to 300 feet above the river. The most northerly ore body shows a face 20 feet wide and 15 feet high. The middle body includes an outcrop 75 feet long and 50 feet high and has been penetrated by cutting a tunnel. Geological conditions would indicate that these bodies are connected within the hill. Samples of these ores on a.n.a.lysis varied from 26% to 40.5% of chromic oxide.

The deposits of the Cayojuan group contain probably about 22,500 tons of available chrome ore, but may run as high as 60,000 tons. These estimates include 2,000 tons of float ore in the Cayojuan River and the tributary arroyo. The group of deposits is about eight miles by mule trail from an old wharf at Punta Gorda, to which a road will have to be built along the valley of the Cayojuan, a narrow gorge bordered in many places by steep cliffs. A light tramway for mule cars, or a narrow gauge steam railway, will probably be the most economical way of removing the ore.

The Potosi chrome claim is located on Saltadero Creek four miles above its mouth. This is a tributary of the Yamaniguey River. The ore body is a steeply dipping lens that reaches a depth of more than 100 feet and at one place has a thickness of 250 feet with a length along the strike, of 45 feet. The upper edge crops out about 325 feet above the creek bed, and about 600 feet above sea level. The ore is medium to coa.r.s.e grained.

Some of the material in the drifts is spotted but most of the outcropping and float ore is black and of good appearance. According to the a.n.a.lysis that accompanied the report of G. W. Maynard, the representative ore contains 35% to 41% chromic oxide. This deposit contains from 10,000 to 20,000 tons and the work of getting the ore to the coast involves rather a difficult problem in transportation.

A small body of chrome ore occurs on the Constancia claim, three-quarters of a mile south of Navas Bay, and about 100 feet above the sea level. The ore body appears to extend about 50 feet along the face of a gently sloping hill. It is not of a uniform quality, being largely a spotted ore; that is chromite mixed with serpentine ganue.

About six feet of better ore, however, is exposed in a cut some 25 feet in length. This contains 39.4% chromic oxide. Water for concentration is available near by in the Navas River, and a road could easily be built to the bay, but this is not deep enough for steamers, so it would have to be lightered four miles north to Taco Bay, or ten miles southeast to Baracoa. Another body containing about 10,000 tons of chrome ore of low-grade lies in the mountain eight miles south of Navas Bay.

The reserves of marketable chrome ore that have been prospected in Cuba up to the summer of 1918, range from 92,500 long tons to 170,000. The largest known deposits of chrome ore, or at least the largest of those visited by the engineers Burch and Burchard in the spring of 1918, are those of the Caledonia, and the Cayojuan and the Potosi claims, near the northeast coast of Oriente Province, in a region of rather difficult access. According to indications, they will probably yield 130,000 tons of ore, most of which can be brought to the present commercial grade by simple concentration.

The next largest group of chrome ore deposits is near Camaguey. They are very easy of access, but are of a lower grade than those of Oriente.

They appear to contain a maximum of about 40,000 tons of ore that can be gathered by hand from the surface.

Near Holguin, Cardenas and Matanzas, are small stocks of ore ready for shipment, perhaps 1,000 tons. The most productive chrome mine operating in the fall of 1918 seemed to be that of the "Britannia Company,"

located about twelve miles southwest of Cardenas and about 80 miles from Havana. Two carloads a day were being shipped by rail from Coliseo to Havana, and thence by ferry to Key West and northern smelters.

The manganese ores of Cuba occur princ.i.p.ally in sedimentary rocks such as limestone, sandstone and shale, that in places have become metamorphosed, but in the most heavily mineralized zones are a.s.sociated with ma.s.ses of silicious rocks, locally temed "jasper" and "byate." In one locality the manganese and its silicious a.s.sociates were found in igneous rocks, such as Lat.i.te-porphyry and Lat.i.te. The sedimentary rocks with which manganese deposits are usually a.s.sociated are in some places nearly horizontal, but generally show dips ranging from a few degrees to forty-five or more. The inclined beds usually represent portions of local folds. Some faulting is shown in the vicinity of various manganese deposits and may have influenced the localization of the deposits.

Manganese ore is found in Oriente, Santa Clara and Pinar del Rio provinces, but only in Oriente has it been found in large commercial quant.i.ties. In Oriente the deposits are in three areas, one north and northeast of Santiago de Cuba, another south of Bayamo and Baire, and the third on the Caribbean coast between Torquino Peak and Portillo. The first two include the most extensive deposits on the Island. In Santa Clara ore has been found near the Caribbean coast west of Trinidad, and in Pinar del Rio Province manganese ore occurs north of the city of Pinar del Rio and farther west near Mendoza.

The deposits of the northeast coast and those south of Bayamo, distant from each other approximately 100 miles, show nevertheless an interesting concordance in alt.i.tude. They stand from 500 to 1200 feet above sea level and nearly all of them are at alt.i.tude near 600 and 700 feet, suggesting a relation between the deposition of the manganese and a certain stage in the physiographic development of the region. Most of the manganese ore deposits are above drainage level, on the slopes of hills of moderate height, the maximum relief in the immediate vicinity of the deposits seldom exceeding 500 feet.

The deposits of manganese ore examined in Cuba are rather diverse, but may be grouped into three general physical types--buried deposits, irregular ma.s.ses a.s.sociated with silicious rock or "jaspar," and deposits in residual clay. The buried deposits comprise several varieties, one of the most common being of poorly consolidated beds of sandy chloritic material, cemented, with manganese oxides, that fill inequalities in the surface of hard rocks. Other bedded deposits clearly replace limestone, shale conglomerate or other rocks, and tabular ma.s.ses of ore are interbedded with strata of nearly horizontal limestone. The ore consists largely of Pyrolusite, but many deposits contain Psilomelane, Manganite and Wad, or mixtures of all these materials. The richness of the deposits varies considerably. Most of the richest ma.s.ses are a.s.sociated with the "jaspar," but ma.s.ses that have replaced limestone are also very rich.

The deposits of manganese examined in the Santiago district comprise the Ponupo Group, the Ysobelita, Botsford, Boston, Pilar, Dolores, Laura, San Andrea, Cauto or Abundancia, Llave and Gloria Mines, together with the Caridad and Valle prospects. All of these properties except the two prospects are producing ore. The Ponupo, Ysobelita and Boston mines were opened many years ago and have produced a large quant.i.ty of ore. The Ponupo and Ysobelita are still relatively large producers, though the grade of ore is not so high as that shipped in the earlier days. The Ponupo mine is connected with the Cuba Railroad at La Maya by a branch two miles long, and a narrow gauge track from Cristo, on the Cuba Railroad, runs to the Ysobelita mine three miles distant. Extensions of this line to the Boston and Pilar mines can be made with little additional outlay. The Dolores and Laura mines are near the Guantanamo & Western Railroad, not far from Sabanilla station, and the Cauto mine is adjacent to the Cuba Railroad at Manganeso Station. The other mines are from one to eight miles from the railroad, to which the ore is hauled mainly by oxcarts. In the rainy season these roads are impa.s.sable, and even in the dry season they include many difficult places, so that the quant.i.ty of the output is much less than could be mined under different circ.u.mstances.

The ore is mined by hand, mostly from open cuts, though short drifts and tunnels have been run into lenses of ore at the Ponopu, Cauto and Laura mines, and a slope has been driven on a thin tabular ma.s.s of ore between strata of limestone, dipping about 34 degrees, at the Botsford.

High grade ore may be selected in mining the richer parts of these deposits, but most of it requires mechanical treatment, such as long washing and jigging to free it from clay, sand and other impurities. At one mine the ore is cleaned by raking over a horizontal screen in a stream of water. Log washers are in operation at some mines and under construction at others. At one time a system of washing, screening and jigging is employed. They daily production of manganese ore in March, 1918, from this district, was about 300 tons.

The approximate average composition of the ore now shipped is as follows:

Manganese 38.885% Silica 12.135% Phosphorus .084% Moisture 11.201%

The greater part of the manganese ore from this district contains from 36% to 45% manganese, a few thousand tons running over 45%.

The manganese deposits examined by Messrs. Burch and Burchard south of Bayamo consist of the Manuel, Costa group, 18 to 23 miles by wagon road southwest of Bayamo; the Francisco and Cadiz groups, 15 and 20 miles southeast of the same city; and Guinea, Llego and Charco Redondo, seven to eight miles southeast of Santa Rite; and the Adriano and San Antonio mines, 9 to 10 miles south of Bayari. Other deposits, further to the southeast, are in what is known as the Los Negros district. But little mining has been done so far in this district. Deposits of milling ore are available and will undoubtedly be developed later if prices remain favorable.

It was estimated in April, 1918, that the output of manganese from this district, during 1918, would not exceed 12,000 tons, half of which would be high-grade ore carrying from 45% to 55% of manganese. Later developments, however, indicated a much larger output.

The reserve of manganese ore in this section was estimated at about 50,000 tons, but this does not include the Los Negros district which lies further southeast, 25 to 35 miles from the railroad. Engineers who have examined this zone believe that with good transportation facilities it will yield a large output of high-grade ore from many small deposits.