MINES AND MINING
After a lapse of more than four centuries, there are grounds for
believing that the dreams of the early Spanish conquerors, who overran
Cuba shortly after its discovery by Columbus, may be realized, though
not exactly as they expected. Gold may never be found in paying
quantities, yet the mineral wealth of the Island may exceed in value its
present agricultural output, which amounts annually to hundreds of
millions of dollars. The followers of Columbus as a rule cared little
for the more quiet pursuits of agriculture, but were obsessed with a
craving for the precious metals, and during the first half of the 16th
century, with the aid of the Indians, mined and shipped a sufficient
amount of gold to encourage greatly the rulers of Spain, who were quite
as persistent in their craze for the yellow metal as were the pioneers
of the New World.
Narvaez, Velasquez’s most active lieutenant, at the head of 150 men in
1512, marched from Oriente westward in a wild search for gold. Samples
of this metal were found in various places and sent back to Velasquez,
who forwarded them to King Ferdinand. The seven cities founded within
the next two years were said to have been selected, not owing to the
fertility of their soil or on account of advantageous locations, but
solely with reference to their proximity to gold deposits.
In spite of these early discoveries, however, the amount of gold found
in Cuba, although encouraging at the time, has never approached the
value of other metals far more common and found in almost unlimited
quantities. The district that first seems to have yielded a fair amount
of gold was along the shores of the Arimao River, where the Cubenos
panned a few hundred dollars in nuggets from the bed of the stream, and
this determined the location of the city of Trinidad in 1514.
The first and largest shipment of gold from the Island of Cuba,
amounting to $12,437, was forwarded to Spain in the summer of 1515, and
was converted into coin of the realm by the King. Since the royal share
was one-fifth of all produced, it would seem that the total yield during
the first four years in Cuba amounted to $62,000.
The large quantities of gold found in Mexico by Cortez, some ten years
later, so greatly excited the Spanish conquerors in their quest for this
metal, that gold mining in Cuba gradually became an abandoned industry,
and by 1535 had practically ceased. Since that time there have been no
discoveries that would seem to justify further search.
Some time during the year 1529, copper was discovered on the crest of a
hill known as Cardenillo, about ten miles west of Santiago de Cuba.
Mines in this vicinity had apparently been previously worked by the
Cubeno Indians, who did not enlighten the Spaniards in regard to their
existence. The value of the find was not recognized until a certain
bell-maker, returning as a passenger from Mexico, visited the mines and
analyzed samples of the ore. As a result of his report the people of
Santiago soon became aroused over the prospective value of the find and
petitioned the crown for experts and facilities with which to develop
the mine.
Dr. Ledoux, the famous French metallurgist, carefully analyzed the ore
from these mines, and as a result reached the conclusion that the
natives of Cuba, although apparently making no use of the copper
themselves, had trafficked with the Indians of Florida, since in the
many assays made of the copper relics of those tribes, it was found that
the same percentage of silver and gold were contained in them as was
found in the ore of the Cuban deposits. No other copper ores known have
percentages of silver and gold so closely identical to those of “El
Cobre.”
Little was done, however, toward the development of the Santiago mines
until 1540, when the Spanish crown found itself short of material with
which to make castings for its artillery and ordered an investigation of
the Cuban copper deposits. In April of 1540, a German returning from a
Flemish settlement in Venezluela visited “El Cobre” and entered into an
agreement with the town council to work the mine. The ore yielded,
according to the records, from 55% to 60% of pure copper, carrying with
it also gold and silver. Samples were again sent to Spain to be tested
by the crown. In 1514 forty negroes were set to work in the mines, under
the direction of Gaspar Lomanes, and smelted some 15,000 pounds.
In 1546 the German referred to above, John Tezel of Nuremberg, returned
from Germany, where he had carried samples of ore from the “El Cobre”
and reported it “medium rich in quality and very plentiful in quantity.”
Tezel spent the remainder of his life, 20 years, in exploiting the
copper of that section.
Up to 1545 Juan Lobera had shipped 9,000 pounds of Cuban Copper to
Spain. In the spring of 1547 still further shipments that had arrived in
Seville and were ordered cast into artillery to be placed in the first
fort in Cuba, La Fuerza, for the protection of the City of Havana. Three
cannon were cast, of which one, a falconet, burst in the making, and was
perhaps responsible for the report that Cuban copper was of “an
intractable quality.”
Don Gabriel Montalvo, appointed Governor of Cuba in 1573, was much
impressed by the reports he had heard of the rich copper deposits near
the city of Santiago de Cuba, and visited some of the old workings, but
found the native Cubenos very reluctant to give him information in
regard to mineral deposits, fearing evidently that they would be
compelled to work in them as miners.
A copper deposit was soon afterwards found near Havana, and samples of
ore were forwarded to Spain with the request that 50 negroes be detailed
to exploit the mine. The quality of the ore was apparently satisfactory
for the casting of cannon, and the king ordered that it be used for
ballast in ships returning from Havana, in order to furnish material for
the Royal Spanish Navy.
In 1580, some mining was done, but the find soon proved to be a pocket
and not a true vein, and the cost of transportation to Havana was
declared prohibitive, in spite of the fact that it showed a “fifth part
good copper.” Other copper mines were afterwards reported in the
neighborhood of Bayamo, near the southeastern center of the Province of
Oriente.
In May, 1587, although comparatively little copper had been taken from
“El Cobre” mine, due largely to lack of food crops in the vicinity with
which to supply the slaves, the Governor reported that “There is so much
metal, and the mines are so numerous that they could supply the world
with copper, and only lately there is news of a new mine of even better
metal than the rest.”
Effective work in these mines began in 1599. The much needed protection
from the incursion of pirates and privateers, that had long preyed on
Spain’s possessions in the West Indies, revived industries of all kinds
in Cuba, especially copper mining and ship-building. Juan de Texeda, who
had been commissioned by the King to go to Havana and do what he could
towards protecting the rich shipments of gold that were being sent from
Mexico to Spain against the attacks of the English Admiral, Drake,
sampled Cuban copper and pronounced it excellent. On the site of the
present Maestranza Building, now devoted to the Department of Public
Works and the Public Library, Texeda soon established a foundry, where
he “cast the copper into both cannon and kettles.”
The mining of copper with profit depends on the price of the metal in
the market and on the cost of extracting and transporting the ore to the
smelter. This, of course, is true with all metals, hence it frequently
happens that mines containing abundant ore are not worked, owing to the
fact that the cost of production, when taken into consideration with the
market price, eliminates the possibility of profit. During the past
century the mines of “El Cobre” and vicinity, the extent of whose
deposits seem to be almost unlimited, have been worked at such times and
to such an extent as the market price of the ore would seem to justify.
Indications, such as boulders that through seismic disturbances or
erosion seem to have rolled down from their original beds, and
occasional outcroppings of copper-bearing ore, are found in every
Province of the Island, although up to 1790 but few explorations worthy
of mention were made outside of the Province of Oriente. The demands for
metals of all kinds, especially chrome, manganese and copper, have
resulted in more or less desultory prospecting since 1915, which has
resulted in finding outcroppings of copper scattered throughout the
mountains of Pinar del Rio. Claims have been located near Mantua,
Vinales, Las Acostas, Santa Lucia, Pinar del Rio, and at various places
between La Esperenza and Bahia Honda along the north coast.
Reports of copper or “claims,” resulting from traces found, have been
made also in the Isle of Pines and at Minas, only a short distance east
of the city of Havana, in that province. Copper claims have been
registered near Pueblo Nuevo, too, in the Province of Matanzas. In the
province of Santa Clara, claims have been recorded in the districts of
Cienfuegos, Trinidad and Sancti Spiritus. Several very promising copper
mines have been opened up in this province that will undoubtedly yield a
profit if worked under intelligent management and with the judicious
employment of capital. In the Province of Camaguey, copper has been
discovered near Minas, and as several different places along the line of
the Sierra de Cubitas. In Oriente, copper claims have been registered
near Holguin and Bayamo, while “El Cobre,” of course, has been famous
for its yield of ore since the days of the Spanish conquerors.
The excessive demand for copper resulting from the War in Europe,
together with the high prices offered for that metal, recalled the fact
that many years ago Spanish engineers and prospectors, among the hills
of Pinar del Rio, frequently found small outcroppings of copper ore, and
in some cases sank shafts for short distances, where the ore had been
removed and carried to the coast on mule back. The low price of copper
at that time, however, and the scarcity of labor following the abolition
of slavery at the conclusion of the Ten Years’ War, discouraged serious
work on the part of the old timers, traces of whose efforts still remain
at various points along the northern slope of the Organos Mountains.
The first record we have of the exploration of the mineral zone in which
the famous copper mine of this Province was discovered, dates back to
1790, but it resulted in no definite or profitable work. An English
company of which General Narciso Lopez was president, during the early
part of the 19th century, made some explorations in the district of El
Brujo and Cacarajicara, located in the mountains back of Bahia Honda;
but the defeat of Lopez’s revolutionary forces, and his subsequent
execution in 1851, put an end to the effort.
Shortly after the Spanish American War, Col. John Jacob Astor, the
American millionaire, became interested in the copper deposits of Pinar
del Rio, which resulted in the establishment of several claims, none of
which, however, were developed. Shortly after this a Mr. Argudin located
claims known as Regelia and Jesus Sacramento, the former only two
kilometers from that of the mine Matahambre. A small amount of
preliminary work was done, but apparently proved unpromising.
In 1912 Alfredo Porta, a well-known citizen and politician of Pinar del
Rio, interested Mr. Luciano Diaz, a former Secretary of the Treasury and
a man of some means, in a claim which he had denounced some eight
kilometers back from La Esperanza, on the north coast of the province.
Messrs. Porta and Diaz secured the services of an experienced mining
engineer, Mr. Morse, who visited the district, made a careful survey of
the claim, and informed the owners that in his estimate Matahambre was
worthy of the investment of any amount of capital, since the grade of
the ore, and the amount exposed through Mr. Morse’s preliminary work,
was sufficient to place it in the list of paying mineral properties.
Work began at Matahambre in the early part of 1913 under the technical
direction of C. L. Constant, of New York. During the first year a number
of galleries, only a little below the surface, were thrown out in
different directions. Paying ore found in these galleries was very
promising. The first two carloads of ore, shipped by rail from the City
of Pinar del Rio to Havana, sold for a sufficient amount of money to pay
for all of the preliminary work that had been done. In 1915, a shaft was
sunk to a depth of 100 feet and afterwards carried down to the 400-foot
level, where it about reached the level of the sea. Later this shaft was
sent down 150 feet further. The ore taken out at the 400-foot level
proved to be the highest grade of all found, although it is said that no
ore was encountered at any depth that was not of sufficient value more
than to pay for the cost of mining. In fact the percentage of gold and
silver in many cases has paid for the expense of mining the copper. In
1918, six shafts, known as 5, 6, 7, 8, 9 and 10, were in operation, and
all yielding excellent ore. There are some 15 different varieties of
copper ore taken from Matahambre.
The ore for some time was conveyed to the docks at Santa Lucia with mule
teams and motor trucks. These were eventually replaced by wire cables
and the ore was sent to the coast by gravity, greatly decreasing the
cost of transportation. Splendid wharves and receiving sheds, dumps,
etc., have been built at Santa Lucia, whence the ore is lightered out to
deep water anchorage. Fully 300 tons a day are now being removed and
conveyed to the landing. An average of 8,000 tons a month is shipped in
steamers that can take aboard 800 tons a day. This mineral is consigned
to the United States Metal Refining Company. In 1916, thirty-three
steamers carried 75,000 tons of mineral to this Company.
Quite a little city has sprung up around the mine, and 2,000 men are
given employment by the Company. Comfortable quarters have been erected
for the officials, employees and other members of the force. A large
amount of ore was mined in 1918 and held for the completion of a new
concentration plant, which will enable the Company to utilize ore which
under war freight rates would not have been profitable to export.
Following the demise of Sr. Luciano Diaz, his son Antonio Diaz assumed
control and is carrying on the work of the proposed improvements.
At the time of the closing of the Spanish régime in Cuba, fourteen
mineral claims had been made in the Province of Pinar del Rio. Between
1909 and 1911, 212 were denounced, including 48 of the Company headed by
Mr. Astor. From 1911 to 1918, 2970 claims were registered in the Bureau
of Mines. A large proportion of the interest in copper mining in Pinar
del Rio was undoubtedly the result of the wonderful wealth that has come
from Matahambre, the ore from which mined in 1916 was valued at
$5,500,000.
Not until the early part of the 19th century did the presence of those
enormous deposits of iron ore found throughout the mountain districts of
Oriente present themselves to the outside world as a profitable
commercial proposition.
Nearly all of the great iron deposits of Oriente lie within a few feet
of the surface; and on the southern slopes of the Sierra Maestra it is
necessary only to scrape the dirt from the side of the hills, take out
the ore and send it down to the sea coast by gravity. Similar conditions
exist at the Mayari mines on the north coast, just back of Nipe Bay,
where the deposits need nothing but washing with cold water. The soil
being thus removed at little cost, the iron is ready for shipment to the
smelters of the United States.
In spite of the fact that this ore was found to be equal to the best
Swedish, and that nature in her own laboratories had supplied the
requisite amount of nickel and manganese, making these mines of Oriente
perhaps the most valuable in the world, but little attention has been
paid to this marvellously rich source of minerals, beyond those few who
are drawing dividends from the industry. The recent purchase of the
Spanish American Iron Company’s holdings at Daiquiri for $32,000,000,
however, has called the attention of mining interests in the United
States to the fact that millions of tons of untouched ore still lie in
the eastern provinces of Cuba. Twenty-five percent of the area of
Oriente contains wonderful deposits of ore, mostly iron, and awaits only
the necessary capital to place it on the markets of the world.
This nickeliferous iron ore, in which the presence of nickel, so
essential to the making of steel, has been contributed by nature in just
the right proportions, is found in large quantities also in the
provinces of Camaguey and Pinar del Rio. The extent of these mineral
deposits is not yet known, but millions of tons are in sight, awaiting
only cheap transportation to bring them into the markets of the world,
where the grade and quality of the ore will undoubtedly command
satisfactory prices.
Up to the present time nearly all of the iron ore exported from Cuba
comes from the large deposits of Oriente. The iron on the south coast is
loaded into the steamers from the wharves at Daiquiri and Juraguay. That
on the north coast, brought down from the Mayari mines, is shipped from
the harbor of Nuevitas.
Below are given the tons of copper and iron shipped from Cuba during the
year from July, 1917, to June, 1918:
IRON COPPER
tons tons
July to December, 1917 272,403 41,809
January to June, 1918 218,301 52,569
Total 490,704 94,378
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. Grass covered hills, rising
more or less abruptly from the surface, seem to be composed of solid
masses of iron ore. So great is the value of this mineral zone that the
North Shore 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 quantity 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 associate 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
masses, ranging in thickness from one to more than fifty feet. The ore
is generally fine grained to medium coarse, 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 masses 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 quantity 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 analysis, but it has not
shown either the nature or the extent of the deposits. On the surface,
however, there is a considerable quantity of ore in the form of broken
rocks or coarse 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 quantities 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. Analysis 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 altitude 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 analysis 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 analysis 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 analysis 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 coarse 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 analysis 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 principally in sedimentary rocks such
as limestone, sandstone and shale, that in places have become
metamorphosed, but in the most heavily mineralized zones are associated
with masses of silicious rocks, locally temed “jasper” and “byate.” In
one locality the manganese and its silicious associates were found in
igneous rocks, such as Latite-porphyry and Latite. The sedimentary rocks
with which manganese deposits are usually associated 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
quantities. 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 altitude. They stand from 500 to 1200 feet
above sea level and nearly all of them are at altitude 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 masses associated 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 masses
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 masses
are associated with the “jaspar,” but masses 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 quantity 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 impassable, and
even in the dry season they include many difficult places, so that the
quantity of the output is much less than could be mined under different
circumstances.
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 mass 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.
Aside from difficult transportation facilities in some districts, one of
the chief obstacles in the way of a large yield of ore from the mines
has resulted from an inability to hold a sufficient number of miners at
certain mines, owing to an inadequate supply of foodstuffs. Many workmen
preferred to work in the sugar mills where good food was more readily
obtained and living conditions were easier. Lack of explosives also
handicapped mining in some districts. The building of narrow gauge
railroads in which the Cuban Federal Government will probably assist
will greatly contribute to the successful or profitable mining of
manganese in the Province of Oriente. The fact that most of the ore is
removed during the dry season, when the Cuba Company’s roads are taxed
to the limit in conveying sugar cane to the mills, also renders
transportation by rail rather uncertain.
Despite the handicaps outlined above, operators of manganese mines are
striving to increase their output, and there is a strong interest taken
everywhere in Cuba in developing manganese prospects. If railway cars
and ships are provided for transporting the ore, food for the mine
laborers, and explosives for blasting, the outlook for a steadily
increasing production is good. The output for 1918 was estimated at
between 110,000 and 125,000 tons, more than 90% of which runs from 36%
to 45% manganese, the remainder being of a higher grade. The reserves
of manganese ore in the mines above referred to in Oriente Province are
estimated at from 700,000 to 800,000 tons, 85% of which is located in
the district northeast of Santiago.