Читать книгу The History of Cuba (Vol. 1-5) - Willis Fletcher Johnson - Страница 9

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Between these first merely tentative and inconclusive visits of Columbus to Cuba, in which so much was imagined and so little learned or done, and the actual occupation and settlement of the island, which were reserved for a few years later, it will be profitable to pause for a brief space, to review what science has revealed to us of not merely the pre-Columbian but indeed what we may term the archaic history of this chief member of the Antillean group. It is a history written in the rocks and soils, in the mountains and plains and rivers; in brief, the natural history of the island.

This was something at which Columbus could merely have guessed, if indeed he had taken the trouble to think of it at all. He knew only that it was a fair land to look upon and promised to be a pleasant land in which to dwell; and his successors in the quest hoped to find its river beds and its mountain rocks rich with the gold which they coveted. That was all. It remained for the ampler knowledge and the more patient and painstaking research of later years to analyze the structure of the island, to discern the causes and the processes through which it had been developed into its present beautiful and opulent condition, and to learn that on the surface and just below the surface of its almost infinitely variegated face there lay the potency and the promise of wealth beyond the utmost limits of the dreams of those conquistadors of ancient Spain who were oestrus-driven by the auri sacra fames.

Let us consider, then, the geological history of Cuba, so far as it has been ascertained; and the topography of the land as it has been revealed through a far more comprehensive survey than that of the Great Admiral's enraptured vision.

It is, of course, impossible to know the geological history of a country until its paleontology has been thoroughly studied and investigated. Where formations of different geological ages are lithologically so similar as to be often indistinguishable, the only method of differentiating them is by their fossils. Some paleontological work has been done in Cuba, but the specimens collected were not accompanied by the necessary data.

In the present imperfect state of our knowledge of the stratigraphy and areal geology of the island, it would be hazardous to attempt to indicate the times at which the various levels were developed, or to designate the periods during which they remained above the level of the sea. To do this would require a detailed knowledge of nearly all the various phases of its geology.

The oldest rocks in Cuba, with the possible exception of the schistose limestones of Trinidad, are composed of granites and serpentines. The relative age of these rocks, to the central mass of limestones in the province of Pinar del Rio, has not been determined, but we do know that the oldest igneous rocks were themselves folded, faulted and subjected to other processes of metamorphism, and that subsequent to the changes to which they were subjected, the entire region was uplifted and deeply eroded before the cretaceous sedimentation began. No data are available for determining the geologic period at which the pre-cretaceous erosion began, but the region has doubtless been standing above the waters of the ocean for a very long interval, since the amount of rock carried away has been manifestly great.

The surface upon which the cretaceous sediments were deposited, appears to have been reduced by erosion to a very low relief, so that the land was a featureless plain when the cretaceous subsidence began. The time interval required for the accomplishment of this erosion must have been very long, since when it began the region was undoubtedly mountainous.

The complex character and disturbed altitude of the pre-cretaceous rocks, the granites, diorites and other granular rocks which appear on the surface because of this erosion, were originally formed deep within the crust of the earth, and therefore furnish a reason for believing that this period of erosion was exceedingly long.

It has been suggested that during the Jurassic times, the southeastern coast of the United States was connected by a long isthmus, following the line of the Antilles, to the northeastern coast of South America. The data presented would seem to indicate that at least the eastern half of Cuba stood high above the level during this period of the earth's history, and although data concerning the western half are less definite, it too was probably composed of high land masses.

The elevation, and long period of erosion just described, were followed by subsidence, and on the surface of these old rocks the cretaceous formations were deposited. The lowest cretaceous rocks yet found are composed of an arkose, derived in large part from the original igneous mass. The main body of the strata is composed of limestones, and such fossils as they contain belong to the genera similar to those of the cretaceous rocks of Jamaica—Radiolites, Barrettra, Requienia, etc.

During this time the whole of the Island of Cuba was probably submerged below the level of the sea. The cretaceous rocks in Santa Clara province occur in the bottoms of synclines, and the projected dips appear sufficiently to carry the beds over the tops of the dividing anti-clinal axis. It is believed, however, that the depth of the cretaceous sea over the island was probably never very great.

Owing to a lack of paleontological data, the history of the island during the Eocene time is vague, but it is probable that a large part of it was submerged. This is certainly true of the province of Oriente, where Eocene fossils have been collected. During, and possibly previous to that period, volcanic agencies were active in Oriente, since volcanic rocks are found interbedded with sediments of the Eocene age. The same forces were probably active in other sections of the island, and the intrusion of Diorite porphyries in Santa Clara and other provinces probably took place during that period.

A portion of the island, at least in the vicinity of Baracoa, was deeply submerged during the lower Oligocene times, as is proved by the occurrence of radiolarian earth beneath the upper oligocene limestones near the above town. Radiolarian oozes are at present being formed on the sea bottom at depths of between 2,000 and 4,000 fathoms. This, of course, does not prove that the deposits of Baracoa were laid down at so great a depth as present day dredging would indicate, but we can at least feel confident that they were formed in very deep water. This does not imply however that the whole island was sunken to the abysmal depths.

During the upper Oligocene time very nearly the whole island was undoubtedly submerged. Previous to this volcanic agencies had been very active throughout the larger portion of the island. Mountain building in Oriente had begun before the deposition of upper Oligocene strata, and the Sierra Maestra had already been elevated to a considerable height above the sea. It is probable that the sea at this time covered the whole of the island, with the exception of portions of Oriente province along its north and south coast, and occasional high peaks along the axis of the provinces further west.

The Miocene period was one of general uplift. The whole of the island as we at present know it, was above the level of the ocean's waters. There were foldings and uplifts during this period, and volcanic elevation along the axial line being greater than at the sides. It is probable that the folding of the Oligocene strata noted in the vicinity of Havana and Matanzas took place during this time. It may be inferred that the central portion of the province of Oriente was more highly elevated than the coastal portions, since upper Oligocene limestones occur in this section at considerably higher elevations than along either the north or south coast.

It is furthermore very probable that the terracing of the Oligocene coral reefs, such as may be seen in the vicinity of the city of Santiago, was taking place during that time. All the evidence goes to show that these are wave-cut terraces. It may be added here that all of the elevated Pleistocene coral reefs recorded are plastered on the surface of the upper Oligocene formations, or in some instances older geologic rocks. This applies to every later coral terrace that has been described, beginning with Cabanas and extending entirely around the island to the City of Santiago.

The existence of marine Pliocene in Cuba has not been proved. There may be pliocene rocks in the vicinity of Havana some 60 feet above the sea level. If these are true Pliocene, it would indicate a subsidence during that time of from ISO to 180 feet. The character of the fauna found in the quarry on Calle Infanta does not indicate a greater depth than from SO to 70 feet for the water in which the limestone was deposited.

Subsequent to this deposition, there was an elevation which caused the land to stand some forty or fifty feet higher than it does to-day. This probably took place in early Pleistocene times, at which time the Isle of Pines and Cuba were connected. One reason for the belief in this elevation is the existence of an old, deep and comparatively narrow cut in the bed of the present channel leading out of Havana harbor. There is further evidence of a general elevation found in borings for water, three miles southeast of the city of Santiago.

At a depth of some 70 feet below the sea level, in the Rio San Juan Valley, stream-carried pebbles were found. This would indicate that the bottom of this valley once stood at least 70 feet or more above sea level. Subsequent to this elevation, there was a subsidence varying from 40 to 70 feet. There were doubtless other slight oscillations during the Pleistocene period, and these may be going on at the present time, although we have no evidence from records of actually measured monuments established since the Spanish occupation of the island.

Paleontologic, biologic and physiographic research seems to indicate that there has been no land connection between Cuba and North America at any time since the beginning of the Tertiary, unless perhaps during the Oligocene period, and it seems probable there was no connection whatever during cretaceous times.

Cuba furnishes a very interesting field, not only for geologic research, but for a far more extended study and survey of its many important mineral zones both for scientific and for economic reasons.

Topographically the surface of Cuba may be divided into five rather distinct zones, three of which are essentially mountainous. The first includes the entire eastern third of the province of Oriente, together with the greater part of its coast line, where the highest mountains of the island are found. The second includes the greater part of the province of Camaguey, made up of gently rolling plains broken by occasional hills or low mountains, that along the northern coast, and again in the southeast center of the province, rise to a height of approximately 1,500 feet above the general level.

The next is a mountainous district including the greater part of eastern Santa Clara. The fourth comprises the western portion of this province together with all of Matanzas and Havana. The surface of this middle section is largely made up of rolling plains, broken here and there by hills that rise a few hundred feet above the sea level.

The fifth includes the province of Pinar del Rio, the northern half of which is traversed from one end to the other by several more or less parallel ranges of sierras, with mean altitudes ranging from 1,000 to 2,000 feet, leaving the southern half of the province a flat plain, into which, along its northern edge, project spurs and foot hills of the main range.

The highest mountains of Cuba are located in the province of Oriente, where their general elevation is somewhat higher than that of the Allegheny or eastern ranges of the United States. The mountainous area of this province is greater than that of the combined mountain areas of all other parts of the island. The mountains occur in groups, composed of different kinds of rock, and have diverse structures, more or less connected with one another.

The principal range is the Sierra Maestra, extending from Cabo Cruz to the Bay of Guantanamo, forty miles east of Santiago. This chain is continuous and of fairly uniform altitude, with the exception of a break in the vicinity of Santiago where the wide basin of Santiago Bay cuts across the main trend of the range. The highest peak of the island is known as Turquino, located near the middle of the Sierra Maestra, and reaching an altitude of 8,642 feet.

The hills back of Santiago Bay, separating it from the Valley of the Cauto, are similar in structure to the northern foothills of the main sierra. In the western part of the range, the mountains rise abruptly from the depths of the Caribbean Sea, but near the City of Santiago, and to the eastward, they are separated from the ocean by a narrow coastal plain, very much dissected. The streams which traverse it occupy valleys several hundred feet in depth, while the remnants of the plateau appear in the tops of the hills.

East of Guantanamo Bay there are mountains which are structurally distinct from the Sierra Maestra, and these continue to Cape Maysi, the eastern terminus of Cuba. To the west they rise abruptly from the ocean bed, but further east they are bordered by terraced foothills. Towards the north they continue straight across the island as features of bold relief, connecting with the rugged Cuchillas of Baracoa, and with "El Yunque" lying to the southwest.

Extending west from this eastern mass are high plateaus and mesas that form the northern side of the great amphitheatre which drains into Guantanamo Bay. Much of this section, when raised from the sea, was probably a great elevated plain, cut up and eroded through the ages since the seismic uplift that caused its birth.

The most prominent feature of the northern mountains of Oriente Province, west of "El Yunque," is the range comprising the Sierras Cristal and Nipe. These extend east and west, but are separated into several distinct masses by the Rio Sagua, and the Rio Mayari, which break through and empty into harbors on the north coast. The high country south of these ranges has the character of a deeply dissected plateau, the upper stratum of which is limestone.

The character of the surface would indicate that nearly all the mountains of the eastern part of Oriente have been carved through erosion of centuries from a high plateau, the summits of which are found in "El Yunque" near Baracoa, and other flat topped mountains within the drainage basins of the Mayari and the Sagua rivers. The flat summits of the Sierra Nipe are probably remnants of the same great uplift.

Below this level are other benches or broad plateaus, the two most prominent occurring respectively at 1,500 and 2,000 feet above sea level. The highest summits rise to an altitude of 2,800 or 3,000 feet. The 2,000 foot plateau of the Sierra Nipe alone includes an area estimated at not less than 40 square miles. It would seem that these elevated plateaus with their rich soils might be utilized for the production of wheat, and some of the northern fruits that require a cooler temperature than that found in other parts of Cuba.

In the province of Oriente, the various mountain groups form two marginal ranges, which merge in the east, and diverge toward the west. The southern range is far more continuous, while the northern is composed of irregular groups separated by numerous river valleys. Between these divergent ranges lies the broad undulating plain of the famous Cauto Valley, which increases in width as it extends westward. The northern half of this valley merges into the plains of Camaguey, whose surface has been disturbed by volcanic uplifts only by a small group known as the Najassa Hills, in the southeast center of the province, and by the Sierra Cubitas Range, which parallels the coast from the basin of Nuevitas Bay until it terminates in the isolated hill known as Loma Cunagua.

The central mountainous region of the island is located in the province of Santa Clara, where a belt of mountains and hills following approximately northeast and southwest lines, passes through the cities of Sancti Spiritus and Santa Clara. Four groups are found here, one of which lies southwest of Sancti Spiritus and east of the Rio Agabama. A second group is included between the valleys of the Agabama and the Rio Arimao.

The highest peak of Santa Clara is known as Potrerillo, located seven miles north of Trinidad, with an altitude of 2,900 feet. A third group lies southeast of the city of Santa Clara, and includes the Sierra del Escambray and the Alta de Agabama. The rounded hills of this region have an altitude of about 1,000 feet although a few of the summits are somewhat higher.

The fourth group consists of a line of hills, beginning 25 miles east of Sagua la Grande, and extending into the province of Camaguey. The trend of this range is transverse with the general geological structure of the region.

East of the city of Santa Clara the hills of this last group merge with those of the central portion of the province. The summits in the northern line reach an altitude of only a thousand feet. The principal members are known as the Sierra Morena, west of Sagua la Grande, Lomas de Santa Fe, near Camaguini, the Sierra de Bamburanao, near Yaguajay, and the Lomas of the Savanas, south of the last mentioned town.

In the province of Pinar del Rio, we find another system, or chain of mountains, dominated by the Sierra de los Organos or Organ mountains. These begin a little west of Guardiana Bay, with a chain of "magotes" known as the "Pena Blanca," composed of tertiary limestone. These are the result of a seismic upheaval running from north to south, almost at right angles with the main axis of the chains that form the mountainous vertebrae of the island.

Between the city of Pinar del Rio and the north coast of La Esperanza, the Organos are broken up into four or five parallel ridges, two of which are composed of limestone, while the others are of slate, sandstones and schists. The term "magote," in Cuba, is applied to one of the most interesting and strikingly beautiful mountain formations in the world. They are evidently remnants of high ranges running usually from east to west, and have resulted from the upheaval of tertiary strata that dates back probably to the Jurassic period.

The soft white material of this limestone, through countless eons of time, has been hammered by tropical rains that gradually washed away the surface and carved their once ragged peaks into peculiar, round, dome-shaped elevations that often rise perpendicularly to a height of 1,000 feet or more above the level grass plains that form their base. Meanwhile the continual seepage of water formed great caverns within, that sooner or later caved in and fell, hastening thus the gradual leveling to which all mountains are doomed as long as the world is supplied with air and water. The softening and continual crumbling away of the rock have formed a rich soil on which grows a wonderful wealth of tropical vegetation, unlike anything known to other sections of Cuba, or perhaps to the world.

The valley of the Vinales, lying between the city of Pinar del Rio and the north coast, might well be called the garden of the "magotes," since not only is it surrounded by their precipitous walls, but several of them, detached from the main chain, rise abruptly from the floor of the valley, converting it into one of the most strangely beautiful spots in the world.

John D. Henderson, the naturalist, in speaking of this region, says: "The valley of the Vinales must not be compared with the Yosemite or Grand Cañon, or some famed Alpine passage, for it cannot display the astounding contrast of these, or of many well-known valleys among the higher mountains of the world. We were all of us traveled men who viewed this panorama, but all agreed that never before had we gazed on so charming a sight. There are recesses among the Rocky Mountains of Canada into which one gazes with awe and bated breath, where the very silence oppresses, and the beholder instinctively reaches out for support to guard against slipping into the awful chasm below. But the Valley of Vinales, on the contrary, seems to soothe and lull the senses. Like great birds suspended in the sky, we long to soar above it, and then alighting within some palm grove, far below, to rejoice in its atmosphere of perfect peace."

A mountain maze of high, round-topped lomas, dominates almost the entire northern half of Pinar del Rio. It is the picturesque remnant of an elevated plain that at some time in the geological life of the island was raised above the surface 1,500, perhaps 2,000, feet. This, through the erosion of thousands of centuries, has been carved into great land surges, without any particular alignment or system.

Straight up through the center of this mountainous area are projected a series of more or less parallel limestone ridges. These, as a rule, have an east and west axis, and attain a greater elevation than the lomas. They are known as the Sierras de los Organos, although having many local names at different points. Water and atmospheric agencies have carved them into most fantastic shapes, so that they do, in places, present an organ pipe appearance. They are almost always steep, often with vertical walls or "paradones" that rise 1,000 feet from the floor or base on which they rest.

The northernmost range, running parallel to the Gulf Coast, is known as the "Costanero." The highest peak of Pinar del Rio is called Guajaibon, which rises to an altitude of 3,000 feet, with its base but very little above the level of the sea. It is probably of Jurassic limestone and forms the eastern outpost of the Costaneros.

The southern range of the Organos begins with an interesting peak known as the Pan de Azucar, located only a few miles east of the Pena Blanca. From this western sentinel with many breaks extends the great southern chain of the Organos with its various groups of "magotes," reaching eastward throughout the entire province. At its extreme eastern terminus we find a lower and detached ridge known as the Pan de Guanajay, which passes for a few miles beyond the boundary line, and into the province of Havana.

Surrounding the Organos from La Esperanza west, and bordering it also on the south for a short distance east of the city of Pinar del Rio, are ranges of round topped lomas, composed largely of sandstone, slate and shale. The surface of these is covered with the small pines, scrubby palms and undergrowth found only on poor soil.

From the Mulato River east, along the north coast, the character of the lomas changes abruptly. Here we have deep rich soil covered with splendid forests of hard woods, that reach up into the Organos some ten miles back from the coast. Along the southern edge of the Organos, from Herredura east, lies a charming narrow belt of rolling country covered with a rich sandy loam that extends almost to the city of Artemisa.

Extensions, or occasional outcroppings, of the Pinar del Rio mountain system, appear in the Province of Havana, and continue on into Matanzas, where another short coastal range appears, just west of the valley of the Yumuri. This, as before stated, has its continuation in detached ranges that extend along the entire north coast, with but few interruptions, until merged into the mountain maze of eastern Oriente.

Outside of the mountainous district thus described, the general surface of Cuba is a gently undulating plain, with altitudes varying from only a few feet above the sea level to 500 or 600 feet, near El Cristo in Oriente. In Pinar del Rio it forms a piedmont plain that entirely surrounds the mountain range. On the south this plain has a maximum width of about 25 miles and ascends gradually from the shores of the Caribbean at the rate of seven or eight feet to the mile until it reaches the edge of the foothills along the line of the automobile drive connecting Havana with the capital of Pinar del Rio.

North of the mountain range, the lowland belt is very much narrower and in some places reaches a height of 200 feet as a rule deeply dissected, so that in places only the level of the hill tops mark the position of the original plain.

The two piedmont plains of Pinar del Rio unite at the eastern extremity of the Organos Mountains and extend over the greater part of the provinces of Havana and Matanzas and the western half of Santa Clara. The divide as a whole is near the center of this plain, although the land has a gradual slope from near the northern margin towards the south.

In the neighborhood of Havana, the elevation varies between 300 and 400 feet, continuing eastward to Cardenas. The streams flowing north have lowered their channels as the land rose, and the surface drained by them has become deeply dissected, while the streams flowing toward the south have been but little affected by the elevation and remain generally in very narrow channels.

East of Cardenas the general elevation of the plain is low, sloping gradually both north and south from the axis of the island. Considerable areas of this plain are found among the various mountain groups in the eastern half of Santa Clara province, beyond which it extends over the greater part of Camaguey and into Oriente. Here it reaches the northern coast between isolated mountain groups, extending as far east as Nipe Bay, and toward the south, merges into the great Cauto Valley.

From Cabo Cruz the plain extends along the northern base of the Sierra Maestra to the head of the Cauto Valley. Its elevation near Manzanillo is about 200 feet, whence it increases to 640 feet at El Cristo. In the central section of Oriente, the Cauto River and its tributaries have cut channels into this plain from 50 to 200 feet in depth. In the lower part of the valley these channels are sometimes several miles across and are occupied by alluvial flats or river bottoms. They decrease in width toward the east and in the upper part of the valley become narrow gorges.

A large part of this plain of Cuba, especially in the central provinces, is underlaid by porous limestone, through which the surface waters have found underground passages. This accounts for the fact that large areas are occasionally devoid of flowing surface streams. The rain water sinks into the ground as soon as it falls, and after flowing long distances under ground, emerges into bold springs, such as those of the Almendares that burst out of the river bank some eight miles south of the City of Havana. Engineers of the rope and cordage plant, just north of the City of Matanzas, while boring for water, found unexpectedly a swift, running river, only ten feet below the surface, that has given them an inexhaustible supply of excellent water.

Most of the plains of Cuba above indicated have been formed by the erosion of its surface, and are covered with residual soil derived from the underlying limestones. Where they consist of red or black clays they are, as a rule, exceedingly fertile. Certain portions of the plains, especially those bordering on the southern side of the mountains of Pinar del Rio, are covered with a layer of sand and gravel, washed down from the adjoining highlands, and are, as a rule, inferior in fertility to soils derived from the erosion of limestone. Similar superficial deposits are met in the vicinity of Cienfuegos, and in other sections of the island, where the plain forms a piedmont adjacent to highlands composed of silicious rocks.

The most striking and perhaps the most important fact in regard to the climate of Cuba is its freedom from those extremes of temperature which are considered prejudicial to health in any country. The difference between the mean annual temperature of winter and that of summer is only twelve degrees, or from 76 degrees to 88 degrees. Even between the coldest days of winter, when the mercury once went as low as 58 degrees, and the extreme limit of summer, registered as 92 degrees, we have a difference of only 34 degrees; and the extremes of summer are seldom noticed, since the fresh northeast trade winds coming from the Atlantic sweep across the island, carrying away with them the heated atmosphere of the interior.

The fact that the main axis of the island, with its seven hundred mile stretch of territory, extends from southeast to northwest, almost at right angles to the general direction of the wind, plays a very important part in the equability of Cuba's climate. Then again, the island is completely surrounded by oceans, the temperature of which remains constant, and this plays an important part in preventing extremes of heat or cold.

Ice, of course, cannot form, and frost is found only on the tops of the tallest mountain ranges. The few cold days during winter, when the thermometer may drop to 60 after sundown, are the advance waves of "Northers" that sweep down from the Dakotas, across Oklahoma and the great plains of Texas, eventually reaching Cuba, but only after the sting of the cold has been tempered in its passage of six hundred miles across the Gulf of Mexico.

A temperature of 60 degrees in Cuba is not agreeable to the natives, or even to those residents who once lived in northern climes. This may be due to the fact that life in the tropics has a tendency to thin the blood, and to render it less resistant to low temperature; and also because Cuban residences are largely of stone, brick or reinforced concrete, with either tile or marble floors, and have no provision whatever against cold. And, although the walls are heavy, the windows, doors and openings are many times larger than those of residences in the United States, hence the cold cannot readily be excluded as in other countries. There is said to be but one fireplace on the Island of Cuba, and that was built in the beautiful home of an American, near Guayabal, just to remind him, he said, of the country whence he came.

Again, in the matter of rainfall and its bearing on the climate of a country, Cuba is very fortunate. The rains all come in the form of showers during the summer months, from the middle of May until the end of October, and serve to purify and temper the heat of summer. On the other hand, the cooler months of winter are quite dry, and absolutely free from the chilling rains, sleets, snows, mists and dampness, that endanger the health, if not the life, of those less fortunate people who dwell in latitudes close to 40 degrees.

Cloudy, gloomy days are almost unknown in Cuba, and the sun can be depended upon to shine for at least thirty days every month, and according to the testimony of physicians nothing is better than sunshine to eliminate the germs of contagious diseases. Hence we can truthfully say that in the matter of climate and health, Cuba asks no favor of any country on earth.