Part 9

The Chilean Andes correspond with the Western Cordillera of Bolivia and Peru, and consist almost entirely of Jurassic and Cretaceous beds, together with the products of the Tertiary eruptions. The Mesozoic beds are thrown into a series of parallel folds which run in the direction of the chain and which are generally free from any complications such as overthrusting or overfolding. The Cretaceous beds form a synclinal upon the eastern side of the chain (and, in general, beyond the Chilean boundary), while the Jurassic beds are thrown into a number of folds which form the axis and the western flank. Through the Mesozoic beds are intruded granitic and other igneous rocks of Tertiary age, and upon the folded Mesozoic foundation rise the volcanic cones of Tertiary and later date. The Trias is known only at La Ternera near Copiapó, where coal-seams with Rhaetic plants have been found; but the rest of the Mesozoic series, from the Lias to the Upper Cretaceous, appears to be represented without a break of more than local importance. The deposits are marine, consisting mainly of sandstone and limestone, together with tuffs and conglomerates of porphyry and porphyrite. These porphyritic rocks form a characteristic feature of the southern Andes, and were at one time supposed to be metamorphic; but they are certainly volcanic, and as they contain marine fossils they must have been laid down beneath the sea. They are not confined to any one horizon, but occur irregularly throughout the Jurassic and occasionally also amongst the Cretaceous strata. They form, in fact, a special facies which may frequently be traced laterally into the more normal marine deposit of the same age. The fauna of the Mesozoic beds is very rich, and includes forms which are found in northern Europe, others which occur in central Europe, and others again which are characteristic of the Mediterranean region. It lends no support to Neumayr's theory of climatic zones. A large part of the chain is covered by the products of the great volcanoes which still form the highest summits of the Chilean and Argentine Andes. The rocks are liparites, dacites, hornblende and pyroxene andesites. The recent lavas of the still active volcanoes of the south are olivine-bearing hypersthene-andesite and basalt.[1]

_Climate_.--The climate of Chile varies widely, from the tropical heat and extreme arid conditions of the northern coast to the low temperatures and extreme humidity of western Tierra del Fuego and the southern coast. The high altitudes of the Andean region also introduce vertical zones of temperature, modified to some extent by the rainless plateaus of the north, and by the excessive rainfall of the south. In general terms it may be said that the extremes of temperature are not so great as in corresponding latitudes of the northern hemisphere, because of the greater expanse of water in comparison with the land areas, the summers being cooler and the winters warmer. The cold antarctic, or Humboldt, current sweeps northward along the coast and greatly modifies the heat of the arid, tropical plateaus. The climate of northern and central Chile is profoundly affected by the high mountain barrier on the eastern frontier and by the broad treeless pampas of Argentina, which raise the easterly moisture-laden winds from the Atlantic to so high an elevation that they sweep across Chile without leaving a drop of rain. At very rare intervals light rains fall in the desert regions north of Coquimbo, but these are brought by the prevailing coast winds. With this exception these regions are the most arid on the face of the globe, highly heated by a tropical sun during the day and chilled at night by the proximity of snow-covered heights and a cold ocean current. Going south the temperature slowly falls and the rainfall gradually increases, the year being divided into a short rainy season and a long, dry, cloudless season. At Copiapó, in 27° 22' S., 1300 ft. above the sea, the mean annual temperature is 60° and the rainfall about 1 in., but at Coquimbo, in 29° 56' S., the temperature is 59.2° and the rainfall 1½ in. At Santiago, in 33° 27' S., 1755 ft. above the sea, the mean temperature is 54° and the annual rainfall 16½ in., though the latter varies considerably. The number of rainy days in the year averages about 21. At Talca, in 35° 36' S. and 334 ft. above sea-level, the mean annual temperature is nearly one degree above that of Santiago, but the rainfall has increased to 19.7 in. The long dry season of this region makes irrigation necessary, and vegetation has something of a subtropical appearance, palms growing naturally as far south as 37°. The climate is healthy and agreeable, though the death-rate among the common people is abnormally high on account of personal habits and unsanitary surroundings. In southern Chile the climate undergoes a radical change--the prevailing winds becoming westerly, causing a long rainy season with a phenomenal rainfall. The plains as well as the western slopes of the Andes are covered with forest, the rivers become torrents, and the sky is covered with heavy clouds a great part of the year. At Valdivia, in 39° 49' S. and near the sea-level, the mean annual temperature is 52.9° and the annual rainfall 108 to 115 in., with about 150 rainy days in the year. These meteorological conditions are still more accentuated at Ancud, at the north end of the island of Chiloé, in 41° 46' S., where the mean annual temperature is 50.7° and the annual rainfall 134 in. The equable character of the climate at this point is shown by the limited range between its summer and winter temperatures, the mean for January being 56.5° and the mean for July 45.9°. The almost continual cloudiness is undoubtedly a principal cause, not only of the low summer temperatures, but also of the comparatively high winter temperatures. Frosts are infrequent, and snow does not lie long. The climate is considered to be healthful notwithstanding the excessive humidity. The 600 m. of coast from the Chonos Archipelago south to the Fuegian islands have a climate closely approximating that of the latter. It is wet and stormy all the year through, though the rainfall is much less than that of Ancud and Valdivia. The line of perpetual snow, which is 6000 ft. above sea-level between lat. 41° and 43°, descends to 3500 (to 4000) ft. in Tierra del Fuego, affording another indication of the low maximum temperatures ruling during the summer. At the extreme south, where Chilean territory extends across to the Atlantic entrance to the Straits of Magellan, a new climatic influence is encountered in the warm equatorial current flowing down the east coast of South America, which gives to eastern Tierra del Fuego a higher temperature than that of the western shore. The Andes, although much broken in these latitudes, also exert a modifying influence on these eastern districts, sheltering them from the cold westerly storms and giving them a drier climate. This accounts for the surprising meteorological data obtained from Punta Arenas, in 53° 10' S., where the mean annual temperature is 43.2° and the annual rainfall only 22.5 in. Other observations reduce this annual precipitation to less than 16 in. According to observations made by the Swedish Antarctic Expedition (1901-1903), at Orange Bay, Hoste Island, in lat. 55° 31' S., long. 68° 05' W., which is more exposed to the westerly storms, the mean temperature for 11 months was 41.98° and the total precipitation (rain and snow) 53.1 in. The mean maximum temperature was 49.24°, and the mean minimum 35.83°. The observations showed 284 days with rain or snow, of which 70 were with snow.

_Flora_.--The indigenous flora of Chile is less extensive and less interesting than those of Argentina and Brazil, but contains many peculiar genera and species. A classification of this flora necessitates its division into at least three general zones--the desert provinces of the north, central Chile, and the humid regions of the south. The first is an arid desert absolutely barren along part of the coast, between Tacna and Copiapó, but with a coarse scanty vegetation near the Cordilleras along watercourses and on the slopes where moisture from the melting snows above percolates through the sand. In the valleys of the Copiapó and Huasco rivers a meagre vegetation is to be found near their channels, apart from what is produced by irrigation, but the surface of the plateau and the dry river channels below the sierras are completely barren. Continuing southward into the province of Coquimbo a gradual change in the arid conditions may be observed. The higher summits of the Cordilleras afford a larger and more continuous supply of water, and so dependent are the people in the cultivated river valleys on this source of water supply that they watch for snowstorms in the Cordilleras as an indication of what the coming season is to be. The arborescent growth near the mountains is larger and more vigorous, in which are to be found the "algarrobo" (_Prosopis siliquastrum_) and "chañar" (_Gourliea chilensis_), but the only shrub to be found on the coast is a species of _Skytanthus_. Near the sierras where irrigation is possible, fruit-growing is so successful, especially the grape and fig, that the product is considered the best in Chile. In regard to the indigenous flora of this region John Ball[2] says: "The species which grow here are the more or less modified representatives of plants which at some former period existed under very different conditions of life." Proceeding southward cacti become common, first a dwarfed species, and then a larger columnar form (_Cereus quisco_). The streams are fringed with willows; fruit trees and alfalfa fields fill the irrigated valleys, and the lower mountain slopes are better covered with a thorny arborescent growth. The divides between the streams, however, continue barren as far south as the transverse ranges of mountains across the province of Aconcagua.

To some degree the flora of central Chile is of a transition character between the northern and southern zones. It is much more than this, however, for it has a large number of genera and species peculiarly its own. A large majority of the 198 genera peculiar to the South American temperate regions belong exclusively to central Chile. This zone extends from about the 30th to the 36th parallel, perhaps a little farther south to include some characteristic types. The evergreens largely predominate here as well as in the extreme south, and on the open, sunburnt plains the vegetation takes on a subtropical aspect. One of the most characteristic trees of this zone is the _peumo_ (_Cryptocarya peumus_), whose dense evergreen foliage is everywhere conspicuous. The _quillay_ (_Quillaja saponaria_) is another characteristic evergreen tree of this region, whose bark possesses saponaceous properties. In earlier times the coquito palm (_Jubaea spectabilis_) was to be found throughout this part of Chile, but it has been almost completely destroyed for its saccharine sap, from which a treacle was made. One of the most striking forest trees is the _pehuen_ or Chilean pine (_Araucaria imbricata_), which often grows to a height of 100 ft. and is prized by the natives for its fruit. Three indigenous species of the beech--the _roble_ (_Fagus obliqua_), _coyhue_ (_F. Dombeyi_), and _rauli_ (_F. procera_)--are widely diffused and highly prized for their wood, especially the first, which is misleadingly called _roble_ (oak). Most of the woods used in construction and manufactures are found between the Bio-Bio river and the Taytao peninsula, among which are the _alerce_ (_Fitzroya patagonica_), _ciprés_ or Chiloé cypress (_Libocedrus tetragona_), the Chilean cypress (_L. Chilensis_), _lingue_ (_Persea lingue_), laurel (_Laurus aromatica_), _avellano_ (_Guevina avellana_), _luma_ (_Myrtus luma_), _espino_ (_Acacia cavenia_) and many others. Several exotic species have been introduced into this part of Chile, some of which have thriven even better than in their native habitats. Among these are the oak, elm, beech (_F. sylvatica_), walnut, chestnut, poplar, willow and eucalyptus. Through the central zone the plains are open and there are forests on the mountain slopes, but in the southern zone there are no plains, with the exception of small areas near the Straits of Magellan, and the forests are universal. In the variety, size and density of their growth these forests remind one of the tropics. They are made up, in great part, of the evergreen beech (_Fagus betuloides_), the deciduous antarctic beech (_F. antarctica_),[3] and Winter's bark (_Drimys Winteri_), intermingled with a dense undergrowth composed of a great variety of shrubs and plants, among which are _Maytenus magellanica, Arbutus rigida, Myrtus memmolaria_, two or three species of _Berberis_, wild currant (_Ribes antarctica_), a trailing blackberry, tree ferns, reed-like grasses and innumerable parasites. On the eastern side of the Cordillera, in the extreme south, the climate is drier and open, and grassy plains are found, but on the western side the dripping forests extend from an altitude of 1000 to 1500 ft. down to the level of the sea. A peculiar vegetable product of this inclement region is a small globular fungus growing on the bark of the beech, which is a staple article of food among the Fuegians--probably the only instance where a fungus is the bread of a people.

It is generally conceded that the potato originated in southern Chile, as it is found growing wild in Chiloé and neighbouring islands and on the adjacent mainland. The strawberry is also indigenous to these latitudes on both sides of the Andes, and Chile is credited with a species from which the cultivated strawberry derives some of its best qualities. Maize and quinoa (_Chenopodium quinoa_) were known in Chile before the arrival of Europeans, but it is not certain that they are indigenous. Species of the bean and pepper plant are also indigenous, and the former is said to have been cultivated by the natives. Among the many economic plants which have been introduced into Chile and have become important additions to her resources, the more prominent are wheat, barley, hemp and alfalfa (_Medicago sativa_), together with the staple European fruits, such as the apple, pear, peach, nectarine, grape, fig, olive and orange. The date-palm has also been introduced into the southern provinces of the desert region. Among the marine productions on the southern coast, a species of kelp, _Macrocystis pyrifera_, merits special mention because of its extraordinary length, its habit of clinging to the rocks in strong currents and turbulent seas, and its being a shelter for innumerable species of marine animals. Captain FitzRoy found it growing from a depth of 270 ft.

_Fauna._--The fauna of Chile is comparatively poor, both in species and individuals. A great part of the northern deserts is as barren of animal life as of vegetation, and the dense humid forests of the south shelter surprisingly few species. There are no large mammals in all this extensive region except the Cetacea and a species of the _Phocidae_ of southern waters. Neither are there any dangerous species of Carnivora, which are represented by the timid puma (_Felis concolor_), three species of wildcats, three of the fox, two of _Conepatus_, a weasel, sea-otter and six species of seal. The rodents are the most numerously represented order, which includes the _coypu_ or nutria (_Myopotamus coypus_), the chinchilla (_Chinchilla laniger_), the tuco-tuco (_Ctenomys brasiliensis_), a rabbit, and 12 species of mice--in all some 12 genera and 25 species. The coypu, sometimes called the South American beaver, inhabits the river-banks, and is highly prized for its fur. It is also found along the river-courses of Argentina. The ruminants are represented by a few species only--the guanaco (_Auchenia huanaco_), _vicuna_ (_A. vicugna_), _huemul_ (_Cervus chilensis_), which appears on the Chilean escutcheon, and the _pudu_ deer, a small and not very numerous species. There are two species of the Edentata, _Dasypus_ and _Pichiciego_, the latter very rare, and one of the opossums. European animals, such as horses, cattle, sheep, swine and goats, have been introduced into the country and do well. Sheep-raising has also been inaugurated with some degree of success in the vicinity of the Straits of Magellan. The avifauna, with the exception of waterfowl, is also limited to comparatively few species. Birds of prey are represented by the condor, vulture, two species of the carrion-hawk (_Polyborus_), and owl. The Chilean slopes of the Andes appear to be a favourite haunt of the condor, where neighbouring stock-raisers suffer severe losses at times from its attacks. The _Insessores_ are represented by a number of species. Parrots are found as far south as Tierra del Fuego, where Darwin saw them feeding on seeds of the Winter's bark. Humming-birds have a similar range on this coast, one species (_Mellisuga Kingii_) being quite numerous as far south as Tierra del Fuego. A characteristic genus is that of _Pteroptochus_, of which there are three or four species each characterized by some conspicuous peculiarity. These are _P. megapodius_, called _El Turco_ by the natives, which is noticeable for its ungainly appearance and awkward gait; the _P. albicollis_, which inhabits barren hillsides and is called _tapacollo_ from the manner of carrying its tail turned far forward over its back; the _P. rubecula_, of Chiloé, a small timid denizen of the gloomy forest, called the _cheucau_ or _chuca_, whose two or three notes are believed by the superstitious natives to be auguries of impending success or disaster; and an allied species (_Hylactes Tarnii_, King) called the _guid-guid_ or barking bird, whose cry is a close imitation of the yelp of a small dog. The southern coast and its inland waters are frequented by several species of petrel, among which are the _Procellaria gigantea_, whose strength and rapacity led the Spaniards to call it _quebranta huesos_ (breakbones), the _Puffinus cinereus_, which inhabits the inland channels in large flocks, and an allied species (_Puffinuria Berardii_) which inhabits the inland sounds and resembles the auk in some particulars of habit and appearance. There are numerous species in these sheltered channels, inlets and sounds of geese, ducks, swans, cormorants, ibises, bitterns, red-beaks, curlew, snipe, plover and moorhens. Conspicuous among these are the great white swan (_Cygnus anatoides_), the black-necked swan (_Anser nigricollis_), the antarctic goose (_Anas antarctica_) and the "race-horse" or "steamer duck" (_Micropterus brachypterus_).

The marine fauna is less known than the others, but it is rich in species and highly interesting in its varied forms and characteristics. The northern coast has no sheltered waters of any considerable extent, and the shore slopes abruptly to a great depth, which gives it a marine life of no special importance. In the shoal waters about Juan Fernandez are found a species of codfish (possibly _Gadus macrocephalus_), differing in some particulars from the Newfoundland cod, and a large crayfish, both of which are caught for the Valparaiso market. The sheltered waters of the broken southern coast, however, are rich in fish and molluscs, especially in mussels, limpets and barnacles, which are the principal food resource of the nomadic Indian tribes of those regions. A large species of barnacle, _Balanus psittacus_, is found in great abundance from Concepción to Puerto Montt, and is not only eaten by the natives, by whom it is called _pico_, but is also esteemed a great delicacy in the markets of Valparaiso and Santiago. Oysters of excellent flavour are found in the sheltered waters of Chiloé. The Cetacea, which frequent these southern waters, are represented by four species--two dolphins and the sperm and right whale--and the _Phocidae_ by six species, one of which (_Phoca lupina_) differs but little from the common seal. Another species (_Macrorhinus leoninus_), popularly known as the sea-elephant, is provided with short tusks and a short trunk and sometimes grows to a length of 20 ft. Still another species, the sea-lion (_Otaria jubata_), furnishes the natives of Tierra del Fuego with an acceptable article of food, but like the _Phoca lupina_ it is becoming scarce.

Of Reptilia Chile is singularly free, there being recorded only eleven species--five saurians, four ophidians, one frog and one toad--but a more thorough survey of the uninhabited territories of the south may increase this list. There are no alligators in the streams, and the tropical north has very few lizards. There are no poisonous snakes in the country, and, in a region so filled with lakes and rivers as the rainy south, only two species of batrachians. The insect life of these strangely associated regions is likewise greatly restricted by adverse climatic conditions, a considerable part of the northern desert being absolutely barren of animal and vegetable life, while the climate of Tierra del Fuego and the southern coast is highly unfavourable to terrestrial animal life, for which reason comparatively few species are to be found. Writing of a journey inland from Iquique, Charles Darwin says (_Journal of Researches, &c._, p. 444): "Excepting the _Vultur aura_, ... I saw neither bird, quadruped, reptile, nor insect." Of his entomological collection in Tierra del Fuego, which was not large, the majority were of Alpine species. Moreover, he did not find a single species common to that island and Patagonia. These conditions subsist with but few modifications, if any, from the Straits northward to the 42nd parallel, the extreme humidity, abnormal rainfall and dark skies being unfavourable to the development of insect life, while the Andes interpose an impassable barrier to migration from the countries of the eastern coast. The only venomous species to be found in central Chile is that of a spider which frequents the wheat fields in harvest time.