Lake Junin, or Chinchay-cocha, in the second section, is 36 m. long by 7 m. broad, and 13,232 ft. above the sea. Its marshy banks are overgrown with reeds and inhabited by numerous waterfowl. From this lake the river Xauxa flows southwards through a populous valley for 150 m. before entering the forests. Lake Titicaca (see Bolivia), in the fourth or most southern section, is divided between Peru and Bolivia. It receives a number of short streams from the ranges shutting in the upper end of the valley; the largest is the Ramiz, formed by the two streams of Pucara and Azangaro, both coming from the Knot of Vilcañota to the north. The Suches, which has its source in Lake Suches, falls into Lake Titicaca on the north-west side, as well as the Yllpa and Ylave. The principal islands are Titicaca and Coati (at the south end near the peninsula of Copacabana), Campanaria (9 m. from the east shore), Soto and Esteves. There are two other lakes in the Collao, as the elevated region round Titicaca is called. Lake Arapa, a few miles from the northern shore of Titicaca, is 30 m. in circumference. Lake Umayo is on higher ground to the westward. The lake in Peru which is third in size is that of Parinacochas on the coast watershed, near the foot of the snowy peak of Sarasara. It is 12 m. long by 6 broad, but has never been visited and described by any modern traveller. The smaller alpine lakes, often forming the sources of rivers, are numerous.
The great rivers of the sierra are the Marañon, rising in the lake of Lauricocha and flowing northward in a deep gorge between the Maritime and Central Cordilleras for 350 m., when it forces its way through the mountains at the famous Pongo de Manseriche and enters the Amazonian plain. The Huallaga rises north of Cerro Pasco, and, passing Huanuco, flows northwards on the other side of the Central Cordillera for 300 m. It breaks through the range at the Pongo de Chasuta and falls into the Marañon. he other great rivers are tributaries of the Ucayali. The Pozuzu, flowing eastward from the Knot of Cerro Pasco, joins the Pachitea, which is the most important northern affluent of the Ucayali. The Xauxa, becoming afterwards the Mantaro, receives the drainage of Xauxa, Huancavelica and Ayacucho. The southern valleys of this part of the sierra furnish streams which form the main rivers of Pampas, Pachachaca and Apurimac. These, uniting with the Mantaro, form the Ené, and the Ené and Perené (which drains the province of Tambo) form the Tambo. The Vilcamayu rises on the Knot of Vilcañota, flows north through a lovely valley, received the Yanatilde and Paucartambo on its right bank, and, uniting with the Tambo, forms the Ucayali. Most of these main streams flow through profound gorges in a tropical climate, while the upper slopes yield products of the temperate zone, and the plateaus above are cold and bleak, affording only pasture and the hardiest cereals.
The great variety of elevation within the sierra produces vegetation belonging to every zone. There is a tropical flora in the deep gorges, higher up a sub-tropical, then a temperate, then a sub-arctic flora. In ascending from the coast-valleys there is first an arid range, where the great-branched cacti rear themselves up among Sierran Flora and Fauna. the rocks. Farther inland, where the rains are more plentiful, is the native home of the potato. Here also are other plants with edible roots—the oca (Oxalis tuberosa), ulluca (Ullucus tuberosus), mashua (Tropæolum tuberosum), and learcó (Polymnia sonchifolia). Among the first wild shrubs and trees that are met with are the chilca (Baccharis Feuillei), with a pretty yellow flower, the Mutisia acuminata, with beautiful red and orange flowers, several species of Senecio, calceolarias, the Schinus molle, with its graceful branches and bunches of red berries, and at higher elevations the lambras (Alnus acuminata), the sauco (Sambucus peruviana), the queñuar (Buddleia incana), and the Polylepis racemosa. The Buddleia, locally called oliva silvestre, flourishes at a height of 12,000 ft. round the shores of Lake Titicaca. The most numerously represented family is the Compositae, the grasses being next in number. The temperate valleys of the sierra yield fruits of many kinds. Those indigenous to the country are the delicious chirimoyas, paltas or alligator pears, the paccay, a species of Inga, the lucma, and the granadilla or fruit of the passion-flower. Vineyards and sugar-cane yield crops in the warmer ravines; the sub-tropical valleys are famous for splendid crops of maize; wheat and barley thrive on the mountain slopes; and at heights from 7000 to 13,000 ft. there are crops of quinua (Chenopodium quinua). In the loftiest regions the pasture chiefly consists of a coarse grass (Stipa ychu), of which the llamas eat the upper blades and the sheep browse on the tender shoots beneath. There are also two kinds of shrubby plants, a thorny Composita called “ccanlli” and another, called “tola,” which is a resinous Baccharis and is used for fuel.
The animals which specially belong to the Peruvian Andes are the domestic llamas and alpacas and the wild vicuñas. There are deer, called taruco (Cervus antisensis); the viscacha, a large rodent; a species of fox called atoc; and the puma (Felis concolor) and ucumari or black bear with a white muzzle, when driven by hunger, wander into the loftier regions. The largest bird is the condor, and there is another bird of the vulture tribe, with a black and white wing feather formerly used by the Incas in their head-dress, called the coraquenque or alcamari. The pito is a brown speckled creeper which flutters about the rocks. There is a little bird, the size of a starling, with brown back striped with black, and white breast, which the Indians call yncahualpa; it utters a monotonous sound at each hour of the night. A partridge called yutu frequents the long grass. On the lakes there is a very handsome goose, with white body and dark-green wings shading into violet, called huachua, two kinds of ibis, a large gull (Larus serranus) frequenting the alpine lakes in flocks, flamingoes called parihuana, ducks and water-hens. Many pretty little finches fly about the maize-fields and fruit-gardens, and a little green parakeet is met with as high as 12,000 ft. above the sea.
The third division of Peru is the region of the tropical forests, at the base of the Andes, and within the basin of the Amazon. It is traversed by great navigable rivers. The Marañon, having burst through the defile of the Pongo de Manseriche (575 ft. above sea level), and the Huallaga through that of Chasuta, enter the forests and unite after separate courses of about Montaña. 600 and 400 m., the united flood then flowing eastward to the Brazilian frontier. After 150 m. it is joined by the Ucayali, a great navigable river with a course of 600 m. The country between the Huallaga and the Ucayali, traversed by the Eastern Cordillera, is called the Pampa del Sacramento, and is characterized by extensive grassy plains. The forests drained by the Maranon, Huallaga and Ucayali form the northern portion of the Peruvian montana. The southern half of the montaña is watered by streams flowing from the eastern Andes, which go to form the river Madre de Dios or Amaru-mayu, the principal branch of the river Beni, which falls into the Madeira. The region of the Peruvian montana, which is 800 m. long from the Maranon to the Bolivian frontier, is naturally divided into two sections, the sub-tropical forests in the ravines and on the eastern slopes of the Andes, and the dense tropical forests in the Amazonian plain. The sub-tropical section is important from the value of its products and interesting from the grandeur and beauty of its scenery. Long spurs run off from the Andes, gradually decreasing in elevation, and it is sometimes a distance of 60 or 80 m. before they finally subside into the vast forest-covered plains of the Amazon basin. Numerous rivers flow through the valleys between these spurs, which are the native home of the quinine-yielding cinchona trees. The most valuable species, called C. Calisaya, is found in the forests of Caravaya in south Peru and in those of Bolivia. The species between Caravaya and the headwaters of the Huallaga yield very little of the febrifuge alkaloid. But the forests of Huanuco and Huamalios abound in species yielding the grey bark of commerce, which is rich in cinchonine, an alkaloid efficacious as a febrifuge, though inferior to quinine. With the cinchona trees grow many kinds of melastomaceae, especially the Lasiandra, with masses of purple flowers, tree-ferns and palms. In the warm Valleys there are large plantations of coca (Erythroxylon Coca), the annual produce of which is stated at 15,000,000 ℔. The other products of these warm valleys are excellent coffee, cocoa, sugar, tropical fruits of all kinds, and gold in abundance. In the vast untrodden forests farther east there are timber trees of many kinds, incense trees, a great wealth of rubber trees of the Hevea genus, numerous varieties of beautiful palms, sarsaparilla, vanilla, ipecacuanha and copaiba. The abundant and varied fauna is the same as that of the Brazilian forests.
Geology.[1]—The Eastern Cordillera, which, however, is but little known, appears to consist, as in Bolivia, chiefly of Palaeozoic rocks; the western ranges of the Andes are formed of Mesozoic beds, together with recent volcanic lavas and ashes; and the lower hills near the coast are composed of granite, syenite and other crystalline rocks, sometimes accompanied by limestones and sandstones, which are probably of Lower Cretaceous age, and often covered by marine Tertiary deposits. Thus the orographical features of the country correspond broadly with the geological divisions.
The constitution of the Mesozoic band varies. Above Lima the western chain of the Andes is composed of porphyritic tuffs and massive limestones, while the longitudinal valley of the Oroya is hollowed in carbonaceous sandstones. From the analogy of the neighbouring countries it is possible that some of the tuffs may be Jurassic, but the other deposits probably belong for the most part to the Cretaceous system. The carbonaceous sandstone contains Gault fossils. Like the similar sandstone in Bolivia, it includes seams of coal and is frequently impregnated with cinnabar. It is in this sandstone that the rich mercury mines of Huancavelica are worked.
Farther north, in the department of Ancachs, the Mesozoic belt is composed chiefly of sandstones and shales, and the limestones which form so prominent a feature above Lima seem to have disappeared. The Cordillera Negra in this region is in many places cut by numerous dikes of diorite, and it is near these dikes that silver ores are chiefly
- ↑ See L. Crosnier, “Notice géologique sur les départements de Huancavelica et d’Ayacucho,” Ann. des mines, 5th series, vol. ii. pp. 1–43, Pl. 1 (1852); A. Raimondi, El Departamento de Ancachs y sus riquezas minerales (Lima, 1873); G. Steinmann, “Ueber Tithon und Kreide in den peruanischen Anden,” Neues Jahrb. (1882), vol. ii. pp. 130-153, Pls. 6-8; K. Gerhardt, “Beitrag zur Kenntniss der Kreideformation in Venezuela und Peru,” Neues Jahrb., Beil.–Bd. XI. (1897), pp. 65-117, Pls. 1, 2; J. Grzybowski, “Die Tertiärablagerungen des nördlichen Peru und ihre Molluskenfauna,” Neues Jahrb., Bell.–Bd. XII. (1899), pp. 610-664, Pls. 15-20.
