The Western Highland Region, as a whole, has been one of intense igneous activity dating at least from the Jurassic, and perhaps earlier time, to the recent activity of Lassen's Peak, in California since 1894. This igneous activity is probably the one fact most largely responsible for the great metallic wealth of the region, gold, silver, copper, lead, zinc and many other minerals occurring in very rich deposits in many widely separated localities. Coal of Cretaceous and Tertiary age is also an important economic produce, and petroleum occurs in enormous quantities in California, and in lesser amounts in other localities.
South America.— The mineral belt of South America centres upon the great continental backbone of the Andes, following along the entire western coast' Other small areas add their tribute, notably the coastal uplift of south eastern Brazil, known as the great Brazilian Plateau. The territory available for profitable exploration and development is, broadly speak ing, boundless. Somewhere within the region may be found every mineral having commercial value, scattered far and wide from the mother lodes by the grindings of glaciers and other erosive agencies, for South America exceeds any other part of the world in the abundance of its mineral wealth. After the advent of the Spaniards in the 16th century, Bolivia rivalled Mexico in the billions of dollars of silver taken from its mines, while a few of its mines yielded billions of dollars of gold. Hundreds of mil lions of dollars of gold were also extracted from the soil of Peru,..Colombia, Brazil and the Guianas. At the present day, with her treasures practically untouched, South America holds several world records in the mineral market. The entire supply of the world's bismuth comes from Bolivia ; by far the largest supply of thorium is furnished by the monazite sands of Brazil; the unparalleled nitrate deposits of Chile supply practically all of the world's con sumption of nitric acid, and practically all of its consumption of iodine. Colombia is the only considerable source of platinum outside of Russia; the tin production of Bolivia stands second on the world's tally sheets; Colombia supplies the world's demands for fine emeralds; Brazil is second only to south Africa in the production of diamonds, and for many years was first; the asphalt lakes of Trinidad and Bermudez supply the world. Coal exists in large quantities all through the Andes region. In many localities wide seams are exposed to view for long distances along the slopes and in the sides of ravines, millions upon millions of tons being in sight. Some of these coal veins come down almost to tide water — as at Paracas and near Trujillo, Peru. Good coal found also along the coast of Ecuador; in southern Chile coal is mined extensively at Lota and Coronel, at the former place the mines running out under the sea for more than half a mile; deposits also exist in the Acon cagua region near Rio Blanco. In Colombia coal exists in many widely separated localities; good bituminous coal in the interior and lignite beds near the coast; in Venezuela there is cca: of fair quality. Indifferent development of thi primal commodity, however, is the cause of the retardation from which the mineral industries of South America suffer. The only consider able active oil production in South America is in the Lobitos fields of Peru. In Bolivia, hos ever, there is an immense oil belt 150 miles long, which continues over the national bound ary into Argentina to Comodoro Rivadairx At Santander, Colombia, there is an oil area 100 miles in length and 60 miles in width, an petroleum has been found in the upper Mag dalena district. A large field also exists n Venezuela near the city of Maracaibo.
Iron exists in enormous quantities and of unrivalled quality through all South America awaiting development. In the Brazilian plateau are billions of tons of ore, carrying up to 50 per cent of the metal, but coal and transporta tion are lacking for its successful utilization Great iron deposits, notably at Tofo, are found in Chile. Other important deposits also in Colombia and Peru. Four-fifths of the world's supply of vanadium is produced by a single mine in Peru, to the extent of 3,000 tons annually. Bolivia, Argentina and Brazil furnish about one-tenth of the total production of tungsten, while the great sulphur mine at Tinguirirca, Chile, holds another record as con taining the richest sulphur deposits known.
Consult reports, bulletins and monographs of the United States Geological Survey ; reports of the Canada Geological and Natural History Survey; Suess 'Das Antlitz der Erde> (The Face of the Earth, Prague 1883-88), and, more particularly, the excellent version entitled (la Face de la Terre,) translated and annotated by Emm. de Margerie (Paris 1911) ; Pirsson and
Schuchert, (A Text-Book of Geology) (Nes York 1915) ; Felix and Lank, and Paliontologie der Republik Mexico) (Leipzig 1890): Steinmann, (Sketch of Geology of South America) (in American Naturalist, Vol. XXV, 1891) ; Mill, (International Geography' ; Rus sell, I. C., (North America.) Climatic In a continent prac tically spanning the entire space from pole to pole, every variety of climate may be inferred; and with every elevation from sea line to everlasting ice even in the tropics. each latitude is sure to contain as endless va rieties in itself. In both North America and Asia the western side is both warmer and of more even temperature than the eastern, (M ing to ocean currents generated in the tropics and flowing eastward, the Gulf Stream through the Atlantic, the Kuro Shiwo through the Pa cific. The Rockies, however, give a peculiar character to western North America, to be mentioned later, and even in interior Alaska the isotherms rise— the parallel of Dawson City in the Klondike is that of the north end of Hudson Bay and far into south Greenland. The eastern side of both continents has about the same climatic belts: China corresponds fairly to the United States, and Peking has a climate not unlike Boston. But if we com pare eastern North America with Europe, and to a less extent South America with the East, the leading trait is its greater cold every zone from just below Great Bear Lake; Pet rograd and Christiania are on a level with the southern tip of Greenland. Sitka has much the same parallel as Aberdeen ; Copenhagen and Moscow, Glasgow and Edinburgh, corre spond with central Labrador, northern James Bay and some aistance north of Lake Winni peg. All the British Isles, all the Netherlands and the greater part of Germany, are north of the city of Winnipeg, which itself is about on the parallel of Paris; Saint Paul and Ottawa correspond to Bordeaux, Turin and Bucharest, centres of wine and roses; Boston and Chicago to Rome, New York to Naples; Philadelphia is south of Madrid and Constantinople; Wash ington corresponds to Lisbon and Corfu, Saint Louis to Athens. The thirtieth parallel is about that of New Orleans and the Isthmus of Snez; the twentieth passes through the heart of Mexico, also just below Calcutta and Mecca, and through the Sudan and Sahara; the tenth through Venezuela, also through Guinea and just above Ceylon. The equator touches Quito and the mouth of the Amazon, and also divides Sumatra and Borneo and Lake Victoria Nyan za; the Amazon and the Kongo traversing about the same zones. Even allowing for the elevation of the Mexican plateau, the tempera tures of India and of the deserts of Arabia and Africa cannot be paralleled even on our tropi cal coasts, The difference is due to environ ing conditions and internal structure combined. Above the European mass is a partially thawed sea; above that limit in America lie many hun dred miles of ice-clad land masses, while to the northeast is the continental mass of ice capped Greenland, piercing deep into the east ern side the polar inlet of Hudson Bay. But a partial cause is the mountain framework which in Europe lies mainly east and west and in America north and south. In the latter, there fore, what is practically ( long plain stretches from the Arctic Ocean to the Gulf of Mexico, the polar \vied, fi n d in e no obstruc tion as they swevp southward. "I here is not a spot in North America east of the Rockies abso lutely secure from intense frosts; and there are no definite north-and-south climatic belts, the only sharp divisions being those east and west of the Rockies. In Europe and west Asia, on the contrary, where the mountains cut off the polar winds, the climate will often vary from north-temperate to semi-tropic within a score of miles. This isolation of different parts, giving the most varied lives and habits time to grow into deep-set racial distinctions, has produced by their varied strains and inter action the splendid civilization of the Western world; while the two great plains which fill the centre of each continent, linked by a fer tile and temperate plateau, in itself the most tempting of all, gave no opportunity for differ entiation, and the undiversified monotony of a single racial stock and culture was one of the influences which kept progress at a spot reached by European races thousands of years before.