Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/73

Rh 5IA.] C A L 59 The total thickness may be from 3000 to 4000 feet ; the ironstone series is a group of shales containing nodular ironstone about 1500 feet thick, but diminishing westward. Numerous coal seams are worked at different points, but they cannot be traced continuously for more than a short distance without change. In the upper series an average of 11 seams/ together about 120 feet thick, are known in the eastern or Raniganj district, and 13 seams, together 100 feet, on the western side. Occasionally single seams acquire a great thickness (from 20 to 80 feet), but the average of those worked locally is from 12 to 18 feet. In the lower series, 4 seams, together G9 feet, are known. The coals are generally of inferior quality, containing a con siderable amount of ash, and are non-coking in character. The coals of the lower series are better, yielding fairly good coking and gas coal at Sanktoria, near the Barrakur River. A small coal-field at Kurhurbali, near Luckeeserai, on the East Indian Railway, has recently been developed to a considerable extent for locomotive purposes. It covers about 1 1 square miles, with an aggregate of 3 seams, vary ing from 9 to 33 feet in thickness. They are of better quality than those of any other Indian cool-field at present known, and are of great value to the railway, which is now supplied with fuel at a lower rate than probably any other railway company in the world. There are several other coal-fields in Bengal, especially that at Jherria, near the sacred mountain of Parisnath, those south of Hazaribagh, and those on the Sone River, but none are as yet developed to any extent, being away from the great lines of communication. On the western side of India the principal workings are at Mopani, on the Nerbudda, on the line of the Great Indian Peninsular Rail way, the coal being used by the railway. It is of inferior quality, and the strata are inclined at a considerable angle, rendering the working difficult. _ In the Central Provinces a new coal-field of considerable extent has been recently discovered, almost entirely by boring, on the Wardha and Chanda districts, on the upper tributaries of the Godaveri, a considerable portion being within the Nizam s province of Berar. It is probable that this may become one of the most important sources of coal supply for Central and Western India, but no great amount of work has as yet been done upon it. Besides the above, there are several other known coal fields, for details of which the reader is referred to the Reports of the Geological Society of India. The age of the Indian coals is generally supposed to be Permian, the only fossils that have been found in them being plants which are referred to Permian types in Europe. If, however, the overlying sandstones, containing reptilian fossils, generally reputed to be of Triassic age, should, as seems likely, prove to be Permian, it is not improbable that the coal-bearing strata may actually belong to the period of the upper coal measures, and the Indian coal-fields would then be strictly analogous to the deep irregular basins of Southern France and Central Europe, with which they have many structural points in common. No marine strata, or anything approximating to the char acter of the Carboniferous limestone, are known anywhere on the plains of India, although they are found in the salt range of the Punjab and in the Himalayas. The coal-fields of China are known, from the researches of Baron von Richthofen, Prof. Pumpelly, and other travellers, to cover a very large area, comparable only with those of North America; but, as may be imagined, no very detailed information has as yet been obtained concerning them. According to the first-named authority, there are no newer formations than the Trias in China other than alluvial deposits of enormous thickness, but Palaeozoic strata, from the Silurian Howards, are developed on a very large scale. Coal of Carboniferous age exists in Manchuria, mostly in inaccessible mountain valleys, and further west all along the Great Wall. Near Peking there are beds 95 feet thick, which supply the city with fuel. The most extensive development is to the west and north-west, on the south of the great mountain range which stretches across Western China, where there is an area of Carboni ferous strata of 100,000 square miles. The great plain of China is bounded by a limestone escarpment from 2000 to 3000 feet high, which is capped by a plateau covered by 30,000 square miles of coal measures, in which the coal seams, 30 feet thick, lie perfectly hori zontal for 200 miles, and are reported to extend beyond the frontier into Mongolia. Most of the localities are, how ever, far in the interior. The coal of Shantung, though not near good harbours, is the most accessible of all Chinese coal from the sea. It also occurs in the other maritime provinces, but in districts offering fewer facilities for export. It is obvious, from the enormous dimensions given to these coal-fields, that it will be a long time before anything like a moderately accurate estimate of their value can be obtained. In Japan coal is worked at several points, but no detailed Japan account of the mode of its occurrence has been published. At the island of Takasima, near Nagasaki, a colliery is worked by the Japanese Government for the supply of their steamers on a tolerably large scale. In the great islands of the Indian and South Pacific Oceans, coal-bearing strata are known at many different points ; but in the absence of systematic investigation, no general estimate can be formed of their position, extent, or value. In the Dutch settlements, coal has been found in Sumatra and Borneo, the best known deposit being that of Borneo. Pengaron, on the south-east of the latter island, where a mine has bsen worked by the Dutch authorities for several years. The section of the strata, as proved by a level, shows a series of 15 seams above 1 foot in thickness, together about 36 feet, in about 520 feet of measures, 6 of these having been worked. The best appear to be somewhat similar to the steam coal of the North of England. In the British settlement of Labuan, off the north coast of Borneo, 5 Labuan. workable seams, together about 27 feet thick, are estimated to cover the whole island. This is probably of Tertiary age, but approximates in composition to many of the non- coking coals of the coal measures. The Labuan coal is also remarkable for containing large masses of fossil resin. The most important southern coal deposits, however, are Australia those of Australia, which extend, with short intervals, from the Gulf of Carpentaria to Bass s Straits. In the northern districts, the distribution appears to be somewhat similar to that seen in South America, Secondary and Tertiary basins occupying the ground near the sea, while true Carboniferous coal is found further inland; but in New South Wales, where their development is greatest, older coal-bearing strata extend along the eastern slope of the continent, be tween the parallels of 29 and 35 degrees S. latitude, covering a very large area in several detached portions, the largest probably exceeding 12,000 miles, and come down to the sea. The principal workings are situated near Newcastle, at the mouth of the Hunter River, at Wollongong, 60 miles south of Sydney, and at Hartley, about 90 miles inland. The coal seams vary from 3 to 30 feet in thickness Li the Newcastle district, 16 seams above three feet thick being known. The coals are mainly of a free-burning class, but some are bituminous, giving a good coke. In the upper most part of the series oil shales and cannel are found. The age of the Australian coal measures has been the subject of considerable controversy. Formerly it was supposed that they were Oolitic, from the supposed affinities of the fossil plants ; but it has since been shown that the coal -bearing