Page:Encyclopædia Britannica, Ninth Edition, v. 18.djvu/746

714 in Shropshire and Biddings in Derbyshire, two other coal fields ; also in a peat-bog at Down Holland, near Orms- kirk, in Lancashire, but never in commercial quantities. The greatest supply has not been more than fifty gallons a day, and even that soon diminished." A tar-spring was known at Coalport, in Shropshire, early in the present century. Although there are extensive deposits of solid bitumen in eastern France and Switzerland, the petroleum springs that occur at Saint Boes, Basses Pyrenees, are un important. In Alsace, at Lobsann and Bechelbronn, petro leum has been obtained for many years for local uses. Although reported from many localities in Germany, the only point that has promised to be of any importance is the Liineburg heath, south of Hamburg. Petroleum is also reported near Holle, in Dithmarschen, Schleswig-Holstein. On the eastern shores of the Adriatic in Dalmatia and Albania and in the Ionian Islands, petroleum springs have been mentioned by the writers of classical antiquity. In Armenia and Persia petroleum has been used for un known centuries, and it appears to be widely distributed in the mountains that surround the tableland of Iran. In Algeria, Egypt, Kashmir, the Punjab, Assam, Java, and other East Indian islands petroleum is reported. In North America the successful development of the petroleum-fields of north-west Pennsylvania following the completion of Drake s well led in a few years to the drilling of wells in a great many localities where petroleum-springs had been observed. The following so-called " petroleum-fields " have produced oil in commercial quantities more or less valuable. Name. Maximum produc tion in Yield in barrels to 1880. | Oil Creek, Venango county, Pennsylvania Pithole, ,, Central Alleghany, ,, ,, Lower Alleghany, Butler and Clarion counties , , Tidioute, Venango and Warren counties ,, Bullion, Venango county ,, Bradford, M Kean county ,, Warren, Warren county ,, Smith s Ferry, Beaver county ,, Mecca, Trumbull county, Ohio 1862 1866 1871 1874 1874 1877 1881 1878 1879 1 A conti prodi 1865. 35,517,297 8,816,289 6,182,900 37,342,978 4,674,345 2,312,090 ! 44,574,921 j 448,213 339,631 nuous small iction since No record. Grafton, Lorain county, ,, ... Macksburg, Washington county, ,, Horse Neck, Pleasants county, W. Virginia Volcano, Wood county, ,, Burning Spring, Wirt county, ,, Glasgow, Barren county, Kentucky Santa Clara Valley, Ventura county, Cali fornia Besides these localities petroleum has been observed over an area 1500 miles long by an unknown breadth in the valley of the Mackenzie and its tributaries, and in New Brunswick, Newfoundland, and other portions of eastern Canada. It also occurs at many different points along the Appalachian system of mountains from Point Gaspe on the St Lawrence to northern Alabama. It has been noticed in Kansas, Missouri, Wyoming, Colorado, and Texas in the United States, in southern Mexico, in the West India Islands, and in the northern states of South America. Petroleum is one- of the most widely distributed substances occurring in nature, but an examination of the geograph ical localities in which it chiefly occurs will show them to be intimately connected with the principal mountain-chains of the world. Geological Relations. It has been frequently remarked that petroleum occurs in all geological formations, from the Silurian up to the Tertiary. While this is true as a general statement, it is misleading, for petroleum is not uniformly distributed through all formations, but occurs principally in two epochs of geological history ; these are the Silurian and the lower half of the Tertiary. The vast accumulations along the principal axis of occurrence in the western hemisphere are found in Silurian and Devonian rocks ; the most productive axis of occurrence in the eastern hemisphere lies in the Eocene and Miocene of the Car pathians, Transylvania, and the Caucasus. In England the small quantity of petroleum that has been observed has sprung from the Coal-measures. In the valley of the Rhone and in Savoy it is in Jurassic limestones. The bitumen of the Apennines, of Dalmatia and Albania, of Roumania, Galicia, and the Caucasus, issues for the most part from rocks that are Eocene. But little is known respecting the geology of the bitumen of Asia Minor and Persia ; the Punjab is also Eocene, and the little that is known of the deposits in Burmah and the East Indian Islands indicates that they are of the same age. East of -the Mississippi river petroleum has been reported from localities that describe an ellipse upon the border of the Cincinnati anticlinal, which consists of an elevation of Silurian rocks extending from central Kentucky to Lake Erie, with the city of Cincinnati nearly in its centre, slop ing beneath the newer formations in all directions. Start ing at Great Manitoulin Island, in the northern part of Lake Huron, it is next reported at Port Huron, Michigan : Chicago, Illinois ; Terre Haute, and in Crawford county, Indiana ; Henderson, Cloverport, Bowling Green, and Glasgow, Kentucky; and around Nashville, and south-east wards to Chattanooga, Tennessee, where the Silurian rocks again reach the surface. Turning north, the line extends almost unbroken through the eastern counties of Kentucky into Ohio and West Virginia, into Pennsylvania and New York, the ellipse being completed by the petroleum-fields of Canada. At Great Manitoulin Island petroleum was obtained in the Trenton limestone, at Chicago and Torre Haute in the Niagara limestone, both of which are Silurian. The Kentucky geologists regard the great Devonian black slate as the source of the oil in that State. There it is found saturating sandstones at Glasgow, and in crevices at Burkesville and other points on the Cumberland river. In the neighbourhood of Nashville, where the Lower Silurian rocks reach the surface, petroleum occurs within geodes, which are enclosed in the solid mass of the blue limestone. North-east of Nashville the present location of the oil is found to be in rocks that lie in an ascending series. Around Burkesville it is found in the Upper Silurian, immediately beneath the Devonian black slate. Farther north it lies in the Devonian and Subcarbonifer- ous sandstones, which, in Johnson county, Kentucky, are now partly above the drainage-level of the country. The so-called "oil-break" of West Virginia and Ohio yields petroleum from sandstones that lie within the Coal- measures. Still farther to the north-east, in Pennsylvania and New York, the oil-sands are all found beneath the Coal-measures in the Upper Devonian, while in Canada they again descend to the Lower Devonian. " Petroleum exists in the Cretaceous rocks which extend along the eastern slope of the Rocky Mountains from British Colum bia to Mexico, and in many of the interior valleys." The bitumen of the Pacific slope, of Mexico, the West Indies, and South America, is Miocene in California and Eocene in Trinidad and Peru. From these statements it will be seen that there is a vast area in the Mississippi valley, estimated at 200,000 square miles, beneath which petroleum has been obtained, the formations of which are nowhere more recent than the Coal-measures. Another vast area, extending from California through Mexico to Peru, and including the West India Islands, yields petroleum from Tertiary rocks ; while on the eastern continent a belt of country extends from the North Sea to Java, the bitumen-bearing rocks of which are Tertiary so far as is known. At present