reous rocks underlying these formations outcrop, and at different points limestones and marls have an important influence on the character of the soil. No detailed investigation from a geological standpoint has yet been made on the soils of the southern part of the State. A paper on the Mineral Resources of Georgia read by Prof. S. W. McCallie before the International Mining Congress held at Boise City, Idaho, in the latter part of July, 1901, will form a fitting conclusion to this chapter on the Geology of Georgia. All of the great divisions of geological history are represented in Georgia with the exception probably of the Jura-trias. The northern and central parts of the State known as the Crystalline area are made up largely of gneisses and schists, which are supposed to represent the southern extension of the old Archean continent. To the northeast of this ancient land surface and comprising the greater part of ten counties in the extreme northwestern part of the State, occur the Paleozoic rocks; while to the south, extending over an area of 30,000 square miles, are the wide-spread deposits of the Cretaceous and the Tertiary periods. A State thus endowed with such diversity of geological formations must necessarily possess extensive and varied mineral resources. In the discussion of these resources, many of which are in a large measure at present in an incipient stage of development, only those will be considered whose economic importance can not be questioned. The red and the brown iron ores constitute one of the most important mineral resources here to be considered, and one that has been a continuous source of revenue to the State for more that half a century. These ores are confined mainly to the Paleozoic area of Northwest Georgia, where they occur in large quantities. The brown iron ores, or more properly speaking, the limonites, are most abundant in Polk, Bartow and Floyd counties. Nevertheless, workable deposits are also to be found in every county in the northwestern part of the State with only one or two exceptions. The brown iron ores are confined chiefly to two different geological horizons, viz., the Weisner quartzite, and the Knox dolomite, the former of Cambrian, and the latter of Silurian age. The Weisner quartzite, which corresponds to the Potsdam sandstone of New York, is an extensive deposit of mountain-making metamorphic sandstone, forming the eastern boundary of the Paleozoic rocks. At many points the formation has been subjected to intense pressure during the process of mountainmaking, and as a result, its strata are frequently much folded and brecciated. Along the line where the dynamical forces have acted most energetically is a great displacement in the strata known as the Cartersville fault near which all of the main iron ore deposits of the Weisner quartzite are located. These ores, which always run high in metallic iron and low in sulphur and other impurities, often occur in well-defined fissure-veins, but generally they are found in the form of irregular de posits in the residual clays, or as thick sheets, or blankets, overlying the metamorphic sandstone. The fissure-veins vary from a few feet to several yards in width and frequently continue for a quarter of a mile or more in length. They always dip at a high angle and apparently extend to a great depth. The ore of these veins is generally more or less porous and is usually of an excellent quality. The blanket deposits are not so plentiful as the residual or the fissure deposits; nevertheless they are of special economic interest on account of the large quantities of ore which they contain. These deposits in the extreme northeastern part of Bortow county, in what is known as the Sugar Hill district, often mantle the mountain side to the depth of many feet. One of the deposits of this district has been producing daily for the last few years from twenty to thirty cars of high grade ore, and yet there still remain large quantities of the ore in sight. It is questionable whether there are to be found anywhere in the south brown iron ore deposits which will surpass, or even equal in extent, the blanket deposits of the Weisner quartzite of Bartow county. The brown iron ores of the Knox dolomite formation occur chiefly in the form of pockets or irregular deposits in the residual clays. These deposits are quite variable in size. Sometimes they produce only a few carloads of ore but generally they are far more extensive and cover a considerable area. Some of the individual deposits in the vicinity of Cedartown have been worked on an extensive scale for more than twenty years without exhausting the supply of ore. It is not an uncommon thing to find the deposits extending over six or eight acres, but in such cases the deposit is not equally rich in all parts. The depth to which the ores of the Knox dolomite formation extend, as well as its surface dimensions, is variable. In some instances the deposits are very superficial, extending only a few feet below the surface, while in other cases they have been worked to the depth of eighty feet or more without reaching their limit. In addition to the above brown iron ore bearing formations there are two others, viz.: the Deaton limestone and the Fort Payne chert, which have also produced considerable ore. The ore from these formations is similar to the ore occurring in the Knox dolomite series though, as a general rule, it does not run as high in metallic iron. The total amount of brown iron ore produced from these several deposits last year aggregated more than 400,000 tons, thus making Georgia the third in the list of brown iron ore producing States in the south. The Red Iron Ores.-The red, or fossil, iron ores of Georgia are confined chiefly to three counties in the extreme northwestern part of the State. These ores occur in what is known as the Rockwood formation, which is the northern extension of the Red Mountain, or the Clinton iron ore bearing series of Alabama. Stratigraphically, the Rockwood formation occupies the same position in the geological scale as the fossil iron ore bearing rocks of New York and Pennsylvania. The Rockwood formation in Georgia is made up of shales, sandstones, and thin-bedded limestones with from one to three beds of fossil iron ore. The formation, though not necessarily ridge forming itself, always out crops along the side or at the base of the mountains and ridges. It is exposed at the base of Sand, Lookout, Pigeon and Dirt Seller's mountains, and also along the slopes of Taylor's Ridge, where it attains a total thickness of several hundred feet. The workable iron ore is found usually near the center of the Rockwood formation, where it occurs in continuous beds varying from a few inches to several feet in thickness. Each of the beds, which usually dip at a low angle, generally carries two varieties of ore, viz.: the soft ore and the hard ore. The soft ore, which forms the weathered part of the bed, rarely ever extends to a depth of more than ten or fifteen feet below the surface. It differs from the hard ore mainly in having little or no lime present, and as a consequence, always runs higher in metallic iron than the hard ore. The relative chemical composition of the soft and the hard ore is shown by the following analyses: Hard Ore.-Metallic iron, 32.19; lime, 23.19; phos., 0.804. Some idea may be had as to the abundance of the red fossil iron ores of Georgia, when it is stated that the aggregate length of the outcroppings of the beds, which average more than two feet in thickness, is about 150 miles, and that in places the ore can be economically mined to the depth of more than 200 feet. The output of the red iron ores of Georgia last year was not so great as that of the brown iron ores. Nevertheless, should the price warrant it, the output of these ores could be increased to meet almost any demand. Coal. The coal measures of Georgia which occur in the northwestern part of the State, form the the northern extension of the Warrior Coal Field of Alabama. They are confined chiefly to Sand and Lookout mountains in Dade, Walker, and Chattooga counties, where they cover a total area of about 200 square miles. The coal formation of Georgia, as elsewhere in the great Appalachian coal fields, is divided into upper and lower measures. The upper measures are best developed on Lookout mountain, in the vicinity of Durham coal mine, where they attain a maximum thickness of about 900 feet. This division of the coal formation carries seven different coal seams, but only one is worked at present. The lower coal measures are not so thick by many feet as the upper. However, they carry a greater number of workable coal seams. In the vicinity of Cole City, on Sand mountain, as many as three different seams have been worked in the lower measures more or less extensively. In addition to the three workable coal seams here mentioned, the lower measures contain two other seams which are probably also workable in places. The coal obtained from both coal measures is an excellent quality of bituminous coal, well suited for coking and steam purposes. At present, there are three coal mines being operated in the State, two on Lookout, and one on Sand mountain, with a total output of about 14,000 tons per day, the greater part of which is used for coking purposes. Two of the mines, here referred to, are in the upper coal measures of Lookout, and the other is in the lower measures of Sand mountain. The mines on the |