In the Ural Mountains for the greater part the ores are associated with igneous rocks. The most important deposits are in the neighborhood of Gora Blagodat, in the northern Ural regions, and near Gora Mongnitnaja, in the southern Urals. The ores are mainly magnetite and limonite and come from an extremely large number of small mines. In central Russia, over widely scattered areas, are deposits of calcareous ores, clay ironstones, and bog ores. Many of the deposits are thin and can not be profitably worked. The only reserves in southern Russia of any importance are divided among three centers: Krivoi-Rog, the Donetz basin, and the Kertsch peninsula. By far the most important deposits are the magnetite-hematite ores in the region of Krivoi-Rog. The ironstones of the Coal Measures in the Donetz basin and the limonite of the Kertsch peninsula are of secondary importance. The mines of Krivoi-Rog are extensively worked, and their reserves are estimated at some 86 million tons of commercial ore. The mines are controlled mainly by the following three companies: the Briansk company; Krivoi-Rog Iron Ore Co.; and the Providence company. The following table shows the production of iron ore in different parts of Russia in 1912: TABLE 18.--OUTPUT OF IRON ORE IN RUSSIA Long tons Southern Russia 5,679,000 Ural 1,817,000 Central Russia 286,000 Other Russia and Siberia 6,000 --------- Total 7,788,000 The ore reserves of Russia may be summarized by districts as follows: IRON-ORE RESERVES IN RUSSIA Millions of tons Ural 282 Central Russia 789 Southern Russia 536 Caucasus 14 ----- Total 1,621 Eckel[38] reviews the iron-ore situation in Russia as follows: On their face the ore reserves noted seem satisfactory enough, and until the data are examined more critically it is difficult to explain why the relatively large furnishing capacity of the Moscow and other central Russian districts is so far out of line with the comparatively small ore production of that area. As a matter of fact, however, the large total ore reserves credited to central Russia are in reality less important than they seem, owing both to grade of ore and thinness of the ore bodies. From an international viewpoint the ore deposits of southern Russia are the ones which require most attention; for these are so located as to be of importance to foreign competitors, while the total reserve tonnage is high, and the grade of much of the ore is excellent. [38] ECKEL, E. C.: “Iron Ores, Their Occurrence, Valuation and Control,” 1914, p. 326. Actual available ore reserves of merchantable grade in Russia are estimated at 865 million tons.