somewhat inferior and much of it is mixed with oxide of iron. Freshly fractured fragments are quite hard, and steel gray to black in color. In the northern half of section 12 (Tp. 33 N., R. VI E.) and on adjacent land to the north and east, wad is frequently encountered. On the roadside, eastward from the intersection of the county roads, a few feet of a low grade of ore is exposed for some distance. Northward, in a field and in the bank of a small branch, similar occurrences are common. Shallow prospecting pits were put down and in every case the ore extended several feet from the surface. Usually, the character of the bog ore is poor, but some higher grade deposits, which may prove extensive upon development, are also present. In section 2 beds of manganese which crop out near a small branch have been found to underlie an area of considerable extent. Much of the ore here is the earthy, black variety and is tolerably free from impurities. Southeast of the last named locality, in the northwest quarter of section 1, the diamond-drill in prospecting for galena passed through a manganese bed at a number of points. In the surface clays, which overlie the indurated rocks, manganese was found at depths varying from 30 to 60 feet; some layers were a foot thick, besides many thin seams. The quality of the manganese is superior to that known to exist elsewhere within the limits of the sheet. It is of a steel-gray color, with metallic to brilliant lustre. In the samples collected no impurities could be detected and it should be classed as a very high grade ore. It is doubtless suitable for both speigeleisen and ferro-manganese. Very little silica can be detected and the percentage of iron is low. Seven to eight miles south of Fredericktown at a point just beyond the boundary of the sheet there is another deposit of manganese quite different in character from those already described. This is a decidedly black earthy variety. Macroscopically it appears pure, except for a few fine quartz grains. Other deposits occur at numerous points and fragments of the common bog ore are frequently noticed on the slopes of the chert hills. NICKEL AND COBALT. The paragenesis of nickel and cobalt ore is very intimate. Both minerals are closely associated with the ores of iron, copper and lead. The common occurrence is the black earthy cobalt or asbolite which usually contains from one to five per cent of nickel, and massive linnæite which also carries some nickel. An analysis of the galena from the Old Copper mines in the southwestern corner of the Mine la Motte tract gave Chauvenet 1.68 per cent of nickel and 0.63 per cent of cobalt. The lead ore from the Neidner shaft on the estate gave the same analyst: Lead (metallic). Copper... Nickel. Cobalt PER CENT. 65.53 Trace 4.26 1.42 The nickel ore from the Jack diggings showed 2.27 per cent of the metal and 1.66 per cent of cobalt. In this connection it is of considerable interest to learn that nickel as well as manganese occurs in appreciable quantities in the massive crystallines of the region. Analyses, by Melville, of a fine-grained granite (I), and two porphyries (II and III) from a locality (Tp. 33 N., R. V E., Sec. 5) three miles northwest of Silver mines, but just outside of the boundaries of the sheet, gave the following results: Comparatively little attention, however, has been paid to the mining of the ores alone and what has been shipped has been mined in connection with lead. Yet the product obtained is not unimportant. At Mine la Motte alone the output of speiss for the last twenty years has amounted to over 570,000 pounds, that of matte 827,000 pounds, and of nickel sulphide | 36,000 pounds. The amount taken from the Old Copper mines is not known with exactness, but it appears sufficient to make a total of all the the cobalt and nickel products something like 710 short tons. As the mining of the minerals is commonly a secondary matter much of the material is not cared' for. SILVER. The occurrence of silver within the limits of the Mine la Motte area is of unusual interest from the fact that nowhere else in the state have deposits of like character been found. The metal is found in true quartz-filled fissure veins, a considerable number of which exist in the region. The largest is located on the St. Francois river about eight miles directly west of Fredericktown (Tp. 33 N., R. V E., Sec. 12, SE. of SW. qr.) at a place now known as the Einstein Silver mine. The rock, for a considerable distance around the locality, is a coarse-grained, red, biotite granite, or granitite, a part of the great central field. It is cut by dikes of diabase and by quartz veins, the largest of which is about four feet in thickness. The locality has manifestly been the seat of considerable disturbance, as is indicated by the great number of fissures. The fact that some have been filled with the basic rock material, and some with other vein stuffs, clearly shows that the formation of the two sets did not take place at the same time. The general trend of the diabase or greenstone dikes is nearly in a north and south direction; while that of the quartz veins is a little south of west. The former are nearly vertical; the latter dip to the southeast ward about 60 degrees. The locality is unique in furnishing, besides silver-bearing galena, a number of minerals which are found nowhere else in the state. The vein-stuffs are of such peculiar kinds and the wall-rock has been so altered for a distance of several feet that it is quite manifest that fumarole action has been vigorous. A large amount of micaceous material which may be regarded as sericite, has been produced. Associated with it are other minerals usually not met with, and these are also scattered through the gangue, which is largely quartz, and the argentiferous galena. The feldspar in the wall-rock has been almost completely changed to the sericite, which occurs in fibrous masses. A dark lithia mica, zinnwaldite, occurs; also topaz, fluorite and wolframite. The amount of silver contained in galena varies greatly. In some cases as high as 300 ounces to the ton are reported; in others scarcely a trace. The average of 50 assays was about 46 ounces to the ton. |