"main" fault, which appears in shafts Nos. 1 and 2, passes through mine No. 5 also. A number of drill-holes have been sunk on both sides of it at different points and in the bed of Village creek a shattered exposure of limestone is to be seen with slickensided surfaces, which marks the line, though no prominent break can be recognized and no crevice exists there. That this fault bas some influence on the distribution of the ore is doubtless true, but what this influence has been is another question. As is plainly seen in the mine the throw along it amounts to only a few feet, at least in mines Nos. 1 and 2. East of this, however, the throw amounts to much more, as is shown by the depths at which the basal sandstone is encountered in the different drill-holes. From these it would appear that the throw at some points must be at least 150 feet. " Shaft No. 6.-This mine is opened near the the old "Rattlesnake" diggings. The areal extent of the workings is approximately 2200 square yards. The depth of the shaft is 122 feet. The sequence passed through in sinking to the ore bed is as follows:

Diggings. In addition to the large amount of lead ore taken from the shafts at Mine la Motte the area bas also been very profitably worked for ore at and near the surface, where sballow pits and short slopes have been dug. The principal developments are the Jack, the Seed-tick, the Rattlesnake, the Wildcat, the Bluff and the Hardscramble diggings. These are scattered over a large area. Prior to about seventeen years ago, all mining which had been carried on for over a century and a half was done in these diggings.

Production.-From the time of the discovery of the deposit about the year 1720 up to 1878, the output of ore about equaled the amount that has been produced during the last decade and a half. In the latter period deep mining has been the system and work has gone on uninterruptedly. The total amount of lead produced since the beginning is over 100,000 tons.

The dressing works and furnaces are at the ends of tramways and the system of treating the ore, from the beginning until a finished product is secured, shows excellent arrangement. The degree of perfection reached in the dressing of the ore at the works is showing by the following analyses of the tailings taken from the superintendent's records:

Aside from the regular output of lead there has been a large sale of nickel matte, nickel sulphide, speiss, copper sulphide and copper matte. Within the last 20 years the shipments of these alone have amounted to over $120,000.00.

Except in one case arsenic is not present in the ores, although so commonly associated with cobalt and nickel. Neither have any traces of zinc been found.

DOE RUN MINES.

Doe Run is a comparatively new mining camp. Although its development runs back scarcely a decade it is one of the most important mines in the state. Previous to ten years ago no surface diggings nor prospecting had been done. Since the original shaft was sunk many drill-holes and several shafts have been put down. At the present time the ore is being

taken chiefly from a single opening. The general sequence of the strata is well shown in shaft No. 2.

65

10

2

3. Limestone, mixed with galena in varying amounts...

The details of that portion of the section which is deemed rich enough in ore to be worked profitably are given below:

Details of Workable Ore Body.

8. Limestone, yellowish, bearing galena freely disseminated..

INCHES. 12

6.

7. Limestone, light grayish yellow, with a considerable amount of galena 6 Limestone, dark gray, siliceous, streaked with lighter colored galena abundantly disseminated throughout.....

4

5.

Limestone, dark gray, clouded, in part sandy, galena disseminated and along joints especially...

8

3.

Limestone, dark gray, slaty, earthy, slightly mineral-bearing.

9

8

13

4. Shale, with galena crystals well disseminated.

2. Limestone, dark gray, very sandy, heterogeneous texture, small amount of galena present..

1. Limestone, rearly white, hard, barren..

Various diamond-drill borings have revealed many features which must be taken into consideration in prospecting and in mining. Most of the drilling in the vicinity of Doe Run has been done within a distance of one mile from the northwest corner of the sheet. The records indicate clearly a general absence of the basal sandstone, the depth to the crystalline floor, and the height above this floor that the granite bowlders occur. The distance to solid granite without regard to the topographic position of the holes ranges between a few and 200 feet. For example, a hole in which granite was reached at 21 feet down lies about 150 yards northwest of one giving granite at 262 feet, while the elevation of the shallow hole is not more than 10 feet above the other. The general plan of the mine is shown in the accompanying diagram (figure 26), in which both levels are represented.

The lower of two levels worked is the more extensive. The general direction of the slope of the limestone strata in

the workings is south 70 degrees east. The average dip is about six degrees. (See figure 20).

Few faults occur. At one point in the southern portion of the mine is a small displacement having a downthrow of

Figure 26. Plan of the Doe Run Lead Mine.

about 6 inches, decreasing to the southeast. Its strike is South 40 degrees west. The walls do not afford lead ore. In a few places along the fault there are narrow channels partly filled with clay. Faulting appears to have had but little or no influence upon the deposition of the ores and no ore is found along the walls of the faults. The disturbances, other than those marked by the sharp cracks and crevices

$$.35 beneath

Opening wide

filled with ore, appear to have taken place after the ore was deposited. The individual cracks are often confined to a single stratum and have no apparent relation to one another. The total output to date has been over 21,000 tons. Since 1891 the Flat River mines have been opened and the ore has been treated at Doe Run, the amount being 35,000 tons.

The system of handling the ore is very complete, from the time the contents of the cars from the mines are dumped at the crushers until the roasted product is taken from the furnace. The product from the mill is about 75 per cent galena, the remainder pyrites and chat. The roast analyses 70 per cent lead, 15 per cent silica, 4 per cent sulphur and 6 per cent iron. The other constituents are lime, magnesia, alumina and water. The silica mentioned is added just before the roast is removed, in order to "cinder" the mass and facilitate fusion. This sand is especially well adapted to this use. It is finegrained and 97 per cent pure. From eight to ten thousand pounds of roasted ore are drawn off in twenty-four hours from each of the four furnaces. The dressing works are run continuously, handling the ore from the Doe Run shaft as well as from the company's shaft at Flat River, which lies about seven miles northward on the Mississippi River and Bonne Terre railway.

EINSTEIN MINE.

The Einstein mine is of special interest for the reason that it is the only example in the state or in the Mississippi valley of a fissure vein. The place is commonly known as the Silver mines. It is located eight miles directly west of Fredericktown on the St. Francois river (Tp. 33 N., R. V E., Sec. 12, SE. of SW. qr.). As its importance is on account of the silver ore found it will be considered more at length in another place. The silver is contained in galena. But little has been done to operate for the lead.

MINOR WORKINGS AND PROSPECT HOLES.

In the neighborhood of Fredericktown considerable prospecting has been done and some ore taken out. Nifong and Brewin had a shaft sunk in the vicinity of the town. The