Scenes and Adventures in the Semi-Alpine Region of the Ozark Mountains of Missouri and Arkansas

by Henry Rowe Schoolcraft

We have examined large portions of this rock, in all its varieties, for organic remains; but have not succeeded in finding any well-characterized species, although a further and fuller search might, and probably would, disclose some species. We observed a single mass of the rock, an imperfectly columniform structure, apparently organic. The rock is rather vesicular than cavernous in its structure. The heavy deposit of diluvium conceals the surface. But if the appearances in the mine-diggings are to be received as general indicia, the surface of the concealed rock is extremely rough and irregular, standing up, in the mineral soil, in huge lumps, which renders the general depth at which it may be reached, a question of great uncertainty.

It has been intimated that the sparry-compact, and the dull granulated varieties of the limestone, are often contiguous; and we have seen, by the examination of a hard specimen, that they are geologically identical as a formation. If this compact variety from the mines be compared with the principal formation in the precipitous cliffs forming the western banks of the Mississippi, in front of the mine tract, they will be found to coincide in so many points, that these two localities may be deemed parts of the same formation, and as being identical in age. The principal differences consist in the occurrence of organic remains in the strata along the banks of the Mississippi; a discovery attributable to the more full exposure of these cliffs to observation. There is also an apparent absence of the granulated, or sand-lime variety. These two calcareous tracts are not, however, continuous, being separated by a formation of granular quartz, or white crystalline sandstone, which runs nearly parallel with the Mississippi for a distance, a few miles west of it. This stratum of rock, which appears to be rather a quartzose sandstone than a granular quartz, reappears west of Potosi, in the barren area called the Pinery, and is also apparent at several localities between the waters of the Maramec and the St. Francis.

At a point thirty miles west of the Mississippi, in about the latitude of St. Genevieve, the primitive formation reveals itself in a series of mountain masses of granite, which cover a comparatively extensive area. This tract appears to be the nucleus of the country, rising through the great secondary formations which intervene between the Alleghany and the Rocky mountains. Its western limits have not yet been explored; but it probably covers an area of not less than a hundred square miles. The mines lie north of it. This granite is composed almost exclusively of reddish feldspar and quartz. The proportion of mica is small, and this mineral is often absent. It has been employed as a material for millstones. It is connected with greenstone, which is sometimes porphyritic.

We have now three formations of rock, as constituting the mine series; and it only remains to point out their relative position and extent, with the best means at our command. This might seem to be a very simple process, and would indeed be so, were it not that the area over which the formations extend is extensive, and is covered with deep formations of the diluvial and alluvial character, bearing a forest. The primitive is immediately succeeded by the two latter. Mine à La Motte is situated in the mineral diluvium, and is distant about two miles from the granite on Blackford's fork. The first appearance of rock, in situ, north of this point, is at Rock creek, a few miles distant, where the granular quartzose sandstone appears. There is no further appearance of rock in this direction for many miles. The white crystalline sand-caves of St. Genevieve are seated in this formation. It is again disclosed on the Platten creek, and in the elevations west of the Joachim creek, called Fort Rock, and in the white sand-caves near Herculaneum. Whether it is continued farther in the approach to the Maramec, cannot be stated; but the line of country which is thus traversed by it, is probably sixty miles. The only point where this rock appears on the banks of the Mississippi, is in the range of the Cornice Rocks.

Proceeding west across this formation, the mineral diluvium succeeds, and conceals the rock formations; but, wherever they are disclosed by the action of the streams, and by excavations, the metalliferous limestone appears, which constitutes the lowest stratum yet found in the mine region proper. But it is to be observed, that no excavations of any considerable depth have been made; the rock has not been penetrated to any great depth. The principal seat of the mines consists of the area included within the circuits of the Grand river and Mineral Fork, constituting the main tributaries of the Maramec. These streams extend something in the shape of a horse-shoe around the mines. Immediately west and south-west of this area, the white sandstone reappears, extending south towards the granite. The position of the two formations may be represented by a pair of expanded dividers, opening northward; the two shanks of which denote the sandstone ridges, and the head, or rivet, the primitive.

The most valuable mineral products of the mines, in addition to lead, are iron and salt; the latter of which is made, in limited quantities, at a saline spring at Madansburgh, in the county of St. Genevieve. Other indications of it exist at one or two localities in the township of Bellevieu, and on the Maramec river, where efforts were formerly made to manufacture salt.

Iron-ores are found at numerous points; but no body of the ores of this metal is known, comparable, in extent or value, to the locality of Bellevieu, called the Iron Mountain. The ore exists, at this place, in a very massive form. It is in the state of a micaceous oxide. It has been tried in a slag furnace, and smelted easily, without a flux. The iron obtained was of a very malleable quality, and spread freely under the hammer. This locality is embraced by the waters of Cedar creek, which, at the distance of seven miles, are stated to afford a water-power adequate for the reduction and working of the ore. About five miles distant, at Stout's settlement, occurs another body of this ore.

Zinc is found, in the form of a sulphuret, in small quantities, at several of the lead-mines in Washington county. A single mass of the sulphuret of antimony has been discovered in the granitical district, which affords also a locality of coarse graphite, and some other minerals, which will be noticed in the sequel.

A sulphur spring exists a few miles west of the Mississippi, in Jefferson county. The water issues, in a copious stream, from an aperture, situated near a cliff of the compact limestone. It is of a bright, transparent quality, but indicates, by its taste, its sulphureous impregnation, and deposits sulphur, in a whitish pulpy form, on the pebble-stones and fallen vegetation of the brook which issues from the spring.

Topographically considered, the mine country is a hilly and uneven tract, having a considerable elevation above the waters of the Mississippi. It is well watered, with numerous springs, brooks, and streams, and, from the prevalence of a firm diluvial soil, affords facilities for roads. The climate is favorable to health. The manner in which the smelting of the ores is performed, being in the open air, is probably less injurious to those engaged in it, than if the furnaces were enclosed with buildings.