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Geology of Ozark Ranges

Debow's Review

November 1869

PART OF MISSOURI NOT YET UNDERSTOOD

With a purpose as far as possible to aid in the development of the mineral and industrial resources of this State, your correspondent }as been rapidly scanning its extreme southeastern part. In this field an anomaly presents itself in the geological structure of this region. It is in the fact that around the base of the outlying spurs of the Ozark ranges, in Scott and other counties, may be found the remarkable circumstance of a succession of strata, shelving inwardly towards the southwest; where, within a few miles of each other, are presented the earliest, or primitive rocks, up to alluvial or last member of the quartanary system. Between the Devonian and the lower tertiary there is a hiatus in the order of' rising successions. And, as the exposure from the Devonian, descending, is limited, I will confine present observations to the tertiary and drift. Earthquakes and traditions have succeeded in casting obscurity over this singular region. To ascertain to what extent the stories of the early 'settlers, concerning the ejectment of quantities of coal through the earthquake fissures and sand blows might be true, we need only carefully consider the thing in connection with the absence of the coal formation. That the settlers were mistaken is certain, but only 'n so far as they mistook lignite for coal.

A TERTIARY OCEAN

Doubtless swept almost up to the base of granite hills, separating the mouths of the Ohio and Mississippi from each other nearly two hundred miles. The Mississippi waters entered this ocean near Cape Girardeau, if not at Grand Tower; those of the Ohio at the falls below Louisville; the Cumberland at Harper, and the Tennessee at Muscle Shoals. Around the southwestern rim of this great sea the White, Arkansas and Pied rivers, with minor ones, disembogued their waters, many hundreds of miles from their present mouths. This vast western indentation of the Atlantic was gradually filled up by accumulated silts from the surrounding highlands, and by a constant elevation of the ancient shores. Swift currents, that drove in from the south, aided by periodical winds, carried vast quantities of asphaltum-which originally oozed out of the bottom of the present Gulf of Mexico as petroleum. This process is still going on, as can be seen any day in the bituminous matter cast upon the Texan and Mexican coasts. This asphaltun, sometimes in masses as large as a horse, and of every other size, down to the fineness of slime, was cast upon the shores of a rapidly receding ocean; and, in consequence of alluvial deposits, forming a surface over this material, we find millions of acres, or most of the alluvial portions of the Southwestern States underlaid with this substance, so often taken to be coal.

IT IS FOUND

Either as lignitic mud, lignitiferous clay, brown coal, pitchy lignite and jet. Of such vastness were these deposits that on Crowley's Ridge, Arkansas, in Louisiana and Mississippi, a minima of eighteen feet is found in a succession of four layers-one being seven feet thick. The effect, then, of the earthquake of 1811 was to reveal the fact that these lignite beds extend under all the sunken region in Missouri and Arkansas, comprising within this State, alone, forty-eight townships.

THE ECONOMIC VALUE OF LIGNITE

As a fuel, analysis of the Crowley's Ridge jet shows it to have but two percent of ash, while the less pure, from other exposures, contains as high as thirty per cent. of ash. Its value is, therefore, intermediate between Illinois coal and wood, for fuel.

THE MOST USEFUL PRODUCTIONS

Of this region are pipe clay, potters' clay, fire clay, and many colored clays that are well adapted to use as paints. The colors are pink, violet, yellow, cream, and various other tints, At two estutarian points on these clay deposits attempts are being made to utilize them. The Cape La Crutz company is extracting hundreds of tons of varicolored clays, which, after preparation, are excellent and cheap paints.

WOOLFORD'S POTTERY

It is one of the old institutions of Bollinger county; and I understand that a pottery is to be established in the vicinity of Commerce -on the Mississippi, in this county-where good clay is abundant. Several of the clays burn lighter colored, in the fire, and some are rood fire clays when properly mixed with pure quartz sand, or old pounds of brick, retorts, or crucibles. Other interesting objects abound in the drifts of the quarternary period. The gravel beds contain many valuable gems, as agate, sand, cornelian, jasper and chalcedony, or silicified palm. The fossil remembrancers of by-gone ages are Astraca, Favorites, (called petrified honey-comb) or silicified corals; Planicosta, Aonxeras Tnlritella, &c., &e., and Zeugledoii's; together with some sulphate of lime, sulphate of magnesia, or gypsum, and common salt. The prospects of a speedy and thorough development of tl-he almost innumerable resources of which this region, and in a very marked degree, Scott county, is possessed, seem excellent, when viewed in the light of the great industrial population new turning its course hitherward.-         [Correspondence Missouri Republican.