Turkey Run State Park History

“Now we learn by what patient periods the rock is formed. It is a long way from granite to the oyster.”
– Emerson.

GEOLOGIC HISTORY

The geology of Turkey Run may be said to have begun when the great masses of sandstone, from which the gorge is carved, were deposited upon the vast inland sea which covered this area during the time when coal was being formed. After the deposition of this sandstone, which geologists call the Mansfield, this great sea became shallow, being replaced by marshes of no great depth. In these marshes, under tropical conditions, a rank vegetation sprang up. Here flourished the lordly evergreens of Carbonic time—the Lepidodendron (sometimes called the “Scale Tree”) and the Sigillaria, whose trunk bears a delicate seal-like impression upon its surface. More than a hundred varieties of the former have been described, some of whose trunks have measured a hundred feet. The latter, the largest of carboniferous trees, bore trunks reaching six feet in diameter and more than a hundred feet in height. Here, too, grew the Calamites, or giant rushes, and tree ferns of bewildering variation. This accumulated vegetation was at length buried under subsequent deposits and later transformed into coal under the great pressure which resulted. Following this came marine conditions similar to that which exists under our present seas until several hundred feet of sediment had been deposited above the massive layer of Mansfield sandstone. Later this sea receded permanently and land conditions prevailed. Then followed a long period of weathering and erosion, during which time prodigious layers containing coal, hundreds of feet in thickness and overlying the sandstone, were removed. The reader will realize that we are talking, not in hundreds and thousands of years but in geologic ages when we speak of these various phases.

Ages, then, went by—ushering in new events. The climate gradually changed until it became very cold, approximating the present Arctic conditions, until, upon the scarred surface of the Mansfield sandstone, there rested thousands of feet of ice which, moving slowly southward, cut deeply into the sandstone upon which it rested. Again the climate became mild, the ice retreating meanwhile and at length disappearing. In its wake were deposited immense quantities of loose sand, gravel, clay and boulders, brought from the far North—filling in the former valleys and destroying the existing systems of drainage. During this process the raging water carved new channels for itself, establishing an entirely new drainage system.

Sugar Creek was one of these newly made streams and became a part of the new drainage system, cutting its way easily through the drift deposit and on through the underlying sandstone. The surface water of the region, now assuming the proportions of a devastating flood, concentrated at a depression along its course, which point was the beginning of Turkey Run. Through thousands of years, subsequently, the erosional force of water has been continued, lengthening and deepening the gorge thus formed. The upper layer of sandstone, more resistant because of compounds of iron and silica which cemented and strengthened it, has disintegrated less rapidly than the underlying strata; so that the gorge has not widened as rapidly as it has deepened. The erosion of the softer layer underneath has been augmented by cracking and splitting due to freezing, with the result that the gorge is often wider at the bottom than at the top.

Thus, to geologic processes, we owe much of the charm of Turkey Run. These varying phases of the earth’s history may be studied with ease and certainly with profit by the non-scientific visitor. The erratic boulders which one picks up, carried upon the glacier’s back from the “Land of Snows,” may tell us somewhat of their former habitat and much of the uncanny force of glacial action. Along the stream channels may be found numerous cauldron-like basins in the sandstone. These are the so-called “glacial mills,” which are precisely like those which may be seen in the famous Glacier Garden of Lucerne. They are the result of the erosional action of glacial cataracts which, with the aid of the abrasive force of stray boulders caught in some rock depression, have whirled about till the softer rock mass has been hollowed as with a chisel—the abrading boulders assuming the shape of an almost perfect sphere. Then, too, one may chance to discover some lingering souvenir of the coal-measure era—a fragment of some once living plant—now a sermon in stone. To the diligent searcher after knowledge here are opportunities galore.

At a number of points along Turkey Run, particularly through Newby Gulch, one may observe examples of the curious and interesting formation known as calcareous tufa, sometimes improperly called tuff. Underground water, and surface water as well, often possesses great disintegrating force. In this state it dissolves more limestone than it can carry away in solution—thus percolating waters throw down a deposit of calcareous limestone which, upon exposure to the air, hardens into a compact mass. If there is a rapid motion to the water, as when it is dashed into spray in a cascade, carbonic acid gas is liberated—thus rendering the lime insoluble and hastening the process of deposition.

If we were to examine one of these newly made rock masses we should find it to consist of fragments of wood, broken twigs, leaves, mosses and other organisms, coated over with the deposited lime—or in a complete state of petrifaction. Thus it is possible, at Turkey Run, to study the actual processes through which fossils have been formed. The formation of tufa is often quite rapid, as, for example, there are certain deposits in Sicily in which the rate is one foot in four months.

If it were possible to look upon the Turkey Run of interglacial times we should have much difficulty in recognizing the fauna which existed here. Today, in northern Indiana, workmen often come upon the semi-fossilized bones of these creatures buried in some glacial deposit, from which we are enabled to definitely determine the character of animal life which existed here before the advent of man.

Of the elephant tribe we have the mammoth and mastodon—cumbersome creatures akin to our modern species. The musk-ox, or ovibos, once made this region their habitat—though now found only in the far North, much varied in type. The giant beaver, or Castoroides, would have dwarfed his modern descendant. Strange as it may seem to us, the camel once flourished here, though quite different in form from that with which we are familiar. The giant sloth, in many variations of size and bearing an armor-plate of small bones secreted under the skin, crippled his way through the Indiana forests; his claw-feet bent inward so that he must walk upon their sides.

It would be tiresome to mention the wide variety of animals and birds which were indigenous to northern Indiana when Turkey Run assumed its present contour. It is interesting, though painful to our state pride, to know that many of the notable specimens of these extinct creatures were first discovered in Indiana, but grace the museums of other states. Many notable collections secured at great expense in Indiana have found their way to foreign museums, while our own state has not yet provided a fitting building in which they might be preserved for all time.