ONYX CAVE (9)

Five miles southwest of Arlington, near the Boiling Spring in the Gasconade, is Onyx Cave, so named because much workable stalagmite occurs in it. It has a number of branches, some of which have been explored for several hundred yards without coming to the end. The entrance is 90 feet in width. A pile of talus at the front, lying partly inside the cavern, reaches nearly to the roof; it has a height of 26 to 28 feet above the level of the wet, muddy floor. Drainage is through a small aperture in the north wall, whose outlet is not known. Apparently the bedrock lies at a considerable depth; it is not visible at any point in the steep ravine leading from the mouth of the cave to the river. Formerly a large quantity of ashes covered much of the inner slope of the talus, where it is protected from the weather; but most of them have been hauled away to scatter over the fields. They extend to a greater depth than any digging was ever carried. The cavern has long been a refuge for stock, and this, with the trampling of many visitors, has mingled all the superficial deposits, so that, while ashes may be seen mixed with the débris, no ash beds are now to be found.

There must be a very pronounced cavernous condition in this vicinity. At a number of places, even extending to a distance of 2 miles from Onyx Cave, the passage of a wagon produces a rumbling sound, indicative of a cavity at no great depth. There are also many sink holes, some closed, forming ponds, others with free openings. They are so numerous that no one of them drains any considerable area. The largest of these sinks measures from top to top of its slopes about three-fourths of a mile long and half a mile wide. Around much of its margin are vertical cliffs; there are few places where descent is practicable. It is 300 feet deep, perhaps more; for when the Gasconade, more than a mile away, is at flood stage the water from it, backing through an underground passage, breaks in at two different points not at the same elevation, and covers the nearly level floor of the depression, about 15 acres in area, to a depth or 15 to 20 feet.

Another sink, near this, is conical in form, a fourth of a mile across and more than 200 feet deep.

GOAT BLUFF CAVE (10)

Goat Bluff Cave, 4 miles west of Arlington, on the left bank of the Gasconade, is at the foot of a vertical cliff 50 feet high, the slope above rising about as much higher to the crest of the ridge. A few yards to the west is a slight ravine through which, with a little effort, the top of the hill may be reached. In front, the declivity, while steep as earth will lie, furnishes fairly easy passage to and from the river which lies 200 feet below.

The entrance to the cave is an arch 30 feet high and 75 feet wide, facing a little east of south. The width holds nearly the same for 90 feet, whence it rapidly contracts to 20 feet; the roof meanwhile descending to 10 feet above the floor. The extreme rear of this chamber is nearly filled with large blocks of stone. At the front part the floor is several feet higher along the west wall than at the east; this condition being due to the combined action of accumulation from the ravine above mentioned and erosion by a little rivulet which emerges from a crevice 30 feet within the entrance and flows at the foot of the east wall. Beyond this the floor is practically level across the inclosed space, with a slight and uniform ascent toward the rear. No evidence of rock bottom appears at any point.

A preliminary cut at the outer margin of the cave showed two distinct, sharply separated strata. The lower is a red or yellow clay containing much angular gravel such as usually results from disintegration of limestone in which chert is abundant. Above this is a deposit of very loose fine material. Toward the rear the upper deposit had been disturbed by "curiosity seekers," who reported finding much evidence of prehistoric occupation, such as ashes, charcoal, fragments of pottery, and worked flint, as well as several skeletons, the latter "in a sitting position." The last part of this statement is a mistake. The bodies were closely flexed and placed on the side; the bones settled to the bottom of the grave, while the skull, if intact, is reached first by excavators and the conclusion drawn at once that it is "on top of the other bones." This error of observation is quite common among relic hunters, and is not unknown among student investigators.

In order to dispose of material removed in excavating, it was necessary to start a trench from the slope outside the mouth of the cave. As it progressed the substratum of clay became wetter and more difficult to dig. At 40 feet from the beginning, where the trench was 11 feet deep, the seeping water accumulated until it covered the bottom of the trench, so that no greater depth could be reached. A crowbar forced downward for 18 inches, as far as it could be driven, did not reach solid bottom. Not the slightest trace of human agency was found anywhere below the top of the clay, and from this point excavations were confined to the upper stratum, to which alone the following description is applicable.

This deposit was composed partly of fine loose earth, probably carried in by the wind and on the feet of persons and animals; partly of roof dust; and partly of ashes. A considerable portion of it was roughly stratified in layers of varying extent and thickness, though much of it was irregular, and it was mingled throughout with campsite débris. Occasional layers of roof dust several feet across in any direction and of varying thickness, from a faint streak to 6 inches, so closely resembled ashes that many persons could not be convinced of its true character. Its occurrence in this manner indicates that during considerable periods the cave was unoccupied, or at most used only as a temporary refuge. The intermittent character of occupancy is also shown by the distinct segregation of numerous successive layers of kitchen refuse.