ARCHEOLOGICAL INVESTIGATIONS 



I. EXPLORATIONS IN THE OZARK REGION OF CENTRAL 



MISSOURI 



By Gerard Foavke 



INTRODUCTION 



The geological structure of that portion of southern Missouri 

 which lies to the westward of the Archean rocks near the Mississippi 

 River is peculiarly suitable for the development of caverns. The 

 Ozark uplift produced far-reaching undulations, and there seem to 

 have been no violent disturbances which would result in extensive 

 faults, considerable displacements, or a pronounced inclination of the 

 strata. Jointing and pressure cleavage, however, gave rise to in- 

 numerable crevices in the limestone, through which percolating sur- 

 face water found its way into all parts of the formations. By its 

 solvent power this water gradually enlarged the crevices into pas- 

 sages which, multiplying and uniting, drained constantly increasing 

 areas until they formed subterranean streams with a perpetual flow. 

 Thus began caverns; and these grew in depth, width, and height 

 as the rock was eroded and dissolved. Tributary crevices were sub- 

 ject to the same action ; and there was finally created by each of these 

 water systems a network of cavities whose ramifications sometimes 

 extend throughout several townships. In time, sections of the roof, 

 here and there, became so thin from the combined erosion taking 

 place both above and below as to be unable to sustain their own 

 weight ; the overlying strata fell into the cave, and the volume of 

 water flowing through it was augmented by drainage which had pre- 

 viously been disposed of on the surface. All this had to seek an out- 

 let somewhere, except in those rare instances where it maintains its 

 downward course until, below the level of any open stream it can 

 reach, it encounters an impervious stratum and must lose itself in the 

 deep rocks. Usually, however, it emerges in the face of a bluff or on 

 the side of a hill ; and the opening becomes " the mouth of a cave." 

 Occasionally, in such situations, the water continues to flow out ; but 

 usually it finds a way to reach a lower level, and so the cave in time 



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