osit Cave at 22 feet 144

26. Cross section of Fort Deposit Cave at 26 feet 145

27. Cross section of Fort Deposit Cave at 28 feet 145

28. Cross section of Fort Deposit Cave at 30 feet 145

29. Cross section of Fort Deposit Cave at 351/2 feet 146

30. Cross section of Fort Deposit Cave at 471/2 feet 146

31. Cross section of Fort Deposit Cave at 60 feet 146

32. Cross section of Fort Deposit Cave at 70 feet 147

33. Cross section of Fort Deposit Cave at 90 feet 147

34. Cross section of Fort Deposit Cave at 93 feet 148

35. Cross section of Fort Deposit Cave at 175 feet 149

36. Cross section of Fort Deposit Cave at 180 feet 149

37. Plan of House Mound in St. Francois County, Mo. 168

* * * * *

[Illustration: PLATE 1 a, Cave on Big Piney River, three miles
east of Big Piney, Pulaski County. Mo. (Courtesy of Dr. P.J.
Heuer, St. Louis)]

[Illustration: PLATE 1 b, Cave on Big Piney River, in Texas
County, Mo. (Courtesy of Dr. P.J. Heuer, St. Louis)]

[Illustration: PLATE 2 a, Bluff at mouth of Spring Creek, Pulaski
County, Mo. (Courtesy of Dr. P.J. Heuer, St. Louis)]

[Illustration: PLATE 2 b, Pillman's, or Spring Creek, Cave,
Pulaski County, Mo. (Courtesy of Dr. P.J. Heuer, St. Louis)]

ARCHEOLOGICAL INVESTIGATIONS

I. EXPLORATIONS IN THE OZARK REGION OF CENTRAL MISSOURI

BY GERARD FOWKE

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 innumerable
crevices in the limestone, through which percolating surface water
found its way into all parts of the formations. By its solvent power
this water gradually enlarged the crevices into passages 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.