CHAPTER II. 

 GEOLOGICAL FORMATIONS OF MISSOURI 



The stratified rocks of Missouri belong almost entirely to 

 the Paleozoic system. From the northward as far down as the 

 Missouri river, approximately, a great mantle of glacial detritus 

 hides from view for the most part the more ancient rocks. In 

 the southeastern corner of the state a small area is occupied 

 by unconsolidated elastics of comparatively recent date. 



S^ot taking into account the glacial deposits, the north- 

 western two-fifths of the state is made up of the youngest of 

 the Paleozoic rocks — the Coal Measures; the south-central 

 one-third of the province by the oldest stratified rocks — the 

 great Magnesian limestone series. An arrow belt bordering 

 the Mississippi nearly the entire length of the state exposes 

 the Lower Carboniferous limestone; while a thin strip, between 

 the oldest and youngest paleozoic sediments sparingly repre- 

 sents the great interval of time between the deposition of the 

 two, which in other regions is filled by such enormous thick- 

 nesses of Silurian and Devonian strata. ( See map.) 



The chief topographical feature of the state has long been 

 known in the Ozark uplift, a broad plateau with gentle quaqua- 

 versal slopes, rising to a height of more than 1500 feet above 

 mean tide, and extending almost entirely across the southern 

 part of the district. On all sides the borders of this highland 

 area are deeply grooved by numberless streams flowing in 

 narrow gorges. Against its nucleus of very ancient granites 

 and porphyries the great " Ozark " series of magnesian lime- 

 stone was laid down. Then the area occupied by these rocks 

 was elevated, and around its margins were deposited success- 

 ively the other members of the Paleozoic. The Ozark region 

 was thus the first land to appear within the borders of the 

 present state of Missouri. 



