234 B. HA WORTH — THE OZARK UPLIFT AND ORE DEPOSITS 



greater part or all of the Ozark area, being buried to variable depths in 

 different places. 



LIMESTONES 



Limestone is the most abundant of all rocks found in the area. It is 

 Lower Silurian and Cambrian in age in the eastern part of the territory, 

 and Lower Carboniferous or Mississippian in the western, as is shown by 

 the admirable geological maps published by the Missouri Geological 

 Survey. In general these limestones are very compact and firm ; but 

 in some places they are filled with minute openings, particularly in the 

 east where they carry such large quantities of disseminated lead ore; 

 also, they are frequently cut by vertical or semi-vertical fissures carry- 

 ing ores, particularly around the border areas. 



SANDSTONES 



The sandstone is moderately abundant in the eastern and southern 

 parts of the territory, th ^greater part of it being of Lower Silurian or 

 Cambrian age. Although its distribution is comparatively irregular, it 

 is found in great abundance in the southeastern mining area, and also 

 in many parts of southern Missouri and northern Arkansas. In the 

 southwest, in the same geologic formation, it is much less abundant, as 

 is shown by numerous deep wells drilled here and there throughout the 

 southwest mining district. Strangely, a deep well at Neodesha, Kansas, 

 about oo miles west and a little north of Galena, shows that below a 300- 

 foot bed of Lower Carboniferous limestone and flint, and beginning at 

 about 1,370 feet below the surface, the Silurian sandstone continues 

 almost uninterruptedly for over 1,000 feet, or to the bottom of a well 

 2,412 feet deep. Throughout this distance an occasional limestone was 

 encountered, but more than three-fourths of the entire 1,000 feet were 

 occupied by sandstone. If reliance can be placed on the records kept by 

 the drillers of the deep wells in the vicinity of Joplin and Carthage, 

 where so much Silurian limestone was found, and I know of no reason 

 for doubting them, it will be seen that the geographic distribution of 

 the Silurian sandstone is unexpectedly irregular. 



FLINT OR CHERT 



The southwest mining area includes probably the heaviest bodies of 

 flint rock known in the world. Here in different places such bodies are 

 known to be nearly 300 feet thick and have a lateral extent of from 3 to 

 5 miles. The formations are the Lower Carboniferous or Mississippian 

 limestone, with the Hint interbedded in a most irregular manner. Around 



