Page:History of Southeast Missouri 1912 Volume 1.djvu/17

Rh material lying above the Azoic formation; the action of these streams has worn down their bed until in some eases they have come to the dikes of hard rock lying transversely across the stream bed. The hardness of the granite has prevented its wearing away as rapidly as the other portions of the valley and this fact has given rise to rather peculiar formations. The stream has ordinarily carved this wall of rock thrust across its course, but carved it much more slowly than the remaining parts of its stream bed so that it is hemmed into close quarters at these places. They are locally called "shut-ins." One of them is to be seen on Stout's creek in the vicinity of Arcadia and there are many others in the same region.

The Ozark region of Missouri has its highest elevation along the line extending from Jefferson county to the southwest through Iron and into Barry and White counties; east and west of this line the elevation gradually becomes less. The highest points in Southeast Missouri are Shepherd Mountain having an elevation of twelve hundred feet, Pilot Knob with an elevation of 1,118 feet covering an area of three hundred and sixty acres and Iron Mountain which rises 228 feet above the plain and covering an average of five hundred acres.

This Ozark region contains one of the greatest mineral regions in all the world. Judged by the variety of minerals as well as by the immense quantities of some of them, the area deserves to take first place among mineral sections. The precious metals are not found in paying quantities, but a large number of other minerals are so found. The mineral which exists in this region in greatest abundance is lead which has attracted the attention of miners from the very earliest times; perhaps the greatest deposits of lead ore to be found in the entire world are in this section. Lead, however, is not the only mineral which is produced in paying quantities, iron is found in a number of these