282 Hazvorth on the Archczan Geology of Missouri 
I._ GENERAL CONSIDERATIONS. 
A. Geograptiy. 
The area covered by the work of which the following is a 
summar}' lies in the vicinity of Pilot Knob, and Iron Mountain, 
Missouri. This famous mining district is known by name to 
almost evervone. It lies on the main line of the St. Louis, Iron 
Mountain, and Southern railroad, southwest of St. Louis about 
eighty-five miles. The principal places mentioned is this paper 
are located as follows: Iron Mountain, eighty-two miles below 
St. Louis; Pilot Knob, eighty-seven; Ironton, one mile below 
Pilot Knob. It is the county seat of Iron county, and the largest 
town in the district described; Piedmont, about thirty miles 
below Ironton; Syenite, a granite quarry, fifteen miles east- 
northeast of Ironton; Mine La Motte station, sixteen miles cast 
of Ironton ; the mines b}^ this name are two and a half miles 
farther east; Graniteville, three miles northwest of Pilot Knob; 
and the vSilvcr Mines, ten miles southeast of Ironton. 
The only two streams which will be referred to very often 
are the St. Francois river and Stout's creek. The former rises 
near Graniteville, flows to the north a short distance, then forms 
a big horse-shoe curve and flows south, passing Syenite and the 
Silver Mines. Stout's creek passes south of Ironton, then 
flows almost due east to the St. Francois, thus shutting in a 
large area in the horse-shoe bend of the St. Francois. 
The Archaean area covers irregularly outlined portions of no 
less than ten different counties. To the west it extends as far 
as Texas county ; to the north and northeast as far as Washing- 
ton, St. Francois, and Ste. Genevieve counties. To the east it 
passes through Madison county ; and to the south nearly through 
Wayne county. But only a small portion of this territory is 
covered by the Archa?an rocks. 
Throughout the whole Archcean area the surface is exceed- 
ingly rough. Narrow valleys along the streams with high and 
irregular hills beyond, rising from three to six hundred feet, is 
perhaps as good a description as can be given. Sometimes 
there is a long divide between two streams which is much more 
neai'ly level than the hilly portion just mentioned. 
