SHUMARD—GEOL. OF STE. GENEVIRVE. 413 
the headwaters of the Fourche a Duclos. On all these 
streams, i 
mass, frequently forming bold escarpments with m 
and sometimes exposed to the height of 150 feet. 
Ervptive Rocks. 
These consist chiefly of granite and green stone and occur 
on the a hardy ches of the Aux Vases, and near the Min- 
eral Fork of the Saline. 
Granite —This rock differs but little from. the granite ex- 
Haga in the vicinity of the Iron Mountain. Felspar of the 
esh-colored variety predominates greatly over quartz 
Sometimes, it is coars the felspar being immode- 
tals, but at athe times it possesses a fine tex- 
tare, j is quite hard, and ma dressed in almost an deaira- 
Vases, : m ty expo- 
sed in the | re vo ti st ec ag the ae qr. of 8. 2, aoe 
Bele » to its very head. Not far from the lower gee 
rg hg above the ae hey 
for a s distance of abou three m ailes, Proje ect 
ibennen; shoo 
ing gs couse 
above the s 
