224 GEOLOGY OF ILLINOIS. 



shale; but I was unable to detect this partiug at Prospect Hill, proba- 

 bly on account of the tumbled masses of rock and debris which may 

 have covered it up. 



The Conglomerate is also seen in the south-eastern and south-western 

 part of the county. On sec. 34, T. 10, E. 6, at what is known as the 

 " Stone Fort," it is a massive pebbly-sandstone sixty to seventy feet 

 thick, where it forms an abrupt escarpment on the south face of the 

 ridge, 150 to 160 feet above the Little Saline river which flows along 

 the foot of the ridge. This ridge appears to be a continuation of the 

 Gold Hill axis ; and so far as I have been able to discover in traversing 

 its course, the strata present here the appearance of an anticlinal axis, 

 as they dip about 10° to the northward. 



The name of the latter locality is derived from an old fort like inclo- 

 sure built upon the highest part of the Conglomerate. It contains an 

 area of three or four acres, which is surrounded by a semi-circular wall 

 of sandstone three or four feet high. The rocks of which this wall was 

 built furnish no evidence of having been quarried, but on the contrary, 

 present the appearance of having been loose stones picked from the 

 surface and thrown into the wall-heap without any attempt at order in 

 their arrangement. This ancient fort was well protected on the south 

 side by a bastion or perpendicular wall of Conglomerate sixty to seventy 

 feet thick on its exposed vertical face. In this " fort " we have 

 undoubtedly another monument of a pre-historic race of men who 

 inhabited this Continent at so remote a period that do clue to their his- 

 tory can be obtained from the existing races of Indians — the tradition 

 of whose forefathers give no account of the Mound and Fort-builders. 



While standing on the parapet of this ancient strong-hold, the mind 

 naturally wandered back over the immense lapse of time since this for- 

 tress or citadel was thronged with beings who were filled with hopeful- 

 ness, or oppressed with all the cares and anxieties of life peculiar to 

 man, and who, no doubt, felt proud of the supposed security against 

 their foes obtained by the selection of so strong a position. Here pro- 

 bably they placed their sentinels to give the alarm on the first approach 

 of an enemy ; here likewise, the elite of the community may have 

 assembled to contemplate the grand and beautiful scenery around their 

 strong-hold ; for, then as now, the Little Saline river had cut its pass- 

 age through the Conglomerate ridge, and its banks were strewed with 

 cyclopean blocks fallen from the parent mass above. 



Coal Xo. 5. — This bed of coal is the fifth in the ascending order on 

 Saline river in Gallatin county, but in Saline county it is the lowest 

 workable seam that I have been able to identify. It is opened and 

 worked by Messrs. Temple & Castles, on sec. 24, T. 9, E. 7, one mile 

 west of the salt works, where it outcrops on the east side of a short 



