WHITESIDE COUNTY. 153 



edges, and in many ravines inside of its boundary lines, good exposures 

 and artificial outcrops . may be examined. Hock creek cuts into the 

 Niagara, and Elkhorn creek cuts into the Galena limestone, but the Cin- 

 cinnati rocks and shales run over the one and come from under the other, 

 in less than one mile from either stream. Along its northern limits 

 it rises to the altitude of almost a hill, overlooking the low-lying 

 Galena deposits of Carroll county. Three or four quarries are opened 

 along the face of this elevation. The average thickness of these expos- 

 ures is about twenty feet. The stone is thin-bedded, easily broken, close 

 in texture and light in color, having a dry or baked appearance. The 

 bottom layers are thicker bedded and have a faint green and blue tinge. 

 It is an argillaceous shaly limestone. At Bressler's mill on the east side 

 of the ridge there is a low outcrop just above the water's edge. Here 

 the rocks are stained by iron-impregnated waters, flowing from some 

 springs just above them. Nearly a mile north-west of this is Dr. L. S. 

 PEXMXGTON'S large quarry, opened at a considerable distance from, and 

 elevation above Elkhorn creek. The exposure is stripped of the over- 

 laying clay and worked into about thirty feet. A drain is constructed to 

 lead off the water. The upper portion of the quarry is thin-bedded, but 

 the layers can be lifted in immense slabs. No better nagging stone can be 

 obtained anywhere. The lower portions of the quarry are thicker-bedded, 

 compact and very blue. On section three, in the township of Hopkins, 

 there is another splendid quarry of this stone. The part worked is 

 about twelve feet thick. It is covered by a few feet of finely comminu- 

 ted, light-colored clay. A circular pool of sweet, clear, cold water, fed 

 by some ' large springs, lies in placid tranquillity almost in the quarry, 

 and throws off a laughing stream. The stone here is a hard, thicker- 

 bedded, compact, argillaceous limestone, unlike the usual crumbling 

 shales of the Cincinnati group. Two or three of the bottom layers are 

 of a deep ultra-marine blue color, with shaly and clayey partings of a 

 few inches thickness between them. The locality is known as Keeker's 

 quarry. It is now owned by Dr. PEXXIXGTON. 



There is another quarried exposure nearly a mile north of this, at 

 Harvey's. The stone here are soft, shaly, and crumbling. The tooth 

 of time makes sad havoc with them. When exposed to the atmosphere 

 they soon begin to decay. 



Here I noticed some disturbances in this usually quiet formation. 

 Over a few sections it seems to be thrown out of shape. Not far off 

 some Niagara rocks are found where they do not belong, according to 

 outcrops and the signs in the surrounding hills. These lost Niagara 

 rocks are evidently not in situ, but have been moved probably by the 

 drift forces. 



The lithological character of the Cincinnati rocks examined in this 

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