BOOXE COUNTY. 99 



many miles over the surrounding country, and into the city of Belvi- 

 dere. The quarry, or rather series of quarries, is a source of profit, not 

 so much on account of the valuable properties of the stone, as on ac- 

 count of the ease with which they can be quarried and the scarceness of 

 all kinds of stone in the county. We noticed here flagging stones 

 twelve by twenty-one feet, and three or four inches thick, without an 

 apparent crack. 



On some parts of tbe rocky walls here exposed to the air, the "tooth 

 of time" has made a marked impression. The rock is crumbling and 

 decaying' rapidly. Draw the finger over it and a shower of small frag- 

 ments fall to the rocky floor. 



About Garden Prairie, near the line between this and McHenry 

 county, this formation is quarried and hauled north aud north-west 

 over the county for seven or eight miles, for purposes of ordinary stoue 

 masonry. 



At no other places in the county is it worked. Xo natural outcrops 

 exist, on account of the ease with which it disintegrates and covers up 

 its natural outcrops ; but it is not difficult to trace its boundaries by the 

 gently undulating elevations, the marshy springs along their base, the 

 color of the waters that trickle down the slopes, and the nature of the 

 overlying clays themselves. 



The formation here is uufossiliferous to a high degree. Nothing but 

 a few indistinct tracings of fucoids or sea weeds were noticed. 



The Galena Limestone. Two-thirds of this county perhaps is under- 

 laid by the lead-bearing rocks of the Trenton limestone. And yet in 

 all this extent of superficial area there is but one good outcrop, and one 

 place where the Galena is worked to any extent or advantage. This 

 is at the exposure on Beaver creek, about three and a half miles north- 

 west of Belvidere. Here the quarry is worked to the depth of thirty- 

 live feet. The stone is massive aud solid. Some of the bottom layers 

 are from six to eight feet in thickness. Much stone has been quar- 

 ried here for the construction of the railroad bridge at Belvidere and 

 for building purposes in the surrounding country. 



The country round the quarry is barrens and oak openings, with brush- 

 wood and a thin whitish soil. The upper strata of this outcrop are thin 

 enough to be readily removed with pick and wedge and crowbar ; but 

 the lower ones can only be displaced by patient blasting. 



I found here many of the characteristic fossils, such as Receptaculites 

 snlcata, Murchisonia graciti*. M. (jigas, Pleurotomaria angulata, Ambony- 

 cliia, BeUeropko*) and fragments of Ortliocera. 



Leaving this quarry, my examinations indicate that both Beaver 

 creek and the Piscasaw. for their whole length in this county, are un- 

 derlaid by the Galena limestone. From Belvidere, on a line east of 



