GEOLOGY OP LA SALLE COUNTY. 



15 



This section is substantially the same as that 

 o-iven in " Geolog'ical Surrey of Illinois, Vol. Ill," p. 

 281, and in the "Economical Geoloo-y of Illinois," 

 Vol. II., p. 230. Nos. 32 and 33 have been added, and 

 the phraseolog-y of the list somewhat chang-ed. 



Hydraulic limestone was formerly quarried in a 

 low ridg*e in the valley or bottom about a mile south- 

 west of the railroad station at Utica. This was No. 

 22 of the above section, and to g'et it 20 and 21 were 

 removed, 20 furnishing" a verj^ gfood building' stone, 

 while 21, has the appearance of being- made up 

 of irregfular masses and frag-ments of older rocks, for 

 the pieces are of different shades, and vary in hardness, 

 and as the ang-les are sharp cannot have been carried 

 far from the place of orig-in; is traversed by many 

 cracks and breaks very irreg'ularly, and is adapted to 

 coarse, roug-h work .onh^ It also contains many small, 

 irregfular cavities, some of which are filled with deli- 

 cate ag-g-reg'ations of milk-colored cr3'stals of no g'reat 

 beauty, while others are nearly empty. 



With time these quarries have been pushed toward 

 the village, and the cement rock is now mined instead 

 of removing- the overla3Hng- material, as was formerly 

 the practice. The same plan is pursued at the works 

 two miles west of Utica station, where Nos. 31. 32 

 and 33 are mined. These beds come to the surface no- 

 where else in the State- 

 In the Illinois Reports, as well as in W. W. Calk- 

 ins' article in Baldwin's Histor}^ of La Salle county, it 

 is stated that these beds yield no fossils. This is in- 

 correct, for the writer has obtained, g-enerally in poor 

 condition, from Nos. 20 and 21 alone a species of mur- 

 chisonia very abundant; a small trilobite one-third 

 inch across; two brachiapods, and eig-ht or nine other 

 species of shells. In the water lime or cement rock 



