GEOLOGY OF LA SALLE COUNTY. 



11 



o'allei\y of statues, each of which is a perfect repre- 

 sentation of the orig-inal, a fac simile of the individual, 

 not a copy of a type or of a conventionalized hg-ure, 

 but a true cast, or the thing- itself that once lived and 

 moved and had a being- either on the land or in the seas 

 of a world, that with all our research and efforts the 

 most powerful imag-ination can but dimly or frag'- 

 mentarily reproduce. 



From the rocks we may g-ather much concerning- 

 the conditions under which the}' were laid down, 

 whether in deep or shoal water, on the sea shore, 

 in qui^t bays or in swamps swept by tides and subject 

 to inundations from some g-reat river and much else, 

 while from the shells and bones we can, in a measure, 

 re :onstruct the life of the sea, and in part of the land 

 and from leaves and stems restore in part at best 

 the veg'etation of worlds gfone by, of ag-es that we may 

 not count a past eternity. 



In our reg-ion at least the limestones are richest in 

 fossils, and these are g-enerally in g-ood condition. 

 Some of the sandstones contain a considerable number 

 of fossils, but these are often poorly preserved and much 

 less satisfactory than those of the limestones. The 

 shales and clay slates are in places richly fossiliferous, 

 and among- the remains entombed in them are a multi- 

 tude of ferns beautifully preserved. 



The g-eolog-y of La Salle count3% while simple 

 in outline, presents some problems of no little interest. 

 The rocks of the western part have been g-reatly dis- 

 turbed, and this convulsion has made its effects felt at 

 a considerable distance. Ag-ain, the connection of the 

 various areas of coal has been much discussed, and 

 very different opinions have been held by parties well 

 qualified to judge. 



