SCIIUYLER COUNTY. 77 



tains are the remains of species of animals now living, or but recently become 

 extinct. Hence this formation is unconformable with those below it, and may 

 be found immediately overlying either of them, even the lowest, if the others 

 are absent. If the geological series was complete, we should have above the 

 Coal Measures, and intervening between that formation and the Quaterna- 

 ry, the whole of the Secondary and Tertiary series, embracing many thou- 

 sand feet in thickness of strata, and representing, in their fossil contents, all the 

 missing links in the great chain of organic life, which connect the paleozoic 

 age with the present. But as the Quaternary is the most recent of all the 

 geological systems, it may be found resting directly upon any of the above de- 

 posits, from the Tertiary to the most ancient stratified or igneous rocks that out- 

 crop on the surface of the earth. This system includes the alluvial deposits of 

 our river valleys, usually termed Alluvium; the Loess, a deposit of buff-colored 

 marly sands and clays, most conspicuous in the vicinity of the river bluffs, and 

 the Drift, which usually consists of brown or bluish gray, gravelly clays, with 

 water-worn boulders of various sizes, from an inch to several feet in diameter. 

 There is probably no locality in the county where these deposits exceed a hun- 

 dred feet in thickness, and they attain their greatest development in the vicini- 

 ty of the river bluffs, where the Loess attains its greatest thickness, and rests 

 upon the Drift clays. In the interior of the county, the Loess is generally 

 wanting, and the drift deposits generally range from thirty to fifty feet in, 

 thickness, and consist of unstratified clays, with sand and gravel, enclosing 

 water-worn boulders of granite, sienite, gneiss, porphyry, horn-blende and 

 quartzite, and also the rounded fragments of the limestones and sandstones of 

 the adjacent region. Fragments of copper, lead ore, coal, iron and other min- 

 erals are often found in the Drift, or in the gravel beds' in the valleys of the 

 small streams, but their occurrence in this position is no indication of the prox- 

 imity of any valuable deposit of these minerals, and the fragments which are 

 found in this position are far removed from the beds from which they originally 

 came Small quantities of gold are reported to have been found in the washed 

 gravel of this formation, but nowhere yet in sufficient, quantity to pay the 

 ordinary price of the labor necessary to secure it, and it is quite certain that, in 

 many cases, the material mistaken for gold, is either pyrites of iron or yellow 

 mica"; the former, derived from the Coal Measures or other stratified rocks of 

 the adjacent region, and the latter from the decomposed boulders of sienite or 

 gneiss, transported from the northern shores of the great lakes. 



Carboniferous System. 



Coal Measures. This term is applied to the upper division of the Carbon- 

 iferous System, and it embraces all the coal seams and the associated strata, 



