WAEREN COUNTY. 397 



this report shows two groups of areas in the county, as has been already 

 stated, viz., the uplands and the alluvial landn. This latter division de- 

 mands a brief description at this point. The valley in which the Great 

 Miami now flows, and the two south-eastern branches of this valley that 

 were occupied by the river in some earlier period of its history, together 

 contain not less than seventy-five square miles. This area constitutes one 

 of the finest agricultural districts in the State. Land embracing a greater 

 number of advantages, in fact, is scarcely to be found anywhere. The 

 following points are to be observed : 



1 The bedded rock has been cut out to a greater depth than existing 

 agencies can account for throughout most of this area. The rocky floor 

 is very seldom laid bare by the river, and it is as seldom struck in any 

 excavations or borings that are made in the valley. 



2. The valley is filled with immense accumulations of gravel and 

 bowlders. These gravel-beds undoubtedly overlie deposits of bowlder 

 clay in many parts of the valley. Indeed these deposits are occasionally, 

 though rarely, struck in wells and similar excavations ; and sometimes 

 they even approach very near the surface. The gravel is of various 

 sorts and sizes, and indicates various degrees of strength in the currents 

 that have transported it. Large quantities of sand are distributed 

 through it. In composition, it is principally limestone, thus agreeing 



• with the pebbles and bowlders that fill the Drift clays of the country, 

 but, unlike the true Drift pebbles, it has lost the marks of the previous 

 stage in its history, viz., the shaping which it received under the glacial 

 sheet. Its pebbles no longer show the polish and striation due to this 

 stage, but, on the other hand, bear unmistakable marks of having been 

 fashioned in running water. 



3. The gravel beds are in all cases covered with considerable deposits 

 of -loam and sand, which form the present surfaces of the valley. These 

 deposits are arranged in three natural and well marked divisions, viz., 

 the first bottoms, the second bottoTns, and the gravel terraces, sometimes called 

 the third bottoms. Of this series, contrary to the general order in geology, 

 the lowest member, viz., the first bottoms, is the newest, and the highest 

 member viz., the gravel terraces, is the oldest. In other words, the first 

 and second bottoms do not extend beneath the gravel terraces, and con- 

 sequently do not result from the denudation of portions of the valley. 

 The gravel terraces are at least one hundred feet above low water of the 

 river now. They are generally left in small and isolated fragments on 

 the margins of the valley, but sometimes they are found to hold consid- 

 erable areas. In the vicinity of the village of Trenton they can be seen 



