44 



from ;i few feet, as at Rensselaer, to two hundred feet. Tlie latter extreme depth 

 lias lieen found nowhere, so far as I have learned, except on the moraine which 

 extends in a northeasterly direction across the county, passing one and a half 

 miles north of Eensselaer. 



This moraine is possibly the most marked topographic feature of the county. 

 In width it will average probably a mile, and in height it varies from twenty to 

 eiii'litv feet. It is said by Mr. Leverett, of the V. S. Geological Survey, to extend 

 northeastward into Pulaski County and southwestward through Newton CouDty 

 into Illinois, and is thought by him to possibly be interlobate between the Sagi- 

 naw-Erie lobe from the northeast and the Lake Michigan lobe from the north. 



One of the lirst things to attract attention in the study of this locality is the 

 great number of sandy ridges everywhere prevailing. With reference to direction 

 it appears that there are two classes of these. One class extends almost parallel 

 with the above mentioned moraine. I have observed them in Pulaski and Jasper 

 counties, northwest of Monon, and in passing over the Monon Railway from two 

 miles northwest of Rensselaer to Parr. The other class, which I have observed 

 onlv south of the moraine, have an average course of about S. 30° E., and conse- 

 (juentlv run in a direction almost at right angles to it. It is the latter class to 

 M-hich we wish to invite attention. 



These ridges are of two types, each fre(|uently passing into the other. For 

 convenience we will speak of them as the symmetrical and the unsymmetrical. 



The most common form is the symmetrical. These are low, broad, symmetri- 

 cal ridges. They vary in widtli from forty yards to an eighth of a mile. Though 

 freipiently running into each other they are in the main parallel, and often are 

 crowded so close together as to give the surface a billowy appearance. The 

 troughs between them always contain rich, black soil, formed from the decay of 

 peaty matter, and indicating former shallow lakes. An excellent view of this 

 type is presented along the "Line Road" from Rensselaer to Remington for a 

 distance of five miles south of ihe former place. The view along this road shows 

 them to run east and west, but a short distance to the east they swing to the south 

 and southeast. All the ridges of this class are composed largely of sand, though 

 they contain enough vegetable mould to prevent shifting by winds, and permit of 

 an excellent yield to the farmer. I have never noticed any gravel in them except 

 north of the Iroquois, in the vicinity of the large moraine. Bowlders are sone- 

 times seen along and near their bases, but seldom on the swell of the ridge, ex- 

 'cept also in the vicinity of the large moraine. 



The unsymmetrical type differs from the symmetrical in size and shape, in 

 ■being composed more largely of sand, and in not being so numerous. They are 



