THE VALPARAISO MOEAIN1C SYSTEM. 357 



gan and Saginaw lobes, since the sandy and gravelly phase is confined 

 nearly to the portion of the Lake Michigan belt closely associated with the 

 Saginaw lobe. These causes are not antagonistic and may supplement each 

 other; possibly other causes will be found to have been effective in produc- 

 ing the large amount of sand and gravel. 



The surface of the moraine is strewn with a moderate number of 

 bowlders. They are mainly crystalline rocks of Canadian derivation. The 

 great majority fall below 3 feet in diameter. There are, however, occasional 

 immense bowlders of Corniferous limestone and of sandstone found on the 

 Michigan portion of the morainic system. In western Bangor Township, 

 Van Buren County, sandstone bowlders are scattered over a tract about a 

 mile and a half from north to south and scarcely half a mile in width. The}" 

 are most abundant in sees. 16 and 17, on a prominent knoll which is situ- 

 ated on the border of the section. One bowlder on this knoll was made 

 use of to build a large stone house in Hartford, Michigan. Two other large 

 bowlders still remain on the knoll, the larger one 24 by 24 by 21 by 21 feet 

 on the sides; the other 24 by 30 by 18 by 15 feet. They each stand 6 or 8 

 feet above the surface and extend an unknown distance beneath. The 

 owner of the farm on which they are situated states that he dug down 6 

 feet by the side of one of them and did not reach the bottom. Similar 

 bowlders are found in Bloomingdale Township, scattered over a belt nearly 

 3 miles in length and scarcely 100 rods in width. The north end is near 

 the Base Line in sec. 4, and the south end in sec. 17, about a half mile 

 west of Bloomingdale station. They abound on the most prominent points 

 along this line, but are seldom found on the low land between the knolls. 

 They are embedded in the ground at various angles, some standing nearly 

 on edge. The largest ones measure 15 or 20 feet in diameter and stand 6 

 or 8 feet above the surface. It is reported that similar large sandstone 

 .bowlders occur in sec. 33, Bloomingdale Township, but these were not visited 

 by the writer. These sandstones are mainly of red or pink color, but a 

 few specimens are brown. A large limestone block was noted in sec. 11, 

 Hartford Township, Van Buren Count}". It had been uncovered to the 

 extent of about a rod square, and had been quarried to a depth of about 3 

 feet, yet neither its lateral limits nor its bottom had been reached. A 

 bowlder of the same kind of limestone occurs on the base line between 

 Bloomingdale and Cheshire townships, less than a mile west of the north 



