LOCAL NOTES 



The Bluffs.':' About two and a half miles north of Byifon the river 

 has cut thru a pre-glacial divide, forming the best gorge in its whole course. 

 On the west side the dolomite rocks rise precipitously though pretty well 

 screened by the trees on the talus, which is sometimes washed by the spring 

 floods. The east side is well covered with forest, with here and there a 

 ledge of rock outcropping. The bluff is well marked for only about half a 

 mile, but extends to the north much farther, lying back many rods froni 

 the present channel of the river. The most picturesque of the several 

 ravines cutting the bluff is the most southerly, lying about oncTeighth of a 

 mile from its south end. It is shady, cool and damp, even on the hottest 

 summer days. Before the upland timber was cleared off to make room for the 

 plow, there were several delightful springs which supplied a perennial stream 

 down this gorge, whose bed is now dry much of the year. A salietit rock, 

 easily reached from above or below, locally known as Black Hawk's pulpit, 

 stands near the middle of the principal bluff. The view to the north and 

 south from the crest of the bluff is worth not only the climb from the road, 

 but a journey of many miles. 



The Gravel Fill. In later glacial times, the water rushing thru the 

 gorge at The Bluffs carried a load of coarse sediment which it was com- 

 pelled to drop when it spread out in the broad pre-glacial valley to the 

 south. This formed the terrace on which the village of Byron is situated.. 

 The gravel beds are highest near the mouth of the gorge, and fall away at 

 a scarcely noticeable rate down stream. In places they are scantily covered 

 with soil. In the village they are covered with several feet of clay, topped 

 with a rich loam. In the gravel pit of the Great Western Railway, the 

 details of the structure of river deposits — cross-bedding, stratification, etc., 

 can be well studied. The gravel pit is replacing the stone quarry in these 

 days of cement construction. 



The Galena-Trenton Bock. The glaciers that passed over this region 

 removed the weathered rock, leaving the firm rock surface covered with till. 

 Here and there on places of considerable slope the rain-wash has removed 

 the clay, sand and gravel, leaving occasional bowlders perched on the bed 

 rock. Where the drift has been removed, the bed rock has been shattered 

 by changes of temperature to a depth of a few feet, below which the firm 

 rock appears. These exposed places are most convenient for opening 

 quarries. Before the common use of cement in construction, the quarries 

 supplied the surrounding country with stone, and some of it was shipped 

 forty or fifty miles to the east. Now the quarries are seldom worked. 

 The rock is compact, stands the weather fairly well, and can be burned for 

 lime. It contains abundant fossils — corals, crinoids, cephalopods, etc. 

 Specimens of Orthoceras four or five inches in diameter have been found. 



The Big Spring. About two miles southwest of Byron, from a rock 

 crevice at the foot of a hill washed by the river in flood, gushes a little 

 stream of clear, cool water. This spring is typical of those that abound in 

 limestone regions. It is one of the few still surviving the destruction of 

 the forests which once covered the uplands bordering the river. It has 

 shrunk to less than half its former volume, and its companion springs a few 

 rods on either side have disappeared entirely. The spring is fed by the 

 rain water which seeps down thru the soil and collects in the cracks of the 

 rock. The cracks are enlarged by the slow dissolving of their sides, till 

 an underground system of channels is formed. The deforestation of the 

 land results in a rapid run-off of the rain, and robs the spring of its water 

 supply. 



