164 GEOLOGY OF ILLINOIS. 



northwardly along the west fork of Little Wabash, the change from low 

 to high ground is very gradual, the country at the same time increasing 

 in fertility. The growth in the south part of township 11, E. G E., 

 consists of elm, grape vines, wahoo, laurel oak, black haw, arrow wood, 

 hazel, and honey locust. Farther north the land continues rich, with a 

 growth principally of bur oak, shell bark hickory, black walnut, chest- 

 nut oak, pignut hickory, sassafras, red bud, ash and mulberry, and a 

 carpet of pennyroyal and goosegrass. Near Windsor the surface is 

 either flat or gently undulating, with a deep rich black soil. From the 

 high ground at Windsor there is an exceedingly easy descent towards 

 Sand creek. At the edge of the timber north-west I noticed four species 

 of Cratceffus, also laurel oak, elm, pin oak and hickory, and the surface 

 of the ground was covered with pennyroyal. On Richland and Brush 

 creeks the hills are not generally very high — about 50 feet near the mouth 

 of Richland, becoming lower further up stream ; its bottoms are one- 

 eighth to one-quarter of a mile wide and not too low to be cultivated, and 

 have a growth of white walnut, elm, black walnut, sycamore, coffee tree, 

 bur oak, sassafras, red bud, coral berry, and raspberry. From the 

 bluffs the ascent is gentle to white oak and post oak flats and small 

 prairies. In the southern part of the county on the west side of the 

 Kaskaskia river, broken and flat ridges extend to the flat prairies; 

 towards the centre of the county these gradually rise to the mounds. 



Between Mitchel's and Beck's creeks there are a series of mounds 

 extending from the southern part of the county as far north as Mud 

 creek. Northwardly near Prairie Bird there are several low mounds. 

 The soil on the highest is of a reddish color, sometimes containing a 

 good deal of gravel and sand. The high timbered mounds near 

 Williamsburg have on them a good growth of white oak, black oak, 

 shell bark and common hickory, red bud, sassafras and hazel. The 

 mound slopes are very rich, and sustain a growth of elm, cherry, wal- 

 nut, hickory, mulberry, hackberry, red bud and hazel. 



The bottoms of Beck's creek are one-quarter of a mile wide, low and 

 flat, with mostly pin oak, laurel oak, elm, ash, hackberry, buckeye, 

 maple and sugar trees; the hills are low, sloping at 15° to 20°, and 

 sustain a growth of white oak, black oak, shell bark hickory, plum, 

 hazel, etc. Near the edge of the neighboring prairie the surface is flat 

 and sometimes swampy, with pin oak and button bush (Cephalanthus 

 occidentalis.) 



Robinson's and Mud creeks are sluggish streams with muddy banks 

 and wide bottoms and generally low hills, the highest not above 50 

 feet in bight. On the hills the timber for the most part consists of 

 white oak, black oak and occasionally post oak and black jack ; some- 

 times there are low ridges where black oak and black hickory prevails, 



