HENDERSON COUNTY. 279 



the beds were covered, and others could be examined only with much difficulty. 

 I am indebted to Prof. A. H. Worthen for the following section, which was 

 made by him about a mile and a half southeast of Biggsville: 



FEET. 



1. Loess 10 to 12 



2. Gravel, sand and clay 12 "15 



3. Blue plastic clay, with pebbles 15 



4. Quartzose sandstone 2 



5. Band of broken, rotten limestone 1 



& Blue marly clay, stratified 15 "20 



7. Band of broken magnesian limestone 1 



8. Keokuk beds 25 "30 



No. 4 of the section probably belongs to the Coal Measures, while Nos. 5, 6 

 and 7 belong to the St. Louis group. West of Biggsville it was again recog- 

 nized in section 17. Commencing below the Drift, a section of the strata gave 

 the following : 



FEET. IN. 



1. Shale and yellow clay 10 



2. Soft, yellow sandstone 10 



3. Blue clay shale 2 



4. Keokuk beds (not measured) 



Nos. 1. 2 and 3 of this section belong to the St. Louis group. South of this, 

 along Ellison creek, thin outliers may exist, but none were recognized. 



Keokuk Limestone. This division of the Sub-carboniferous series is found 

 along the southern line of the county, at and near Dallas City. It rises to the 

 north or northeast, and on going up the bluff road about a mile, it disappears, 

 having either run out, or is so deeply covered by the Drift as not to be exposed 

 along the streams. East of Dallas City this limestone appears, forming the 

 bluffs of Camp creek, but on going down the creek, northwest, it soon runs 

 out, and the lower layers exposed are Burlington limestone. The Keokuk beds 

 again appear in section 11, township 9, range 4. A section at this point is as 

 follows : 



FEET. IN. 



1. Soil and Drift (not measured) 



2. Yellow clay shale, containing a few gcodes 1 to 2 



3. Limestone 3 2 



4. Blue clay shale ? 



North of this it is again exposed on South Henderson creek. Its most west- 

 erly outcrop along this stream, is about two miles east of Sagetown, in section 

 13, township 10, range 5. Here it appears near the top of the bluff, and a 

 mile or two up the stream it forms the bed of the creek. Its most easterly ex- 

 posure is about three miles southeast of Biggsville, in section 26, township 10, 

 range 4. A short distance west of Biggsville, in section 17, the rocks exposed 

 in the creek bluff gave the following section : 



