THE SWEETLAND CREEK BEDS 69 



uppermost ledge of the limestone, which runs out as if worn 

 away. The surface of the limestone has been partly uncovered 

 by the creek. It is brown in color, uneven from erosion and fre- 

 quently studded with nodules of iron pyrites or covered by a con- 

 tinuous incrustation of the same mineral. In the west bank of 

 the creek the basal sandstone of the Coal Measures overlies the 

 eroded edges of numbers 6, 7, and 8 in the above section, which 

 rise under it in a hillock. In the gully to the east the section is 

 continued higher up and the Coal Measures do not appear. 

 Some distance farther up Sweetland Creek they are again seen 

 unconformably overlying the dark gray shale in the east bank, 

 with erosion contours extending down three feet into the lower 

 formation. At this place the basal conglomerate contains rounded 

 lumps of the dark shale, three or four inches in diameter. Still 

 farther up the creek the darker shale corresponding to number 

 1 1 in the above section appears at several places in the bed of 

 the stream, rising in one instance about five feet in the bank. 

 The last seen is about one hundred paces south from the wagon 

 bridge near the north line of section 27. In each of these places 

 the characteristic green layers with their accompanying network 

 of green threads in the confining dark shale may be seen. 



About three fourths of a mile west of Sweetland Creek, near 

 the east line of section 28, in Sweetland township, a smaller 

 stream exposes the following section. 



Number Feet 



5. Coal Measures. 



4. Alternate layers of dark and greenish shale - - - - - 4 

 3. Fine grained, light yellowish-gray, impure dolomite in thin ledges 2]/ 2 

 2. Greenish shaly rock with a thin, harder layer below - - -2% 

 1. Upper ledges of the Cedar Valley limestone, ferruginous and worn 



superficially .__.___-_ 1-2 



In Camhel Run, which comes down to the river through the 

 northwest corner of section 21, in the same township, a similar 

 succession of layers is seen at the point where the stream passes 

 the line of the river bluffs. The following section appears very 

 clearly. 



