204 IOWA ACADEMY OF SCIENCES. 



GYMNOSPERM^. 



CONIFERiE. 



JiDiipenis Virginia IK I Linn. Red Cedar. 



Rare. Found on steep bluffs along North River and 

 Cedar Creek. In Douglas Township there was a 

 small grove on a rocky bluff, wherein the trees 

 reached a foot or more in diameter. 



A TERRACE FORMATION IN THE TURKEY RIVER 

 VALLEY, IN FAYETTE COUNTY, IOWA. 



BY G. E. FINCH. 



The Turkey River flows, in the lower part of its course, 

 through the driftless area in Fayette county, through wide 

 bottom lands. These are usually a half-mile, sometimes a 

 mile or more in width, showing considerable progress in 

 base-leveling. 



Fringing the bluff's on one or both sides of the river may 

 usually be found a " bench," rising ten or twenty feet 

 above the general level of the valley. A few rods north- 

 west of the Huntsinger bridge over the Turkey River in 

 Dover township, Fayette county, a small tributary called 

 Dry Run, coming from the north, has cut into the side of 

 one of these terraces from top to bottom, showing in a 

 broad, concave curve, a section about 300 feet long and 

 25 feet high. Several formations are exposed. Starting 

 at bed rock and extending upward about three feet, is an 

 iron-stained formation that seems to be residual. It is 

 composed largely of cherty fragments from the lower part 

 of the Maquoketa shales with a smaller mixture of green- 

 stones and quartz pebbles, all imbedded in rusty earth. 

 Above this occurs some eight feet of a loess-like material, 

 merging into a soil at the top. Somewhat abruptly above 

 this, the bank changes to thin-bedded sand and gravel 

 strata for about four feet. Then occurs six feet of lime- 

 stone fragments with a small percentage of glacial peb- 

 bles, packed so close and even in horizontal layers as to 



