AREA SOUTHWEST OF STUART 697 



ness found at the Earlkam quarries and lie beneath 8 feet of red shale 

 unlike that reported elsewhere. 



The limestone above the red shale (number 7), the uppermost of the 

 three limestone beds north of Stuart, contains many shell fragments and 

 some crinoid stems, but it is unlike either the Winterset or the so-called 

 De Kalb (really Westerville) Jimestone; especially is it unlike the latter 

 in the number of Fusulina, with which it seems to have been correlated 

 instead of with the Winterset, for it is that bed and not the Winterset 

 that contains the Fusulinas. Thus this stratum 6 (number 7) does not 

 fit into the Winterset section. 



From the above comparisons it is evident that the limestone beds in 

 the hills along Deer Creek north of Stuart do not belong to the Kansas 

 City division of the Missouri stage. They do, however, agree in character 

 and in fossil content with the beds northwest of Earlham and they follow 

 without break the beds farther north of Stuart, at Dale City and Glendon. 



Area Southwest of Stuart, along Middle Kiver, north Side of 



Fault to Fault-line 



Looking southwest from Stuart, one comes upon limestone that Middle 

 River reaches in section 16, Jefferson township, Adair County, at a point 

 6 miles west and 3 south from Stuart. The river crosses the level of the 

 bottom of this limestone within a mile, but the thickness in the ravines 

 bordering the valley on the west increases to 17% feet 5 miles down the 

 river, where limestone was formerly quarried. Here likewise the abun- 

 dance of Reticularia perplexa, associated with Composita subtilita and 

 Spirifer cameratus, in a thick bed beneath a thin shaly upper portion, 

 reproduces the conditions found northwest of Earlham. To further em- 

 phasize the relation, a recent boring for coal near Howell's store reached 

 an 18-inch seam of coal at a depth of 95 feet below the side of the ravine. 

 This is the seam found outcropping along Deer Creek north of Stuart, 

 mined northwest of Stuart, and formerly at Eureka mine, in western 

 Adair County, but not found near the surface east of the fault. 



A mile farther south there is a slight exposure of the same limestone 

 in the center of section 13, Grove township. A mile straight east from 

 this point is another exposure of limestone, on the south side of the river, 

 in the northeast quarter of the southeast quarter of section 18, Harrison 

 township. Here, at a lower level than at the limestone a mile west, one 

 comes on beds far above the others stratigraphically, for the grouping of 

 beds and the presence of the dark chert with Fusulina are characteristic 



6 This stratum is Bain's number 5, as given on page 448 of the Geology of Guthrie 

 County. Iowa Geological Survey, vol. vii. 



XLVI— Bull. Geol. Soc. Am., Vol. 33, 1921 



