50 



GEOLOGICAL RECONNOISSANCE 



SECTION OF MARION COUNTY— Continued. 



o 

 o 



42 



31 



20 



-.-aMEITJTiaB 



ML 

 ML ML 



ML 



ML ML 

 ML 



ML ML 



Bench of grey magnesian limestone. 



Thin-bedded, light - colored magnesian 

 limestone. 



Bench of solid, grey magnesian limest. 



Thin -bedded magnesian limestone, in 

 beds of a few inches in thickness, ex 

 tending down into the bed of Sugar 

 Loaf creek. 



0) 



fa 



4 



12 



II 



20 



307 



Three quarters of a mile south of the Mitchell farm, the following sec- 

 tion was obtained in a hill known as "Mitchell's Hill:'" 



Height. 



148 feet.) 

 142 " \ 



Thickness. 



6 



Top of the loose pieces of chert and sandstone 



Hard, light-grey magnesian limestone, with occasional 

 beds of chalcedonic chert, most abundant in the 



76 " lower part 76 



56 " Quartzose sandstone and chert 10 



26 " Magnesian limestone 40 



25 " Intercalated bed of siliceous magnesian limestone 1 



1 " Magnesian limestone, with red and yellow bands 15 



Slope and bank extending down to the bed of upper 



Sugar-loaf creek 



Plate 3 represents a distant view of Sugar-loaf hill, of Marion, a 

 conspicuous land-mark, lying in the eastern part of Sugar-loaf prairie. 

 This hill is 300 feet above the level of Sugar-loaf creek, near the Coka 



farm. 



It is composed of thin-bedded magnesian limestones, overlaid by chert 

 at top, and underlaid by light-colored earthy limestone, like the so-called 

 "Cotton Rock," of Missouri. 



A voluminous spring issues from the cavernous spaces in the rocks on 

 the east side of lower Sugar-loaf creek, affording a valuable water-power, 

 available at all seasons of the year, with but little variation as to quantity 



