WARREN COUNTY. 297 



of the bluffs. In the east part of section 7, they are overlaid by heavy beds of 

 Coal Measure sandstone. Small quarries have been opened at various points 

 from here to the east half of section 8, where, a few rods south of the Cedar, 

 and along some small runs that put into it, there are extensive quarries. The 

 rock obtained here is mostly taken to Monmouth and its vicinity. At this 

 place, and for some distance up the creek, the bluffs are not as high as farther 

 down, and the Coal Measure strata have been largely, and in some places en- 

 tirely removed. From here to the middle of section 9, though occasionally 

 outcropping, the rock has been but little worked. At this point there is a 

 small quarry on a run coming in from the northeast. Near this, along a branch 

 entering the Cedar from the south, the rock has been almost continuously 

 worked, from near the mouth of the stream to the center of section 16. In 

 the southeast quarter of section 9, the Burlington limestone disappears beneath 

 the strata of the Coal Measures, and does not again appear to the eastward, 

 along Cedar creek. 



In section 24, township 9, range 1, the strata dip to the north of west and 

 the south of east, forming an anticlinal. As only a few feet of the beds were 

 exposed, I was unable to determine, accurately, the direction of the dip and the 

 trend of the anticlinal. To the eastward, the Coal Measures thicken, and it is 

 not probable that the limestone is again exposed. 



The limestones of this group are generally rich in fossil remains, which are 

 well preserved, and the rock is largely composed, in most cases, of the frag- 

 ments of crinoidea, and at almost every point where it is exposed, more or less 

 good fossils may be obtained. Among the Brachiopoda found here, were 

 Spirifer Grimesi, S.plenus, Productus semireticulatus, var: Hurlwgtonensis, Or- 

 this Michdmi, and O. Swallovi. 



The crinoidea are not as common as farther west, but some fine ones were ob- 

 tained there, among which were Actinocrinus rotundus, A. oBlatus, Satocrinui 

 Verneuilianus, B. Christy i, B. Kbnlncki, B. pyriformis, Ayaricocrinus, Granato- 

 crinus Norwoodi, and Pentremites elongatus. 



Kinderhook Group. The beds of this group, which underlie the Burlington 

 limestone, are, as far as exposed in this county, composed of shale, with 

 occasional layers that are more or less calcareous or arenaceous, and compact. 

 Some of the more compact portions might be used for building purposes, where 

 not exposed to the weather ; but an abundance of far superior building stone 

 renders this unnecessary. It seems probable that but a few feet of the upper 

 portions of the group are exposed at the different outcrops, but being, appa- 

 rently, destitute of fossils, it is difficult to recognize the beds. At Rockwell's 

 mill, section 35, township 12, range 3, there is an exposure which gives this 

 section : 



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