244 GEOLOGICAL RECONNOISSANCE 



CONCLUSION. 



It will be seen, on review of this Report, that the northern part of the 

 counties lying north of the Arkansas river, are bounded by a chain ot 

 mountains, which are crowned, on their summits, with massive conglome- 

 rate or thick-bedded sandstones, locally pebbly, belonging to the millstone 

 grit series. These massive sandstones are underlaid by reddish and dark- 

 colored shales of great thickness, especially towards the south-east, ae 

 three hundred feet have actually been measured where they still extend 

 beneath the drainage of the country. Thin seams of coal are found in 

 the upper part of the dark shales, in all the counties from Crawford to 

 Pulaski,* one of these veins appears to be persistent, and has been identi- 

 fied, by its organic remains, over a great extent of country. Though 

 often interrupted by extensive waves, which must have taken place 

 in a great degree before the deposition of the superimposed sandstones, 

 the general horizontality of the strata is well preserved. The axis of 

 these waves appears to be parallel to the strike of the strata, and the 

 elevated ranges produced from this cause are always capped with the 

 millstone grit, with sometimes one or two hundred feet of shale over- 

 lying it. After reaching the eastern boundary of Pulaski county, the dark 

 underlying shales, with the incumbent sandstones, disappear either ty 

 dipping to the south-east, or what is most likely the case, they have been 

 removed by denudation, and buried beneath heavy deposits belonging to 

 the quaternary period. 



Permit me to take the present occasion, to acknowledge the many acts 

 of kindness experienced at the hands of the citizens of the various counties 

 through which I passed, which have promoted and facilitated the objects 

 of the Survey. Where these are numerous and universal, it would be 

 invidious to particularize individual ca:es. 



EDWARD T. COX, 



Assistant Geologist. 



* Though I did not see any coal in Pulaski, I was credibly informed by Mr. Elliott, that he had 

 found a thin scam not far from the Kellogg mines; and he promised, if possible, to meet me at the 

 Klines and show it. 



