1897.J ASHLEY — GEOLOGY OF ARKANSAS. 247 



led to this classification, as Marcou ^ and others have been, by find- 

 ing at Little Rock the highly contorted shales at the '* Little Rock " 

 and a few miles above, at '^ Big Rock," the almost horizontal sand- 

 stone strata. In 1842, Dr. W. Byrd Powell ^ questioned Feather- 

 stonhaiigh's correlation with the grauwacke, but he accepted it as 

 the best that could be given, but included the sandstones in the same 

 classification. Dr. Englemann saw something of the region be- 

 tween Little Rock and Hot Springs, but he found no fossils, and the 

 only suggestion as to correlation was that the sandstone at Little 

 Rock was '' most probably analogous to that of Lake Superior."' 



Owen refers this region to the Millstone Grit,"* including in 

 the same formation the novaculites, which we now know to be 

 Silurian. 



He concludes that these beds have an immense thickness from 

 observing sections many miles long, where the beds appear to dip 

 steadily in one direction. This has since been shown to be due to 

 a number of consecutive overturns. 



Subsequent Observers. — Since the beginning of the present survey, 

 several of its members have crossed this region. No fossils were 

 found, and so, though Mr. Branner provisionally referred these 

 beds to the Lower Carboniferous,* he thought it better to speak of 

 them simply as Paleozoic. 



Extent of Beds. 



It can be assumed with some degree of certainty that the strata 

 exposed over the area under discussion are continuous. This refers 

 only to the beds as a whole, not to individual layers. 



The extent to the south and east can only be conjectured, but as 

 no thinning out could be detected, the strata may have had a con- 

 siderable extent in those directions. 



As will be discussed later, it has been suggested that the Ouachita 



1 Exploration and Survey for a Railroad from the Mississippi River to the 

 Pacific Ocean, Vol. iii, Pt. iv, p. 122. 



"^ A Geological Report upon the Fourche Cove and its Immediate Vicijiity, hy 

 W. Byrd Powell, M.D., Litde Rock, 1842. 



'^ Froc. A. A. A. S., v, 1S51, p. 199. 



* Second Report of a Geological Reconnoissance of the Middle and Southern 

 Counties of Arkansas, made during the years 1859-61, by D. D. Owen, Phila- 

 delphia, i860, pp. 32, 33, 95, no, 124. 



• Geol. Surv. of Ark.,A.n. Rep. for 18S8, Vol. ii, p. 262. 



