138 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



In the course of the survey a Hue was run along the Ohio Eiver, and 

 the succession there is interpreted as follows: 



Coal formation. Seams of coal associated with beds of sandstone, shale, clay, and 

 limestone. 



1. Oolitic limestone. 



2. Encrinital strata, Siliceo-calcareons series with occasional beds 

 of clay. 



3. Black bituminous aluminous slate. 



4. Fossiliferous and inferior strata of the Subcarboniferous group, 

 consisting of (1) Fossiliferous bed of Ohio Falls. (2) Water- 

 lime and variegated strata. (3) Sand or burr stone. (4) Blu- 

 ish or brownish limestone. 



Subcarboniferous 

 group 



On page 25 the rocks of the State are classified into three forma- 

 tions : 



1. A bituminous coal formation. 



2. A limestone formation (similar to the Mountain limestone of European 



geologists). 



3. A diluvium. 



In this report the Carboniferous group is restricted to the coal-bear- 

 ing rocks, or what is now called the Coal Measures. 



All the fossiliferous rocks below the Coal Measures were called " Sub- 

 carboniferous." The author said : 



To this group may with propriety be applied the name Subcarboniferous, as indi- 

 cating its position immediately beneath the coal, or Carboniferous group of Indiana ; 

 [and in a foot note], " The fossils generally coincide closely with those of the Carbon- 

 iferous or Mountain limestone of Europe ; but as no perfect seams of coal have ever 

 yet been observed alternating with these deposits in this country, and as most of its 

 fossils differ decidedly from those of the coal formation, it would seem to preclude 

 the possibility of including it, here at least, as some European geologists do their 

 Mountain limestone, in the Carboniferous group. * * * I prefer designating it by 

 the term "Subcarboniferous," which merely indicates its position beneath the Car- 

 boniferous group without involving any theory. 1 



In the second report, published the same year, Owen briefly reported 

 details for various counties of the State. The " Encrinital strata of 

 Harrison County" are said to " correspond to the Encrinital 7 of Dr. 

 Troost" of the "well known iron region of Tennessee." The rocks 

 below the fossiliferous strata of the Falls of Ohio were correlated with 

 the " Cliff strata" of Dr. Locke, of Ohio, and " most of the rapids and 

 falls in the State are produced by these cliff rocks." 2 And in the dis- 

 cussion of the rocks near Lockport and near Delphi, the author re- 

 marks : 



The whole of the rock formation which I have just been describing I consider as 

 belonging to the strata inferior to the black bituminous aluminous slate, including 

 part, if not the whole, of the Cliff strata. 



In the latter part of the report a comparison is made between the 



geological formations of Indiana and those of Ohio. 



1 Report of a Geological Reconnoissance of the State of Indiana made in the year 1837 in conformity 

 to an order of the legislature. By David Dale Owen, M. D., geologist of the State, 1839, pp. 12, 13. 



2 Second Report of a Geological Survey of the State of Indiana made in the year 1838. By David 

 Dale Owen, 1839, p. 17. 





