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says: "The well-known Wabash flaggings are here counted of Lower 

 Helderberg age." Dr. Phinney, in a report on the natural gas field of 

 Indiana, eleventh United States Geological Survey, dissents from this 

 opinion, and says: "The exposures in the vicinity of Wabash have been 

 considered Niagara limestone, as the fossils are identical with those found 

 at Marion, where the exposure is undoubtedly Niagara.' In the Wabash 

 County report or 1891 forty species of fossils are tabulated, which were 

 collected from the quarry stone. The most of these were characteristic 

 Niagara fossils. The Illinois geologists have always considered the equiva- 

 lent beds of that State as of Niagara age. 



By some writers great significance is attached to the brecciated struc- 

 ture in determining the age of the stone in which its occurs. However, 

 Dr. Phinney describes the Waterline at Kokomo as "an even-bedded lime- 

 stone." About Logansport, he says, the Lower Helderberg is a common 

 rock, and "finely exposed," but, so far as known, never shows a brecciated 

 surface. If the Waterline formation is excluded from the Lower Helder- 

 berg it is probable no true representative of that period is to be found in 

 Indiana. 



Prof. Dana, in the fourth edition of his Manual of Geology, assigns 

 the Waterline formation to the Salina group. And in a bulletin of the 

 Geological Society of America, May, 1900, Mr. Charles Schuchert presents 

 facts to show that all of the Lower Helderberg above the Waterline and 

 Tentaeulite limestone should be included with the Devonian. Mr. Schuch- 

 ert seems to consider the Tentaeulite limestone as transitional to the 

 Lower Helderberg. Of twenty-six species found in the Tentaeulite beds 

 of New York, only four are known to occur in some higher member of the 

 Lower Helderberg. In Ohio, out of thirteen species described from the 

 hydraulic limestone only four are known to occur m the higher beds. 

 So, then, in view of what is now known, it seems safe to assume that 

 the Wabash County unconformities and" pronounced irregularities of bed- 

 ding were the result of forces in operation near the close of the Niagara 

 epoch, and at all events before the close of the Silurian age. 



The subdivisions of the Niagara group in Southern Indiana have been 

 much better defined and correlated than those of the Wabash Valley. The 

 remarkable uniformity in the bedding of the Laui'el limestone from Con- 

 nersville to the Ohio River has been fully described, and the Waldron 

 shale exposures traced from Milroy to Charlestown landing. Slight irregu- 

 larities of bedding had been noticed in the layers immediately above the 



