IOWA ACADEMY OF SCIENCE 
209 
The fragmental appearance and the separation into two distinct por- 
tions at the falls strongly resemble these features in the limestone at the 
base of the Missouri stage in Iowa (the Hertha, or so-called Fragmental) ; 
but even at Winterset a portion of the uppermost Earlham limestone is 
slightly fragmental. 
At the falls there is a bridge over a small, ravine which empties into 
Big Creek. A few hundred yards south along this small ravine one 
comes to quarries where heavy beds of the Winterset limestone are 
conspicuous. For a short distance back north toward the falls nothing 
is visible (the shale is concealed). Then one comes directly to the top 
of the limestone which is continuous with the limestone at the falls 
itself. A few rods downstream from the falls is another quarry where 
a section revealed but sixteen feet not exposed. — too little by far to 
contain any considerable deposit of limestone and associated beds of 
shale. Then, standing on the limestone at the mill, we looked back up 
the stream to where the limestone (Winterset) which we had first visited 
appeared beside the stream. It is needless to say that in the face of 
such evidence it was necessary to agree that Broadhead’s Bethany Falls 
Limestone (his No. 78) is not the “Fragmental” of Iowa but the 
“Earlham.” 
But the array of argument which Mr. Greene had to present was not 
exhausted. The next day we took a carriage sixteen miles across coun- 
try to Gilman City, and then went afoot east down a ravine known as 
Tombstone Creek. In a short distance we came upon a ledge of lime- 
stone (Be Kalb) over perhaps fifteen feet of very fossiliferousi shale 
containing Meekella striatoeostata, Productus costatus, P. nebraseensis, 
P. cora, P. longispinus, a bed of Chonetes verneuiliana, Rhombopora 
lepidoden dr oides, Myalina subquadrata and Ambocoelia planoconvexa. 
Here also were the two layers of blue limestone. (The beds above, which 
at Winterset contain so many Derbya crassa, were not well exposed.) 
Here again the horizon is unmistakable. It is the horizon exposed at the 
railroad bridge previously mentioned. Following the ravine down we 
came next upon about thirteen feet of Winterset limestone, then, as 
measured by the barometer, thirteen feet of Galesburg shale with in- 
cluded black shale as at Winterset, then eighteen feet of Earlham lime- 
stone splendidly exposed, and with the top fragmental as at Bethany 
Falls. Then, following this same creek bed down, the top of the “Frag- 
mental” (Hertha limestone) soon appeared beyond a railroad bridge. 
To the south this Hertha limestone rises above the level of the track 
within a short distance, where this formation is seen divided by a foot 
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