122 IOWA ACADEMY OF SCIENCE 



Qualitative chemical examination of the red clay reveals the 

 presence of ferrous and ferric iron, carbonates, calcium, silica 

 and aluminum. The oolites are largely siliceous but contain 

 also calcium carbonate and iron. 



Similar outcrops of the ferriginous material are found on the 

 east side of Lore Hill at elevations which indicate that the bed 

 lies in a practically horizontal position and probably is con- 

 tinuous throughout the hill. In one of these outcrops fragments 

 of impure, cherty dolomite occur just above the iron band. 



On the north side of the hill, twenty-one feet above the iron 

 band, a small quarry exposes typical Niagaran dolomite contain- 

 ing the following fossils : l 



Halysites catenulatus. 

 Lyellia (probably americana). 

 Strepte'asma sp. 

 Cystoid (plate only). 

 Plectambonites sp. 

 Orthis flabellites. 

 Dalmanella elegantula. 

 Platystrophia daytonensis. 

 Leptaena rhomboidalis. 



Evidently then the iron band lies at or near the contact of the 

 Niagaran and Maquoketa. It is possible that most of the twenty- 

 one feet concealed may belong to the recently described Alexan- 

 drian Series. 2 



Fig. 9. 



The diagram (figure 9) illustrates the probable conditions at 

 Lore. Since the undisturbed layers are nowhere exposed it is 

 not possible to ascertain the actual conditions. The thin band 

 of ferruginous oolite lies between the soft, plastic shales of the 

 top of the Maquoketa and the massive dolomite of the lower 

 Niagaran. Probably the iron band originally was indurated, 

 and this may yet be the condition at some distance within the 



identified by Professor T. E. Savage, of the University of Illinois. 

 -Savage, T. E., Stratigraphy and Paleontology of the Alexandrian Series: 

 Bull. 111. Geol. Survey No. 23, 1913. 



