98 GEORGE D. HUBBARD Vol. XXII, No. 3 



surround the stem and the cementing has been done in con- 

 centric shells. Layers are thicker in the central part, which 

 fact makes the concretion thicker in its equatorial zone. Only- 

 partial cementing has yet been effected, and acid tests indicate 

 that the cement is calcium carbonate. 



All the concretions were yellow or brown, although embedded 

 in the blue clays. It is obvious that oxidized iron from the 

 upper layers is penetrating the blue with the calcium carbonate 

 and that both are being deposited, thus solidifying the clay and 

 sand of the concretions. Yet the structure is still soft and 

 can be easily cut with the finger nail. We have here a number 

 of concretion shapes still in the process of making. 



A few hundred yards north or down the slope lakeward 

 from this deposit is the shore line of Lake Whittlesey, a 

 precursor of the present Lake Erie; and some three miles south 

 is the abandoned beach of the Maumee stage. This latter 

 beach is known east of Elyria as Butternut Ridge, and the 

 former is now occupied through the business section of town 

 by Main Street. The clays and sands then are between the 

 Maumee and Whittlesey beaches and therefore belong to the 

 Maumee Lake stage. While Maumee Lake was held in on the 

 north and east by ice and overflowed through the Fort Wayne, 

 Indiana, outlet, its waves and currents built the Maumee beach 

 around the Elyria embayment, and on its floor were laid the 

 clays and sands found in the excavation. Hence the con- 

 cretions can be correlated with the Maumee Lake stage and 

 can be shown to be wholly post-glacial. Concretions have 

 been completed in a time period equal to this, but those found 

 at Elyria seem to be still in the process of growth and 

 cementation. 



