On the John G. Miller farm, Section 27, Waterloo Township, Black Hawk County, the writer examined very carefully an area which was excavated for fill for grading of the new four-lane highway into west Waterloo. The area through which the new highway was surveyed was very low ground which flooded when Black Hawk Creek, a tributary of the Cedar River, overflowed. Thus, it became necessary to construct a high road bed through this area. To secure material for the grade, a hill about 25 feet in height was entirely leveled. The top of the hill was capped by about six to eight feet of what was undoubtedly Iowan drift. Below the Iowan, there was a deposit of several feet of interglacial material which was unquestionably Buchanan. The term Buchanan was first used by Dr. Samuel Calvin and is still in use to designate the interglacial between the Kansan glacial stage and the Iowan glacial stage. This interval now includes the Yarmouth interglacial stage, the Illinoian glacial stage and the Sangamon interglacial stage
