98 YEARBOOK, PUBLIC MUSEUM, MILWAUKEE. [Vol. I. 



Milwaukee Car Shops of the Chicago, Milwaukee & St. Paul Rail- 

 way. From Thirty-sixth Street westward to the northward bend 

 of the Menominee, the valley of that river is cut through a series 

 of very coarse gravels which were deposited there with a thickness 

 of more than sixty feet. In several places, these gravels are over- 

 lain by ten or twelve feet of clay, which probably represents a some- 

 wdiat later deposition occurring in cjuieter water after the first stage 

 of the building of the delta had been finished. In these clays, from 

 time to time, there appears a few scattered glacial boulders, usually 

 of comparatively large size, and quite conspicuous. These, it is 

 believed, are boulders that have been dropped from icebergs which 

 broke away from the Lake Michigan glacier and floated in the 

 waters of Lake Lapham. This is evident from their presence in 

 otherwise very fine lake clays, and also from the fact that they are 

 relatively few in number and so widely scattered in their location. 

 A fine section of this glacial delta deposit can be seen in the old 

 gravel pit on the east bank of the Menominee river directly op- 

 posite from Story's Quarry. All the features before mentioned, 

 can be readily seen at this locality. Farther eastward along the 

 tracks of the Chicago, Milwaukee & St. Paul Railway, the gravel 

 is cemented together with a calcareous cement, and in some places, 

 forms at present a true conglomerate. This very resistant rock 

 protrudes from the cliff in lenticular masses, as it is more difficult 

 of erosion than the unconsolidated gravel by which it is surrounded. 

 At Thirty-sixth Street an abrupt transition from these gravel beds 

 to the ordinary glacial till is seen in this section. This abrupt 

 change from the one form of deposition to the other can be in- 

 terpreted, according to the ideas of the writer, only as marking 

 the edge of the glacial lake at that particular time. 



On the south side of the Menominee river to the south of the 

 Johnston factory in the Village of West Milwaukee, these gravels 

 again appear and have been extensively removed for use in con- 

 crete and other work. At this place, they are considerably thinner 

 than on the north side of the Menominee river, averaging less than 

 twenty feet in thickness, and no example of the calcareous 

 cementation has been observed in them. The gravels in both places 

 are extremely cross-bedded as would be expected in material of that 

 coarseness. In a railroad cut made near the Perry Products plant 

 on National Avenue in West Milwaukee, a series of beds appear 



