1921] EDWARDS AND RAASCH, UPPER DEVONIAN STRATA. 89 



made from this material showed that the black shale contained a fauna 

 of Lingulae described by Dr. H. F. Cleland as : 



1. Liiigula iiiihvaukcciisis, Cleland. 



2. L. sp. Hiidt. near L. couiplanata. 



The presence of these forms led him to suggest that these shales 

 should, perhaps, be correlated with the Genesee formation of New 

 York. '' A boring made near the shaft at this time, showed the relation 

 of the different rocks seen in the dump. Below forty-two feet of drift 

 deposits, the boring penetrated fifteen feet of dark shales. Beneath this 

 a blue shaly limestone was encountered which was recognized as being 

 the same rock that formed the upper layers in the cement quarry on the 

 Milwaukee river, three miles to the northwestward. Five other borings 

 were sunk along the line of this tunnel, each extending into the bed- 

 rock but none of these encountered ^he dark shale, although the Hamilton 

 limestone was present in each hole. 



The construction of two additional tunnels during the years 1912- 

 1917, has added considerably to our knowledge of the shales overlying 

 the Hamilton in this region. One of these, the Shore Tunnel, extends 

 northeastward along the shore of Lake Michigan from the west end of 

 the old North Point Intake Tunnel to the end of Linwood Ave. in Lake 

 Park. From this point, another tunnel known as the Linwood Avenue 

 Intake Tunnel extends northeastward under the waters of Lake Michi- 

 gan a distance of 6,500 feet from the shore. Preliminary to the excava- 

 tion of these tunnels, a number of borings were made along their course 

 and the records are preserved in the ofifice of the City Engineer. From 

 these, the section shown in figure 49 was constructed. Five borings 

 were made along the line of the Shore Tunnel, of which three entered the 

 bed rock. However, the formations overlying the Hamilton were dis- 

 covered only in the two borings at the extreme ends of the tunnel. The 

 existence of an erosion channel lying transversely across the line of the 

 tunnel is shown by the center boring which failed to reach rock at a 

 depth of 160 feet. 



Three additional borings were sunk along the line of the Linwood 

 Avenue Intake Tunnel, all of which entered the bed-rock and in all of 

 which the post-Hamilton deposits were penetrated. Most of the infor- 

 mation concerning the thickness and succession of these beds was de- 

 rived from the borings. Overlying the blue shaly limestone of the 

 Hamilton three separate shale divisions were encountered. These are : 



-'^Cleland, H. P.; The Fossils and Stratigraphy of the Middle Devonic of 

 "Wisconsin, Wis. Geol. & Nat. Hist. Survey, Bull. -1, 11)11. 



