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on the line of strike of the most northerly outcrops of slate, 

 south of the conglomerate, in the first section ; indicating that 

 the concealed portion of that section is probably conglomerate, 

 and that on the line of the second section the granite has cut 

 off all of this band of slates. Where it approaches the granite, 

 the conglomerate, like the slate, becomes very hard and firm. 

 In the second section, as well as the first, this rock is appre- 

 ciably finer and more arenaceous toward the borders. These 

 two sections are complementary, both being essential to a 

 proper understanding of the structure of this uncrystalline belt. 



After crossing Adams Street, going west, the next outcrop 

 on the line of this anticlinal occurs immediately west of the 

 Granite Branch of the Old Colony Railroad, very near where 

 it crosses the common boundary of Milton and Quincy. The 

 rock is a coarse conglomerate, similar to the last, but more dis- 

 tinct. Beyond this, I could find no ledges of either slate 

 or conglomerate, until near Randolph Turnpike. The inter- 

 vening drift, however, is full of large boulders of both these 

 rocks, especially the latter, a plain indication of the continu- 

 ance of the anticline in this direction. The hard, obscurely 

 stratified, argillaceous (or felsitic) and quartzose beds forming 

 a narrow band between the uncrystallines and the granite, and 

 marked on the map as belonging to the Shawmut group, may 

 possibly be of Primordial age ; the stratigraphic position, how- 

 ever, is almost certainly between the conglomerate and 

 granite. 



On Randolph Turnpike, the granite is succeeded toward 

 the north by a considerable amount of exotic rock, probably 

 diorite, which is followed by several hundred feet, traverse 

 measure, of stratified beds, consisting of grits, sandstone, quartz- 

 ite, and slate, all distinctly interstratified, and dipping N. 30°— 

 60°. Some of the sandstone, consisting entirely of the debris 

 of the granite, would be difficult to distinguish from the parent 

 rock, but for the narrow intercalated bands of brownish slate. 

 The same series is exposed south of the cemetery, a few rods 

 east of the turnpike. It appears to be rich in endogenous 



