212 



is a mass of conglomerate about 10 feet across, lying in the 

 meadow, and is possil)ly only a bowlder. Assuming it to be 

 in situ, or nearly so, it probably represents the most north- 

 erly conglomerate (13) of the Hersey Street section. 



The section afforded by this group of ledges, it will be 

 observed, overlaps on the south and supplements the section 

 along Hersey Street, the two together affording a nearly com- 

 plete section of the conglomerate series. The melaphyr of this 

 section is the typical variety, greenish and purplish in color, and 

 compact to highly amygdaloidal and scoriaceous in texture. 

 The amygdules consist chiefly of epidote and quartz, and are 

 usually small, or, if larger, rather scattering and not crowded. 

 As a whole the rock is very massive, but portions of the bed 

 show irregular vcinlets and segregations of epidote and fer- 

 ruginous (piartz ; and the distribution of the amygdaloidal and 

 scoriaceous melaphyr is such as to suggest that this may be a 

 composite flow. The contact between the melaphyr and the 

 arenaceous conglomerate is veiy clearly exposed for about ten 

 feet on the highest part of the ridge. It is straight, exactly 

 parallel with the strike of the conglomerate, and shows only 

 minute irregularities, variations of an inch or so from the mean 

 line. The melaphyr does not penetrate the conglomerate any 

 more distinctly than the conglomerate penetrates the melaphyr. 

 Some irregular cracks in the lava appear to have been filled 

 with fine sand, which is now highly ferruginous ; but aside from 

 these there are no distinct inclusions of the sedimentary rocks 

 in tlie melaphyr. On the other hand, a few small pebbles of 

 melaphyr similar to this were observed in the conglomerate, 

 within a few inches of the contact. The conglomerate and 

 sandstone exhibit no special alteration or unusual induration at 

 this point ; and in every way the fsicts are favorable to the view 

 that the melaphyr is contemporaneous and not intrusive. 



Between the ledges just described and those next to the west 

 there is a ga[) of six hundred feet, occupied by the valley of 

 Town Brook and the railroad. But immediately beyond West 



