26 GUIDE TO LOCALITIES. 



A mile to the westward across the fields is Hiiit's cove, where a 

 great development of melaphyr is bordered by conglomerate, im- 

 portant strike faults intervening ; and the conglomerate is overlain 

 conformably by more than a thousand feet of slate. A part of 

 the conglomerate contains pebbles and boulders of limestone, 

 probably derived from the Cambrian series of this region. 



From Squirrel hill southwestward across Beal street to Beal's 

 cove we have a practically complete section from the granite and 

 felsite np through the entire conglomerate series and five hundred 

 feet into the overlying slate series ; and in Hingham village, on 

 and near the line of Hersey street, this section is repeated, but 

 the beds are inverted and the great slate series cut out by a strike 

 fault. 



Aside from the melaphyr, the only igneous rock of this area 

 meriting special attention is the red felsite, a truly effusive type, 

 characterized by fluidal and brecciated structure, of which many 

 handsome boulders may be seen in the stone walls on Lincoln and 

 Thaxter streets, on the north side of Bradley hill. Ledges of the 

 red felsite formerly existed on the line of Lincoln street, but were 

 obliterated in the grading of the road. The unique character 

 and limited area of this rock have made it useful in tracing the 

 distribution of the drift of the region. 



The area traversed in this excursion embraces a number of very 

 typical drumlins and some good developments of the sand-plains 

 marking the lower levels of glacial lake Bouve. 



Literature. 



Crosby, W. 0.— Geology of the Boston Basin. (Bos. Soc. Nat. Hist., 

 Occasional Papers, vol. iv, part 2, 1894.) 



MILL COVE, NORTH WEYMOUTH. 



Outcrop of lower Cambrian strata. 



Route. — Train from Old Colony station (Kneeland street) to Quincy 

 electric car from Quincy to North "Weymouth, thence walk south on 

 Pearl street, about half a mile; or by train to Weymouth Highlands, and 

 thence walk northwest about half a mile. 



The red Cambrian slates outcrop in the road ; but the best ex- 

 posures are one-fourth mile to the west, on the wooded point which 

 is partly isolated by the salt marsh at the north side of the cove. 

 About seven hundred feet of strata are exposed, mostly red slate, 

 with several thin beds of white crystalline limestone and innumer- 



