1875.] 401 [Dodge. 



There are slate outcrops along North Street in Belmont, and Bel- 

 mont Street in Watertown, also on each side of the river, once in 

 the Cattle Market, and again in " Morse's Field" near Newton Cor- 

 ner. To the eastward of these places, there is probably no outcrop 

 on this line of strike. In the College Yard at Cambridge, however, 

 slate was reached twelve feet below the surface while excavations 

 were being made for a sewer in 1871. The quarry at Morse's Field 

 varies from pure slate with conchoidal fracture to fine sandstone. 

 The dip is 50° N. N. W., and the strike N. 70° E. This is undoubt- 

 edly part of the Cambridge slates. Other slates in Brighton and 

 Newton must be scrutinized carefully before pronouncing as to their 

 age. The outcrops along the Boston and Albany Railroad to the 

 eastward of Newton Corner Station, near the boundary of the two 

 towns, are perhaps of the same age as the last mentioned. So, per- 

 haps, some of those along the great uplifts of hornblendic rock in 

 Brighton along Cambridge Street. Others are clearly part of the 

 conglomerate formation. Of the former kind, also, are perhaps the 

 ledges in Newton, and at the south-west corner of Waverly and Cot- 

 ton Streets; east of Murray Street and the immense mass of diorite 

 on its west side (strike E. N. E.) ; on the west side of Murray Street 

 south of Highland Avenue; the small outcrop across Fuller Street 

 (strike N. 50° E.); and the one near the river at Newton Upper 

 Falls in the north-west corner of Boylston arid Chestnut Streets. The 

 curiously crumpled slates at the corner of Maple and Auburn Streets 

 at West Newton probably belong under this head also. Their dip is 

 quite high, some 70° to 80°. 



(&.) There is a second band of slates crossing West Roxbury and 

 Dorchester in an E. N. E. direction from the southern corner of 

 Newton. There is here a band of territory a mile wide, which forms 

 a geographical valley between the higher conglomerate lands on each 

 side, though encroached on here and there by gravel hills; in which 

 valley are extensive low meadows and the principal streams of that 

 vicinity. The Dedham Branch Railroad turns aside to utilize the 

 convenient course so provided. The conglomerate which elsewhere 

 accompanies the slates is absent here so that they appear alone or 

 nearly so. The slates stand in a nearly vertical position with a strike 

 corresponding to the direction of the valley. They crop out along 

 the Boston and Providence R. R., Dedham Branch, a few rods north- 

 east of Spring Street Station, West Roxbury, and again on each side 

 of Beach Street bridge ; on opposite corners where Madison Street 



PROCEEDINGS B. S. K. H. — VOL. XVII. 26 JUNE, 1875. 



