278 INDEX. 



Brookline, Primordial series in, 229-237. 

 Burbank, L. S., conglomerate in Medford, 259. 



geology of Nashua Valley, 131, 138-139, 154, 157, 158, 159, 160. 



minerals in Montalban limestone, 125. 



relations of mica slate and argillite, 143. 



relations of mica slate and gneiss, 142. 



stratigraphy of Montalban system, 125. 



Calf Island, rocks of, 223. 



Carboniferous system in Mass. and Rhode Island, conditions of deposition of, 275. 



Charles River, Primordial estuary of, 251. 



synolinal of, 259. 

 Chiastolite slate, 138. 



Concretionary structure in petrosilex, 57-63. 

 Conglomerate, Montalban, alteration of, 139, 145-153. 



relations to argillite, 144. 



stratigraphy of, 146-147. 

 Conglomerate, Primordial, absence of, from Boston Harbor, 216. 



amygdaloid pebbles in, 190, 197, 198, 200, 210, 214, 218, 

 220, 222, 231, 241, 254. 



boulders in, 204, 222, 231, 232, 240. 



breccia pebbles in, 191, 197, 209. 



breccia structure in, 219. 



cleavage in, 220-222. 



composition of, 231, 266. 



conformable with slate, 189. 



dykes in, 230-234. 



faults in, 227, 228, 232, 233, 265-266. 



ferruginous, 251-252. 



induration of, 200. 



irregular stratification of, 190, 249. 



joints of, 229-230, 233, 238, 245, 246. 



limestone pebble in, 204. 



pinite in, 220-221, 231, 240, 251, 252, 267, 269-272. 



quartz veins in, 230, 233. 



relations to amygdaloid, 209, 232, 238, 240-241. 



relations to slate, 185-191, 205, 207, 209, 210, 221, 222-223, 

 224, 226, 227, 235, 239, 240, 241-244, 246, 249, 250, 254. 



theory of its glacial origin, 187. 



thickness of, 200, 227, 232-233, 245, 265-266. 



supposed slate pebbles in, 189-190. 



underlies the slate, 186-190. 



See Slate and Primordial series. 

 Connecticut Valley, granite in, 134-135. 



syenite in, 42. 

 Copper-bearing beds of Lake Superior, age of, 179. 



compared with Shawmut group, 179. 

 relations to Huronian, 179. 



Dana, J. D., origin of petrosilex, 57. 



