280 INDEX. 



Gneiss, Montalban, dips of, 136. 



relations to mica slate, 141-143. 

 Grovernor's Island, slate on, 236-237. 

 Granite, Huronian, 27-45. 



distribution of, 39-42. 

 distribution of principal types of, 29-34. 

 extravasation of, 36-39, 208. 

 general relations of, 42-45. 

 passage of hornblendio variety into diorite, 34. 

 porphyritic, 29. 



relations to conglomerate, see Conglomerate, 

 relations to Montalban schists, 39. 



relations to Naugus Head series, 43, 44, see also Naugus Head series, 

 relations to petrosilex, 31-33, see also Petrosilex. 

 relations to Primordial series, 193-194. 

 relations to slate, see Slate, 

 stratification of, 35. 

 variation of, 28. 

 Montalban, 130-135. 



in Bristol and Plymouth Counties, 132-134. 

 in Connecticut Valley, 134-135. 

 general relations to intersected rocks, 130. 

 relations to gneiss, 130, 131, 134, 140-141. 

 porphyritic, 131, 132. 

 Granulite in Beverly, 35, 74. 

 Grape Island, rocks of, 209. 

 Green Island, rocks of, 223. 

 Green Mountains, age of, 127. 

 Gulf of Maine, eastern border of, 5, 7. 



general relations of, to Eoaoio formations, 162-163. 



geology of, 4, 7. 



glacial detritus in, 6. 



outlines of, 4. 



submarine contours of, 4, 5. 



Hangman's Island, rocks on, 213. 



Hingham, geology of, 201-206. 



Hitchcock, C. H., argillite of the Nashua Valley, 11. 



divisions of the Huronian system, 117. 

 Norian system in Eastern Mass., 25. 



Triassic age of diorites in vicinity of Salem and Boston, 25. 

 Hitchcock, Edward, analysis of siderite, 114-115. 



boundaries of granite and gneiss in S. E. Mass., 133. 



geology of Western Mass., 126. 



joint structure, 230. 



limestone in Lynnfield, 115. 



magnesian limestones, 112. 



Montalban limestones, 139. 



petrosilex in Hingham, 92. 



petrosilex in Plymouth, 92-93. 



