INDEX. 281 



Hitchcock, Edward, relations of granite and gneiss, 132. 



relations of granite and petrosilex, 32, 91, 95. 

 relations of mica slate and gneiss, 141, 143. 

 steatite in Montalban system, 125. 

 stratigraphy of the Nashua Valley, 154, 157. 

 supposed Devonian beds in Narragansett basin, 274-275. 

 syenite in Connecticut Valley, 42. 

 Holmes, Dr. Ezekiel, on the New E'ngland peninsula, 1. • 

 Hornblendic gneiss, Huronian, 105-112. 

 Hull, slate on, 213. 



Hunt, T. Sterry, amygdaloid referred to Huronian system, 177. 

 copper-bearing beds of Lake Superior, 179. 

 flinty slate of Newport, 180. 

 Huronian system in Eastern Mass., 24-25. 

 Laurentian system in Eastern Mass., 25, 43. 

 metamorphism, 153. 



Montalban system, 13, 123-127. ^ 



Naugus Head series, 21. 

 Norian system in New Brunswick, 20. 

 Norian boulder on Marblehead Neck, 21. 

 origin of petrosilex, 57. 

 pinite, 89. 



pinite in Saugus, 272. 

 relations of granite and petrosilex, 100. 

 sequence of Eozoic formations, 21. 

 water of the Boston artesian well, 236-237. 

 Huronian system of Eastern Mass., 24-122. 

 diorite of, 101-104. 

 disturbance of, 26. 



Eozoon canadense in limestone of, 114. ■ ' 



faults in, 120-122. 

 general relations of, 13. 

 general relations of the rocks of, 116-122. 

 limestone of, 112-116. 

 lithological constituents of, 26. 

 outlines and area of, 24. 

 petrosilex of, 45-101. 

 quartzite of, 105-112. 

 relations to Naugus Head series, 14. 

 .stratified diorite of, 105-112. 

 stratified group of, 105-112. 

 stratigraphical relations to Montalban, 153-154. 

 Hyatt, Alpheus, geology of Salem and Marblehead, 21. 

 origin of banded petrosilex, 67-69. 

 relations of granite and petrosilex, 33. 

 relations of petrosilex and breccia, 49. 

 veins in diorite, 103. 

 Hyde Park, breccia in, 174-175. 

 no true slate in, 217. 

 Jackson, C. T., analysis of petrosilex, 76. 



