6/4 STRATIGRAPHICAL GEOLOGY. 



FORMATIONS IN NEW HAMPSHIRE. 

 I. Stratified Groups. 



Thickness 



U f Modified drift, including kames, gravel, and sand deposits, Champlain '" feet. 



clays, 250 



200 



W ( 



U V Total Cenozoic, 450 



'Upper Helderberg (Vermont), 200, Lower Helderberg, 500, . . 700 



Calciferous mica schist, 4,800 



g r Staurolite slate, 3,000 



c i Mica schist, often stauroliferous, 3, 300 



g [Quartzite, 1,000 



Cambrian slates (Connecticut valley), 3,000 



Total Paleozoic, 15,800 



Kearsarge andalusite group, i ,300 



O Rockingham mica schist, 6,000 



O ■> Merrimack group, 4,300 



21 



g I Glacial drift 



Ferruginous slates, with steatite (probably repetition of preceding), 



Total Paleozoic? 11,600 



( Auriferous conglomerate, 50 to 300 



Lyman group, 2,330 



Lisbon group, containing steatite and serpentine, .... 3,539 



Swift Water series, 4,400 



^ Hornblende schist, 1,580 



Total Upper Huronian, 12,129 



Lower Huronian, porphyries of Massachusetts, 



Labrador system, 



Franconia breccia, .......... 



Fibrolite schists, with gigantic granite veins, . .... 1,370 



< ^ Ferruginous schists, ......... 



Concord granite, 



^ Gneisses and feldspathic mica schists, 10,000 



Total Montalban, 



Lake Winnipiseogee gneiss, ....... 



Bethlehem gneiss — fine-grained, 



g J Bethlehem gneiss— ordinary, 



Porphyritic gneiss, 



Total Laurentian, 34,900 



Total, 86,249 



