X CONTENTS. • 



Limestone in Stoneham and Newbury, - - - 312 



Origin of Limestone, - 313 



Scapolite Rock : Mineralogical Characters, - 314 



Quartz Rock: Order of superposition in the older rocks, 316 



Mineralogical Characters of Quartz Rock, - - 317 



Its Topography, ------ 320 



Dip, Direction, and Character of the Strata, - - 322 



Mineral Contents, ------ 323 



Theory of Quartz Rock, ----- 324 



Mica Slate : Mineralogical Characters, - - 327 



Its Topography, ------ 331 



Its Stratification, with the Dip and Direction of the Strata, 337 



Veins of Segregation in Mica Slate, ... 341 



Mineral Contents, ----- 342 



Theory of Mica Slate, ... - - 349 



Talcose Slate : Its Definition, - 352 



Mineralogical Characters, ----- 353 



Its Topography, - 355 



Dip, Direction, and Character of the Strata, - - 358 



Mineral Contents, ------ 359 



Theory of Talcose Siate, ----- 364 



Serpentine : Mineralogical Characters, - - - 365 



Topography, Stratification, and Associated Rocks, - - 366 



Mineral Contents, ------ 371 



Theory of Serpentine, ----- 372 



Horblende Slate : Dr. Macculloch's Views, - - 373 



Its Mineralogical Characters, - 374 



Its Topography, - 377 



Dip, Direction, &c of the Strata, - 380 



Mineral Contents : Theory of Hornblende Slate, - - 381 



Gneiss : How distinguished from Granite, - - - 382 



Its Mineralogical Characters, - 383 



Its Topography, ------ 385 



Its Stratification : Dip and Direction of the Strata, - - 390 



Mineral Contents, - - - - - - 395 



Theory of Gneiss, ----- 400 



UNSTRATIFIED ROCKS. 



Modes in which they occur and their theory, _ - - 403 



Manner of representing them on the Map, - - - 404 



Greenstone : Its Definition, &c. ------ 404 



Its Mineralogical Characters, 405 



Its Topography, - - - 412 



Relative Position of the Greenstone of Massachusetts, - - 417 



Veins of Greenstone, 425 



Chemical effects of Greenstone upon other rocks, - - 429 



Mineral Contents, - - - - - 433 



