12 THE GEOLOGIST'S TRAVELING HAKD-BOOK. 



The principal area of this terrane known in the United States is in Essex 

 County, New York, where it covers several hundred square miles, and, although 

 highly inclined, rests unconformably, according to Professor Hall, upon the 

 Laurentian. It is well displayed upon the shore of Lake Champlain between Port 

 Kent and Westport, and forms some of the the highest hills of the interior. A second 

 large area of Norian occurs north of Montreal, where it is similarly related to the 

 Laurentian, and passes below the Potsdam sandstone. Other localities along the 

 valley of the St. Lawrence are at Chateau Eicher near Quebec, at Bay St. Paul, the 

 Bay of Seven Islands, and on the River Moisie. Extensive areas of it also exist on 

 the coast of Labrador. The same rock has been found on the east shore of Lake 

 Huron, and in Wyoming Territory. Boulders of it are occasionally found along 

 the eastern shores of Maine and Massachusetts, and also in northern New Jersey, 

 whence it is conjectured that the Norian terrane may occur in the South Mountain. 



1 c. Huron ian. The name of Huronian was given, hi 1855, by the geological 

 survey of Canada, to a great series of more or less schistose crystalline rocks, shoM T n 

 to rest unconformably upon the Laurentian gneisses, on the north shores of the 

 lakes Huron and Superior, and to make up a part of the Huron Mountains, on the 

 south side of the latter. A similar terrane forms a great portion of the Atlantic 

 belt in Newfoundland, in the province of Quebec, and in western New England, 

 where these rocks have been described as the Green-Mountain series, and are 

 traced southwestward along the Blue Ridge. Another range of the same stretches 

 along the northwest side of the Bay of Fundy, and thence is traced, at points, 

 along the coast of Maine, to eastern Massachusetts and Rhode Island. The rocks 

 of this series are everywhere highly disturbed, often vertical, and have a thickness 

 of many thousand feet. 



In this series, the gneisses of the Laurentian are represented by rocks consisting 

 essentially of an admixture of orthoclase-feldspar and quartz, which frequently 

 assumes the character of a jaspery petrosilex, becoming porphyritic by the presence 

 of crystals of feldspar, and of quartz, in a compact base. In other cases, it becomes 

 granular, constituting a eurite, and passing into a fine-grained gneissic rock, the 

 colors being generally of some reddish or purplish tint. These petrosilex rocks, 

 which resemble the halleflinta of the Swedish geologists, are sometimes schistose, 

 and finely laminated, but at other times are compact, and almost destitute of 

 stratification. The basic portions of this terrane are represented by varieties of 

 greenstone (diorite or diabase) which are often chloritic, and pass by insensible 

 degrees into chloritic schists, frequently with epidote. Steatites and dark colored 

 serpentines also abound in parts of this series, besides what are commonly called 

 talcose or nacreous schists, owing their peculiar characters to a soft hydrous mica, 

 which is not unfrequently disseminated in very quartzose beds, and gives to such 

 a schistose character. The limestones of this series are, for the most part, 

 dolomitic, and often weather to a rusty yellow, from the presence of more or 

 less carbonate of iron. These dolomites are sometimes replaced by crystalline 

 magnesite. Portions of this terrane, including alike chloritic, dioritic and quartzose 

 rocks, are conglomerate in character, frequently containing pebbles derived from 

 the Laurentian, with others from unknown sources. The Huronian series abounds 

 in ores of copper, chrome, nickel and iron. To it belong the specular and magnetic 

 ores of northern Michigan ; while the ores of these same species hi southeastern 

 Missouri are found in Huronian petrosilex-porphyries. These last are best seen in 



