XIII. ] GEOGNOSY OF THE APPALACHIANS. 279 



New Hampshire having, however, shown the existence of rocks 

 supposed to belong to this series in the region of the White 

 Mountains, a brief history of it will not be out of place ; while 

 for further details the student is referred to a paper by the present 

 writer in the American Journal of Science for February, 1870 

 ((2) XLIX. 180). The rocks of this series were recognized by 

 Emmons in Essex County, New York, and described by him in 

 1842, in the geology of the Northern District of that State 

 (page 27). They were by him correctly regarded as identical 

 with the hypersthene rock of the Western Islands of Scotland, 

 described by MacCulloch, and were looked upon as intru- 

 sive. Similar rocks in erratic masses abound in the valley of 

 the St. Lawrence, but were first found in place by Logan, and 

 described by me in the Eeport of the Geological Survey of 

 Canada for 1852 (page 167). They were shown by Logan to be- 

 long to a great stratified series, which was at first included by him 

 in the Laurentian. Subsequent investigation, however, showed 

 that these rocks rest unconformably on the Laurentian gneiss, 

 and he therefore called them Upper Laurentian. Inasmuch as 

 they are largely displayed in Labrador, and moreover consist in 

 great part of labradorite feldspar, the name of the Labradorian 

 series was also given to them. In 1870 it was shown by me, in 

 the paper above referred to, that these rocks were apparently 

 identical with the norites of Esmark, found in Norway under 

 conditions very like those of the Labradorian rocks of North 

 America, and that this name of norite, given in allusion to 

 that country, has the right of priority. I therefore propose to 

 speak of them by that name, and moreover to designate as the 

 Norian series the great formation of crystalline stratified rocks 

 of which the norites make 'up so large a part. The typical 

 norites consist chiefly of a triclinic feldspar, varying in com- 

 position from anorthite to andesine, but generally near labra- 

 dorite in composition. The color of these rocks is ordinarily 

 some shade of blue, from bluish-black or violet to bluish- 

 gray, smoke-gray, or lavender, more rarely passing into flesh- 

 red, and occasionally greenish-blue, greenish or bluish white. 

 The weathered surfaces are opaque white. These norites are 



