246 DR. THOMAS STERRY HUNT ON THE 
§ 79. We owe to Prof. Henry Wurtz a valuable paper, published in 1859, on the 
mineralogy of the northward extension of the King’s-Mountain belt, as seen in Gaston and 
Lincoln counties in North Carolina. He there noticed the itacolumite-rock, and its sup- 
posed relations to the diamond, described the anhydrous iron-ores under the names of mag- 
netite-schist and hematite-schist, and moreover what he called a pyrites-schist. He farther 
observed great interstratified beds of limonite, which he regarded as derived from the 
alteration of pyrites, found unchanged in the deep workings of these ores. With them, 
and elsewhere in the talcose schists of the region,he observed the frequent occurrence 
of black earthy manganese-oxyd, containing much cobalt and some nickel.* It is worthy 
of notice in this connection that both the magnetites and the limonites of this horizon in 
Pennsylvania generally contain more or less cobalt, as shown in numerous analyses by 
Genth and McCreath. The pyrites found at the Cornwall iron-mine in Pennsylvania is 
also cobaltiferous.. 
The magnetic and specular ores found so abundantly in the Primal series of Pennsyl- 
vania, and already described at length, are evidently the equivalents of those described by 
Lieber and by Wurtz, and constitute an important and widely-extended ore-bearing hori- 
zon. The silicate mingled with the magnetites in many of the Pennsylvania deposits, is 
probably more nearly related to pyroxene than to tale in composition. The mineralogy 
of all of these deposits demands careful study, inasmuch as they belong to a distinct and 
well-marked horizon of crystalline rocks, the importance and geological significance has 
hitherto been to a great extent overlooked by American geologists. 
The Itacolumitic series of Lieber, with its estimated approximative thickness of 
5000 feet, being evidently the Lower Taconic of Emmons, it remains to be seen whether 
the upper blue limestone, provisionally regarded by Lieber as distinct, really belongs to a 
higher horizon, or is a member of the series. In the latter case, the upper schists and the 
roofing-slates of the Lower Taconic are unrepresented in this area, and have probably been 
removed by erosion. The best locality for the study of the whole series is, according to 
Lieber, at Limestone Springs in the Spartanburg district. 
§ 80. In this connection mention should be made of the occurrence of several narrow 
belts of Lower Taconic rocks folded in the gneiss of the Highlands east of the Appalachian 
valley, in northern New Jersey, where they have been carefully studied and described 
by Cook, and are well seen in the Pohatcong and Muscanetcong valleys. They also extend 
into southeastern New York, where little is known of their distribution, and where they 
have been confounded with the older Laurentian rocks, into which they were supposed, 
by Nuttall, Mather and H. D. Rogers, to graduate.t In New Jersey, where Cook has shown 
the fallacy of this view, the Auroral limestones, associated with limonites, and often over- 
laid with slates, are found resting directly on the gneiss, or with a thin interyening layer 
of the Primal sandstone. These strata are much folded and faulted, and sometimes present 
overturned flexures, giving the whole succession an eastward inclination.f All of these 
rocks above the gneiss are, in accordance with the classification of Rogers in Pennsylvania, 
referred by Cook to the infra-Trenton portions of the Champlain division. The relations of 
the Green-Pond Mountain conglomerate, found in this region, will be noticed farther on. 

* Amer. Jour. Science, xxvii., pp. 24-81. 
+ Hunt, Azoic Rocks, pages 40, 42. 
{ Cook, Geology of New Jersey, 1868, pages 70, 144. 

