18 Messrs. Foster and Whitney on the 
fore described, variously colored, white, ash-grey and flesh-red, 
and beautifully veined with tints of a deeper hue. It calcines 
readily into lime, and affords beautiful ornamental materials. 
Along the valley of the Carp, between Jackson Forge and Teal 
lake, beds of novaculite, or fine-grained silicious slate, are found 
interstratified with beds of quartz. It has been already quarried 
at several points, for hones, and there is, even now, a considerable 
demand for them. ‘The beds are exceedingly fissile, and full of 
flaws at the surface, so that much of the mass is comparatively 
worthless; but it is believed that the blocks taken from a greater 
depth, and beyond the action of atmospheric agents, will be free 
from these imperfections. Messrs. Smith and Pratt have estab- 
lished a factory for the purpose of sawing these blocks, at the 
month of a small stream, near the Marquette landing, and are 
driving a thrifty business. 
Between the quartz range and Dead river, the underlying rock 
consists, in the main, of chlorite and talcose slates, intersected by 
three belts of igneous rocks, ranging nearly east and west. 
e la Beche, in reference to the greenstones and schistose rocks 
of Bossiney, Cornwall, remarks that, “there is so intimate a mix- 
ture of compact and schistose trappean rocks with the argillaceous 
that the whole may be regarded as one system, the two kinds 
of trappean rocks having been probably erupted, one in a state 0 
igneous fusion, and the other in that of an ash, during the time 
that the mud, now forming slates, was deposited; the mixture 
being irregular from the irregular action of the respective causes 
hich produced them ; so that one may have been derived from 
igneous action, and the other from the ordinary abrasion of preéx- 
isting solid rocks, and they were geologically contemporaneous.” 
This description is applicable to many of the igneous rocks of 
this region. They form neither long lines of dykes, nor axes of 
elevation, but broad sheets bearing the same relation to the slates 
we frequently find, throughont this district, ‘a green pulveruleut 
substance, somewhat resembling chlorite, and containing a large 
amount of magnesia and lime, which is probably in the nature of 
as e same ingredients enter largely into the composition 
of many of the trappean rocks, for they possess a soapy feel, an 
when reduced to a powder, effervesce feebly with acids. 
Co ad NO et» MR a 
= So opener es eynepre ee 
