202 J. D, Dana— Geological Relations of the 
The examples of what appear to be veins or dikes are also 
numerous. They cut eee the chrysolite rock and noryte 
| tony Point and Montrose Point, and 
cmos the crystalline limestone of ‘Ver- 
planck Point. Those at the last-men- 
ee J a vein at Ver rplanck Point. Figure 8 
spore a crossing oft two small veins from the same limestone 
region. Some, if not all, of such veins must, therefore, be true 
t 
the material and its injection into fissures. 
Veins formed in this way are not veins of 
infiltration or segregation, that is, they 
are not due to the filling of fissures by 
material spples slowly in solution or 
vapor; for no difference in coarseness of 
texture or atronture exists between the 
massive rock elsewhere; they are just 
such as have been made by simple injec- 
tion 
There are also peculiarities in the e 
terior of inclusions, and in the walls of 
veins or dikes, in some cases, which fav 
the idea of fusion. At Ver lanck, the Eten B68 of the wall is 
often discolored for two or three ‘inches, and sometimes pen- 
etrated by the material of the vein, or contains minute crystals 
of hornblende; and in other cases, the limestone is impregnated 
8. with the hornblendic or augitic material in 
irregular lines or bands, so that surface erosion 
has left a complexity of small curving ridges. 
The crystallization of the limestone adjoining 
the vein is sometimes coarser than a 
though, in general, no difference is appare 
a small point, just north of the region "of 
veins, part of the limestone is of the coarsest 
; ind, the erystalline grains over a fourth of 
an isa broad, while ‘the larger part is very fine i like 
the most of the Verplanck limestone—a fact that asc the 
local action of escaping hea 
till more positive evidence, if possible, of fusion are shown 
