242 The American Geologist. April, i89i 
advocated, save the following : A rock which they call sienite, 
but which cannot be limited to the altered sandstone or to the 
eruptive granite (since, according to them, it partakes of the 
nature of both) occurs in beds or layers. These are parallel to 
the strike of the white limestones. These beds also, according to 
the writers, dip S. E. with the limestones at an angle of 80°. 
Subordinate to the sienite the}- place 1st limestone, 2d gneiss, 3>d 
queenstone (whatever they mean by it). The sienite, limestone, 
o-neiss, and greenstone, are all evidently regarded by them as 
being of sedimentary origin. Since the greenstones are described 
bv them as being derived from the sienites by an increase of 
amphibole and a dimunition of feldspar, the greenstones are of 
limited extent. 
It is admitted that although the limestones are subordinate to 
the sienite, sienite is interstratilicd with the limestone. 
It is noted by them that the principal minerals are found in the 
sienite in cavities, or at least near to the sienite. They also ob- 
serve that in the grauwacke and the limestone overlying it there 
is present ' ' filiate of lime of a pale violet color, which is 
found in small cavities in the limestone, and appears to have been 
formed by infiltration into it as well as the rocks under it. It 
cannot, therefore, serve to connect these rocks with the sienite in 
the limestone of which it has also been found, or to prove them to 
have been of cotemporaneous origin, as some geologists have sup- 
posed ; but this hypothesis is in direct opposition to the fact 
which we have previously mentioned of its being found resting 
upon the upturned edges of the sienite." 
I quote their words to show the nature of the proof which they 
advance. Their proof of difference in time of deposition of the 
blue and the white limestones, rests upon unconformability. This 
unconformability is shown by pointing out that while the white 
limestones lie under the sienite, or are interstratified with it, the 
blue limestones and the grauwacke lie upon the upturned edges of 
the sienite. The inutility of this argument is at once apparent 
when it is pointed out that an eruptive granite has been confused 
with a foliated and bedded rock of a wholly different nature. 
They failed to find fossils either in the blue limestone or in the 
grauwacke, though they have since been found. 
The next important paper which I have succeeded in finding 
bearing upon this subject is the '-Report on the Geological Survey 
