Vol. 58.] 10 THE PHYSICAL GEOGRAPHY OF THEIR AGE. 197 
details." In the Aigremont breccia the cementing-material is 
calcite, more or less dolomitic. The fragments represent quartz, 
felspar (often plagioclastic), mica (mostly white), a green chloritic 
mineral, containing minute black needles, perhaps replacing biotite, 
gneiss, mica-schist, a microcrystalline green schist, sometimes 
rather quartzose, one or two fragments of a black micaceous schist, 
resembling one in the Binnenthal, compact felstone more or less 
porphyritic, marble (?), limestone with small fragments of organisms, 
some probably foraminifera, (?) chert with traces of radiolaria; also 
fragments of polyzoa, echinodermata, nautiloid foraminifera, and 
an occasional Globigerina. In the grits from the west side of the 
Raverettaz stream the caleareous matrix is more abundant, and so 
are quartz-grains, but the other minerals can be identified, and 
among the rocks, gneiss, a coarse mica-schist, and one representing 
a compact ‘porphyry.’ The dark fragments already mentioned 
prove to be a more or less gritty bituminous-looking rock, possibly 
with a slight cleavage, very probably from the Carboniferous system. 
In one slice (which exhibits a slight tendency to become oolitic) 
fragments of mollusca are rather common, in another those of 
polyzoa ; those of echinodermata also occur. 
The presence of these organisms accords with what has been 
observed by Prof. Renevier, Dr. Schardt, and other Swiss geologists.” 
They place the Flysch at the top of the Eocene, immediately above 
the caleaire &3 nummulites, and state that this fossil and 
schistes a fucoides (Chondrites arbuscula) have occurred 
associated with the breccias. So these must be, as a rule, marine 
deposits, although, as the form of the fragments indicates, they cannot 
have been either very much rolled by the waves or transported far 
by torrents. Yet materials so various must have been collected 
from a fairly large area. ‘The granitoid and gneissoid rocks have a 
general resemblance to what I have seen in adjacent Alpine regions : 
the nearest exposures of such rocks at the present day being 
11 or 12 miles to the south-south-west. The ordinary green schists 
resemble those common in the Pennines; and I saw a similar rock 
in going from Kippel to the Lotschen Pass, which is over 30 miles 
away in an easterly direction. The ‘ porphyry’ reminds me of the 
reddish variety which occurs occasionally in the Swiss Alps, and of 
which a small specimen was given to me many years ago by 
Prof. Renevier, from one of the valleys descending to the Rhone 
from the Dent de Morcles: in this also are the nearest exposures 
of Carboniferous rocks, 11 or 12 miles away.’ 
* T have examined eight slices, four representing the coarse breccia east of the 
Raverettaz Stream, three the grits west of it, and another a breccia, the precise 
locality of which is uncertain. As I had contented myself with a single typical 
specimen of each of the first and second, Iam much indebted to Miss C. A. 
Raisin, D.Sc., for the loan of specimens collected during a visit in 1894. 
* Renevier, ‘ Beitrage z. geol. Karte d. Schweiz’ vol. xvi (1890) p. 427, etc.; 
Favre & Schardt, ibid. vol. xxi (1887) p. 267, etc. ; Schardt, Bull. Soc. Vaud. 
Sci. Nat. ser. 2, vol. xx (1884-85) p. 10, ete. - 
* Thave not forgotten the Miocene deposit with erratics on the Superga 
near Turin, but do not discuss it, as the sections which I saw in J862 were not 
good, and its difficulties are not quite so great as in the case of-the Flysch. 
PZ 
