OF PRE-CAMBRIAN ROCKS 199 
conglomerate and the strata with which it is associated was found 
on the Queensboro road, which crosses the Madoc road at right 
angles. The conglomerate contains very numerous pebbles of 
several different kinds of rock. These are as follows: 
1. Pink felsite. ‘These are most abundant and form the dominant 
element of the conglomerate. 
2. White quartz, resembling vein quartz. 
3. White quartzite. 
4. Amphibolite, dark in color and very fine in grain. 
To the west of the Queensboro road the conglomerate also holds 
some pebbles of cherty and ferruginous rocks resembling those found 
in the iron ranges of the Lake Superior district. 
The pebbles of this conglomerate are often quite round, but 
are usually very considerably flattened. ‘They are sometimes several 
inches in diameter. The rock shows very considerable variations 
in size and abundance of the pebbles in different bands, some bands 
being entirely free from pebbles and resembling a quartzite in appear- 
ance. ‘The conglomerate also shows distinct cross-bedding in certain 
places. It has a nearly vertical attitude, its beds being bent back 
upon themselves in a series of sharp folds. 
On the Queensboro road, to the south of its intersection with 
the Madoc road, the conglomerate is followed by a dark amphibolite 
containing a great number of small corrugated quartz veins, present- 
ing a remarkable autoclastic structure and often pinched out into 
forms closely resembling pebbles. ‘This is succeeded by a series of 
pink felsites, which in their turn are followed by calcareous amphi- 
bolites, and these by crystalline limestones. 
The succession on the Queensboro road from north to south, 
with the approximate thickness of the several occurrences (as exposed), 
is as follows: 
Dark amphibolite, for the most part massive. . . . . . . 600 feet+ 
Conglomerate (probably duplicated by folding) . . . . . . 3,100 “ 
Amphibolite with quartz veins showing autoclastic structure . , > 
IPYARES SHIITES) Stet eg Gy Menel eR Ro ech e ee vO aD tay CL Uae AN a rea at or a 
Calcarecousyamphibolite mess My ieoiaca 1s) ate toMee eal on! oath O35 ve 
Cry stallimeglimeStone errr hi aesecse. se te Soe, (cen BOO. Sf 
Before the conglomerate was laid down it is certain that the 
