Conglomerates in Gneissic Terrams — A . Winch ell. 159 
theory that the conglomerate of Wonder island is one having 
origin long subsequent to the gneiss, and embraced in it by a 
process of folding and squeezing together. For, (1) the con¬ 
glomerate has never been a conglomerate by itself; it never 
rested on another terrane, and could never have been caught 
in any sharp fold of the Saganaga gneiss; (2) If it were a for¬ 
mation so caught, we should find it revealing a greater extent 
along the line if strike; (3) The supposition of a close fold for 
the Wonder island conglomerate is not applicable to the isolated 
pebbles scattered through the gneiss across the whole breadth 
of the belt. These were in some way introduced from without 
into the plastic mass in all positions along lines transverse to 
the bedding. 
If the pebbles were neither older than the gneiss nor newer 
than the gneiss, they were of course simultaneous with it, No 
other view would be conceived unless there were some precon¬ 
ceived theory of the non-sedimentary origin of gneiss to be 
cared for. 
In connection with the interpretation of the Wonder island 
conglomerate, other facts must be considered. I have already 
stated that large angular beams of schistic and gneissic charac¬ 
ter have floated as bodies of extraneous origin in the gneissic 
magma which once existed. In connection with the Basswood 
gneiss I have elsewhere described* many occurrences of this 
nature, and many others in which the schistic fragments attain 
such length, and with so little displacement, as to constitute a 
complicated interbedding of gneissic and schistic strata. I 
have also maintained on such evidence, the original sedimentary 
condition of the gneissic terranes, as against the extravagant 
hypothesis of a succession of almost countless “dikes” perfectly 
parallel with each other and with the beds of the intersected 
formation, and separated from each other by only a few inches 
or even a fraction of an inch of the formation thus wonderfully 
perforated by “dikes.”* I have more recently, in a newly dis¬ 
covered region, estimated as many as five hundred alternations 
of uralitic schist and uralitic gneiss in the breadth of about 
fifty feet,f and I feel confirmed in opinion that the gneisses and 
crystalline schists were originally sedimentary. Thus the facts 
* Fifteenth Ann. Rep. Geol . Minn., pp. 40, 41, 43, 46, 54, 63, 78, 83, 84, 88, 
89,96,97,113,116. 
