48 Editorial Comment. 
existence of the eruptives, Mr. Wadsvvorth supposes to have 
been obtained, not from the ])e(ls of diabase and amygdaloid 
seen now in the upper part of the cliff, which has been imagined 
to have been an ancient shore line which precipitated its debris 
along the shore and incorporated the fragments from the l>lufi 
into the forming sediments of the water, but from some older 
trap outtlows, not seen now in outcrop at this place, but which 
once were uncovered and perhaps extended over large areas of 
that region — trap beds which extend, presumably, intact under- 
neath the bed of Douglass Houghton ravine and also underneath 
the whole of the Keweenaw peninsula. In bulletin No. 23, 
however, Messrs. Irving and Chamberlin have abandoned the 
view of Irving in 18S0 and have adopted that of Wadsworth so 
far as relates to the identiy of the north dip2:)ing sandstones that 
pass below the KeweenaW beds, and the horizontal sandstones 
that appear further down the ravine. They affirm however, 
contrary to the testimony of Mr. Wadsworth, that these beds at 
no place are intercalated with beds of trap, and afford no evidence, 
except that of passing below the trap, of being older than it, 
which evidence, they say, is illusory. 
About a mile southeast from the Douglass Houghton ravine 
is the Torch lake quarry, where the quarried beds are onl}- 2S 
feet lower than the top of the Douglass Houghton fall, thus 
lying high enough to be embraced in the Keweenaw rocks, and 
if not so embraced then necessarily unconformable upon those 
rocks. The evidence is not conclusive. No trap rock is des- 
cribed as in contact with the beds. Mr. Wadsworth has inferred, 
from the dip of the layers of coarser material, and the direction 
of clay masses, that the 'dip is toward the northwest about 45 "^ , 
and that the apparent horizontal bedding is caused by a second- 
ary system of horizontal joints. He therefore considers this 
rock as a conformable constituent portion of the Keweenaw rocks, 
Messrs. Irving and Chamberlin reexamined the quarry together,. 
and they concluded that the rock is essentially horizontal. The 
lines of sedimentation seen by Wadsworth they regard as a false 
bedding such as is common in the eastern sandstone. The evi- 
dence of the facts, whatever they may be, touching this quarry 
has only an indirect bearing on the subject of the investigation. 
If the rock dips northwest it is in conformity with the idea of the 
